Signal classification method and device, and coding/decoding method and device
16 claims: 13 independent, 3 dependent
- 1オーディオまたは音声処理に関する復号化方法であって、 ビットストリームを復号化して、現在のフレームの高周波数帯域信号、または前記現在のフレームの前記高周波数帯域信号の特性パラメータを得るステップと、 前記高周波数帯域信号、または前記高周波数帯域信号の前記特性パラメータを、前記現在のフレームの低周波数帯域信号のエネルギー減衰値に応じて減衰させ、前記エネルギー減衰値は、 符号化の際に、符号化前の 前記低周波数帯域信号を符号化することによって生じる前記低周波数帯域信号のエネルギー減衰を示すステップ であって、前記エネルギー減衰値は、前記低周波数帯域信号のエネルギーとローカルで復号化することによって得られた信号のエネルギーの比に従って得られる、ステップ とを備え 、前記高周波数帯域信号、または前記高周波数帯域信号の前記特性パラメータを、前記現在のフレームの前記低周波数帯域信号の前記エネルギー減衰値に応じて減衰させる前記ステップは、 前記高周波数帯域信号、または前記高周波数帯域信号の前記特性パラメータを、前記エネルギー減衰値および前記現在のフレームの前記高周波数帯域信号の信号クラスに応じて減衰させるステップを備え、 前記高周波数帯域信号、または前記高周波数帯域信号の前記特性パラメータを、前記エネルギー減衰値、および前記現在のフレームの前記高周波数帯域信号の前記信号クラスに応じて減衰させる前記ステップは、 前記現在のフレームの前記高周波数帯域信号の前記信号クラスが遷移クラスである場合、前記エネルギー減衰値に応じて高周波数帯域時間領域信号、または前記高周波数帯域信号の時間領域エンベロープを減衰させるステップを備え る復号化方法。
- 2前記方法が、前記ビットストリームを復号化して、前記現在のフレームの前記高周波数帯域信号の信号クラスを得るステップをさらに備 える 請求項1に記載の方法。
- 3前記ビットストリームを復号化して前記エネルギー減衰値を獲得するステップであって、前記エネルギー減衰値が、前記現在のフレームの前記低周波数帯域信号のエネルギーと前記現在のフレームの前記低周波数帯域信号を符号器によって符号化したことの結果をローカルで復号化することによって得られた信号のエネルギーの比を示すステップをさらに備える請求項1に記載の方法。
- 4前記エネルギー減衰値が事前設定された値であり、同一クラスのフレームの低周波数帯域信号のエネルギーと前記同一クラスのフレームの前記低周波数帯域信号を符号化したことの結果を復号化することによって得られた信号のエネルギーの比に応じて前記エネルギー減衰値が得られ、前記同一クラスのフレームが前記現在のフレームの前記高周波数帯域信号と同一の信号クラスのデータフレームである請求項1に記載の方法。
- 5オーディオまたは音声処理に関する符号化方法であって、 現在のフレームを低周波数帯域信号と高周波数帯域信号に分割するステップと、 前記高周波数帯域信号、または前記高周波数帯域信号の符号化されるべき特性パラメータを、前記低周波数帯域信号のエネルギー減衰値に応じて減衰させるステップであって、前記エネルギー減衰値は、前記低周波数帯域信号を符号化することによって生じる前記低周波数帯域信号のエネルギー減衰を示すステップ であって、前記エネルギー減衰値は、前記低周波数帯域信号のエネルギーとローカルで復号化することによって得られた信号のエネルギーの比に従って得られる、ステップ と、 前記減衰された高周波数帯域信号、または前記高周波数帯域信号の前記減衰された符号化されるべき特性パラメータを符号化するステップとを備え 、 前記高周波数帯域信号、または前記高周波数帯域信号の前記符号化されるべき特性パラメータを、前記低周波数帯域信号の前記エネルギー減衰値に応じて減衰させる前記ステップは、 前記高周波数帯域信号、または前記高周波数帯域信号の前記符号化されるべき特性パラメータを、前記エネルギー減衰値および前記高周波数帯域信号の信号クラスに応じて減衰させるステップを備え、 前記高周波数帯域信号、または前記高周波数帯域信号の前記符号化されるべき特性パラメータを、前記エネルギー減衰値、および前記高周波数帯域信号の前記信号クラスに応じて減衰させる前記ステップは、 前記高周波数帯域信号の前記信号クラスが遷移クラスである場合、前記エネルギー減衰値に応じて高周波数帯域時間領域信号、または前記高周波数帯域信号の符号化されるべき時間領域エンベロープを減衰させるステップを備え る符号化方法。
- 6前記方法が、前記高周波数帯域信号の信号クラスを判定するステップをさらに備 える 請求項 5 に記載の方法。
- 7前記低周波数帯域信号を符号化し、前記低周波数帯域信号を符号化したことの結果をローカルで復号化するステップと、前記低周波数帯域信号のエネルギーと前記ローカルで復号化するステップによって得られた信号のエネルギーの比を前記エネルギー減衰値として使用するステップとをさらに備える請求項 5 に記載の方法。
- 8前記エネルギー減衰値が事前設定された値であり、同一クラスのフレームの複数の低周波数帯域信号のエネルギーと前記同一クラスの フレームの 前記低周波数帯域信号の符号化結果を復号化することによって得られた信号のエネルギーの比に応じて前記エネルギー減衰値が得られ、前記同一クラスのフレームが前記現在のフレームの前記高周波数帯域信号と同一の信号クラスのデータフレームである請求項 5 に記載の方法。
- 9オーディオまたは音声処理に関する符号化デバイスであって、 現在のフレームを低周波数帯域信号と高周波数帯域信号に分割するように構成された分割ユニットと、 前記高周波数帯域信号、または前記高周波数帯域信号の符号化されるべき特性パラメータを、前記低周波数帯域信号のエネルギー減衰値に応じて減衰させるように構成され、 前記エネルギー減衰値は、前記低周波数帯域信号のエネルギーとローカルで復号化することによって得られた信号のエネルギーの比に従って得られ、 前記エネルギー減衰値は、前記現在のフレームの前記低周波数帯域信号を符号化することによって生じる前記低周波数帯域信号のエネルギー減衰を示す補正ユニットと、 前記減衰された高周波数帯域信号、または前記高周波数帯域信号の前記減衰された符号化されるべき特性パラメータを符号化するように構成された符号化ユニットとを備え 、 前記補正ユニットは、前記高周波数帯域信号、または前記高周波数帯域信号の前記符号化されるべき特性パラメータを、前記エネルギー減衰値、および前記高周波数帯域信号の信号クラスに応じて減衰させるように構成され、 前記補正ユニットは、前記高周波数帯域信号の前記信号クラスが遷移クラスである場合、前記エネルギー減衰値に応じて、高周波数帯域時間領域信号または前記高周波数帯域信号の符号化されるべき時間領域エンベロープを減衰させるように構成され る符号化デバイス。
- 10前記高周波数帯域信号の信号クラスを判定するように構成された信号クラス判定ユニットをさらに備え る請 求項 9 に記載のデバイス。
- 11前記低周波数帯域信号を符号化し、前記低周波数帯域信号を符号化したことの結果をローカルで復号化して、前記低周波数帯域信号のエネルギーと前記ローカルで復号化することによって得られた信号のエネルギーの比を前記エネルギー減衰値として使用するように構成されるエネルギー減衰値獲得ユニットをさらに備える請求項 9 に記載のデバイス。
- 12前記エネルギー減衰値を設定するように構成されるエネルギー減衰値設定ユニットをさらに備え、前記エネルギー減衰値は、同一クラスのフレームの複数の低周波数帯域信号のエネルギーと前記同一クラスの フレームの 前記低周波数帯域信号を符号化したことの結果を復号化することによって得られた信号のエネルギーの比に応じて得られ、前記同一クラスのフレームは、前記現在のフレームの前記高周波数帯域信号と同一の信号クラスのデータフレームである請求項 9 に記載のデバイス。
- 13オーディオまたは音声処理に関する復号化デバイスであって、 ビットストリームを復号化して、現在のフレームの高周波数帯域信号、または前記現在のフレームの前記高周波数帯域信号の特性パラメータを得るように構成された復号化ユニットと、 前記高周波数帯域信号、または前記高周波数帯域信号の前記特性パラメータを、前記現在のフレームの低周波数帯域信号のエネルギー減衰値に応じて減衰させるように構成され、 前記エネルギー減衰値は、前記低周波数帯域信号のエネルギーとローカルで復号化することによって得られた信号のエネルギーの比に従って得られ、 前記エネルギー減衰値は、 符号化の際に、符号化前の 前記現在のフレームの前記低周波数帯域信号 を 符号化 すること によって生じる前記低周波数帯域信号のエネルギー減衰を示す補正ユニットとを備え 、 前記補正ユニットは、前記高周波数帯域信号、または前記高周波数帯域信号の前記特性パラメータを、前記エネルギー減衰値、および前記現在のフレームの前記高周波数帯域信号の信号クラスに応じて減衰するように構成され、 前記補正ユニットは、前記現在のフレームの前記高周波数帯域信号の前記信号クラスが遷移クラスである場合、前記エネルギー減衰値に応じて、高周波数帯域時間領域信号または前記高周波数帯域信号の時間領域エンベロープを減衰させるように構成され る復号化デバイス。
- 14前記復号化ユニットは、前記ビットストリームを復号化して、前記現在のフレームの前記高周波数帯域信号の信号クラスを得るようにさらに構成さ れる 請求項 13 に記載のデバイス。
- 15前記復号化ユニットは、前記ビットストリームを 復号化 して、前記エネルギー減衰値を得るようにさらに構成され、前記エネルギー減衰値は、前記現在のフレームの前記低周波数帯域信号のエネルギーと前記現在のフレームの前記低周波数帯域信号を符号器によって符号化したことの結果をローカルで復号化することによって得られた信号のエネルギーの比を示す請求項 13 に記載のデバイス。
- 16前記現在のフレームの前記エネルギー減衰値を設定するように構成されるエネルギー減衰値設定ユニットであって、前記エネルギー減衰値は、同一クラスのフレームの低周波数帯域信号のエネルギーと前記同一クラスの フレームの 前記低周波数帯域信号を符号化したことの結果を復号化することによって得られた信号のエネルギーの比に応じて得られ、前記同一クラスのフレームは、前記現在のフレームの前記高周波数帯域信号と同一の信号クラスのデータフレームであるエネルギー減衰値設定ユニットをさらに備える請求項 13 に記載のデバイス。
Independent claims16
147 paragraphs, as filed
This application is filed with the National Intellectual Property Office of the People's Republic of China on May 25, 2011, which is incorporated herein by reference in its entirety, "SIGNAL CLASSIFICATION METHOD AND DEVICE, AND ENCODING AND DECODING METHODS AND DEVICES. Claims the priority of Chinese Patent Application No. 201110138461.1 named.
The present invention relates to the fields of audio and audio technology, and more particularly to signal classification methods and signal classification devices, as well as coding and decoding methods and devices.
Bandwidth expansion techniques have already emerged in audio and audio processing technologies, that is, high frequency band signals are coded using a small number of bits to extend the frequency bandwidth of the audio / audio signal. To be converted. Bandwidth expansion techniques have evolved rapidly in recent years and are also commercially applied in some coders and decoders.
The bandwidth expansion technology currently adopted basically determines the signal class of the high frequency band signal according to the signal characteristics of the high frequency band signal in the input signal, and further, different coding algorithms for different signal classes. , And a multi-mode bandwidth expansion technology that employs different decoding algorithms. Depending on the signal characteristics of the high frequency band signal, the high frequency band signal is divided into four classes: Transient class, Harmonic class, Noise class, and Normal class. Will be done. Certain classification processes divide the high frequency band time domain signal of a frame into several subframes to obtain the time domain envelope of each subframe, and the energy of a subframe is previously If the energy of the subframe is greater than a specific multiple of the energy of the subframe and the energy of that subframe is greater than a certain multiple of the average energy of all subframes in the entire frame, then the high frequency band signal of that frame is in the transition class. The step of determining that there is, and if the frame is not in the transition class, the high frequency band frequency domain signal of the frame is divided into several subbands to obtain the peak-to-average ratio of each subband, but the peak. The to-average ratio is the ratio of the peak energy or peak amplitude of the subband to the average energy or average amplitude of the subband, and the number of subbands having a peak-to-average ratio higher than a specific threshold value, or If it is greater than a certain number, the high frequency band signal of that frame has more than a certain number of steps to determine that it is in the harmonic class and the number of subbands with a peak-to-average ratio less than a certain threshold. In this case, the high frequency band signal of the frame is determined to be noise, and if it is less than or equal to the number, the high frequency band signal of the frame includes a step of determining that it is in the normal class.
The prior art has the following drawbacks.
In the prior art, during signal classification of a high frequency band signal of a frame, only the characteristics of the high frequency band signal of that frame are considered, which is an inaccurate signal classification result for the high frequency band signal of that frame. Bring.
<p> Embodiments of the present invention provide signal classification methods and signal classification devices that provide more accurate signal classification results.</p><p> In view of the above, embodiments of the present invention provide:</p><p> The signal classification method divides the current frame into low frequency band signals and high frequency band signals, and the signal class according to the value requirements of the preset coding / decoding characteristic parameters corresponding to the signal class. The step of determining whether the coding / decoding characteristic parameter of the current frame corresponding to meets the value requirement of the coding / decoding characteristic parameter, and the high frequency band signal of the current frame according to the determination result. Includes a step to determine the signal class.</p><p> The signal classification device is configured to divide the current frame into low frequency band signals and high frequency band signals, and the value requirements of the preset coding / decoding characteristic parameters corresponding to the signal class. Correspondingly, a determination unit configured to determine whether the coding / decoding characteristic parameter of the current frame corresponding to the signal class meets the value requirement of the coding / decoding characteristic parameter, and the determination result. Includes a determination unit configured to determine the signal class of the high frequency band signal of the current frame according to.</p><p> The coding method is the step of dividing the current frame into a low frequency band signal and a high frequency band signal, and the high frequency band signal or the high frequency band signal is encoded depending on the energy attenuation value of the low frequency band signal. The characteristic parameter to be attenuated, however, this energy attenuation value is a step indicating the energy attenuation of the low frequency band signal caused by the coding of the low frequency band signal, and the attenuated high frequency band signal or the high frequency band signal. Includes a step of encoding the attenuated characteristic parameter to be encoded.</p><p> The decoding method is the step of decoding the bit stream to obtain the characteristic parameters of the high frequency band signal of the current frame or the high frequency band signal of the current frame, and the energy attenuation of the low frequency band signal of the current frame. Depending on the value, the characteristic parameter of the high frequency band signal or high frequency band signal is attenuated, but this energy attenuation value is a step indicating the energy attenuation of the low frequency band signal caused by the coding of the low frequency band signal. Including.</p><p> The coding device is configured to divide the current frame into a low frequency band signal and a high frequency band signal, and a high frequency band signal or a high frequency band depending on the energy attenuation value of the low frequency band signal. It is configured to attenuate the characteristic parameters to be encoded in the signal, but this energy attenuation value is a correction unit that indicates the energy attenuation of the low frequency band signal caused by the encoding of the low frequency band signal in the current frame. And an attenuated high frequency band signal, or a coding unit configured to encode the attenuated characteristic parameters of the high frequency band signal to be encoded.</p><p> A decoding unit configured to decode the bitstream to obtain characteristic parameters of the high frequency band signal of the current frame or the high frequency band signal of the current frame, and the decoding device of the current frame. It was configured to attenuate the characteristic parameters of the high frequency band signal, or the high frequency band signal, depending on the energy attenuation value of the low frequency band signal, where this energy attenuation value is that of the low frequency band signal of the current frame. Includes a correction unit that indicates the energy decay of the low frequency band signal caused by the coding.</p><p> In one embodiment of the invention, during signal classification, the coding / decoding characteristic parameters of the current frame are encoded according to the value requirements of the preset coding / decoding characteristic parameters corresponding to the signal class. It is determined whether the value requirement of the / decoding characteristic parameter is satisfied, and whether the signal class of the high frequency band signal of the current frame is the signal class corresponding to the coding / decoding characteristic parameter. And, in this way, the coding / decoding characteristics of the various signal classes are taken into account during the signal classification, resulting in the signal classification for the high frequency band signal of the current frame. Become more accurate.</p><p> In another embodiment of the invention, the high frequency band signal, or characteristic parameter to be encoded in the high frequency band signal, is attenuated according to the energy attenuation value of the low frequency band signal in the current frame, and further the attenuation result. However, the energy of the high frequency band signal obtained by the decoder by being encoded and then sent to the decoder and being decoded is correspondingly attenuated, resulting in a low high frequency band signal. Better effects will be achieved after being combined with frequency band signals.</p><p> In order to more clearly illustrate the technical solution according to an embodiment of the present invention, the accompanying drawings for explaining the embodiment are briefly outlined below. Obviously, the accompanying drawings in the following description are only partial embodiments of the present invention, and one of ordinary skill in the art can derive other drawings from these attached drawings without any creative effort.</p>
<figref num="1">It is a flow chart which shows the signal classification method provided in one Embodiment of this invention.</figref><figref num="2A">It is a flow chart which shows the signal classification method provided in another embodiment of this invention.</figref><figref num="2B">It is a flow chart which shows the signal classification method provided in another embodiment of this invention.</figref><figref num="3">It is a structural diagram which shows the signal classification device provided in one Embodiment of this invention.</figref><figref num="4">It is a flow chart which shows the coding method provided in one Embodiment of this invention.</figref><figref num="5">It is a flow chart which shows another coding method provided in one Embodiment of this invention.</figref><figref num="6">It is a flow chart which shows the decoding method provided in one Embodiment of this invention.</figref><figref num="7">It is a flow chart which shows another decoding method provided in one Embodiment of this invention.</figref><figref num="8">It is a structural drawing which shows the coding device provided in one Embodiment of this invention.</figref><figref num="9">It is a structural drawing which shows the decoding device provided in one Embodiment of this invention.</figref>
The following embodiments of the present invention are various to take into account the coding / decoding characteristics of various signal classes during signal classification and to further clarify the technical solutions according to the embodiments of the present invention. The characteristics of the coding / decoding algorithm for various signal classes are briefly described below.
1. If the class of the high frequency band signal of the current frame is the noise class, then the coding / decoding process of the high frequency band signal of the current frame is during encoding, with the encoder subbanding the high frequency band signal. Includes a step in which the frequency domain envelope to the frequency domain envelope ratios of the corresponding subbands of the low frequency band signal need to be obtained and the ratios need to be sent to the decoder. In this way, the encoder and decoder predetermine the mapping relationship between some subband of the high frequency band signal and some subband of the low frequency band signal. Alternatively, the encoder searches for the subbands that are most strongly associated with the frequency domain envelope of one subband of the high frequency band signal, depending on the frequency domain envelope of the subband of the low frequency band signal. On the decoder, the subband number (ie, the serial number of the found subband of the low frequency band signal), and the frequency domain envelope of that subband of the high frequency band signal vs. the found sub of the low frequency band signal. Sends the frequency domain envelope ratio of the band. During decoding, the decoder searches for subbands of the low frequency band signal corresponding to its subband number, and further, the frequency domain envelope of each subband of the high frequency band signal according to the ratio sent by the encoder, And the frequency domain envelope of the subband of the low frequency band signal specified according to its subband number is determined. The decoder directly uses the excitation spectrum of the specified frequency range in the low frequency band as the excitation spectrum in the high frequency band, so that noise class data frames can be successfully decoded. From the above analysis, the coding / decoding algorithm is that the frequency domain envelope of the subband of the high frequency band signal and the corresponding sub of the low frequency band signal if the class of the high frequency band signal of the current frame is the noise class. During signal classification, the frequency domain envelope of the high frequency band signal is stronger than the frequency domain envelope of the low frequency band signal to take advantage of the interrelationships between the frequency domain envelopes of the band.
2. If the class of the high frequency band signal of the current frame is the predicted class, then the coding / decoding process of the high frequency band signal of the data frame is during encoding, the encoder first multiple low frequency band signals. The step of selecting the subband most strongly related to the excitation spectrum of the subband of the high frequency band signal from the multiple excitation spectra of the subband of the above, and sending the serial number of the selected subband to the decoder at the same time. Includes the step of sending the frequency region envelope of the subband of the high frequency band signal to the decoder. The decoder determines the frequency domain envelope of the entire high frequency band signal according to the received frequency domain envelope of the subband of the high frequency band signal, and from the low frequency band signal according to the received subband serial number. The excitation spectrum of the subband of the high frequency band signal is predicted so that the excitation spectrum of the entire high frequency band signal can be determined. From the above analysis, the coding / decoding algorithm is between the excitation spectrum of the high frequency band signal and the excitation spectrum of the low frequency band signal if the class of the high frequency band signal of the current frame is the predicted class. In order to utilize the interrelationship, the class of the high frequency band signal when the excitation spectrum of the high frequency band signal is strongly related to the excitation spectrum of the low frequency band signal during signal classification is determined to be the predicted class. It can be seen that it is possible to be considered to gain.
3. When the class of the high frequency band signal of the current frame is the transition class, the mode of processing regarding the excitation spectrum is the same as that of the noise class, and therefore the details are not described again here. The difference is that the encoder needs to send both the subframe time domain envelope of the high frequency band signal and the subframe frequency domain envelope to the decoder. The decoder recovers the high frequency band signal in response to the aforementioned information sent by the encoder.
4. If the class of the high frequency band signal of the current frame is the harmonic class, the mode of processing the excitation spectrum is basically the same as for the noise class, so the details will be explained again here. I will not do it. The difference is that the encoder needs to send the frequency domain envelope of the subband of the high frequency band signal to the decoder. The decoder recovers the high frequency band signal in response to the aforementioned information sent by the encoder.
5. If the class of the high frequency band signal of the current frame is a normal class, the mode of processing the excitation spectrum is the same as for the noise class, so the details will not be described again here. The difference is that the encoder needs to send the frequency domain envelope of the subband of the high frequency band signal to the decoder. The decoder recovers the high frequency band signal in response to the aforementioned information sent by the encoder.
Referring to FIG. 1, one embodiment of the present invention provides a signal classification method, but the method particularly includes:
101: Divide the current frame into low frequency band signals and high frequency band signals.
This embodiment of the present invention is carried out by a encoder.
In particular, low-frequency band signals and high-frequency band signals are relative concepts, and in general, the current frame is low in frequency from the center frequency of the current frame by means of a Quadrature Mirror Filter (QMF). It is divided into a band signal and a high frequency band signal. However, the present invention is not limited to such division, and the current frame can also be divided from other frequencies into a low frequency band signal and a high frequency band signal by other processing modes. Is.
102: Value of the preset coding / decoding characteristic parameter corresponding to the signal class Depending on the requirement, the coding / decoding characteristic parameter of the current frame corresponding to the signal class is the coding / decoding characteristic. Parameter value Determine if the requirement is met. The signal class corresponding to the coding / decoding characteristic parameter is a signal class having the coding / decoding characteristic represented by the coding / decoding characteristic parameter.
That is, depending on the value requirement of the preset coding / decoding characteristic parameter corresponding to the signal class, the value of the coding / decoding characteristic parameter of the current frame corresponding to that signal class is encoded / decoded. It is determined whether or not the value requirement of the conversion characteristic parameter is satisfied.
The preset coding / decoding characteristic parameters corresponding to the signal class are the coding / decoding characteristic parameters corresponding to the noise class, the coding / decoding characteristic parameters corresponding to the predicted class, and the harmonic class. Includes at least one of the encoding / decoding characteristic parameters corresponding to.
The coding / decoding characteristic parameters corresponding to the noise class are the interrelationship parameters between the amplitude of the low frequency band frequency domain signal and the amplitude of the high frequency band frequency domain signal, and the energy and high frequency of the low frequency band frequency domain signal. It is one of the interrelationship parameters between the energies of a band frequency domain signal, except that the coding / decoding characteristic parameters corresponding to the noise class are the amplitude (or energy) and high of the low frequency domain signal. Frequency Band Correlation between frequency domain signal amplitude (or energy) Correlation between other feature values of low frequency band frequency domain signals and other feature values of high frequency band frequency domain signals, not limited to parameters It may be a parameter, which does not affect the practice of the present invention.
If the coding / decoding characteristic parameter corresponding to the noise class is the interrelationship parameter between the amplitude of the low frequency band frequency region signal and the amplitude of the high frequency band frequency region signal, this step is particularly relevant for the current frame. The interrelationship parameters between the amplitude of the low frequency band frequency region signal and the amplitude of the high frequency band frequency region signal are preset between the amplitude of the low frequency band frequency region signal and the amplitude of the high frequency band frequency region signal. It is a step to determine whether the value requirement of the interrelationship parameter is satisfied, and the coding / decoding characteristic parameter corresponding to the noise class is between the energy of the low frequency band frequency region signal and the energy of the high frequency band frequency region signal. If the interrelationship parameter is, in particular, the interrelationship parameter between the energy of the low frequency band frequency region signal and the energy of the high frequency band frequency region signal of the current frame is that of the low frequency band frequency region signal. It is a step of determining whether the value requirement of the preset interrelationship parameter between the energy and the energy of the high frequency band frequency region signal is met.
The value requirements for the preset coding / decoding characteristic parameters corresponding to the noise class can be, in particular, greater than or within a certain value range. Correlation between the amplitude of the low frequency band frequency domain signal and the amplitude of the high frequency band frequency domain signal The value requirement of the parameter and the interrelationship between the energy of the low frequency band frequency domain signal and the energy of the high frequency band frequency domain signal. The value requirements of the parameters may be the same or different.
The coding / decoding characteristic parameters corresponding to the predicted class are the interrelationship parameters between the frequency domain coefficient of the low frequency band signal and the frequency domain coefficient of the high frequency band signal, and the absolute frequency domain coefficient of the low frequency band signal. Correlation parameters between the value and the absolute value of the frequency domain coefficient of the high frequency band signal, the correlation parameter between the frequency domain coefficient of the low frequency excitation spectrum and the frequency domain coefficient of the high frequency excitation spectrum, and the low frequency band excitation spectrum. It is one of the interrelationship parameters between the absolute value of the frequency domain coefficient of and the absolute value of the frequency domain coefficient of the high frequency band excitation spectrum. The coding / decoding characteristic parameters corresponding to the predicted class are not limited to the interrelationship parameters described above, but are the interrelationships between other feature values of the low frequency band signal and other feature values of the high frequency band signal. It can be a parameter, or an interrelationship parameter between other feature values of the low frequency band excitation spectrum and other feature values of the high frequency band excitation spectrum, which affects the practice of the present invention. Absent.
This step is particularly current if the coding / decoding characteristic parameter corresponding to the predicted class is the interrelationship parameter between the frequency domain coefficient of the low frequency band signal and the frequency domain coefficient of the high frequency band signal. The interrelationship parameter between the frequency domain coefficient of the low frequency band signal and the frequency domain coefficient of the high frequency band signal of the frame is preset between the frequency domain coefficient of the low frequency band signal and the frequency domain coefficient of the high frequency band signal. It is a step of determining whether or not the value requirement of the interrelationship parameter is satisfied. If the coding / decoding characteristic parameter corresponding to the predicted class is the interrelationship parameter between the absolute value of the frequency domain coefficient of the low frequency band signal and the absolute value of the frequency domain coefficient of the high frequency band signal, then this The step is, in particular, that the interrelationship parameter between the absolute value of the frequency domain coefficient of the low frequency band signal of the current frame and the absolute value of the frequency domain coefficient of the high frequency band signal is the absolute value of the frequency domain coefficient of the low frequency band signal. It is a step of determining whether the value requirement of the preset interrelationship parameter between the value and the absolute value of the frequency domain coefficient of the high frequency band signal is met. This step is particularly current if the coding / decoding characteristic parameter corresponding to the predicted class is the interrelationship parameter between the frequency domain coefficient of the low frequency excitation spectrum and the frequency domain coefficient of the high frequency excitation spectrum. The interrelationship parameter between the frequency domain coefficient of the low frequency excitation spectrum and the frequency domain coefficient of the high frequency excitation spectrum of the frame is preset between the frequency domain coefficient of the low frequency excitation spectrum and the frequency domain coefficient of the high frequency excitation spectrum. It is a step of determining whether or not the value requirement of the interrelationship parameter is satisfied. If the coding / decoding characteristic parameter corresponding to the predicted class is the interrelationship parameter between the absolute value of the frequency domain coefficient of the low frequency excitation spectrum and the absolute value of the frequency domain coefficient of the high frequency band excitation spectrum. This step specifically involves the absolute value of the frequency domain coefficients of the low frequency band excitation spectrum and the circumference of the high frequency band excitation spectrum.
The value requirements for the preset coding / decoding characteristic parameters corresponding to the predicted class can be, in particular, greater than a particular threshold or within a range of values. Value requirements for interrelationship parameters between the frequency domain coefficient of a low frequency band signal and the frequency domain coefficient of a high frequency band signal, the absolute value of the frequency domain coefficient of a low frequency band signal and the absolute value of the frequency domain coefficient of a high frequency band signal The value requirement of the interrelationship parameter between, the value requirement of the interrelationship parameter between the frequency domain coefficient of the low frequency band excitation spectrum and the frequency domain coefficient of the high frequency band excitation spectrum, and the frequency domain coefficient of the low frequency band excitation spectrum. The value requirements of the interrelationship parameters between the absolute value and the absolute value of the frequency domain coefficient of the high frequency band excitation spectrum may be the same or different, which affects the practice of the present invention. Absent.
The coding / decoding characteristic parameters corresponding to the harmonic class are the interrelationship parameters between the frequency domain coefficient of the low frequency band signal and the frequency domain coefficient of the high frequency band signal, and the absolute value of the frequency domain coefficient of the low frequency band signal. And the interrelationship parameters between the absolute values of the frequency domain coefficients of the high frequency band signal, the interrelationship parameters between the frequency domain coefficients of the low frequency band excitation spectrum and the frequency domain coefficients of the high frequency band excitation spectrum, and the low frequency band excitation. It is one of the interrelationship parameters between the absolute value of the frequency domain coefficient of the spectrum and the absolute value of the frequency domain coefficient of the high frequency band excitation spectrum, and the relevant description is the coding / corresponding to the predicted class. It is the same as the description of the value requirement of the decoding characteristic parameter, and therefore the details will not be described again here.
The signal class in the preset coding / decoding characteristic parameters corresponding to the signal class is not limited to the above-mentioned class, and the coding / decoding characteristic parameters corresponding to other signal classes may be preset. It should be noted that this is possible and this does not affect the practice of the present invention.
103: Judge the signal class of the high frequency band signal of the current frame according to the judgment result.
In one implementation, if the value of the current frame coding / decoding characteristic parameter corresponding to the noise class meets the value requirement of the preset coding / decoding characteristic parameter corresponding to the noise class, then the current The signal class of the high frequency band signal of the frame is determined to be the noise class. In one exemplary implementation, the number of subbands with a peak-to-average ratio less than the second threshold is greater than the second predetermined number, and the coding / decoding of the current frame corresponding to the noise class. If the value of the conversion characteristic parameter meets the value requirement of the preset coding / decoding characteristic parameter corresponding to the noise class, then the signal class of the high frequency band signal of the current frame is determined to be the noise class. To.
In one implementation, the preset coding / decoding characteristic parameters corresponding to the signal class are the coding / decoding characteristic parameters corresponding to the predicted class, or the coding / decoding corresponding to the harmonic class. If a characteristic parameter is included, then the coding / decoding characteristic parameter of the current frame corresponding to the predicted class meets the value requirement of the preset coding / decoding characteristic parameter corresponding to the predicted class. , The signal class of the high frequency band signal of the current frame is determined to be the predicted class. Alternatively, if the coding / decoding characteristic parameter of the current frame corresponding to the harmonic class meets the value requirement of the preset coding / decoding characteristic parameter corresponding to the harmonic class, then the current frame The signal class of the high frequency band signal is determined to be the high frequency class. In one exemplary implementation, the number of subbands with a peak-to-average ratio greater than the first threshold is greater than the first predetermined number, and the current frame encoding / corresponding to the harmonic class. If the decoding characteristic parameter meets the value requirement of the preset coding / decoding characteristic parameter corresponding to the harmonic class, then the signal class of the high frequency band signal of the current frame is determined to be the harmonic class. The number of subbands with a peak-to-average ratio greater than or equal to the first threshold is less than or equal to the first predetermined number, and the coding / decoding characteristics of the current frame corresponding to the predicted class. If the parameter meets the value requirement of the preset encoding / decoding characteristic parameter corresponding to the predicted class, then the signal class of the high frequency band signal of the current frame is determined to be the predicted class. Or, as an alternative, the number of subbands with a peak-to-average ratio greater than the first threshold is less than or equal to the first predetermined number and has a peak-to-average ratio less than the second threshold. The number of subbands is less than or equal to the second predetermined number, and the coding / decoding characteristic parameters of the current frame corresponding to the predicted class are the preset coding corresponding to the predicted class.
In one implementation, the preset coding / decoding characteristic parameters corresponding to the signal class are the coding / decoding characteristic parameters corresponding to the predicted class and the coding / decoding corresponding to the harmonic class. When including characteristic parameters, the number of subbands with a peak-to-average ratio greater than the first threshold is greater than the first predetermined number, and the current frame encoding / corresponding to the harmonic class. When the decoding characteristic parameter meets the value requirement of the preset coding / decoding characteristic parameter corresponding to the harmonic class, the signal class of the high frequency band signal of the current frame is determined to be the harmonic class. The number of subbands having a peak-to-average ratio greater than the first threshold is less than or equal to the first predetermined number and has a peak-to-average ratio less than the second threshold. Is less than or equal to the second predetermined number, and the current frame encoding / decoding characteristic parameters corresponding to the predicted class are the preset encoding / decoding characteristics corresponding to the predicted class. If the value requirement of the parameter is satisfied, the signal class of the high frequency band signal of the current frame is determined to be the predicted class. The first threshold and the second threshold may be the same or different.
In yet another embodiment, the full frequency time domain signal of the current frame is divided into N subframes, and the energy of one subframe is the specific energy of the subframe before that subframe. If it is larger than a multiple, the signal class of the high frequency band signal of the current frame is determined to be a transition class.
In this embodiment of the invention, during signal classification, the value of the coding / decoding characteristic parameter of the current frame depends on the value requirement of the preset coding / decoding characteristic parameter corresponding to the signal class. Whether or not the value requirement of the coding / decoding characteristic parameter is satisfied is determined, and whether or not the signal class of the high frequency band signal of the current frame is the signal class corresponding to the coding / decoding characteristic parameter. As determined, the coding / decoding characteristics of the various signal classes are taken into account during signal classification, resulting in more accurate signal classification.
To better clarify the technical solutions provided in the embodiments of the present invention, the technical solutions will be described in detail below via the following embodiments.
201: The encoder divides the entire frequency time domain signal of the current frame into N subframes.
202: The encoder calculates the energy or amplitude of each subframe.
203: The encoder determines if the specified subframe exists in the current frame, and if so, performs step 204, and if not, steps 205. The energy of the specified subframe is greater than a specific multiple of the energy of the subframe before the specified subframe, or the amplitude of the specified subframe is the amplitude of the subframe before the specified subframe. Greater than a specific multiple of.
For example, the energy of a particular subframe in the current frame in the encoder is E<sub>CUR</sub>And the energy of the subframe before that subframe is E<sub>prev</sub>And a predetermined multiple is pre-configured in the coding section and is further assumed to be a, and generally a> 5 and E.<sub>CUR</sub>> a × E<sub>prev</sub>If, the subframe is the specified subframe.
204: The encoder determines that the signal class of the high frequency band signal of the current frame is the transition class, and the process is terminated.
One subframe includes a high frequency band portion and a low frequency band portion, and in general, the energy of the low frequency band portion is larger than the energy of the high frequency band portion, so that two consecutive subframes, that is, subframes For frame 1 and subframe 2, the energy of the high frequency band portion of subframe 1 is 1, the energy of the high frequency band portion of subframe 2 is 6, and the energy of the low frequency band portion of subframe 1 is 100. It is assumed that the energy of the low frequency band portion of subframe 2 is 100, the energy of subframe 1 is 101, and the energy of subframe 2 is 106, and the predetermined multiple is 5. Assuming that, by adopting the solution of step 203, the energy of subframe 2 is less than or equal to a predetermined multiple of the energy of subframe 1, so subframe 2 is not the specified subframe. .. The prior art solution is to determine if the specified subframe is present in the high frequency band signal of the current frame, according to the prior art solution, the height of subframe 2. The frequency band energy is greater than a predetermined multiple of the high frequency band energy of subframe 1, so subframe 2 is the designated subframe. In this way, the data frame is determined to be a transition class only if there is a significant energy jump between the high frequency band portions of the adjacent subframes in view of the entire frequency band of the data frame. It can be seen that the technical solution of determining whether a data frame is a transition class according to an embodiment of the present invention yields more accurate signal classification results.
205: The encoder divides the high frequency band frequency domain signal of the current frame into M subbands.
Prior to step 205, the encoder needs to divide the current frame into a low frequency band signal and a high frequency band signal.
206: Whether the number of subbands in the high frequency band frequency domain signal of the current frame that have a peak-to-average ratio above the first threshold is greater than the first predetermined number. If it is larger than the first predetermined number, step 207 is executed, and if it is less than or equal to the first predetermined number, step 208 is executed.
207: The encoder determines that the signal class of the high frequency band signal of the current frame is a harmonic class and the process is terminated.
208: Whether the encoder has a number of subbands in the high frequency band frequency domain signal of the current frame that have a peak-to-average ratio less than the second threshold value greater than the second predetermined number. If it is larger than the second predetermined number, step 209 is executed, and if it is less than or equal to the second predetermined number, step 211 is executed.
The first predetermined number and the second predetermined number are empirical values obtained through experience, and may be the same or different.
209: The encoder acquires the interrelationship parameter between the energy or amplitude of the high frequency band frequency region signal of the current frame and the energy or amplitude of the low frequency band frequency region signal and the high frequency band frequency region of the current frame. Determines if the value of the interrelationship parameter between the energy or amplitude of the signal and the energy or amplitude of the low frequency band frequency region signal is greater than a given energy threshold or amplitude threshold, and a given energy threshold. If it is greater than the value or amplitude threshold, step 210 is performed, and if it is less than or equal to the predetermined energy threshold or amplitude threshold, step 211 is performed.
This particular process of obtaining the value of the interrelationship parameter between the energy or amplitude of the high frequency band frequency domain signal of the current frame and the energy or amplitude of the low frequency band frequency domain signal involves two aspects: , Not limited to these modes.
First mode: The value of the interrelationship parameter between the subband energy or amplitude of the high frequency band signal and the subband energy or amplitude of the low frequency band signal, each corresponding to these subbands. And calculate the average of the acquired values of these correlation parameters, and then use this average as the energy or amplitude of the high frequency band frequency domain signal of the current frame and the energy or amplitude of the low frequency band frequency domain signal. Used as the value of the interrelationship parameter between amplitudes.
In this way, the encoder and decoder have already determined in advance the mapping relationship between a particular subband of the high frequency band signal and a particular subband of the low frequency band signal, and correspondingly the encoder. Depending on this mapping relationship, the value of the interrelationship parameter between the energy or amplitude of a particular subband of the high frequency band signal and the energy or amplitude of the subband of the low frequency band signal corresponding to that subband. Determine and similarly calculate the values of the interrelationship parameters between the energies or amplitudes of the multiple subbands in the high frequency band and the energies or amplitudes of the corresponding subbands in the low frequency band, and then these interrelationships. The average of the calculated values of the parameters is obtained to obtain the value of the interrelationship parameter between the energy or amplitude of the high frequency band frequency region signal and the energy or amplitude of the low frequency band frequency region signal.
In this way, the encoder has a high frequency, in particular, depending on the subband energy or amplitude pair of the high frequency band signal, and the subband energy or amplitude ratio of the low frequency band signal corresponding to each subband. It is possible to obtain the value of the interrelationship parameter between the subband energy or amplitude of the band signal and the subband energy or amplitude of the low frequency band signal corresponding to those subbands, generally with a ratio of 1. When close to, this indicates a strong interrelationship between the two, and when the value of the interrelationship parameter is large and the ratio is not close to 1, this indicates a weak interrelationship between the two. In addition, the values of the interrelationship parameters are small, or the encoder indicates the difference between the subband energy or amplitude of the high frequency band signal and the subband energy or amplitude of the low frequency band signal corresponding to each subband. Depending on the absolute value of, it is possible to calculate the value of the interrelationship parameter, and in general, if this absolute value is small, this indicates a strong interrelationship between the two, and in addition, of the interrelationship parameter. If the value is large and this absolute value is not small, this indicates a weak interrelationship between the two and the value of the interrelationship parameter is small.
Second mode: The encoder determines the subbands of the low frequency band signal that are most strongly related to the energy or amplitude of each subband of the high frequency band signal, and of each subband of the high frequency band signal. Obtain the values of the interrelationship parameters between the energy or amplitude and the energy or amplitude of the determined most strongly interrelated subbands of the low frequency band signal, and average the acquired values of these interrelationship parameters. Calculate the value and use this average as the value of the interrelationship parameter between the energy or amplitude of the high frequency band frequency region signal of the current frame and the energy or amplitude of the low frequency band frequency region signal.
This aspect will be described below by using an example.
The high frequency band signal contains 10 subbands and the low frequency band signal contains 10 subbands, from the subband of the low frequency band signal to the energy or amplitude of the first subband of the high frequency band and most. Strongly related subbands are searched for and the values of the interrelationship parameters between the two subbands are obtained, as well as from the subband of the low frequency band signal to the second subband of the high frequency band. The subbands most strongly associated with the energy or amplitude of the are searched for, and the values of the interrelationship parameters between the two subbands are obtained so that the 10 interrelationship parameter values are similarly Obtained, the average of these 10 interrelationship parameters is calculated and used as the value of the interrelationship parameter between the energy or amplitude of the high frequency band frequency region signal and the energy or amplitude of the low frequency band frequency region signal. It is supposed to be.
Thus, the particular mode of obtaining the value of the interrelationship parameter between the subband energy or amplitude of the high frequency band signal and the energy or amplitude of the most strongly interrelated subband of the low frequency band signal. , Similar to the first aspect, and therefore no details will be given here again.
The number of subbands can be one or more, and if the number of subbands is one, the value of the interrelationship parameter is calculated directly for the entire frequency band.
210: The encoder determines that the signal class of the high frequency band signal of the current frame is the noise class and the process is terminated.
211: The encoder obtains the value of the interrelationship parameter between the frequency domain coefficient of the high frequency band excitation spectrum of the current frame and the frequency domain coefficient of the low frequency band excitation spectrum, and the frequency domain coefficient of the high frequency band excitation spectrum. To determine if the value of the interrelationship parameter between and the frequency domain coefficient of the low frequency band excitation spectrum is greater than a certain predetermined threshold, and if so, step 212. , If it is below the predetermined threshold, step 213 is executed.
The values of the interrelationship parameters between the frequency domain coefficients of the high frequency band excitation spectrum of the current frame and the frequency domain coefficients of the low frequency band excitation spectrum can be obtained by using a normalized intercorrelation algorithm.
In one embodiment, the values of the interrelationship parameters between the frequency domain coefficients of the high frequency band excitation spectrum of the current frame and the frequency domain coefficients of the low frequency band excitation spectrum can be obtained in the following manner. That is, the encoder determines the subbands of the low frequency band signal that are most strongly related to the frequency domain coefficient of the excitation spectrum of each subband of the high frequency band signal of the current frame, and determines the subbands of the high frequency band signal. Obtain the value of the interrelationship parameter between the frequency domain coefficient of the excitation spectrum of each subband and the frequency domain coefficient of the excitation spectrum of the most strongly associated subband of the low frequency band signal, and further. Calculate the average value of the acquired values of the interrelationship parameter to obtain the value of the interrelationship parameter between the frequency domain coefficient of the high frequency band excitation spectrum of the current frame and the frequency domain coefficient of the low frequency band excitation spectrum. To do so.
The high frequency band excitation spectrum contains two subbands, the low frequency band excitation spectrum contains five subbands, each high frequency band subband contains 20 frequency domain coefficients, and each low frequency band subband. Is assumed to contain a frequency domain coefficient of 40. By using the following equation, the 1st to 20th frequency domain coefficients in the 40 frequency domain coefficients of each subband of the low frequency band signal and the 20 frequency domain coefficients of the first subband of the high frequency band. , 2nd to 21st frequency domain coefficients, 3rd to 22nd frequency domain coefficients, ..., and normalized interrelationship parameter values of 21st to 40th frequency domain coefficients are determined and determined. Also, the maximum of the normalized interrelationship parameter values is obtained, as well as the 40 frequency domain coefficients of each subband of the low frequency band signal, and the 20 of the second subband of the high frequency band. Normality of the 1st to 20th frequency domain coefficients, the 2nd to 21st frequency domain coefficients, the 3rd to 22nd frequency domain coefficients, ..., And the 21st to 40th frequency domain coefficients in the frequency domain coefficients. The normalized interrelationship parameter value is determined, the maximum of the determined, normalized interrelationship parameter values is obtained, the average of the two maximums is calculated, and the height of the current frame is calculated. The values of the interrelationship parameters between the frequency domain coefficient of the frequency band excitation spectrum and the frequency domain coefficient of the low frequency band excitation spectrum are obtained.
<maths num="1"><img file="JP6558745B2_D0001.tif" /></maths>
In this case, a<sub>i</sub>And b<sub>i</sub>Are specific frequency domain coefficients in the subband of the low frequency band signal and specific frequency domain coefficients in the subband of the high frequency band signal, for example, the second to second of the specific subband of the low frequency band signal. If the normalized interrelationship parameter values of the 21 frequency domain coefficients and the 20 frequency domain coefficients of the high frequency band signal are calculated, a<sub>1</sub>Is the second frequency domain coefficient for a particular subband of a low frequency band signal, a<sub>2</sub>Is the third frequency domain coefficient of that subband, a<sub>20</sub>Is the 21st frequency domain coefficient of that subband, and b<sub>1</sub>From b<sub>20</sub>Is the 20 frequency domain coefficients in a particular subband of the high frequency band signal.
Alternatively, in another embodiment, the encoder in this step reciprocally between the absolute value of the frequency domain coefficients of the high frequency band excitation spectrum of the current frame and the absolute value of the frequency domain coefficients of the low frequency band excitation spectrum. The value of the relational parameter is also obtained, and the value of the interrelationship parameter between the absolute value of the frequency domain coefficient of the high frequency band excitation spectrum and the absolute value of the frequency domain coefficient of the low frequency band excitation spectrum is higher than a specific threshold value. It is also possible to determine whether it is larger, execute step 212 if it is greater than the threshold, and execute step 213 if it is less than or equal to the threshold.
212: The encoder determines that the signal class of the high frequency band signal of the current frame is the predicted class and the process is terminated.
213: The encoder determines that the signal class of the high frequency band signal of the current frame is a normal class.
The order of the above-mentioned determination steps is not fixed but can be changed. For example, steps 206 to 211 may be executed first, step 211 is executed, and the determination result is "Yes". If step 212 is executed and the determination result is "No", steps 201 to 204 are executed, but if the determination result in step 203 is "Yes", the high frequency band signal of the current frame is executed. Note that the signal class is determined to be a transition class, and if the determination result in step 203 is "No", the signal class of the high frequency band signal of the current frame is determined to be a normal class. I want to be.
In embodiments of the present invention, the coding / decoding characteristics of the high frequency band signal of the current frame are taken into account during signal classification, and thus the energy or amplitude of the high frequency band frequency region signal and the low frequency band frequency region. If the energy or amplitude of the signal is strongly related to each other, the high frequency band signal is classified into a noise class, the frequency region coefficient of the high frequency band excitation spectrum of the current frame and the frequency region coefficient of the low frequency band excitation spectrum. When are strongly related to each other, the high frequency band signal is classified into the predicted class, resulting in more accurate signal classification, whereas in the prior art, the class is the peak-to-average ratio. The coding / decoding characteristics of the signal are not taken into account, and therefore data frames with noise class coding / decoding characteristics are classified as regular classes and are inaccurately classified. Results can be obtained, and when determining if the high frequency band signal of the current frame is of the transition class, the determination is based on the subframes of the entire frequency band of the current frame. However, it is not executed based solely on the subbands in the high frequency band signal, resulting in more accurate determination results. In addition, because the signal classification is more accurate, when the same number of bits are used, the coding / decoding performance is improved, for example, by the signal classification method in the prior art, the high frequency band signal of a specific frame. The signal class of the high frequency band signal of the frame is determined to be a noise class by the signal classification method provided in the present application, whereas the signal class of is determined to be a normal class. If the instrument and decoder predetermine the mapping relationship between a particular subband of a high frequency band signal and a particular subband of a low frequency band signal, then the encoder determines the energy of the subband of the high frequency band signal or All you have to do is send the subband energy or amplitude ratio of the amplitude to the low frequency band signal, no other information needs to be transmitted, and as a result.
Alternatively, in another embodiment, in step 211, the encoder obtains the value of the interrelationship parameter between the frequency domain coefficient of the high frequency band signal and the frequency domain coefficient of the low frequency band signal of the current frame. Determine if the value of the interrelationship parameter between the frequency domain coefficient of the high frequency band signal and the frequency domain coefficient of the low frequency band signal is greater than a particular threshold, and if so, step 212. If it is below that threshold, then step 213 can be performed. Specifically, the value of the interrelationship parameter between the frequency domain coefficient of the high frequency band signal of the current frame and the frequency domain coefficient of the low frequency band signal can be obtained in the following manner. That is, the encoder determines the subbands of the low frequency band signal that are most strongly related to the frequency domain coefficient of each subband of the high frequency band signal of the current frame, and each subband of the high frequency band signal. Obtain the value of the interrelationship parameter between the frequency domain coefficient of and the frequency domain coefficient of the determined subband of the low frequency band signal most strongly related to that subband, and obtain these interrelationship parameters. The average of the values obtained is calculated, and this average is used as the value of the interrelationship parameter between the frequency domain coefficient of the high frequency band signal and the frequency domain coefficient of the low frequency band signal of the current frame.
Alternatively, in another embodiment, in step 211, the encoder has an interrelationship parameter between the absolute value of the frequency domain coefficient of the high frequency band signal of the current frame and the absolute value of the frequency domain coefficient of the low frequency band signal. To determine if the value of the interrelationship parameter between the absolute value of the frequency domain coefficient of the high frequency band signal and the absolute value of the frequency domain coefficient of the low frequency band signal is greater than a certain threshold. If it is greater than the threshold, step 212 can be executed, and if it is less than or equal to the threshold, step 213 can be executed.
Alternatively, in another embodiment, the number of subbands with a peak-to-average ratio less than the second threshold is greater than the second predetermined number, and the coding of the current frame corresponding to the noise class. The value of the / decoding characteristic parameter meets the value requirement of the preset coding / decoding characteristic parameter corresponding to the noise class (ie, the amplitude and high frequency band frequency of the low frequency band frequency domain signal of the current frame. The interrelationship parameters between the amplitudes of the region signals meet the preset value requirements, or the interrelationship parameters between the energy of the low frequency band frequency domain signal and the energy of the high frequency band frequency domain signal are preset. If the value requirement is met), the signal class of the high frequency band signal of the current frame is determined to be the noise class.
The number of subbands with a peak-to-average ratio greater than the first threshold is greater than the first predetermined number, and the values of the current frame coding / decoding characteristic parameters corresponding to the harmonic class are: Meets the value requirements of the preset coding / decoding characteristic parameters for the harmonic class (ie, the interrelationship parameters between the frequency domain coefficients of the low frequency band signal and the frequency domain coefficients of the high frequency band signal, or The interrelationship parameter between the absolute value of the frequency domain coefficient of the low frequency band signal and the absolute value of the frequency domain coefficient of the high frequency band signal, or the frequency domain coefficient of the low frequency band excitation spectrum and the frequency domain coefficient of the high frequency band excitation spectrum. Interrelationship parameters between, or between the absolute value of the frequency domain coefficient of the low frequency band excitation spectrum and the absolute value of the frequency domain coefficient of the high frequency band excitation spectrum, meet the preset value requirements) In this case, the signal class of the high frequency band signal of the current frame is determined to be the harmonic class.
The number of subbands having a peak-to-average ratio greater than the first threshold is less than or equal to the first predetermined number, and the number of subbands having a peak-to-average ratio less than the second threshold is The value of the current frame encoding / decoding characteristic parameter corresponding to the predicted class, which is less than or equal to the second predetermined number, is the preset encoding / decoding characteristic parameter corresponding to the predicted class. (That is, the interrelationship parameter between the frequency domain coefficient of the low frequency band signal and the frequency domain coefficient of the high frequency band signal, or the absolute value of the frequency domain coefficient of the low frequency band signal and the high frequency band signal. The interrelationship parameter between the absolute values of the frequency domain coefficients, or the interrelationship parameter between the frequency domain coefficient of the low frequency band excitation spectrum and the frequency domain coefficient of the high frequency band excitation spectrum, or the frequency domain coefficient of the low frequency band excitation spectrum. The signal class of the high frequency band signal in the current frame is predicted if the interrelationship parameter between the absolute value of and the absolute value of the frequency domain coefficient of the high frequency band excitation spectrum meets the preset value requirement). It is judged that it is a class.
If it has already been determined by using the technical solution described above that the data frame does not belong to the transition class, noise class, harmonic class, and predicted class, then the data frame belongs to the normal class. Can be determined.
The value requirements for the coding / decoding characteristic parameters corresponding to the harmonic class and the value requirements for the coding / decoding characteristic parameters corresponding to the predicted class may be the same or different. Does not affect the practice of the present invention.
Referring to FIG. 3, one embodiment of the present invention provides a signal classification device, provided that the device is specifically configured to divide the current frame into low frequency band signals and high frequency band signals. Depending on the value requirements of the split unit 10 and the preset coding / decoding characteristic parameters corresponding to the signal class, the coding / decoding characteristic parameters of the current frame corresponding to that signal class are encoded / decoded. Decoding characteristic parameter values The determination unit 20 includes a determination unit 20 configured to determine whether it meets the requirements, and the determination unit 20 is a value of a preset encoding / decoding characteristic parameter corresponding to the signal class. Judgment unit 20, which determines whether the value of the coding / decoding characteristic parameter of the current frame corresponding to the signal class meets the value requirement of the coding / decoding characteristic parameter, depending on the requirement. Depending on the determination result of whether the signal class of the high frequency band signal of the current frame is the signal class corresponding to the coding / decoding characteristic parameter, the signal class corresponding to the coding / decoding characteristic parameter is determined. It includes a determination unit 30 configured to determine whether the signal class has the coding / decoding characteristics represented by the encoding / decoding characteristic parameters.
In one embodiment, the preset coding / decoding characteristic parameters corresponding to the signal class include the coding / decoding characteristic parameters corresponding to the noise class, provided that the coding / decoding corresponding to the noise class. The characteristic parameters are the interrelationship parameters between the amplitude of the low frequency band frequency domain signal and the amplitude of the high frequency band frequency domain signal, and the mutual relationship between the energy of the low frequency band frequency domain signal and the energy of the high frequency band frequency domain signal. One of the related parameters. In this case, the signal classification device determines whether the number of subbands in the high frequency band signal of the current frame that have a peak-to-average ratio less than the second threshold is greater than the second predetermined number. It is possible to further include a second peak-to-average ratio determination unit 40 configured to determine, where the determination unit has a number of subbands with a peak-to-average ratio less than the second threshold. , The value of the current frame encoding / decoding characteristic parameter, which is greater than the second predetermined number and also corresponds to the noise class, is the value requirement of the preset encoding / decoding characteristic parameter corresponding to the noise class. If the condition is satisfied, the signal class of the high frequency band signal of the current frame includes a noise class determination unit 31 configured to determine that it is a noise class. Alternatively, the signal classification device may not include a second peak-to-average ratio determination unit 40, where the other device or chip may have a second threshold in the high frequency band signal of the current frame. It is used to determine if the number of subbands with a smaller peak-to-average ratio is greater than a second predetermined number and notify the signal classification device of the determination result.
In another embodiment, the preset coding / decoding characteristic parameters corresponding to the signal class are the coding / decoding characteristic parameters corresponding to the predicted class, or the coding / decoding corresponding to the harmonic class. The corresponding description of the coding / decoding characteristic parameter corresponding to the predicted class and the coding / decoding characteristic parameter corresponding to the harmonic class is the same as the description in the method embodiment. Therefore, the details will not be explained here again. The signal classification device determines if the number of subbands in the high frequency band signal of the current frame that have a peak-to-average ratio greater than the first threshold is greater than the first predetermined number. It is possible to further include a first peak-to-average ratio determination unit 50 configured as such, and the preset coding / decoding characteristic parameters corresponding to the signal class are the codes corresponding to the harmonic class. When including the conversion / decoding characteristic parameters, the determination unit currently has a number of subbands with a peak-to-average ratio greater than the first threshold, greater than the first predetermined number, and corresponds to the harmonic class. If the value of the encoding / decoding characteristic parameter of the frame meets the value requirement of the preset encoding / decoding characteristic parameter corresponding to the harmonic class, then the signal class of the high frequency band signal of the current frame is , Includes a harmonic class determination unit 32 configured to determine that it is a harmonic class. If the preset coding / decoding characteristic parameters corresponding to the signal class include the coding / decoding characteristic parameters corresponding to the predicted class, the determination unit will have a peak pair greater than the first threshold. The number of subbands having an average ratio is less than or equal to the first predetermined number, and the value of the coding / decoding characteristic parameter of the current frame corresponding to the predicted class is pre-corresponding to the predicted class. The signal class of the high frequency band signal of the current frame is predicted to be determined to be the predicted class if the value requirements of the set encoding / decoding characteristic parameters are met. Includes the specified class determination unit 33. Alternatively, the signal classification device may not include the first peak-to-average ratio determination unit 50, and the other device or chip may have a first threshold in the high frequency band signal of the current frame. It is used to determine if the number of subbands with a larger peak-to-average ratio is greater than the first predetermined number and further notify the signal classification device of the determination result. In one exemplary implementation, the predicted class determination unit has a number of subbands with a peak-to-average ratio that is less than the second threshold, less than or equal to the second predetermined number, and the first. The number of subbands with a peak-to-average ratio greater than the threshold is less than or equal to the first predetermined number, and the value of the current frame coding / decoding characteristic parameter corresponding to the predicted class is predicted. The signal class of the high frequency band signal of the current frame is specifically configured to determine that it is the predicted class if the value requirements of the preset encoding / decoding characteristic parameters corresponding to the class are met. To. In this case, the signal classification device determines whether the number of subbands in the high frequency band signal of the current frame that have a peak-to-average ratio less than the second threshold is greater than the second predetermined number. It may further include a second peak-to-average ratio determination unit 40 configured to determine. If the value of the encoding / decoding characteristic parameter of the current frame corresponding to meets the value requirement of the preset encoding / decoding characteristic parameter corresponding to the predicted class, then the high frequency band of the current frame The signal class of the signal is specifically configured to determine that it is the predicted class. In this case, the signal classification device determines whether the number of subbands in the high frequency band signal of the current frame that have a peak-to-average ratio less than the second threshold is greater than the second predetermined number. It may further include a second peak-to-average ratio determination unit 40 configured to determine. If the value of the encoding / decoding characteristic parameter of the current frame corresponding to meets the value requirement of the preset encoding / decoding characteristic parameter corresponding to the predicted class, then the high frequency band of the current frame The signal class of the signal is specifically configured to determine that it is the predicted class. In this case, the signal classification device determines whether the number of subbands in the high frequency band signal of the current frame that have a peak-to-average ratio less than the second threshold is greater than the second predetermined number. It may further include a second peak-to-average ratio determination unit 40 configured to determine.
In one implementation, the preset coding / decoding characteristic parameters corresponding to the signal class are the coding / decoding characteristic parameters corresponding to the predicted class and the coding / decoding corresponding to the harmonic class. The corresponding description of the coding / decoding characteristic parameters corresponding to the predicted class and the coding / decoding characteristic parameters corresponding to the harmonic class, including the characteristic parameters, is the same as the description in the method embodiment. Therefore, the details will not be explained here again. In this case, the signal classification device determines whether the number of subbands in the high frequency band signal of the current frame that have a peak-to-average ratio less than the second threshold is greater than the second predetermined number. A second peak-to-average ratio determination unit 40 configured to determine, and the number of subbands in the high frequency band signal of the current frame that have a peak-to-average ratio greater than the first threshold. Can further include a first peak-to-average ratio determination unit 50 configured to determine if is greater than a first predetermined number, the determination unit having a first threshold. The number of subbands with a larger peak-to-average ratio is greater than the first predetermined number, and the value of the current frame coding / decoding characteristic parameter corresponding to the harmonic class corresponds to the harmonic class. A harmonic class determination unit 32 configured to determine that the signal class of the high frequency band signal of the current frame is a harmonic class if the value requirements of the preset encoding / decoding characteristic parameters are met. And, the number of subbands having a peak-to-average ratio greater than the first threshold is less than or equal to the first predetermined number, and the number of subbands having a peak-to-average ratio smaller than the second threshold. Is less than or equal to the second predetermined number, and the value of the current frame encoding / decoding characteristic parameter corresponding to the predicted class is the preset encoding / decoding corresponding to the predicted class. If the value requirement of the characteristic parameter is met, the signal class of the high frequency band signal of the current frame may be determined to be the predicted class. Further includes the predicted class determination unit 33 formed. Alternatively, the signal classification device may not include a second peak-to-average ratio determination unit 40, and a first peak-to-average ratio determination unit 50, with other devices or chips performing the determination and then. , Used to notify the signal classification device of the determination result.
Although the predicted class determination unit 33, the harmonic class determination unit 32, and the noise class determination unit 31 are depicted in FIG. 7, the determination unit 30 is only any one or two units in a particular implementation. Note that it may only be included.
In yet another embodiment, the device divides the entire frequency time domain signal of the current frame into N subframes, where the energy of one subframe is the specific energy of the subframe before that subframe. If greater than a multiple, the signal class of the high frequency band signal of the current frame further includes a transition class determination unit configured to determine that it is a transition class.
In this embodiment of the invention, during signal classification, the signal class of the current frame is encoded by determining whether the value of the coding / decoding characteristic parameter of the current frame meets the preset requirements. It is determined whether the signal class corresponds to the conversion / decoding characteristic parameters, and in this way, the coding / decoding characteristics of the various signal classes are taken into account during signal classification. As a result, signal classification becomes more accurate. In addition, the more accurate signal classification for the data frame reduces the number of bits transmitted after the data frame is encoded. While the signal classification method in the prior art determines that a particular data frame is a canonical frame, the signal classification method in the present application determines that the data frame is a noise frame, and further encodes and decodes. However, if the mapping relationship between a particular subband of a high frequency band signal and a particular subband of a low frequency band signal is determined in advance, then the encoder has the frequency region envelope vs. low of that subband of the high frequency band signal. It is only necessary to send the ratio of the frequency region envelopes of that subband of the frequency band signal, not the information related to the excitation spectrum, resulting in a reduced number of bits.
The signal classification device may be located on the system side, eg, in a base station, and may be, in particular, a chip or software module in the base station. Alternatively, the signal classification device may be located on the terminal device side and may be, in particular, a chip or software module.
In band-based coding / decoding algorithms, different algorithms are generally used for coding / decoding low frequency band signals and for coding / decoding high frequency band signals, and are generally low. The algorithms used to encode / decode frequency band signals are, among other things, ACELP (Algebraic Code Excited Linear Prediction, algebraic code excited linear prediction), QCELP (Qualcomm Code Excited Linear Prediction), or RCELP (Relaxed code excited). CELP (Code Excited Linear Prediction, code excited linear), which can be linear prediction) prediction). Due to the CELP algorithm, the encoder attenuates the energy of the low frequency band signal when encoding the low frequency band signal. Existing algorithms for encoding / decoding high frequency band signals do not attenuate the energy of high frequency band signals, but if the energy of high frequency band signals is not attenuated, sometimes by decoding the decoder The signal obtained by is unpleasant to hear, and therefore, in order to solve the above-mentioned technical problems, the following embodiments of the present invention are encoded so that the energy of the high frequency band signal is correspondingly attenuated. Methods and decoding methods, as well as encoding and decoding devices are provided.
With reference to FIG. 4, one embodiment of the present invention provides a coding method primarily comprising:
401: Divide the current frame into low frequency band signals and high frequency band signals.
This embodiment of the present invention is carried out by a encoder.
In particular, the low frequency band signal and the high frequency band signal are relative concepts, and in general, the input signal is divided into a low frequency band signal and a high frequency band signal from the center frequency of the input signal by a QMF filter. However, the present invention is not limited to such division, and the input signal can be further divided into a low frequency band signal and a high frequency band signal from other frequencies in other processing modes. is there.
402: The characteristic parameter to be encoded of the high frequency band signal or the high frequency band signal is attenuated according to the energy attenuation value of the low frequency band signal, where this energy attenuation value is the code of the low frequency band signal. It shows the energy decay of the low frequency band signal caused by the conversion.
Prior to this step, the method further comprises determining the signal class of the high frequency band signal of the current frame, provided that the signal class is, in particular, the signal class determination method provided in the prior art, or the present invention. It can be determined by using the signal class determination method provided in the above-described embodiment of the above, which does not affect the practice of the present invention.
The high frequency band signal of the current frame can be the high frequency band time domain signal of the current frame or the high frequency band frequency domain signal of the current frame, and the coding of the high frequency band signal of the current frame. The characteristic parameter to be made can be an energy characteristic parameter to be encoded in the high frequency band signal, in particular the time domain envelope or encoding to be encoded in the high frequency band signal of the current frame. It can be a frequency domain envelope to be.
The characteristic parameters to be encoded in the high frequency band signal, or high frequency band signal, can be particularly attenuated depending on the energy attenuation value and the signal class of the high frequency band signal in the current frame. In another implementation, the encoder is capable of attenuating the high frequency band signals of all signal classes, or the characteristic parameters to be encoded in those high frequency band signals. However, since the signal class of the current frame varies, the characteristic parameters to be encoded for the attenuated high frequency band signal of the current frame or the high frequency band signal of the current frame can also vary. .. For details, refer to the description of the embodiment shown in FIG. In yet another embodiment, only some classes of signals are attenuated, or only certain classes of signals are attenuated, which does not affect the practice of the present invention.
In one particular implementation, the signal class of the high frequency band signal of the current frame can include a noise class, a predicted class, a transition class, a harmonic class, and a normal class, and another particular class. In the embodiment, the signal class of the high frequency band signal of the current frame can include a noise class, a predicted class, a transition class, a harmonic class, a friction sound class, and a voiced sound class. The difference between the signal classes in these two particular implementations is that in the latter implementation, the regular class is divided into a fricative class and a voiced class.
The mode of acquiring the energy attenuation value includes, but is not limited to, the following two modes.
First mode: The encoder encodes the low frequency band signal of the current frame, locally decodes the result of encoding this low frequency band signal, and locally decodes the energy of the low frequency band signal. The ratio of the energy of the signal obtained by doing so is used as the energy attenuation value. The energy attenuation value determined in this way is the most accurate.
Second mode: The energy attenuation value is preset in the encoder and the energy attenuation value is the result of encoding the energy of multiple low frequency band signals in the same class frame and the low frequency band signal in the same class frame. It is obtained according to the ratio of the energies of the signal obtained by decoding the, which in particular obtains the value by training according to these ratios by using the LBG algorithm, and It is possible to use this value as the energy attenuation value, where the same class frame is a data frame of the same signal class as the high frequency band signal of the current frame.
In this way, the corresponding energy attenuation values can be preset for all signal classes, or only for the signal classes that require attenuation. is there. For example, in one particular implementation, if only the fricative class signal needs to be attenuated, it is only necessary to preset the energy attenuation value of the fricative class signal.
403: Encodes the attenuated high frequency band signal, or the attenuated characteristic parameter of the high frequency band signal to be encoded.
The encoder according to the embodiment of the present invention attenuates and attenuates the high frequency band signal or the characteristic parameter to be encoded of the high frequency band signal according to the energy attenuation value of the low frequency band signal of the current frame. The result is encoded and sent to the decoder, and the energy of the high frequency band signal obtained by the decoder by decoding is attenuated accordingly. In this way, the high frequency band signal, after being combined with the low frequency band signal, is pleasing to the user's ear and, as a result, enhances the user experience.
The technical solutions provided in the aforementioned embodiments of the present invention will be described in detail below via the embodiments shown in FIG.
501: By the encoder encoding the low frequency band signal of the current frame, decoding the result of encoding this low frequency band signal locally, and decoding it locally with the energy of the low frequency band signal. The ratio of the energy of the obtained signal is used as the energy attenuation value of the low frequency band signal of the current frame.
502: The encoder determines the signal class of the high frequency band signal of the current frame.
The signal class can be determined, in particular, by using the signal class determination method provided in the prior art or the signal class determination method provided in the aforementioned embodiments of the present invention.
503: The encoder attenuates the high frequency band signal of the current frame, or the characteristic parameter to be encoded of the high frequency band signal, depending on the signal class of the high frequency band signal of the current frame and the energy attenuation value. Let me.
In this step, regardless of the signal class of the current frame, the encoder uses the energy attenuation value to attenuate the energy of the high frequency band signal, but different processing modes are used for different signal classes. In particular, when the class of the high frequency band signal of the current frame is the transition class, the high frequency band time domain signal or the time domain envelope of the high frequency band signal to be encoded is attenuated according to the energy attenuation value. If the high frequency band signal class of the current frame is friction sound class, harmonic class, or normal class, the high frequency band frequency domain signal, or the frequency domain envelope to be encoded in the high frequency band signal, is energy. It is attenuated according to the attenuation value.
504: The encoder encodes the signal class attenuation result and ID of the high frequency band signal of the current frame to obtain a bitstream.
505: The encoder sends a bitstream.
The encoder in this embodiment of the present invention is a characteristic parameter to be encoded for the high frequency band signal of the current frame or the high frequency band signal thereof, depending on the energy attenuation value of the low frequency band signal of the current frame. And the attenuation result encoded and sent to the decoder so that the energy of the high frequency band signal obtained by the decoder by decoding is attenuated accordingly, thus the high frequency band signal After being combined with a low frequency band signal, it is comfortable for the user's ears and, as a result, enhances the user experience.
Alternatively, in one particular implementation, a particular class of data frame can be attenuated, for example, a encoder uses the CELP algorithm to code a low frequency band signal for a particular data frame. When the high frequency band signal of the data frame is a transition class, the low frequency band signal of the data frame generally has a subframe in which an energy jump occurs, and the low frequency band of the data frame. The signal is also generally considered to be a transition class. The CELP algorithm significantly attenuates the low frequency band signals of the transition class and slightly attenuates the low frequency band signals of other classes, in which case the attenuation of the low frequency band signals of other classes can be ignored. Together, only the attenuation of the low frequency band signal of the transition class is taken into account, in which case the high frequency band time region signal of the current frame only if the high frequency band signal of the current frame is of the transition class. , Or the time region envelope to be encoded in the high frequency band signal is attenuated. That is, the high frequency band time domain signal of the current frame, or the time domain envelope of the high frequency band signal to be encoded, is attenuated.
Alternatively, in yet another particular implementation, not only the transition class high frequency band signals need to be attenuated, but also the friction sound class high frequency band signals need to be attenuated. Since the canonical class can be further divided into a friction sound class and a voiced sound class, when the encoder encodes a low frequency band signal of the voiced sound class by using the CELP algorithm, the coding has a small energy attenuation. In addition, when the encoder encodes a friction sound class low frequency band signal, the coding results in a large energy attenuation. Therefore, if the encoder determines that the high frequency band signal of the data frame is of the friction sound class prior to encoding the high frequency band signal of the data frame, the encoder determines that the high frequency of the friction sound class is high. It is necessary to attenuate the frequency domain envelope to be encoded for the band frequency domain signal or the high frequency band signal of the friction sound class. That is, the high frequency band frequency domain signal of the friction sound class or the frequency domain envelope to be encoded of the high frequency band signal of the friction sound class is attenuated.
The energy attenuation value of the low frequency band signal of the current frame used by the encoder in the above embodiment is encoded by the encoder that encodes the energy of the low frequency band signal of the current frame and the low frequency band signal. It is the ratio of the energy of the signal obtained by locally decoding the result of what has been done. Alternatively, in another particular embodiment, it is possible to obtain different energy attenuation values by training by using the LBG algorithm for different signal classes, and then this acquired energy attenuation value. Is preset in the encoder and decoder, for example, if the signal class of the high frequency band signal includes a noise class, a predicted class, a transition class, a harmonic class, and a normal class, training will result in 1 for the noise class. One energy decay value is obtained, one energy attenuation value is obtained for the class predicted by training, one energy attenuation value is obtained for the transition class by training, and one energy attenuation value is obtained for the normal class by training. Be done. A particular mode of obtaining one energy attenuation value corresponding to a particular signal class by training decodes the result of encoding the energy of multiple low frequency band signals of that signal class and the corresponding low frequency band signal. Obtaining the ratio of the energies of the signal obtained by decoding with a device, obtaining one value by training according to these obtained ratios by using the LBG algorithm, and this value. Can be used as the energy attenuation value corresponding to the signal class. In yet another particular implementation, if the normal signal class is further subdivided into a fricative class and a voiced class, the LBG algorithm can be used to train to obtain energy decay values for the fricative and voiced classes. Preconfigured in the encoder and decoder. Alternatively, if only high frequency band signals of some signal classes need to be attenuated, for example, transition
Referring to FIG. 6, one embodiment of the present invention provides a decoding method including:
601: Decoding the bitstream to obtain the characteristic parameters of the high frequency band signal of the current frame or the high frequency band signal of the current frame.
This embodiment of the present invention is carried out by a decoder.
The high frequency band signal of the current frame can be the high frequency band time domain signal of the current frame or the high frequency band frequency domain signal of the current frame, and the characteristics of the high frequency band signal of the current frame. The parameter can be the time domain envelope or the frequency domain envelope of the high frequency band signal of the current frame.
602: The characteristic parameters of the high frequency band signal, or high frequency band signal, are attenuated according to the energy decay value of the low frequency band signal of the current frame, where the energy attenuation value encodes the low frequency band signal. The energy decay of the low frequency band signal caused by this is shown.
The characteristic parameters of the high frequency band signal, or high frequency band signal, can be attenuated, in particular, depending on the energy attenuation value of the low frequency band signal of the current frame and the signal class of the high frequency band signal of the current frame. It is possible. In another embodiment, the decoder can attenuate high frequency band signals of all signal classes, or all characteristic parameters of high frequency band signals, but the signal classes of the current frame vary. Therefore, the attenuated high frequency band signal of the current frame, or the attenuated characteristic parameter of the high frequency band signal of the current frame, can also vary. For details, refer to the description of the embodiment shown in FIG. In yet another embodiment, only some classes of signals are attenuated, or only certain classes of signals are attenuated, which does not affect the practice of the present invention.
For the classification of signal classes of high frequency band signals, a detailed description of the embodiments shown in FIG. 4 is referred to and therefore will not be described in detail here again.
Obtaining the energy attenuation value of the low frequency band signal of the current frame includes, but is not limited to, the following two aspects.
First mode: The decoder analyzes the bitstream sent by the encoder to obtain the energy attenuation value. That is, the energy decay value of the low frequency band signal of the current frame is acquired by the encoder and sent to the decoder, and in particular, the encoder has the energy of the low frequency band signal of the current frame and the low of the current frame. The ratio of the energy of the signal obtained by locally decoding the result of encoding the frequency band signal with a encoder can be used as the energy attenuation value.
Second aspect: The energy attenuation value of the low frequency band signal of the current frame is preset in the decoder, and this energy attenuation value is in the same class as the energy of multiple low frequency band signals of the same class frame. It is obtained according to the ratio of the energy of the signal obtained by decoding the result of encoding the low frequency band signal of the frame, which is especially made to these ratios by using the LBG algorithm. It is possible to obtain a value by training accordingly and to use this value as an energy attenuation value, except that frames of the same class have the same signal class as the high frequency band signal of the current frame. Data frame of.
The decoder in this embodiment of the present invention attenuates the characteristic parameters of the high frequency band signal or the high frequency band signal obtained by decoding, depending on the energy attenuation value of the low frequency band signal of the current frame. The finally obtained high frequency band signal is then combined with the low frequency band signal to be comfortable to the user's ears, resulting in an improved user experience.
The technical solutions provided in the aforementioned embodiments of the present invention will be described in detail below via the embodiments shown in FIG.
701: The decoder receives the bitstream sent by the encoder, but this bitstream is the result of encoding the high frequency band signal and the energy decay value of the low frequency band signal of the current frame. Includes the ID of the signal class of the high frequency band signal of the current frame.
702: The decoder decodes the bitstream to the energy decay value of the low frequency band signal of the current frame, the signal class of the high frequency band signal of the current frame, and the high frequency band signal of the current frame, or Obtain the characteristic parameters of the high frequency band signal of the current frame.
703: The decoder sets the characteristic parameters of the high frequency band signal of the current frame or the high frequency band signal of the current frame, the energy attenuation value of the low frequency band signal of the current frame, and the high frequency band of the current frame. Amplifies according to the signal class of the signal.
In this embodiment, regardless of the signal class of the current frame, the decoder uses the energy attenuation value of the low frequency band signal of the current frame to attenuate the energy of the high frequency band signal, but with various signal classes. Various processing modes are used with respect to. In particular, when the class of the high frequency band signal of the current frame is the transition class, the time domain envelope of the high frequency band time domain signal or the high frequency band signal becomes the energy attenuation value of the low frequency band signal of the current frame. If the high frequency band signal class of the current frame is frictional class, harmonic class, or regular class, it is attenuated accordingly, and the high frequency band frequency domain signal, or the frequency domain envelope of the high frequency band signal, is current. It is attenuated according to the energy attenuation value of the low frequency band signal of the frame.
The decoder according to the embodiment of the present invention attenuates the characteristic parameters of the high frequency band signal of the current frame or the high frequency band signal obtained by decoding, and finally obtains the high frequency band signal. After being combined with a low frequency band signal, it should be comfortable to the user's ears, resulting in an improved user experience.
Alternatively, in one particular embodiment, the decoder can only attenuate a particular class of signal, eg, only if the high frequency band signal of the current frame is in the transition class. The instrument attenuates the high frequency band time domain signal of the current frame, or the time domain envelope of the high frequency band signal. That is, the high frequency band time domain signal of the current frame or the time domain envelope of the high frequency band signal is attenuated.
Alternatively, in yet another particular implementation, not only the transition class high frequency band signals need to be attenuated, but also the friction sound class high frequency band signals need to be attenuated. Therefore, the decoder acquires the high frequency band signal of the fricative class by decoding, and then attenuates the high frequency band signal of the fricative class. That is, the high frequency band signal of the fricative class is attenuated. Alternatively, the decoder obtains the frequency domain envelope of the friction sound class high frequency band signal by decoding and then attenuates the frequency domain envelope of the friction sound class high frequency band signal. That is, the high frequency band signal of the fricative class is attenuated.
In the aforementioned embodiment, the energy attenuation value of the low frequency band signal of the current frame is sent to the decoder by the encoder, and instead, in another particular embodiment, the energy attenuation value is preset in the decoder. That is, it is possible to obtain different energy attenuation values for different signal classes by training by using the LBG algorithm, and then the energy attenuation values obtained are the encoders. And preset in the decoder. This particular implementation is similar to the description of the corresponding part above, and therefore no details will be given here again.
Referring to FIG. 8, one embodiment of the present invention comprises a dividing unit 100 configured to divide a current frame into a low frequency band signal and a high frequency band signal, and a high frequency band signal or a high frequency band signal. The characteristic parameter to be encoded in is configured to be attenuated according to the energy decay value of the low frequency band signal, which is the low frequency band caused by the coding of the low frequency band signal of the current frame. A correction unit 200 indicating the energy attenuation of the signal, the high frequency band signal of the current frame can be the high frequency band time region signal of the current frame or the high frequency band frequency region signal of the current frame. And the characteristic parameter to be encoded in the high frequency band signal of the current frame can be the energy characteristic parameter to be encoded in the high frequency band signal, in particular the high frequency of the current frame. With the correction unit 200, which can be a time region envelope to be encoded or a frequency region envelope to be encoded, the band signal. Provided is a coding device including an attenuated high frequency band signal, or a coding unit 300 configured to encode a attenuated characteristic parameter of the high frequency band signal to be encoded.
To determine the signal class of the high frequency band signal of the current frame, the coding device further includes a signal class determination unit 400 configured to determine the signal class of the high frequency band signal of the current frame. In this case, the correction unit 200 is configured to attenuate the high frequency band signal, or the characteristic parameter to be encoded of the high frequency band signal, according to the energy attenuation value and the signal class of the high frequency band signal. ..
The correction unit 200 attenuates the high frequency band time domain signal, or the time domain envelope of the high frequency band signal to be encoded, according to the energy decay value when the class of the high frequency band signal is the transition class. The frequency domain signal to be encoded in the high frequency band frequency domain signal, or the high frequency band signal, if it is specifically configured in and / or the class of the high frequency band signal is a friction sound class, a harmonic class, or a normal class. Is specifically configured to attenuate according to the energy attenuation value.
To obtain the energy decay value of the current frame, the coding device encodes the low frequency band signal, locally decodes the result of encoding the low frequency band signal, and further encodes the energy of the low frequency band signal. Configured to set the energy attenuation value of the energy attenuation value acquisition unit 500, which is configured to use the ratio of the energies of the signal obtained by decoding locally with and as the energy attenuation value, or the energy attenuation value of the current frame. However, this energy attenuation value is a signal obtained by decoding the result of encoding the energy of multiple low frequency band signals of the same class frame and the low frequency band signal of the same class frame. Obtained according to the energy ratio of, however, a frame of the same class can further include an energy attenuation value setting unit 600, which is a data frame of the same signal class as the high frequency band signal of the current frame. .. Although the energy attenuation value acquisition unit 500 and the energy attenuation value setting unit 600 are depicted in FIG. 8, the coding device includes the energy attenuation value acquisition unit 500 in actual use, but the energy attenuation value setting unit 600 Note that it is possible not to include it, or it is possible to include the energy attenuation value setting unit 600 but not the energy attenuation value acquisition unit 500.
The coding device in this embodiment of the present invention attenuates the characteristic parameters to be decoded from the high frequency band signal, or the high frequency band signal, according to the energy attenuation value of the low frequency band signal of the current frame. The decay result is further encoded and sent to the decoder so that the energy of the high frequency band signal obtained by the decoder by decoding is correspondingly attenuated, thus the high frequency band signal is low. After being combined with a frequency band signal, it is comfortable to the user's ears, resulting in an improved user experience.
Referring to FIG. 9, one embodiment of the present invention is configured to decode a bit stream to obtain characteristic parameters of the high frequency band signal of the current frame or the high frequency band signal of the current frame. The conversion unit 700 and the characteristic parameters of the high frequency band signal or high frequency band signal are configured to be attenuated according to the energy attenuation value of the low frequency band signal of the current frame, and this energy attenuation value is the current energy attenuation value. Provided is a decoding device including a correction unit 800 and a correction unit 800 showing the energy decay of the low frequency band signal caused by the coding of the low frequency band signal of the frame.
To obtain the signal class of the high frequency band signal of the current frame, the decoding unit 700 is further configured and further corrected to decode the bit stream to obtain the signal class of the high frequency band signal of the current frame. The unit 800 is specifically configured to attenuate the characteristic parameters of the high frequency band signal, or high frequency band signal, according to the energy attenuation value and the signal class of the high frequency band signal of the current frame.
In particular, the correction unit 800 attenuates the time domain signal of the high frequency band time domain signal or the time domain envelope of the high frequency band signal depending on the energy attenuation value when the class of the high frequency band signal of the current frame is the transition class. The high frequency band frequency domain signal, depending on the energy decay value, is specifically configured for and / or the correction unit, if the high frequency band signal class of the current frame is friction sound class, harmonic class, or normal class. Alternatively, it is specifically configured to attenuate the frequency domain envelope of a high frequency band signal.
To obtain the energy attenuation value of the current frame, the decoding unit 700 is further configured to decode the energy attenuation value from the bit stream, which energy attenuation value is the energy of the low frequency band signal of the current frame. The ratio of the energy of the signal obtained by locally decoding the result of encoding the low frequency band signal of the current frame with a encoder is shown.
Alternatively, to obtain the energy decay value of the current frame, the decoding device is configured to set the energy decay value of the current frame, which is the low frequency band signal of the same class of frame. Obtained according to the ratio of the energy of the signal obtained by decoding the result of encoding the low frequency band signal of the frame of the same class as the energy of the same class, the frame of the same class is the height of the current frame. It further includes an energy attenuation value setting unit 900, which is a data frame of the same signal class as the frequency band signal.
The decoding device in this embodiment of the present invention determines the characteristic parameters of the high frequency band signal or the high frequency band signal obtained by decoding, depending on the energy attenuation value of the low frequency band signal of the current frame. It is attenuated so that the final high frequency band signal is comfortable to the user's ears after being combined with the low frequency band signal, resulting in an improved user experience.
Those skilled in the art will appreciate that all or part of the steps in the methods according to these embodiments can be performed by a program that directs the relevant hardware. The program may be stored in computer-readable storage media such as read-only memory, magnetic disks, or optical disks.
The signal classification method and signal classification device according to the embodiment of the present invention, and the coding and decoding method and device are described in detail above. The principles and practices of the present invention are described herein through specific examples. Descriptions of these embodiments are provided only to facilitate understanding of the methods and core ideas of the present invention. One of ordinary skill in the art can create various modifications and variations of the invention with respect to a particular embodiment and scope of application according to the ideas of the invention. Therefore, the specification should not be construed as limiting the invention.
10 Division unit 20 Judgment unit 30 Judgment unit 31 Noise class judgment unit 32 Predicted class judgment unit 33 Harmonic class judgment unit
11 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4 Sheet 5 Sheet 6 Sheet 7 Sheet 8 Sheet 9 Sheet 10 Sheet 11
Every citation, both ways
| Document | Relation | Office |
|---|---|---|
| JP2014507688A | Cites | Japan |
| JP2008129541A | Cites | Japan |
| JP2008224902A | Cites | Japan |
| JP2009042734A | Cites | Japan |
| JP2008089999A | Cites | Japan |
| WO2005112001A1 | Cites | World Intellectual Property Organization (WIPO) |
| WO2010066158A1 | Cites | World Intellectual Property Organization (WIPO) |
24 members in 7 offices
Priority claims2
| Document | Office | Kind | Date |
|---|---|---|---|
| 2011101384611 | China | – | |
| 201110138461 | China | A |
Members24
| Document | Office | Kind | |
|---|---|---|---|
| CN102800317A | China | A | |
| WO2012159412A1 | World Intellectual Property Organization (WIPO) | A1 | |
| EP2584560A1 | European Patent Office (EPO) | A1 | |
| US2013117029A1 | United States of America | A1 | |
| EP2584560A4 | European Patent Office (EPO) | A4 | |
| KR20130116917A | Republic of Korea | A | |
| US8600765B2 | United States of America | B2 | |
| US2014046672A1 | United States of America | A1 | |
| JP2014507688A | Japan | A | |
| CN102800317B | China | B | |
| EP2584560B1 | European Patent Office (EPO) | B1 | |
| ES2531575T3 | Spain | T3 | |
| KR101540371B1 | Republic of Korea | B1 | |
| JP2016027411A | Japan | A | |
| JP6018090B2 | Japan | B2 | |
| JP6185530B2 | Japan | B2 | |
| JP2017191341A | Japan | A | |
| JP2019074762A | Japan | A | |
| JP6558745B2This record | Japan | B2 | |
| JP6820360B2 | Japan | B2 | |
| JP2021060618A | Japan | A | |
| JP7177185B2 | Japan | B2 | |
| JP2023022073A | Japan | A | |
| JP2025016508A | Japan | A |
14 legal events, as the office reported them to INPADOC
Over the term
Point at a mark for the eventEvents
| Event | Code | |
|---|---|---|
| Receipt of annual feesJAPANESE INTERMEDIATE CODE: R250R250 | R250 | |
| Receipt of annual feesJAPANESE INTERMEDIATE CODE: R250R250 | R250 | |
| Receipt of annual feesJAPANESE INTERMEDIATE CODE: R250R250 | R250 | |
| Receipt of annual feesJAPANESE INTERMEDIATE CODE: R250R250 | R250 | |
| Receipt of annual feesJAPANESE INTERMEDIATE CODE: R250R250 | R250 | |
| Certificate of patent or registration of utility modelJAPANESE INTERMEDIATE CODE: R150R150 | R150 | |
| First payment of annual fees (during grant procedure)JAPANESE INTERMEDIATE CODE: A61A61 | A61 | |
| Written decision to grant a patent or to grant a registration (utility model)JAPANESE INTERMEDIATE CODE: A01A01 | A01 | |
| Decision of grant or rejection writtenTRDD | TRDD | |
| Request for written amendment filedJAPANESE INTERMEDIATE CODE: A523A521 | A521 | |
| Written request for extension of timeJAPANESE INTERMEDIATE CODE: A601A601 | A601 | |
| Notification of reasons for refusalJAPANESE INTERMEDIATE CODE: A131A131 | A131 | |
| Request for written amendment filedJAPANESE INTERMEDIATE CODE: A523A521 | A521 | |
| Written request for application examinationJAPANESE INTERMEDIATE CODE: A621A621 | A621 |
Numbers
- Publication
- 6558745
- Application
- 145282
Titles2
- Japanese
- 符号化/復号化方法および符号化/復号化デバイス
- English
- Coding / Decoding Method and Coding / Decoding Device
Classification
- CPC, 6
- G10L19/20
- G10L19/18
- G10L19/265
- G10L21/0388
- G10L19/0204
- G10L19/008
- IPC, 1
- G10L19 02
