Content distribution and switching amongst data streams

The present invention relates to a data stream reproduction method and a data stream reproduction method for distributing and switching contents between data streams.

Conventional technology has made it possible to convey information to relevant subscribers more quickly and efficiently. For example, in the cable network space, digital cables now provide subscribers with a large number of channels, allowing each television to receive and play different types of streamed data content.

According to conventional cable technology, each subscriber often has a so-called set-top box in the home to receive encoded digital information sent by the cable company. In many cases, each set-top box receives a large number of standard data streams on each of a number of different channels, decoding the only encoded data stream for display on the display screen.

For example, upon receiving encoded data, the set-top box decodes the received data stream. Once decrypted, each set box in the viewer's home drives the television device with the appropriate "rasterized" signal of the decrypted data extracted from the selected channel. Therefore, the television viewer can watch the corresponding television program transmitted by the cable company.

<p> According to conventional techniques related to IP (Internet Protocol) television (ie IPTV), the transmission of content into the home environment is constrained by the physical reality of twisted pair lines or passive optical networks. Therefore, in addition to transmitting standard packages of multiple signals, a relatively small number of on-demand channels can be transmitted to the relevant subscriber set-top box at home. Due to restrictions on "custom" channels, the server makes intelligent decisions about which few or one channel to send to the set-top box for subscribers to view, based on user / set-top box control. Must be done.</p><p> A problem with traditional transmission of content according to IPTV (Internet Protocol Television) is the inconvenience that each user experiences when switching from one IP television channel to another. For example, the MPEG (Moving Picture Experts Group) data server described above can receive multiple asynchronous MPEG encoded data streams according to one or more Internet protocols. Each encoded data stream already received by the server has its own timing information generated from an independent asynchronous master clock at each source that generates the data stream. As a result, the server only needs to receive information from each source and forward the data stream to the client as requested by the user. The decoder in the client's set-top box processes the received content stream and displays each audiovisual information on the display screen.</p><p> As an example of a user's inconvenience, suppose the user first requests to see certain content. In such a case, the decoder in each set-top box starts a self-synchronization algorithm each time with the newly received data stream to generate state information, and based on the timing information in the received data stream. , Self-synchronize. The timing information in the received data stream allows the decoder in the set-top box to be properly processed to identify when and how various audiovisual signals should be reproduced to the user. After self-synchronizing to the first content stream (eg MPEG stream), each user (eg on a client device such as a set-top box) requests the server to supply different data streams to the set-top box. In prior art, the decoder in the user's set-top box used to decode the preceding data stream before it was possible to play each audiovisual information associated with the newly selected data stream. It is necessary to abandon the state information and re-self-synchronize to the newly selected data stream (which has the corresponding unique timing information for decryption purposes). Therefore, after switching (eg, during the re-self-synchronization process), each user's television will have time to properly display the previously viewed or newly received data stream. In other words, according to traditional methods, when a set-top box attempts to re-self-synchronize (eg, form new decryption state information) in connection with a new data stream or channel switch, the user's screen will be short. , May be blank or blurry.</p>

<p> The following disclosure is an inconvenient switch (eg blackout or blur) experienced as a result of each decoder having to resynchronize (eg generate a new decoder state information set) after receiving a new data stream. Includes several useful embodiments for reducing, mitigating, or eliminating the effects of (image). For example, according to a general embodiment, instead of simply transmitting to each user different selected content, including the first received decoder information (eg timing information), the server sends the newly transmitted data. Modify the stream's decoder information according to the previously transmitted stream (or, in some cases, the master clock associated with the user). Therefore, although the second data stream was initially encoded by timing information unrelated to the first received data stream, each decoder state information used to decode the first content stream is , Make it available for the purpose of decrypting the second content stream.</p><p> According to such an embodiment, the server uses the newly selected content according to the current decoder state information that the requester used to decrypt the first data stream (eg, the first viewed content). Send to requester. That is, the server modifies the first timing information in the second data stream according to the first data stream, based on the differences between the first stream and the respective master clocks used to generate the control data stream. Embodiments include splicing the contents of two or more asynchronous data streams into a single continuous data stream that can be decoded by the subscriber using the same decoder state information. This technique reduces or eliminates inconvenient switching (eg, blackouts or blurry images) that can occur in a short period of time after switching from one independent data stream channel to another.</p><p> More specifically, in an embodiment, the process of collecting and distributing each server, eg, a data stream, is the most recently received content on each of several different asynchronous content streams or broadcast channels (eg, independent data streams). Maintain a buffer repository for (temporarily) storing each of the windows. Each of the various asynchronous content streams is encoded according to its own independent master clock. Each window of content stored in the repository is at least two relevant access points of information from each of multiple content streams (access points are in an encoded stream with no content interruptions or protrusions). Large enough to store an example) at the image boundary, which is an I image in MPEG coded content.</p><p> During transmission, each server produces an output data stream containing a first content stream of several different content streams initially received by the server. As mentioned above, the content contained in the first content stream has relevant decryption information (eg timing information) and the relevant remote recipient (eg set top box) sends the data stream over the network. It is decrypted so that the content from the first content stream can be played back by each media player such as a display screen.</p><p> The server can be configured to receive a "change channel" instruction at the relevant remote receiver who initiates a channel change in response to each user in order to view different content. Upon receiving a channel change instruction from the user, the server outputs content from the second content stream (of multiple asynchronous content streams received by the server) instead of sending content from the first content stream to the output data stream. Send to.</p><p> Instead of sending the first content stream to the output data stream, to facilitate sending (and / or receiving) content from the second content stream, the server sends the decryption information associated with the second content stream. , Modify according to the information related to the first content stream. Therefore, the remote receiver can seamlessly decode the content from the second content stream by using the decoder status information used by the remote receiver to decode the first content stream first. In other words, according to the embodiment, the server modifies the timing information associated with one or more data streams received by the server to splice the first and second contents into a single output data. In one embodiment, the server modifies the timing information associated with the second data stream by an amount equal to the difference between the master clocks that generate the first data stream and the second data stream. Due to the modified timing information contained in the output data stream (eg, moving picture exparts group or MPEG coded data stream), the output data stream is from two or more content streams generated based on different master clocks. Despite containing the content, the recipient can track and play the content in the output data stream generated by the server.</p><p> This technique is suitable for use in applications that allow selection between multiple asynchronous data streams for playback purposes. However, this configuration is not limited to use in such applications, and its variations are also suitable for other applications.</p><p> In addition to being able to implement potentially discrete hardware components such as logic, buffers, registers, etc., other embodiments are configured to support the above techniques for modifying timing information within their respective content streams. It can include hardware platforms such as computerized devices (eg computer processor systems, host computers, personal computers, workstations, etc.). In such embodiments, the computerized device includes a memory system, a processor (eg, a processor), and their respective interconnects. The interconnect combines the processor with the memory system. When executed on a processor, a memory system is encoded by an application (eg, software code) that spawns a process for splicing content associated with multiple data streams, as described above.</p><p> However, other embodiments of the present disclosure include software programs for performing embodiments and operations of the methods outlined above and detailed below. More specifically, embodiments include a computer program product (eg, a computer-readable medium), which also joins content to an output data stream when run on a computerized device as described. Includes computer program logic to do. Computer program logic, when executed on at least one processor having a computing system, causes the processor to perform the operations (eg, methods) described in the embodiments of the present disclosure. Further disclosed configurations are typically software placed or encoded on computer-readable media, such as optical media (eg, CD-ROM), floppy® disks or hard disks, or other media. Code and / or other data structures, such as firmware in one or more ROMs or RAMs or programmable ROM chips, or as microcode, or as an application-specific integrated circuit (ASIC), or as a field programmable gate array (FPGA). Alternatively, it is provided as one or more modules, downloadable software images in a shared library, etc. Software or firmware or other such configuration can be implemented on a computerized device to allow one or more processors in the computerized device to perform the techniques described herein.</p><p> Certain embodiments of the present disclosure are directed to computer program products that include computer-readable media containing instructions that support the generation, management, and / or modification of data streams in accordance with the embodiments. When an instruction is executed by the processor of each computer device, the processor (eg, server) goes through the next step. i) Send content from the first content stream to the output data stream. ii) In response to receiving the instruction, instead of sending the content from the first content stream to the output data stream, the content is sent from the second content stream to the output data stream. iii) Modify the decryption information related to the content from the second content stream according to the decryption information related to the content from the first content stream. iv) Sending the modified decryption information to the output data stream, the recipient of the output data stream receives both the content from the first content stream and the content from the second content stream in the output data stream. The output data stream can be played seamlessly based on the same decoder state information used to decode. Other embodiments of the present application include software programs for performing any of the method steps and operations of the embodiments outlined above and disclosed in detail below.</p><p> As mentioned above, embodiments include a data / content server for performing switching functions relating to streaming data. However, as described below herein, the features described herein include any type of communication device (eg, routers, switches, digital subscriber line access multiplexing devices, etc.) to facilitate so-called high-speed channel changes. It can also be used from cable modem termination systems, passive optical networks, etc.).</p><p> Hereinafter, the objects, features and advantages of the present application described above will be described more specifically by showing suitable embodiments in the drawings. The same reference numerals were used for the same members throughout the various drawings. The drawings are not necessarily on scale and are emphasized to illustrate embodiments, principles, and concepts.</p><p> Instead of simply transmitting to each user different selected content, including the first received decoder information (eg timing information) for the newly selected data stream, the server sends the newly transmitted data stream. The first content, even though the second content stream was generated based on its own independent master clock, modifying the decoder information according to the previously transmitted stream (or possibly the user-related master clock). Make each decoder state information used to decode the stream also available for the purpose of decoding the second content stream. For example, a server according to an embodiment encodes the newly selected content to the requester according to the current decoder state information previously used by the requester (eg, decoder) to decode the previously received content. Send. By modifying the timing information, the server can splice content from two or more asynchronous data streams into a single continuous data stream, even though the data streams have different timing information sets. Can be done. In such an embodiment, each decoder in the set-top box does not need to be self-synchronized based on different or incompatible timing information originally associated with the second data stream. Instead, the decoder in the set-top box utilizes the old decryption state information used to process the first data stream to process the second data stream, including the modified timing information. Therefore, the decoder in the set-top box does not have to abandon the old decoder state information after receiving the data from the second content stream.</p>

<figref num="1">A block diagram of a data distribution environment according to an embodiment.</figref><figref num="2">A block diagram illustrating a data stream manager that modifies timing information in a newly transmitted data stream according to an embodiment.</figref><figref num="3">A table showing an example of switching information according to an embodiment.</figref><figref num="4">A diagram illustrating data junctions from two independent data streams, according to an embodiment.</figref><figref num="5">A diagram illustrating the junction of data streams, including independent frames, according to an embodiment.</figref><figref num="6">Diagram illustrating an architecture for implementing a technique according to an embodiment.</figref><figref num="7">A flowchart for explaining a technique for joining contents according to an embodiment.</figref><figref num="8">A flowchart for more specifically explaining a technique for joining contents according to an embodiment.</figref><figref num="9">A flowchart for more specifically explaining a technique for joining contents according to an embodiment.</figref>

FIG. 1 is a diagram of a data distribution environment 100 according to an embodiment. As shown, the data distribution environment 100 includes stream source 108 (eg, first stream source 108-1, second stream source 108-2, ..., Mth stream source 108-M), network 119. , Server 110, subscriber 199 (eg, first subscriber 199-1, second subscriber 199-2, ..., first J subscriber 199-J). Each stream source 108 includes its own clock 117 and encoder 115. For example, the first stream source 108-1 includes a first master clock 117-1 and a first encoder 115-1 to generate a data stream on the first channel 1. The second stream source 108-2 includes the second master clock 117-2 and the encoder 115-2, and generates a data stream on the second channel 2, and so on. Server 110 includes buffer 120 (eg first buffer 120-1, second buffer 120-2, ... buffer 120-M), multiplexer 130, and data stream manager 140 (eg data stream manager 140-1, Includes Data Stream Manager 140-2, ... Data Stream Manager 140-J).

During operation, each stream source 108 receives and encodes its own content 105 (eg content 105-1, 105-2, ..., 105-M) and streams content (eg MPEG coded content stream). Etc.), which is transmitted to the server 110 via the network 119 (eg, packet switching network, private communication link, etc.). It should be noted here that the server 110 may be any type of data communication device that streams data over a network connection. For example, to facilitate high-speed channel changes, features such as switching capabilities come from any type of communication device (eg routers, switches, digital subscriber line access multiplexing devices, cable modem termination systems, passive optical networks, etc.). Can also be adopted.

In embodiments, the data streams generated by stream source 108 are transmitted according to IGMP (Internet Group Management Protocol), but any type of protocol or source can send different streams to server 110.

Each stream source 108 has an independent clock 117 used by its encoder 115 to generate an encoded data stream for transmission to server 110 over network 119. For example, the first stream source 108-1 operates independently (ie, asynchronously) from the second stream source 108-2, ..., the M stream source 108-M, and the second stream source 108-2 It operates independently (ie, asynchronously) from the first stream source 108-1, ..., and the Mth stream source 108-M, and so on. The first encoder 115-1 of the first stream source 108-1 uses the first master clock 117-1 to generate each content stream on the first channel 1. The other stream sources 108 work in a similar way.

Server 110 includes several buffers 120 that receive the coded content stream generated by stream source 108 and store it at least temporarily. In an embodiment, each buffer stores data for several seconds (eg, playback time) from stream source 108. The amount of buffer may vary from application to application. As an alternative to buffering, the server can maintain a repository (eg memory, storage disk, etc.) that stores the complete program (eg movie) rather than just the last part of the streaming data.

It should be noted here that the server 110 can include additional storage devices that store advertisements targeting different subscribers. While streaming the data to each subscriber, the server 110 inserts corresponding targeted advertisements at appropriate intervals. In an embodiment, the server 110 inserts a targeted ad to adjust the timing information in the content stream so that the subscriber's decoder does not have to self-synchronize with the new timing information associated with the ad. To the content stream, it looks like a continuous content stream.

The multiplexer 130 provides access to the temporarily stored data in the data stream manager 140, and eventually any data stream information temporarily stored in buffer 120 (or permanently stored in their respective repositories). Allows distribution to that subscriber 199. That is, there is no limit to how many data stream managers 140 can send the same data stream to their respective subscribers 199.

In an embodiment, the data stream manager 140 of the server 110 works with the multiplexer 130 to control which of the content streams stored in the buffer 120 is sent to each subscriber 199 based on user feedback. For example, a subscriber, such as the first subscriber 1991, sends any of the multiple content streams to the data stream manager 140-1 for playback on channels 1 through M to 199-1. Notify if it should be. Upon receiving such a replay request, the data stream manager 140 sends the newly requested data stream in place of the old data stream. However, as described in more detail in the figure below, instead of simply sending selected different content, i.e. first send the content stream on channel 1 and then the new (unmodified) content stream. Instead of switching, for example, to send the content stream from channel 2 to each subscriber 199-1, the data stream manager 140-1 launches the conversion access switch information 240-1 (Figure 3), which is new. Select the appropriate read position information for the buffer (eg, each point at which data is read). Data and timing correction factors from this buffer (eg The difference between the master clocks that generate the data stream) is taken out and the decryption information related to the newly transmitted data stream is corrected. That is, as described above, when transmitting new data such as the content from the second channel 2, the data stream manager 140-1 modifies the timing information in the newly transmitted content stream, so that the subscriber The 199-1 does not need to self-synchronize again with new timing information in the newly received data stream. For example, the data stream manager 140-1 can decode a newly received content stream based on the decryption state information used by subscriber 199-1 to decrypt the preceding content stream (channel 1). , Modify the decryption information (eg timing information) in the newly transmitted content stream (2 channel 2 in this example). FIG. 2 is a block diagram illustrating a technique for switching from transmission of one content stream to transmission of another content stream according to an embodiment. As shown, the data stream manager 140-1 includes access manager 208-1, content stream modifier (CSM) 210-1, communication interface 220-1, stream controller 230-1, and switching information 240-1. Including. Subscriber 199.1 includes a remote control 185-1, a communication interface 183-1, a decoder 181-1 and a playback device 179-1 (eg: one or more media players). M) 210-1, communication interface 220-1, stream controller 230-1, switching information 240-1 are included. Subscriber 199.1 includes a remote control 185-1, a communication interface 183-1, a decoder 181-1 and a playback device 179.1 (eg: one or more media players). M) 210-1, communication interface 220-1, stream controller 230-1, switching information 240-1 are included. Subscriber 199.1 includes a remote control 185-1, a communication interface 183-1, a decoder 181-1 and a playback device 179-1 (eg: one or more media players).

In the context of this example, when the data stream manager 140-1 first reads from the first buffer 120-1 at the first read position RP1 and pulls data from the first channel 1 by activating the access manager 208-1. To do. The first buffer 120-1 may be a FIFO (first in, first out) device or repository for storing a segment of streaming data (eg, a 2-second window) associated with the first channel 1 received over network 119. Each buffer 120 may be part of memory where the most recently received data (eg new information frame) is overwritten by the oldest received data (eg old data frame).

Data stream manager 140-1 activates access manager 208-1 (while a switch request is occurring) to content C (all or part of it) and channel 1 in buffer 120-1. Relevant predecessor content, such as content B and content A (not shown), is sent to first subscriber 199-1 via communication interface 220-1.

This first data provided by the data stream manager 140-1 travels through path 201, with first subscriber 199-1 receiving information on communication interface 183-1. After receiving the content stream, the first subscriber 199-1 decodes the content stream (eg MPEG coded data stream) by activating the decoder 181-1 on a device 179 such as a display screen or audio speaker. Reproduce. In connection with this example of supplying data indicator content C from the first buffer 120-1 to the first subscriber 199-1, the user (in the first subscriber 199-1) is the controller 185 (eg wireless remote control). It supplies input to the controller, keyboard, mouse, phone, etc.) and sends a request via path 202, on channel 2 2 with new content stored in data stream manager 140-1 such as buffer 120-2. Communicate your desire to play or receive the content stream of. Upon receiving the request, the stream controller 230-1 accesses the switching information 240-1 (see FIG. 3) as described above.

It should be noted here that many different subscribers can see the data stream of common choice. Each viewer viewing a common channel may have different timing information and real-time, depending on where the entry point of the new channel is when the channel is changed.

As described above, the data stream manager 140-1 of the server 110 activates the correction of the corresponding timing information in the data stream, so that the content stream received by each subscriber via the network even when the switching occurs. Appears like a continuous stream. Other embodiments include dropping modification logic (eg, features related to stream manager 140-1 and buffer 120) into their respective set-top boxes at the subscriber. In such cases, the subscriber can receive and store multiple information channels via a link with 250. The subscriber maintains the switching information 240-1 for the purpose of modifying the timing information in the selected new channel according to the current state of the decoder 181. In this way, there is little or no difference between the time it takes to select and view a new channel and the time it actually plays in each media player. This is because the data stream appears to the decoder 181 to be the same channel, despite the channel change.

FIG. 3 shows the details of the switching information 240-1 according to the embodiment. By maintaining the switching information 240-1 by the data stream manager 140-1, the corresponding first subscriber 199-1 can selectively switch to receive other channels of streaming data. As mentioned above (in connection with FIG. 1), the server 110 includes a plurality of data stream managers 140. It should be noted that each of the data stream managers 140 maintains the relevant switching information so that each subscriber can receive different information streams for playback.

In connection with the example of FIG. 3, switching information 240-1 includes Table 315. Table 315 includes column 1 355, column 2 356, and column 3 357. The first column 355 identifies different information channels that the first subscriber 1991 can select for playback on their respective media players.

The second column 356 indicates the corresponding read position with respect to the buffer 120 used by the access manager 208-1 when switching to the newly selected content stream channel. In embodiments, the read position values in Table 315 present a particular information frame within the newly selected potential stream. For example, in the embodiment, the read position of the second column 356 of the switching information 240-1 corresponds to the corresponding data frame (eg, in each selectable channel). Identifies the position of the I-frame or anchor frame) on which subsequent frames depend in the data stream. One purpose of presenting and switching the anchor frame (specified by the read position) by switching to the newly selected channel is for the decoder 181 associated with each subscriber 199 to switch to the newly selected channel. To be able to experience a vivid transition to the associated audiovisual effect immediately (or after a slight delay). In other words, according to the embodiment, the decoder 181-1 in the first subscriber 191-1 can immediately reproduce the anchor frame. This is because the read position in Table 315 specifies the I frame as the opposite of the P or B frame in the data stream. I-frames are considered anchor frames. This is because the content sequence typically begins with an I image (ie, an intra-coded image or I-frame) as an anchor. Subsequent data in the I image and the previous segment of the next I image in the stream is considered an image group (GOP). Inside the GOP, there are typically several forward-predicted coded or P-images. During decoding, the first P image is decoded using the I image as a base. The P-image provides the difference information that defines the changes in the anchor image that produces the moving image. Each segment can also include a B image, which may be decoded using vector and difference data from the I or P image. Therefore, the I image is followed by the first P image, and so on. When the decoder 181-1 receives the I and P images, the intermediate B image can be decoded by moving the video compensation data forward or backward.

It should be noted that the position of the newly received I-frame in each buffer 120 changes as the newly received data overwrites the old data. Thus according to the embodiment, when new data is stored in buffer 120, the contents of Table 315 are also updated and the old data is overwritten by new data from each data stream, so the second in Table 315. The read position specified in column 356 is updated to suggest a new position for the I-frame.

The third column 357 shows the clock adjustment value (example: timing correction information) made for each content stream during channel switching. In an embodiment, the server 110 operates one or more processes to examine the timing information contained in each of the received data streams and generate an independent master clock (eg, FIG. 1). Grasp the time difference between clocks 117).

Again with respect to FIG. 2, when the user in the first subscriber 199-1 selects the second channel 2 for viewing, the access manager 208-1 seconds because the stream controller 230-1 switches to the second channel 2. Identifies that it must be read from the second read position RP2 of buffer 120-2. In addition, the stream controller 230-1 states that the timing information on channel 2 must be modified based on the timing modification information, eg, the second adjustment value ADJVALUE2 (eg, the difference between the master clocks that generate the data stream). Identify.

When switching from the first channel 1 (eg the channel currently being viewed) to the second channel 2, the content stream modifier 210-1 corrects the timing information in the new second channel 2 by an amount equal to the adjustment value. For example, if the first timing information contained in the data stream of channel 2 is X, the modified timing information to be incorporated into the data stream of channel 2 is X + ADJVALUE2 (ADJVALUE2 is positive or positive or Negative value).

In the embodiment, after accessing the switching information 240-1, the stream controller 230-1 informs the access manager 208-1 of the reading position for reading the data from the new second buffer 120-2 after the switching. The stream controller 230-1 also informs the content stream modifier 210-1 of the timing modifiers to be applied to the newly transmitted data stream, such as ADJVALUE2. Therefore, after switching, the access manager 208-1 accesses the second buffer 120-2 based on the new second read position RP2. In addition, since the content stream modifier 210-1 also corrects the timing information included in the newly transmitted content stream, the content from the second channel 2 is the first, even though it is derived from another master clock. The decoder 181-1 in 1 subscriber 1991 can decode the new content stream from channel 2. In other words, the content stream modifier 210-1 corrects the timing information in channel 2 to receive and decode the data on the new channel, so that the decoder 181-1 is in the current decoder state. It is possible to avoid giving up information and performing a full resynchronization.

It should be noted that in the embodiment (data overflows at the correct position in the buffer), the buffer 120 in FIG. 2 is configured to temporarily store the data as a FIFO, so that each first buffer 120- The content F and content W in the first and second buffers 120-2 represent the most recently received data information, and the content C and content T in the first buffer 120-1 and the second buffer 120-2, respectively, are the oldest. Represents received data information. Assuming that switching occurs while the data stream manager 140-1 reads data from content C on channel 1 and streams it, the content stream modifier 210-1 will use the content stream as shown in FIG. Is sent to the first subscriber 199-1.

FIG. 4 is a diagram for streaming the content during switching according to the embodiment. The content stream modifier 210-1 corrects the decoder information in the second channel 2 to match the decoder information in the first channel 1. Therefore, switching from one channel to another (eg, channel 1 to channel 2) is seamless. In other words, the first subscriber 199-1 continuously prints data (eg content A, B, C, W, X, Y, etc.) despite a channel change during the transmission of content C. Can be played.

Recalling for comparison, in the conventional method described above, the decoder of the first subscriber 199-1 must re-self-synchronize with the newly received data stream in order to reproduce the newly received data stream. Instead, it was blacked out during that time. However, according to the described embodiments, there are no blackouts or unclear transition times. This is because the data from channel 2 is as if it were generated based on the same clock (eg clock 108-1), or based on the timing information used to generate the data stream on channel 1. Because it looks as if it was generated. That is, the content stream modifier 210-1 sets the first timing information (eg, MPEG-based timing information, such as PCR, DTS, PCR, etc.) to the second adjustment value (ie, ADJVALUE2) and / or the specified amount by offset 201. The second channel 2 appears to have been generated based on the same clock as the first channel 1 because it is corrected in. As described above, the clock adjustment value ADJVALUE2 in the third column 357 can represent the time difference between the clocks related to the first channel 1 and the second channel 2, respectively.

FIG. 5 illustrates a more detailed snapshot of the data at a particular time during switching according to the described embodiments. As shown, the output data stream 502 from the data stream manager 140-1 (eg MPEG data stream) has data segments such as segment A, segment B, segment C, segment W, segment X and segment Y. Including. In the context of this example, the output data stream 502 includes an I-frame 510 (eg, an anchor frame, eg, I-frame 510-1, I-frame 510-2, ...). These are independent or independent information frames, and the subsequent parts of each segment (eg B and P images) depend on them. The I-image or I-frame 510 contains a complete data set that defines the placement of all pixels on the display screen. As described above, the I-frame 510 can include the corrected decoder timing information according to the adjustment values specified in Table 315.

Suppose a switch occurs while transmitting information segment C. As already mentioned, upon receiving an instruction to switch from one channel to another, the stream controller 230-1 (Figure 2) accesses the switching information 240-1 in the new channel where the data should be retrieved and transmitted. Identifies the position of the next anchor frame (eg I frame) (via the second read position RP2). In the embodiment, after switching, the data stream manager 140-1 completes the transmission of all data related to segment C in channel 1 by the next I frame associated with segment D. This can result in a slight delay of about 1 second or less, during which the user continues to view the old data stream on channel 1 1 even though he or she has selected to view the new channel.

It should be noted here that in some embodiments, all information remaining in segment C before switching to a new channel (eg, all information in segment C up to the I frame of segment D). It doesn't have to be sent completely. For example, channel switching may occur at a convenient exit point in the middle of segment C (eg, a particular type of frame). In other embodiments, switching to second channel 2 immediately upon detecting a channel switching option is unnecessary for the user to see the requested information when remotely switching from one channel to another. Prevent delays from occurring.

It should be noted that in addition to modifying the timing information in the anchor frame (eg I image 510), the content stream modifier 210-1 can also modify the timing information in the B and P image frames.

As described above, FIGS. 1-5 describe features related to the server 110 and more specifically the data stream manager 140 according to embodiments. FIG. 6 is a diagram illustrating an architectural example for implementing one or more processing functions according to the embodiment.

As shown, the Data Stream Manager 140 described above is implemented in each computer system 310 (eg Server 110) that includes the processor 313 and the corresponding software code (eg Data Stream Manager application 540-1). The embodiments described in this specification can be implemented. As an alternative to the embodiment shown in FIG. 6, the data stream manager 140 can be implemented by hardware components such as logic gates, buffers, or a combination of suitable hardware and software resources.

As shown in FIG. 6, the computer system 310 of this example (eg, a configuration example of the server 110) includes an interconnect 311 connecting a memory system 312, a processor 313, an input / output interface 314, and a communication interface 315. The input / output interface 314 allows the computer system 310 to communicate with the repository 180 and the terminal device 316, such as a handheld mouse, display screen, printer, and the like. The computer system 310 (FIG. 1) that implements the data stream manager 140 may or may not include all or some of these peripherals. The communication interface 315 allows the computer system 310 to receive, process, and distribute streaming data to different target subscribers 199 in the data distribution environment 100.

As shown, the memory system 312 is one or more data stream manager applications that support the ability to receive, modify, and distribute various data streams for end users (eg, data stream manager application 540-1). ). The data stream manager application 540-1 is stored in software code that supports processing functions according to the various embodiments described herein, such as data and / or logical instructions (eg, memory or other computer-readable medium, such as disk. It can be embodied as a code). During operation, processor 313 accesses memory system 312 (and / or repository 180) through interconnect 311 to initiate, actuate, execute, interpret, or otherwise initiate logical instructions for data stream manager application 540-1. Do it the way you want. Execution of the data stream manager application 540-1 produces processing functions in the data stream manager process 540-2. In other words, the data stream manager process 540-2 provides the functionality associated with the data stream manager 140, as extended in connection with Figure 1.

It should be noted here that the data stream manager application running on computer system 310 can be represented in Figure 6 by one or both of the data stream manager application 540-1 and / or the data stream manager process 540-2. Is. For the purposes described herein, specific Data Stream Manager 140-1 is commonly referred to as performing or supporting various steps and functional actions to implement the techniques discussed herein.

It should also be noted that the configuration examples described include the data stream manager application 540-1 itself (ie, logical instructions and / or data that are not executed or executed). The data stream manager application 540-1 may be stored on a computer-readable medium (eg, a floppy (registered trademark) disk), a hard disk, or an optical medium. The data stream manager application 540-1 may be stored in memory system 312, such as firmware, read-only memory (ROM), or executable code as in this example, such as random access memory (RAM). It should be noted that in addition to these embodiments, the other embodiments described include running the data stream manager application 540-1 on processor 313 as the data stream manager process 540-2. .. Those skilled in the art will therefore appreciate that the content stream (310) may include other processes and / or sophroware and hardware components to perform the functions described herein.

FIG. 7 is a flowchart 700 illustrating a technique for distributing data information according to an embodiment. FIG. 7 illustrates the embodiments described in relation to FIGS. 1 to 6. As mentioned above, again the Data Stream Manager 140 and related features may be implemented in hardware and / or software.

In step S710, the data stream manager 140-1 in the server 110 sends the content from the first content stream (eg, the data received on channel 1) to the first subscriber 199-1 in the output data stream. To do.

In step S720, in response to receiving the instruction, the data stream manager 140-1 from the second content stream instead of sending the content from the first content stream to the first subscriber 190-1 in the output data stream. Start sending the contents of (eg data received on channel 2 2) to the output data stream.

In step S730, the data stream manager 140-1 extracts the decryption information related to the content from the second content stream (eg channel 2) to the content from the first content stream (eg channel 1). Correct according to the decryption information related to.

In step S740, the data stream manager 140-1 sends the modified decryption information to the output data stream so that the recipient of the output data stream (eg, first subscriber 190-1) becomes the first subscriber. The output data stream can be played seamlessly based on the same decoder state information that 199-1 used to decode the content from the first content stream. Therefore, the timing information associated with the second data stream (eg, information used for reception and playback purposes) is modified with the information in the first data stream, so that the first subscriber 1991 is the second data stream. There is no need to self-synchronize again with the new timing settings included in.

8 and 9 are combined to form a flowchart 800 (eg, first flowchart 800-1 and second flowchart 800-2) for explaining the data information distribution technique according to the embodiment.

In step S810, the server 110 is a repository for storing each window of the most recently received content for each of a plurality of disparate asynchronous content streams on channels 1 through M (eg buffer 120). To maintain. Each window of content is large enough to store at least two applicable content frames (eg, I-frames or anchor frames) from each of the content streams over network 119.

In step S820, the server 110 receives the first content stream (eg, the data of the first channel 1) as a content stream having the respective decryption information based on the first master clock 117-1.

In step S830, the server 110 receives the second content stream (eg, the data on the second channel 2) as a content stream having its respective decryption information based on the second master clock 117-2. As described above, the first master clock 117-1 and the second master clock 117-2 operate asynchronously or independently of each other.

In step S840, the server 110 transmits the content from the first content stream to the first subscriber 199-1 in the output data stream. In step S850, instead of sending content from the first content stream (eg, channel 1) to the output data stream, server 110 responds to the reception of instructions from first subscriber 199-1. Start sending content from the second content stream (eg channel 2).

In step S910 of FIG. 9, the server 110 transfers the timing information related to the content from the second content stream (eg, the data information received on the second channel 2), the decoder information, and the content from the first content stream (eg, data information received on the second channel 2). Example: Correct according to the decryption information related to (data information received on channel 1).

Sub-step S910 of step S910 In step S920, the server 110 decodes the timing information related to the content from the second content stream related to the content from the first content stream (eg, the data information received on channel 1). Correct according to the information.

In step S930, the server 110 embeds the newly modified timing information in the output data stream. In other words, the server 110 exchanges the first decryption information associated with the content from the second content stream with the modified decryption information. The first subscriber 199-1 is the output data stream, and by recovering the newly modified decryption information, the first subscriber 199-1 abandons the current decryption information and the output data from the server 110. The data stream from the second channel can be played back without having to re-self-synchronize with the data from the second channel sent in the stream.

In step S940, the recipient of the output data stream first decodes the content from the first content stream by sending the modified timing information (for the data related to the second channel) to the output data stream. The output data stream can be played seamlessly based on the same decoder state information used for.

As mentioned above, the techniques described herein are well suited for use in applications that perform operations such as receiving, modifying, and distributing data streams. However, it should be noted that the configurations described are not limited to use in such applications, and these configurations and examples of variations thereof are well suited for other applications.

Although the present invention has been specifically illustrated and described with respect to preferred embodiments, those skilled in the art will vary in form and detail without departing from the spirit and scope of the invention as defined by the appended claims. You will understand that changes can be made. As such, the above embodiments of the present invention are not intended to be limiting. Rather, any limitation on embodiments of the present invention is set forth in the following claims.