Recording and reproducing method for video camera utilizing optical disk

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a video recording / playback device, particularly a video camera to which an optical disc is applied.

【0002】

[Conventional technology]

For example, with the so-called 8mm video camera devices currently on the market, it took a long time to find out because the recorded images could not be randomly accessed, but with video cameras using optical discs, random access has become possible. ..

【0003】

[Problems to be Solved by the Invention]

An object of the present invention is to provide an image reproduction device that can search for a desired image at high speed in an image reproduction device using an optical disk.

【0004】

Another object of the present invention is to provide an image recording device using an optical disk, which automatically creates and records thumbnails of input images at the time of recording.

【0005】

[Means for solving problems]

In order to achieve the present invention, it is configured as follows.

【0006】

The optical disc to be used has a management information recording area and a data recording area, and a part of the data recording area is allocated as a thumbnail recording area. This is to improve the reading speed and the search efficiency when displaying a list of thumbnail images by recording a plurality of thumbnails in a cohesive area on the optical disc.

【0007】

Next, thumbnails are automatically created when shooting with a video camera and recorded on an optical disc. That is, when the operator inputs a recording start instruction, the video camera starts the recording process of the video image input from the camera unit. In the case of recording on an optical disk, the digital quantization data read by the CCD device is temporarily stored in a buffer, and this is code-converted in the MPEG format or the like.

【0008】

At this time, an arbitrary frame image is stored in the same area in the buffer or another buffer area from the buffer. This frame image is, for example, an image for one frame of a moving image formed at 30 frames per second. A thumbnail is created from the frame image in the buffer at the free time of the recording process, that is, at the end of recording or the free time of the CPU during the recording process. Thumbnails may be created in a still image format, such as the JPEG format or a similar image format. The created thumbnail is recorded in the thumbnail recording area. At this time, a time stamp is given to the thumbnail, and it is important that the time stamp uses the recording date and time of the frame image based on the thumbnail, not the creation time of the thumbnail itself.

【0009】

Next, a method of selecting a recorded image using thumbnails and playing it back will be described. First, when the video camera is instructed to display a list of thumbnails, the management information area of the optical disk is searched, the recording area of the thumbnail is recognized, and a plurality of thumbnails are read from the recording area in the order of time stamps and displayed. List in. The time stamp order may be all thumbnails in chronological order using time stamps, or partial display in which thumbnails having a specific relevance are skipped. For example, if you skip thumbnails created within a certain amount of time (for example, within 15 minutes) from the time stamp of the previous thumbnail, you can repeat recording and replaying at short intervals to obtain an appropriate amount of thumbnails even if there are many thumbnails. Only thumbnails can be displayed. Further, when displaying on a display device, it is preferable to superimpose an icon indicating the property of the image on the thumbnail.

【0010】

Next, when the operator selects a thumbnail of the image to start playback, the video camera recognizes it, recognizes the recording location of the moving image attached to the recognized thumbnail, and recognizes the recognized recording location. Play back the moving image from. Here, if the information of the storage area of the moving image corresponding to the thumbnail is added, the target moving image can be accessed without referring to the management information recording area of the optical disk, so that high-speed processing becomes possible.

【0011】

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 2 is a circuit block diagram of a video camera device according to this embodiment. The optical disc 201 is a recording medium such as a DVD-R or DVD-RAM, and a disc having a diameter of 8 cm or a disc having an arbitrary diameter such as 12 cm or 6 cm can be used. The subject image obtained from the optical lens is input to the camera signal processing DSP208 as an electric signal by the CCD sensor 207, converted into Y, U, and V signals, and the image is enhanced. The DSP 208 also generates the drive pulse required for the CCD sensor 207 and the synchronization signal required for video output, and supplies them to each part. The operation key 203 is an input means for operating the video camera device. The camera control microcomputer 210 optimally controls the camera signal processing DSP 208 based on the video information obtained from the state of the optical system and the CCD sensor and the information obtained from the operation of the entire camera. The LCD display panel 215 captures input images and reproduced images. The pickup unit 202 writes and reads a signal to the optical disk 201, and includes a semiconductor laser and a lens. Camera signal processing DSP The digital video signal obtained from the 208 is sent to the MPEG-2 codec 217 as 16-bit parallel data in this example, for example. The MPEG-2 codec unit 217 expands the video of the camera signal processing DSP 208 using a memory unit 212 such as SDRAM as a video memory, and compresses the video data to about 1/60. The compressed video data is output to the system internal bus 205 according to the instructions of the system control microcomputer 213. On the other hand, although the audio signal is not shown, the signal obtained from the microphone built into the camera is A / D converted, compressed by software processing in the system control microcomputer 213, and output by the MPEG-2 codec unit 217. Generates an MPEG data stream by multiplexing with the generated video data. This MPEG data stream is sent to the signal processing circuit 204 via the buffer RAM 206 for avoiding a write error due to vibration or impact received by an optical disk such as a DVD. The signal processing circuit 204 is a circuit that integrates a tracking, focus, and disk spindle servo circuit for a DVD optical disc and an error correction circuit for data writing and reading, and the MPEG data stream is processed into a data format according to the DVD standard. , A correction code is added, digital modulation is performed by the R / W (Read / Write) circuit 216, and the data is recorded on the optical disk 201 by the pickup unit 202.

【0012】

In the case of reproducing video data, the pit information is read from the optical disk 201 in a digitally modulated state by the pickup unit 2, the waveform equalization and the servo signal are detected by the R / W circuit 16, and the signal processing circuit 204 detects the waveform equalization and the servo signal. It is output to the system internal bus 205 as an MPEG-2 video stream. At this time, the buffer RAM 206 is also used. The video and audio data of the system internal bus 205 is controlled for data transfer on the bus by the command of the system control microcomputer 213, and the original video data is restored by the expansion operation by the MPEG-2 codec unit 217, and 16-bit parallel as in the recording. After the signal is converted into an NTSC signal by the camera DSP208, it passes through the LCD control unit 209 and is displayed as a reproduced image on the LCD display panel 215. Similarly, since the NTSC video signal is output from the camera signal processing DSP208, it can be displayed on an external TV from the video output terminal provided on the camera. In addition, video and audio data can also be transmitted to an external personal computer via the USB controller 218. Here, it was explained that a moving image according to the MPEG-2 format is recorded and played back, but this camera can also shoot and record a still image or a JPEG image using an I picture in the MPEG format. The JPEG format encoding operation is almost the same as the MPEG format I picture encoding operation, and the MPEG-2 codec can also perform the JPEG format encoding operation by simply switching a part of the operation of the circuit. The still image output from the MPEG-2 codec is recorded on the optical disk 201 as one file. It is also possible to record only audio data, and by associating a file with a still image in the previous period, it becomes possible to handle it as audio data with a still image.

【0013】

FIG. 3 shows an outline of an example of the outer shape of a video camera to which the present invention is applied and the arrangement of operation keys. The optical lens 29 has a structure similar to that of a known portable 8 mm video camera. The finder 30 for shooting is a small liquid crystal display unit. The direction instruction means key 31 is an instruction key for performing various selection operations from the menu of the image, and each button indicates four directions (up, down, right, left). The Enter key 36 is a key for confirming the selected menu, thumbnail, or the like. The jog dial 32 is an input means for manually operating the camera. The power switch 33 is a switch for the main power supply of the video camera. Here, in a known portable 8 mm video camera, the power switch generally has two types of ON modes, power ON as a playback mode and power ON in a recording mode. There is no need to separate modes. In a video camera using a magnetic tape, if recording is started from the position of the tape that happens to be located, there is a risk of accidentally erasing the data, so the playback mode and the recording mode are separated. However, since optical discs can record from any recording area, there is no concern about malfunctions such as accidentally overwriting the recorded part, so separating the power ON modes rather deteriorates operability. It will be. The REC key 35 is a button for instructing the start and end of recording. Here, the recording standby mode (recording pause) is unnecessary. This is because it is possible to record an image immediately from any point in time without performing a standby operation such as winding the tape around the rotating head, such as a magnetic tape using a rotating head (this is the buffer RAM206). It is also the effect of buffering using). The battery 34 is a removable rechargeable battery. The openable and closable liquid crystal display 37 has a configuration similar to that of a known portable 8 mm video camera, and is provided with, for example, a 2 to 4 inch LCD panel 38, such as an image being recorded and a thumbnail described later. Image, playback image

【0014】

Next, an operation of selecting a desired image from thumbnail images will be described with reference to FIG. 1 in this embodiment.

【0015】

FIG. 1 is used to select a desired image after taking images of a plurality of scenes and is displayed on the finder 30 or the LCD panel 38. A plurality of thumbnail images 101 are displayed on the screen 100. Here, 12 thumbnails are displayed on one screen. Each thumbnail is, for example, an image created by reducing an image (for example, the first image) at a predetermined position in each recording scene, and is recorded in the thumbnail recording area of the optical disk 201, which will be described later, in the format of a still image (for example, JPEG format). .. At the upper left of each thumbnail, icons 102, 103, 104 indicating the characteristics of the image corresponding to the thumbnail are displayed. The movie camera icon 102 indicates that the image corresponding to the thumbnail is a moving image, the icon 103 indicates that it is a still image, and the musical note icon 104 indicates that it is a still image with audio added. .. The content identification icons displayed superimposed on these thumbnails make the characteristics of the recorded data clear at a glance.

【0016】

The scroll bar 105 indicates which part of the thumbnail image over a plurality of pages is displayed. The date and time 106 and the comment 107 are comments of the time when the selected thumbnail image (indicated by the selection frame 110) was recorded and the characters attached to the image. The display of these changes each time the selection frame 110 moves. 108 indicates an operation key for moving the selection frame 110 (here, the direction indicating means key 31), and 109 indicates a key for starting playback of the image corresponding to the selected thumbnail (here, the Enter key 36). ..

【0017】

Next, the procedure for recording thumbnail images will be described with reference to FIG.

【0018】

First, the operator turns on the camera power switch 33 and presses the REC button 35 to immediately start the recording operation (step 61). When the recording operation is started, the unrecorded area is searched from the data recording area on the optical disc 201, and the recording start position is set.

【0019】

Next, the image is captured from the optical lens 29, encoded by the MPEG-2 codec unit 217, and recorded on the optical disk 201 (steps 62 to 64). Unlike magnetic tapes, optical discs do not require synchronous processing of input video coding and recording.If the encoded images are stored in a buffer and recorded intermittently on the optical discs, Power consumption can be saved. In step 62, one frame of the first image at the start of recording is temporarily saved in the buffer together with the time stamp, and is used for creating a thumbnail image described later.

【0020】

Next, it detects whether or not the operator has pressed the REC button 35 again (this means the end of recording), and if so, proceeds to step 66, and if not, returns to step 62 (step 65). .. When the force is completed, a thumbnail image of a predetermined size (for example, 160 × 120 dots) is created using the first frame image stored in the buffer, and recorded in the dedicated recording area of the thumbnail. In this embodiment, an example is shown in which thumbnails are created after shooting and not created during shooting. This is encoding, memory, and Disc management, and each part (204,206,202) of the system control microcomputer 213 and Disc drive is BUSY. Therefore, if there is sufficient margin in these processing systems, thumbnail creation and thumbnail writing (processing of steps 66 and 67) may be performed at the same time as shooting (processing of steps 62 to 64). .. Further, the thumbnail may be created at an arbitrary time point by the operator pressing the thumbnail creation button during playback of the moving image. Since the thumbnail recording unit is separately provided in this embodiment, thumbnails can be added or deleted at any time after recording the moving image.

【0021】

Here, the recording area of the optical disk 201 will be described with reference to FIG. In FIG. 4, the management information area 41 is an area for recording the contents and addresses of information recorded in the data recording area 42, and is generally called a TOC (Table of Contents) or FAT area. The data recording area 42 is an area for recording captured images (moving images, still images, audio). These areas 41 and 42 are generally defined by standards in many cases. FIG. 5 shows an example of data recorded in the data recording area 42, and the thumbnail recording unit 50 is a dedicated recording area for thumbnail images created in this embodiment. This area can be set to any area in the data recording area 42, but it is preferable to set it to a dedicated area separate from the captured video recording unit 55 in order to read out the thumbnail image at high speed. The thumbnail recording unit 50 includes a plurality of thumbnail informations 51 and 52. The captured video recording unit 55 records captured moving images, still images, and sounds in chronological order.

【0022】

Figure 5 (b) shows the details of the information contained in the thumbnail information 51. The video ID 55 indicates which image is the thumbnail, and includes the identification number of the thumbnail (or the identification number of the moving image) and the storage address of the corresponding image (in the case of the thumbnail 51, the start address of the video data 53). Is done. The title 56 is character information indicating the content of the thumbnail information, and is usually added by the operator at any time after the thumbnail is created. The thumbnail data 57 is a still image compressed in a JPEG format. The related information 58 stores, for example, the shooting date and time, the thumbnail creation date and time, and other information.

【0023】

FIG. 8 further describes the image recording operation and the thumbnail image recording operation.

【0024】

The input image 81 input from the optical lens 29 is temporarily stored in the buffer 82, which is a semiconductor memory. The stored image is MPEG-compressed 83, but at the same time, a specific image, for example, the first screen of recording start is copied to the buffer 86. While the input image 81 is subsequently input, the MPEG compressed 83 is continuously performed, the encoded image is stored in the second buffer 84, and is recorded on the optical disk 201. On the other hand, when the recording process of the input image 81 is completed, the image in the buffer 86 is reduced and JPEG-compressed 87 to create a thumbnail image, which is a recording area different from the data from the buffer 84 or the video data itself. It is recorded in addition to. In this way, the MPEG compression process and the JPEG compression process are performed as independent processes. Although the image in the buffer 82 is copied to the buffer 86, it is also possible to copy the I picture of the MPEG image stored in the buffer 84 and use it for creating a thumbnail. Even in this case, the MPEG processing and the thumbnail creation processing can be performed separately. The buffers 82 and 86 in FIG. 8 can use the memory unit 212 in FIG. 2, and the buffer 84 can use the buffer RAM206.

【0025】

Next, the procedure for searching and displaying images using thumbnails will be described using the flowchart of FIG. 7. First, when a list display of thumbnail images is instructed by the operator's instruction, the management information of the optical disk is read out (step 70), the recording area of the thumbnail images is recognized, and a desired number (for example, 12) of thumbnails are added. It is read out in the order of the time stamps (step 71). The read thumbnails are listed as described in FIG. 1 (step 72). When the thumbnail image according to the present invention is not recorded in advance, the first image of the data stream in which the images on the disk are continuous may be read out, and a thumbnail may be generated and displayed from this. However, this method is inefficient because it takes much longer.

【0026】

Next, a desired thumbnail is selected by the operator using the direction indicating means key 31 and the ENTER key 36, and the playback mode selected by the jog dial is determined (step 74).

【0027】

In the case of normal playback, the storage position of the image corresponding to the thumbnail is recognized from the video ID 51 of the thumbnail, and playback of the data from that storage position is started (step 75) and continued until the end (step 76).

【0028】

In the case of special playback, the storage position of the image corresponding to the thumbnail is recognized from the video ID 51 of the thumbnail, and the data from that storage position is specially played back. Special playback includes slow playback, fast forward playback, and the like. In particular, the fast-forward reproduction of this embodiment is realized by skipping the reproduced image. This can be done, for example, by taking out only the I picture from the image recorded in MPEG2 and playing it back, or by taking the 1st, 6th, 11th, 16th ... frames of each frame image taken at 30 frames per second. By regularly extracting the image and reproducing only this image, the same effect as fast-forward reproduction can be obtained. In the case of this example, the images of the 2nd to 5th, 7th to 10th, 12th to 15th frames are not reproduced at all, and the video camera using a normal magnetic tape that fast-forwards by combining the partial images of each frame. The method is different from the fast-forward method. In this way, special playback continues until the end (step 78).

【0029】

In step 73, if the display of the thumbnail image on the next page is selected instead of selecting the playback mode, the process returns to step 72 (step 79).

[Simple explanation of drawings]

[Figure 1]

The figure explaining the operation which selects a desired image from the thumbnail image which concerns on this Example.

[Figure 2]

The circuit block diagram of the video camera apparatus which concerns on this Example.

[Fig. 3]

The figure which showed the outline of the outline of the outline of the video camera which concerns on this embodiment, and the arrangement of the operation key.

[Fig. 4]

The figure explaining the recording area of an optical disk apparatus.

[Fig. 5]

The figure for demonstrating the management information area of an optical disk apparatus, and the information recorded in a data recording area.

[Fig. 6]

A flowchart showing a procedure for recording thumbnail images.

[Fig. 7]

A flowchart showing a procedure for searching and displaying images at high speed using thumbnails.

[Fig. 8]

A conceptual diagram illustrating an image recording operation and a thumbnail image recording operation.

[Explanation of symbols]

100 ... screen, 101 thumbnail images, 102,103,104 ... icons, 105 ... scrollbars, 106 ... date and time, 107 ... comments, 110 ... selection frame, 201 ... optical discs.