JP4470345B2 - Data distribution apparatus and method, data distribution system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a data distribution apparatus and method, and a data distribution system for distributing multimedia data such as moving image data via a network and performing special reproduction on a receiving terminal side.
[0002]
[Prior art]
Conventional data distribution in which multimedia data consisting of video data, audio data, etc. is compressed and stored, distributed via a transmission medium, received by a decoding terminal on the data receiving side, and decoded to display video For example, the system is configured as shown in FIG. FIG. 19 shows a data distribution system that distributes only video data for the sake of simplicity.
[0003]
The conventional data distribution system includes a server device 100 that transmits data and a decoding terminal 200 that receives video data transmitted from the server device 100. In this data distribution system, the server apparatus 100 and the decoding terminal 200 are connected via a transmission medium 300 including a communication line, and video data is transmitted via the transmission medium 300.
[0004]
The server device 100 includes a data storage unit 101 that stores video data, a special playback control unit 102, and a transmission unit 103. The transmission unit 103 transmits the video data to the decoding terminal 200.
[0005]
The decoding terminal 200 includes a receiving unit 201, a decoding unit 202, and a special playback control unit 203, receives video data transmitted from the transmitting unit 103 of the server apparatus 100 by the receiving unit 201, and receives the video data received by the decoding unit 202. Is decoded and output to a display device (not shown) to present the contents of the video data to the user.
[0006]
In such a data distribution system, when performing special reproduction such as fast-forward reproduction or pause, a user operating the decoding terminal 200 inputs a special reproduction designation signal to the special reproduction control unit 203. In response to this, the special reproduction control unit 203 of the decoding terminal 200 transmits a special reproduction request based on the special reproduction designation to the special reproduction control unit 102 of the server device 100.
[0007]
The special reproduction control unit 102 of the server apparatus 100 supplies a control signal S102 indicating the special reproduction request to the transmission unit 103 in response to the special reproduction request from the decoding terminal 200, and the transmission unit 103 uses the special reproduction request according to the special reproduction request. The reproduction video data S 101 is read from the data storage unit 101 and controlled to be transmitted to the decoding terminal 200 via the transmission medium 300.
[0008]
When the above-described conventional data distribution system is used in a home network, video data encoded in conformity with, for example, ISO / IEC13818-2 (MPEG-2video) is used as video data. The video data defined in ISO / IEC13818-2 is defined to be encoded so that a decoder buffer called a vbv buffer compliant with the MPEG2 standard does not overflow and underflow.
[0009]
That is, in FIG. 20, video data is encoded with each DTS (Decode Time Stamp) so that the vbv buffer occupancy does not overflow beyond the vbv buffer size (vbv_buffer_size) and the vbv buffer occupancy does not underflow. There is a need to. Here, the video data is input to the vbv buffer at the transmission rate of the video data (the slope of the occupation locus), and the video data is extracted at the decoding timing (DTS).
[0010]
For example, the nth video frame n having the data size S (n) is extracted from the vbv buffer at the decoding time DTS (n). The video data extracted from the vbv buffer needs to be input to the vbv buffer by the decoding time, and the time from the start of the video frame data to the decoding time of the video frame is the vbv delay (vbv_delay). ) And is encoded in the header of data obtained by encoding the frame.
[0011]
The ISO / IEC13818-2 video frame encoding method includes an I picture (I (Intra) -Picture) that is encoded only from intra-frame data and a B picture that is encoded using motion prediction between frames ( There are B (Bidirectionally predictive) -Picture) and P picture (P (Predictive) -Picture). In a conventional data distribution system, an I picture that does not use prediction processing between video frames is used as the special reproduction video data prepared in advance for special reproduction. The special reproduction data is obtained by extracting I pictures periodically included in the normal reproduction video data and used for special reproduction.
[0012]
Further, in a conventional data distribution system, video data is packetized using, for example, a transport stream (Transport Stream: TS) defined by ISO / IEC13818-1 (MPEG-2 system) as video data to be transmitted, Multiplexing with other audio data or the like is performed. In ISO / IEC13818-1 of TS, a decoder model as shown in FIG. 21 is defined for decoding TS.
[0013]
This decoder model includes a switch unit 401 that switches and outputs an input TS, a transport buffer (TB) 402, a multiplexing buffer (MB) 403, an elementary buffer (EB) 404, a video decoder (D) 405, a reorder buffer. 406 and a switch unit 407, a video packet is selected from the input TS by the switch unit 401 and sent to the transport buffer 402 at the input rate, and is decoded by the video decoder 405 via each buffer 402, 403, and 404. Video output.
[0014]
Such a decoder model is composed of a transport buffer 402, a multiplexing buffer 403, and an elementary buffer 404 whose respective buffer sizes are determined, and the data transfer rate between the buffers is also defined.
[0015]
In this decoder model, the elementary buffer 404 corresponds to a vbv buffer for video data, and ISO / IEC13818-1 defines the necessity of packetizing each buffer so as not to overflow or underflow.
[0016]
Further, transmission data such as TS is further transmitted using a protocol used in the transmission medium 300. For example, a TS satisfying the specification of ISO / IEC13818-1 is “Digital Interface for consumer audio / video equipment” of IEC61883. It is possible to transmit with an IEEE 1394 cable conforming to the IEEE 1394 standard by the method defined in the above. MPEG-2TSover1394, which transmits TS in accordance with the MPEG2 standard according to the IEEE1394 standard, is used for content distribution from a server storing content in a home network to a client such as a TV set in each room. Proposed.
[0017]
[Problems to be solved by the invention]
When special reproduction is performed in the above-described conventional data distribution system, special video data prepared for special reproduction by the server apparatus 100 is distributed via the transmission medium 300. For example, when fast-forward playback is performed as special playback, video data including only ISO / IEC13818-2 I pictures is transmitted. Since video data consisting of only I pictures may cause the vbv buffer to overflow or underflow, special transmission data for special reproduction different from that during normal reproduction must be distributed. Furthermore, the conventional data distribution system requires a special decoding terminal 200 that can perform special reproduction in accordance with a special transmission data format.
[0018]
For example, when fast-forward playback is performed as special playback, video data including only an I / picture of ISO / IEC13818-2 is transmitted. For this purpose, the data storage unit 101 of the server apparatus 100 is different from the normal playback video data. It is necessary to prepare special video data called special reproduction video data.
[0019]
However, for example, when a TS is transmitted by an IEEE 1394 cable by a method defined by IEC61883, the video data for special reproduction cannot be transmitted unless it is a TS defined by ISO / IEC13818-1.
[0020]
Further, even if data transmission is performed in a special distribution data format for special reproduction, a special decoding terminal 200 corresponding to the special distribution data format is required. For example, video data consisting of only ISO / IEC13818-2 I-pictures causes vbv buffer overflow and underflow unlike normal playback video streams that are encoded to satisfy the vbv buffer specification. there is a possibility. Therefore, there is a strong demand for a data distribution method that can be used without using a combination of the special server device 100 and the decryption terminal 200.
[0021]
When a special data distribution method is used for special reproduction, the decoding terminal 200 needs to have a decoding function capable of performing special processing for special reproduction as well as normal reproduction. There is a problem that it becomes complicated. For example, when fast-forward playback is performed on the decoding terminal 200 side, when video data consisting only of ISO / IEC13818-2 I-picture that may cause the vbv buffer to underflow is input, the decoding terminal 200 When all the input data of the picture is not prepared at the decoding time, it is necessary to treat the data of the previous picture as a substitute.
[0022]
Furthermore, in a home network system, when a plurality of decryption terminals 200 are connected to the server apparatus 100, a data distribution method that can be used by the decryption terminal 200 with a simple configuration has been desired. At present, there is no method to realize.
[0023]
For such a problem, a data distribution system as shown in FIG. 22 can be considered. In this data distribution system, special reproduction according to a special reproduction control signal based on a special reproduction designation signal from the data reproduction unit 502, a special reproduction control unit 502 to which a special reproduction designation signal is input, and a special reproduction designation signal is input into the server device 100. A data conversion unit 503 that creates data for use, a multiplexing unit 504, and a transmission unit 505. The reception unit 601 that receives transmission data from the server device 100 via the transmission medium 300 in the decoding terminal 200, and the reception unit 601 The decoding unit 602 is configured to decode the special reproduction data, display it on a display device (not shown), and present it to the user.
[0024]
In such a data distribution system, the data conversion unit 503 is supplied with the special reproduction control signal from the special reproduction control unit 502 and receives the video data from the data storage unit 501 and the data decoded by the decoder 701. Is provided.
[0025]
The decoder 701 reads the designated video data from the data storage unit 501 by an optimum reading method according to the type of special reproduction in accordance with the special reproduction control signal from the special reproduction control unit 502. For example, when a special reproduction control signal that requests fast-forward reproduction is input as the type of special reproduction, the decoder 701 reads video data from the data conversion unit 503 so as to skip B pictures that are not used for decoding.
[0026]
The decoder 701 decodes the read video data and supplies the decoded video signal to the encoder 702 as a decoded video signal. Here, the decoded video signal is read from the data storage unit 501 to reflect the result of special reproduction.
[0027]
The encoder 702 encodes the decoded video signal from the decoder 701 and encodes it to output to the multiplexing unit 504 as video data for special reproduction. The special reproduction video data encoded by the encoder 702 is video data corresponding to the type of special reproduction because the video data read by the decoder 701 reflects the result of special reproduction. . For example, when encoding according to ISO / IEC13818-2 is performed as a video data encoding method, the video data for special reproduction output from the encoder 702 is data that satisfies the regulations of ISO / IEC13818-2.
[0028]
According to such a data distribution system, even when special playback is performed, the video data for special playback converted by the data conversion unit 503 is converted into the same video data format as that for normal playback. Therefore, special reception processing and decoding processing for special reproduction are not required on the decoding terminal 200 side, and further, a control device for special reproduction is not required on the decoding terminal 200 side.
[0029]
However, in the data conversion unit 503 of the server apparatus 100 in the data distribution system shown in FIG. 22, the video data stored in the data storage unit 501 is re-encoded by the decoder 701 and the encoder 702. The processing load is heavy, and there is a risk that the image quality will deteriorate. If the processing delay required for data conversion increases, the delay from when the special reproduction designation signal is input by the user until the content of the special reproduction is actually displayed on the display device at the decoding terminal 200 increases. There is also a problem that it ends up.
[0030]
Therefore, the present invention has been proposed in view of the above-described circumstances, and a data distribution device capable of converting into data obtained as a result of special reproduction without performing decoding and re-encoding of data, and It is an object to provide a method and a data distribution system.
[0031]
[Means for Solving the Problems]
In order to solve the above-described problem, the data distribution apparatus according to the present invention is transmitted to the reproduction apparatus together with a receiving unit that receives a special reproduction request from the outside, transmission data transmitted to the reproduction apparatus, and transmission data. Data storage means for storing insertion data, reading means for reading transmission data and insertion data from the data storage means based on the received special reproduction request, and code generation amount of the read transmission data and insertion data Based on the bit occupancy detection means for detecting the bit occupancy for the control virtual buffer and the bit occupancy detected by the bit occupancy detection means, the additional data is added to the insertion data read by the reading means. In addition, the inserted data adjusting means for adjusting the data size of the inserted data and the bit occupation amount detecting means A switching output for switching and outputting the transmission data whose quantity is detected and the insertion data whose data size has been adjusted by the insertion data adjusting means based on the type of special reproduction included in the special reproduction request received by the receiving means Means, and transmission means for transmitting the transmission data and insertion data output from the switching output means to the reproduction apparatus.
[0032]
In order to solve the above-described problem, the data distribution method according to the present invention receives a special reproduction request from the outside, and transmits the transmission data and transmission data to be transmitted to the reproduction device based on the received special reproduction request. Insert data to be transmitted to the playback device is read from the data storage means, the read data to be transmitted and the bit occupancy amount for the virtual buffer for code generation amount control of the insert data are detected, and based on the detected bit occupancy amount, The additional data is added to the read insertion data to adjust the data size of the insertion data, and the transmission data in which the bit occupancy is detected and the insertion data in which the data size is adjusted are received in the special data received. The output is switched based on the type of special playback included in the playback request, and the output transmission data and insertion data are It is sent to the playback device.
[0033]
In order to solve the above problems, a data distribution system according to the present invention is a data in which a data distribution device that distributes data and a receiving terminal that receives data from the data distribution device are connected via a transmission medium. In the distribution system, the data distribution apparatus includes a receiving unit that receives a special reproduction request from a user, transmission data transmitted to the receiving terminal, and data storage that stores insertion data transmitted to the receiving terminal together with the transmission data. Means for reading transmission data and insertion data from the data storage means based on the special reproduction request received by the reception means, and control of the amount of generated code of the transmission data and insertion data read by the reading means Bit occupancy detection means for detecting the bit occupancy with respect to a virtual buffer for use, and the bit occupancy detection Based on the bit occupation amount detected by the means, the insertion data adjustment means for adjusting the data size of the insertion data by adding additional data to the insertion data read by the reading means, and the bit occupation amount detection means A switching output for switching and outputting the transmission data in which the bit occupancy is detected and the insertion data whose data size has been adjusted by the insertion data adjustment means based on the type of special reproduction included in the special reproduction request received by the reception means And transmission means for transmitting the transmission data and insertion data output from the switching output means to the reception terminal, wherein the reception terminal transmits the transmission data and insertion data from the transmission means based on the special reproduction request. Receiving means for receiving the data as special reproduction data, and decoding means for decoding the special reproduction data received by the receiving means, Provided.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0035]
The present invention is applied to a data distribution system as shown in FIG.
[0036]
The data distribution system includes a server device 1 that distributes accumulated data, and a decryption terminal 10 connected to the server device 1 via a transmission medium 20.
[0037]
The server device 1 includes a data storage unit 2 that stores data, a special reproduction control unit 3, a data conversion unit 4, a multiplexing unit 5, and a transmission unit 6.
[0038]
The data storage unit 2 stores video data and insertion data transmitted from the server device 1 to the decoding terminal 10 via the transmission medium 20. The video data stored in the data storage unit 2 is stored as video data for normal playback that is temporally continuous. The data storage unit 2 reads out the video data and the insertion data in accordance with a request from the data conversion unit 4 and outputs it to the data conversion unit 4.
[0039]
As the insertion data stored in the data storage unit 2, for example, a repeat picture compliant with the MPEG2 standard can be cited. A repeat picture is a picture that indicates that the prediction source video data is repeated when all macroblocks are composed of skip macroblocks.
[0040]
In this example, a case where only video data and insertion data are stored in the data storage unit 2 will be described. However, multimedia data such as still image data, audio data, text data, and graphic data may be used. .
[0041]
The special reproduction control unit 3 includes a reception unit (not shown) for receiving a special reproduction designation signal for requesting special reproduction transmitted from the outside. A special reproduction designation signal received by a receiving unit (not shown) of the special reproduction control unit 3 includes, for example, special reproduction types such as fast-forward reproduction and frame advance reproduction, and designation of video data stored in the data storage unit 2. . The special reproduction control unit 3 supplies a special reproduction control signal including a special reproduction type and video data designation to the data conversion unit 4 in accordance with the special reproduction designation signal.
[0042]
The data conversion unit 4 inputs the specified video data from the data storage unit 2 in accordance with the special reproduction control signal, and performs a data conversion process corresponding to the type of special reproduction on the input video data. At this time, the data conversion unit 4 converts the designated video data into special reproduction data indicating the video data as a result of the designated type of special reproduction while reading the designated video data from the data storage unit 2. The data conversion unit 4 supplies the converted special reproduction data to the multiplexing unit 5.
[0043]
The multiplexing unit 5 multiplexes the special reproduction data from the data conversion unit 4 and the video data read by the data conversion unit 4 from the data storage unit 2 as necessary, and supplies the multiplexed data to the transmission unit 6.
[0044]
The multiplexing unit 5 multiplexes the data from the data conversion unit 4 into a data format to be distributed to the transmission medium 20 when the data includes a plurality of data such as video data and audio data.
[0045]
The transmission unit 6 converts the special reproduction video data from the multiplexing unit 5 into a format for transmission via the transmission medium 20, thereby transmitting the transmission data to the decoding terminal 10 via the transmission medium 20. To do.
[0046]
The decoding terminal 10 includes a receiving unit 11 and a decoding unit 12 connected to the server device 1 via a transmission medium 20.
[0047]
The reception unit 11 receives transmission data transmitted from the transmission unit 6 of the server device 1 via the transmission medium 20. The receiving unit 11 converts the transmission data into a data format that can be processed by the subsequent decoding unit 12, and supplies the data to the decoding unit 12 as video data for special reproduction.
[0048]
The decoding unit 12 decodes the special reproduction video data from the reception unit 11 and outputs it to a display device (not shown), thereby displaying the contents of the special reproduction video data.
[0049]
Next, the configuration of the data conversion unit 4 will be described.
[0050]
The data conversion unit 4 includes a reading unit 21 that reads video data and insertion data from the data storage unit 2, a vbv delay detection unit 22, a stuffing insertion unit 23, and a switching output unit 24.
[0051]
The reading unit 21 reads the designated video data from the data storage unit 2 and reads the insertion data from the data storage unit 2 in accordance with the special playback control signal from the special playback control unit 3. The reading unit 21 selects and reads only the video data necessary for special reproduction out of the designated video data according to the type of special reproduction included in the special reproduction control signal. The reading unit 21 outputs the read video data S1 to the vbv delay detection unit 22, and outputs the read insertion data S2 to the stuffing insertion unit 23.
[0052]
The vbv delay detection unit 22 detects a vbv delay that is information indicating a locus of the bit occupation amount of the vbv buffer encoded for each video data. The vbv delay detection unit 22 outputs the video data from the reading unit 21 to the switching output unit 24 and supplies the detected vbv delay to the stuffing insertion unit 23.
[0053]
Based on the vbv delay from the vbv delay detection unit 22, the stuffing insertion unit 23 adjusts the data size of the insertion data in order to make the bit occupancy trace of the vbv buffer continuous. The stuffing insertion unit 23 adjusts the data size of the insertion data by inserting the stuffing data into the insertion data. The stuffing insertion unit 23 outputs the insertion data after adjusting the data size to the switching output unit 24.
[0054]
For example, since the data size of the repeat picture is smaller than that of the I picture, the stuffing insertion unit 23 can obtain a desirable data size by adding the repeat picture as the stuffing data so that the vbv buffer does not fail. . The data size of the repeat picture when connecting the video data is determined by referring to the vbv delay of the video data used for editing. Note that the insertion data may be composed of a plurality of repeat pictures.
[0055]
The switching output unit 24 switches the video data from the vbv delay detection unit 22 and the insertion data from the stuffing insertion unit 23 and multiplexes them as special reproduction data according to the special reproduction control signal from the special reproduction control unit 3. Output to unit 5. The switching output unit 24 receives the video data from the input terminal b and outputs it from the output terminal a, and also inputs the insertion data from the input terminal c and outputs it from the output terminal a. The video data for reproduction is output to the multiplexing unit 5.
[0056]
Next, a method for inserting insertion data when the video data is switched from the video data A to the video data B by the switching output unit 24 when performing special reproduction in the data conversion unit 4 will be described.
[0057]
FIG. 2 shows the locus of the bit occupancy of the vbv buffer of video data A, and FIG. 3 shows the locus of the bit occupancy of the vbv buffer of video data B. Here, an example in which data after frame n in video data A is switched to data after frame m of video data B and output will be described. That is, when frame n-1 of video data A is an out frame, the end point of frame n-1 is an out point, and when frame m of video data B is an in frame, the start point of frame m is an in point. .
[0058]
According to FIGS. 2 and 3, since the vbv delay of frame n and the vbv delay of frame m are different, when switching is performed by the switching output unit 24, the bit occupation amount of the vbv buffer as shown in FIG. Are not matched, and the buffer size of the vbv buffer overflows or underflow occurs.
[0059]
On the other hand, the data conversion unit 4 inserts between the frame n and the frame m as shown in FIG. 5 in order to maintain the consistency of the locus of the bit occupation amount of the vbv buffer when switching the video data. Data is inserted so that the vbv buffer is not broken before and after the video data switching.
[0060]
That is, the vbv delay detection unit 22 detects the vbv delay of the video data before and after switching in order to make the locus of the bit occupation amount of the vbv buffer continuous when switching the video data by the switching output unit 24. On the other hand, the stuffing insertion unit 23 inserts a repeat picture as stuffing data to adjust the bit size of the vbv buffer, and adjusts the data size of the insertion data. Then, the switching output unit 24 performs switching processing so as to adjust the picture type of the repeat picture and the number of repeat pictures constituting the insertion data to be inserted between the video data A and the video data B, whereby the video data The data size of insertion data to be inserted between A and video data B is determined. As a result, the switching output unit 24 outputs to the multiplexing unit 5 the video data for special playback that does not cause the vbv buffer to fail.
[0061]
Next, the processing of the data conversion unit 4 when a special reproduction designation signal designating pause as the type of special reproduction transmitted from the outside is received by a receiving unit (not shown) of the special reproduction control unit 3 will be described.
[0062]
When the special reproduction control signal that pauses as the type of special reproduction is received by the receiving unit (not shown) of the special reproduction control unit 3, the data conversion unit 4 receives the insertion data after the out frame as shown in FIG. 6. When inserting and releasing the pause, it returns to the video data after the out frame.
[0063]
FIG. 7 shows a processing procedure of the data conversion unit 4 when such processing is performed. According to FIG. 7, when the special reproduction control signal indicating that the video data for normal reproduction is read by the reading unit 21 and the transmission data is transmitted to the decoding terminal 10 is paused ( Step ST11) First, processing for determining an out frame is performed (step ST12). At this time, it is desirable that the reading unit 21 selects video data of a B picture in which the picture type of an out frame is an I picture or a sequence following the I picture. Thereby, the reading unit 21 can increase the image quality during the pause.
[0064]
Next, the data conversion unit 4 inserts the insertion data for a time corresponding to the pause (step ST13), and repeats the process of inserting the insertion data until a special reproduction control signal for canceling the pause is input ( Step ST14).
[0065]
At this time, the reading unit 21 reads a repeat picture as insertion data from the data storage unit 2 as data to be displayed on the decoding terminal 10 side during the pause and outputs the repeat picture to the stuffing insertion unit 23. The stuffing insertion unit 23 adds and adds stuffing data to the repeat picture from the reading unit 21 so as to obtain a data size obtained by multiplying the video data rate by the video frame display interval time in order to prevent the vbv buffer from failing. Output to the output unit 24. The switching output unit 24 outputs the repeat picture from the stuffing insertion unit 23 to the multiplexing unit 5 during the temporary stop.
[0066]
Here, the stuffing insertion unit 23 determines the picture type of the repeat picture so that the number of consecutive B pictures after the out frame is the same as that during normal playback without pause. The display order of previous pictures can be maintained.
[0067]
When the pause is released, the reading unit 21 of the data conversion unit 4 determines the picture type of the first picture after the in-frame (step ST15), and when it is determined that the picture is not a B picture, the normal playback is resumed (step ST15). ST17), the process ends. When the reading unit 21 determines that the picture is a B picture, it performs a correction process (step ST16). When the picture type of the first picture after the in-frame is no longer a B picture, the reading unit 21 returns to normal playback (step ST17) and ends the process. To do.
[0068]
The correction process will be described by taking an example when the normal playback video data in the encoding order and display order as shown in FIG. In the following description, the arrow in the figure is the motion prediction direction, the frame pointed to by the arrow is the prediction destination picture, and the start source of the arrow is the prediction source picture.
[0069]
The normal playback video data shown in FIG. ₆ (I picture with the 6th display order) out-frame, frame B ₄ Is data in-frame. Here, in the normal reproduction video data, the frame immediately after the in-frame is a B picture, and the frame B ₄ , Frame B ₅ Is frame P ₃ , Frame I ₆ Is encoded using the prediction from.
[0070]
In FIG. 8B, the switching output unit 24 sends the frame I. ₆ And frame B ₄ Repeat picture R (B ₁ )-Repeat picture R (P ₉ ) Is shown when inserted. Frame B ₄ And frame B ₅ Repeat picture R (P ₆ ) And repeat picture R (P ₉ ) Using the prediction from (). Frame B ₄ , Frame B ₅ Is essentially frame P ₃ And frame I ₆ Is decoded using the prediction from. In such a case, R (P ₉ ) Is a repeat picture, the decoding result is frame I ₆ But frame R (P ₆ ) Is the frame P ₃ Is different from frame B ₄ , Frame B ₅ Cannot be decrypted correctly.
[0071]
On the other hand, in the correction process, the reading unit 21 receives a frame B, which is a B picture that follows the head of the display order after the in-frame, as shown in FIG. ₄ , Frame B ₅ Is correctly decoded by inserting a repeating repeat picture for correction so as to be replaced with a repeat B picture using only backward prediction. As shown in FIG. 8C, the reading unit 21 repeats the repeat picture R (P ₉ ) Repeat picture R (B ₇ ), Repeat picture R (B ₈ ) Frame B ₄ , Frame B ₅ The process of reading the insertion data from the data storage unit 2 is performed so as to replace. Thereby, in the decoding terminal 10, the frame B ₄ , Frame B ₅ Can be accurately decoded. In addition, the stuffing insertion unit 23 repeats the picture R (B ₇ ), Repeat picture R (B ₈ By inserting stuffing data into (), it is possible to ensure that the vbv buffer is not broken.
[0072]
Note that video data encoded by an encoding method capable of changing a picture display interval, such as an encoding method defined by ISO / IEC 14496-2 (so-called MPEG-4 video), is transmitted. Sometimes, instead of inserting a repeat picture, changing the display time of the picture allows the picture to be repeated in the special reproduction, thereby realizing a pause.
[0073]
Next, processing of the data conversion unit 4 when a special reproduction designation signal designating fast-forward reproduction as the type of special reproduction transmitted from the outside is received by a receiving unit (not shown) of the special reproduction control unit 3 will be described.
[0074]
When a special reproduction control signal for fast-forward reproduction as a type of special reproduction is received by a receiving unit (not shown) of the special reproduction control unit 3, the data conversion unit 4 receives an appropriate I and subsequent frames from the out frame as shown in FIG. The reading unit 21 is operated so that a picture is selected and read out from the data storage unit 2, insertion data is inserted so as not to break the vbv buffer, and when fast-forward playback is canceled, the video data after in-frame is returned.
[0075]
FIG. 10 shows a processing procedure of the data conversion unit 4 when such processing is performed. According to FIG. 10, when a special playback control signal indicating that fast-play playback is performed while video data for normal playback is read by the reading unit 21 and transmission data is being transmitted to the decoding terminal 10 is input ( Step ST21) First, processing for determining an out frame is performed (step ST22). At this time, it is desirable that the reading unit 21 selects video data whose out-frame picture type is I picture. Thereby, the reading unit 21 can improve the image quality immediately after the fast-forward reproduction.
[0076]
Next, the reading unit 21 selects and reads an I picture or a P picture used for fast-forward playback from the normal playback video data stored in the data storage unit 2 (step ST23). Here, the reading unit 21 can increase the image quality during fast-forward playback by selecting an I picture. Further, when the fast-forward playback speed is designated by the special playback control signal from the special playback control unit 3, the reading unit 21 adjusts the fast-forward playback speed by adjusting the interval between pictures to be selected.
[0077]
Next, the video data read in step ST23 is supplied to the vbv delay detection unit 22 from the read unit 21, and the stuffing insertion unit 23 is supplied with the repeat picture (insertion data) read by the read unit 21. The vbv delay detection unit 22 detects the vbv delay using the video data, and the stuffing insertion unit 23 inserts the stuffing data into the repeat picture based on the vbv delay so that the locus of the bit occupancy of the vbv buffer is continuous. Output to the output unit 24. Thereby, the switching output unit 24 inserts repeat pictures and stuffing data into the video data as shown in FIG. 9 (step ST24).
[0078]
Next, the data conversion unit 4 repeats the above-described processing in step ST23 and the processing in step ST24 until fast-forward playback is performed until a special playback control signal indicating cancellation of fast-forward playback is input and it is determined that fast-forward playback is cancelled. When canceling, the process proceeds to the next process (step ST25).
[0079]
When fast-forward playback is cancelled, the reading unit 21 performs processing for selecting an I picture to be in-frame and reading it from the data storage unit 2 (step ST26), and supplies it to the vbv delay detection unit 22.
[0080]
Next, the vbv delay detection unit 22 detects the vbv delay of the video data that is in-frame from the reading unit 21, and the stuffing insertion unit 23 inserts the stuffing data based on the vbv delay so as not to break the vbv buffer. The repeat picture is output to the switching output unit 24 (step ST27).
[0081]
Next, the reading unit 21 determines whether the selected in-frame video data is the head in the closed GOP encoding order (step ST28).
[0082]
When the in-frame video data is the head video data in the closed GOP encoding order, the reading unit 21 returns to the process of reading the video data for normal reproduction (step ST30) and ends the process.
[0083]
Specifically, the frame I that is the head of the closed GOP as shown in FIG. ₂ When the fast-forward playback is canceled with the in-frame as shown in FIG. 11, the decoding terminal 10 can perform decoding without inserting a repeat picture as shown in FIG.
[0084]
On the other hand, when the in-frame video data is not the head video data in the closed GOP encoding order, the reading unit 21 performs a correction process of replacing with a repeat picture having the same data size (step ST29). Returning to the process of reading video data (step ST30), the process ends.
[0085]
Specifically, the frame I that is not the head of the closed GOP as shown in FIG. ₂ When the fast-forward playback is canceled with the in-frame as the in-frame, as shown in FIG. 12B, the B picture continuous from the top in the display order immediately after the in-frame is decoded correctly because the prediction source picture is switched for special playback. Can not do it. Here, the reading unit 21 accurately performs the decoding process on the decoding terminal 10 side by performing a correction process to replace the B picture immediately after the in-frame with repeat pictures R (B0) and R (B1) using only backward prediction. Let The stuffing insertion unit 23 also prevents the picture B before replacement in order to prevent the vbv buffer from failing. ₀ , Picture B ₁ And the repeated picture R (B ₀ ), R (B ₁ The stuffing data is inserted so that the data size becomes equal.
[0086]
In fast-forward playback, the data conversion unit 4 is particularly different from the condition of the picture selected in step ST23 in the in-frame condition determined in step ST26 such that the in-frame always selects a closed GOP. Except for the case of providing ST, the processing in step ST26 and step ST27 may be performed in step ST23 and step ST24, respectively.
[0087]
In addition, when performing fast-forward playback in the reverse direction, the data conversion unit 4 performs processing for arranging the time direction of the I picture selected in step ST23 in the reverse direction.
[0088]
Next, the processing of the data conversion unit 4 when a special reproduction designation signal designating slow reproduction as the type of special reproduction transmitted from the outside is received by a receiving unit (not shown) of the special reproduction control unit 3 will be described.
[0089]
When a special reproduction control signal for slow reproduction as a type of special reproduction is received by a receiving unit (not shown) of the special reproduction control unit 3, the data conversion unit 4 performs normal reproduction from an out frame or later as shown in FIG. 13. A process of inserting a repeat picture between frames of video data is performed, and when slow playback is canceled, the video data returns to the video data after the in-frame.
[0090]
FIG. 14 shows a processing procedure of the data conversion unit 4 when such processing is performed. According to FIG. 14, when video data for normal playback is read by the reading unit 21 and a special playback control signal for slow playback is input during transmission of transmission data to the decoding terminal 10 ( Step ST41) First, processing for determining an out frame is performed (step ST42).
[0091]
Here, when the video data for normal reproduction is a TS defined by ISO / IEC13818-1, the display time information of the I picture or P picture may be encoded and transmitted prior to the picture data. When the repeat picture is inserted, the display time of the I picture and the P picture changes. Therefore, when encoding the display time, the out frame is selected from the I picture or the P picture.
[0092]
Next, in order to obtain the display time of the current I picture or P picture, the reading unit 21 determines the number of repeat pictures to be inserted before the next I picture or P picture after starting slow playback ( Step ST43). The reading unit 21 does not need to determine the number of inserted sheets in advance when the display time need not be encoded. The reading unit 21 controls the speed of slow reproduction according to the number of pictures to be inserted.
[0093]
Next, the switching output unit 24 performs a process of inserting a repeat picture, which is a B picture, between pictures of normal reproduction video data (step ST44), and multiplexes special reproduction video data decoded as slow reproduction. To the conversion unit 5. At this time, the stuffing insertion unit 23 uses the stuffing data so that the data size of the repeat picture to be inserted is the data size obtained by multiplying the video data rate by the display interval time of the video frame, and does not cause the vbv buffer to fail. Guarantee that. Here, when the display time is encoded, the switching output unit 24 performs control so as not to cancel the slow reproduction until the number of repeat pictures determined in step ST43 is inserted. The accuracy of the displayed time is maintained.
[0094]
Next, the data converter 4 determines whether or not a special playback control signal for canceling slow playback is input from the special playback controller 3 (step ST45), and reads normal playback data when canceling slow playback. As described above, when the reading unit 21 operates (step ST46), the process is terminated and the slow reproduction is not canceled, the processes of the above-described steps ST43 and ST44 are repeated.
[0095]
Next, the processing of the data conversion unit 4 when a special reproduction designation signal designating jump reproduction as the type of special reproduction transmitted from the outside is received by a receiving unit (not shown) of the special reproduction control unit 3 will be described.
[0096]
When a special reproduction control signal for performing jump reproduction as a type of special reproduction is received by a receiving unit (not shown) of the special reproduction control unit 3, the data conversion unit 4 performs normal reproduction from an out frame or later as shown in FIG. A process of inserting a repeat picture between the frames of the video data is performed, and the video data after the in-frame is returned. That is, the server device 1 continues playback from different frames of the normal playback video data during transmission of the normal playback video data.
[0097]
FIG. 16 shows a processing procedure of the data conversion unit 4 when such processing is performed. According to FIG. 16, when a special playback control signal for performing jump playback is input while video data for normal playback is read by the reading unit 21 and transmission data is being transmitted to the decoding terminal 10 ( Step ST51) First, the vbv delay detector 22 is operated so as to detect the vbv delay of the frame immediately after the out frame and the in frame. At this time, the reading unit 21 reads out the frame data immediately after the out frame and the in-frame video data from the data storage unit 2 and supplies them to the vbv delay detection unit 22, and also reads out repeat pictures from the data storage unit 2 and inserts stuffing. To the unit 23.
[0098]
Next, the stuffing insertion unit 23 adjusts the data size of the repeat picture by inserting stuffing data based on the detected vbv delay so as not to break the vbv buffer (step ST52).
[0099]
Further, when the display time information before the out frame is encoded prior to the video data and sent to the decoding terminal 10, the server device 1 performs jump playback of the number of B pictures consecutive after the out frame. By determining the picture type of the repeat picture so that the number is the same as the case where it is not performed, the display order of the pictures before the out-frame is maintained.
[0100]
Next, the reading unit 21 determines whether or not the in-frame video data read in the previous step is the head of the closed GOP (step ST53). When it is determined that the in-frame video data is not the head of the closed GOP, the reading unit 21 performs a correction process for replacing with a repeat picture having the same data size as in the above-described step ST29 (step ST54), and video for normal playback Returning to the process of reading data (step ST55), the process ends. As a result, even when jump playback is performed, the server device 1 correctly performs the decoding process on the decoding terminal 10 side, and prevents the vbv buffer from failing.
[0101]
On the other hand, when the reading unit 21 determines that the in-frame video data is the head of the closed GOP, the reading unit 21 returns to the process of reading the video data for normal reproduction (step ST55) and ends the process.
[0102]
Next, the processing of the data conversion unit 4 when a special reproduction designation signal designating frame advance as the type of special reproduction transmitted from the outside is received by a receiving unit (not shown) of the special reproduction control unit 3 will be described.
[0103]
When a special reproduction control signal for frame-by-frame reproduction is received as a special reproduction type by a receiving unit (not shown) of the special reproduction control unit 3, the data conversion unit 4 performs an appropriate operation after an out frame as shown in FIG. An interval I picture or P picture is selected, a process of replacing the selected pictures with a repeat picture is performed, and the video data after the in-frame is returned.
[0104]
FIG. 18 shows a processing procedure of the data conversion unit 4 when such processing is performed. According to FIG. 18, when the normal playback video data is read by the reading unit 21 and a special playback control signal for frame-by-frame playback is input during transmission of transmission data to the decoding terminal 10, (Step ST61) First, the reading unit 21 performs a process of determining an out frame (step ST62). Here, the reading unit 21 can select an arbitrary picture in the normal reproduction video data as an out frame. The reading unit 21 can increase the image quality in the in frame by selecting the I picture as the out frame.
[0105]
Next, the reading unit 21 selects the next I picture or P picture (frame advance playback video data) to be extracted from the normal playback video data (step ST63). Here, when the P picture is selected as the frame-advance playback video data, the reading unit 21 correctly decodes on the decoding terminal 10 side if the picture that is the prediction source of the P picture is replaced with a repeat picture. Therefore, the frame feed playback video data is read from the data storage unit 2 so as to satisfy the condition that the I picture or P picture immediately before the P picture to be selected is not replaced with a repeat picture. In addition, the reading unit 21 selects an I picture as frame-by-frame playback video data in order to increase the image quality during frame-by-frame playback.
[0106]
Further, the reading unit 21 performs a process of reading a repeat picture from the data storage unit 2. At this time, the reading unit 21 adjusts the interval between the video data for frame-by-frame playback by selecting the number of repeat pictures, and controls the time length for each picture.
[0107]
The reading unit 21 supplies the frame-by-frame playback video data read by this processing to the vbv delay detection unit 22 and supplies the repeat picture to the stuffing insertion unit 23.
[0108]
Next, the data conversion unit 4 performs a process of replacing all frame-by-frame playback video data selected in the previous step with repeat pictures (step ST64). When the original picture of the normal reproduction video data is an I picture or a P picture, the reading unit 21 reads the repeat picture from the reading unit 21 so that the original picture is a B picture. In this case, the repeat picture is read out from the reading unit 21 so as to be replaced with a repeat picture consisting of a B picture. Thereby, the data converter 4 can hold the display order for each picture type. The stuffing insertion unit 23 adds stuffing data to the repeat picture so that the data size of the repeat picture is equal to that of the picture before replacement in order to ensure that the vbv buffer does not fail.
[0109]
Next, the data conversion unit 4 repeats the processing in step ST63 and the processing in step ST64 described above until a special playback control signal indicating cancellation of frame advance playback is input and it is determined that frame advance playback is cancelled. When the forward reproduction is canceled, the process proceeds to the next process (step ST65).
[0110]
When the frame-by-frame playback is canceled, the reading unit 21 determines whether or not the I picture or P picture immediately before the in-frame is replaced with a repeat picture (step ST66). Returning to the process of reading data (step ST69), the process ends.
[0111]
On the other hand, when it is determined that the reading unit 21 has been replaced, the reading unit 21 performs the same processing as in the above-described step ST28 and step ST29. That is, the reading unit 21 determines whether or not the selected in-frame video data is the head in the closed GOP encoding order (step ST67), and the in-frame video data is in the closed GOP encoding order. When it is determined that it is the head of the video, the process returns to the process of reading video data for normal reproduction (step ST69), and the process is terminated. Further, when the in-frame video data is not the head video data in the closed GOP encoding order, the reading unit 21 performs a correction process of replacing with a repeat picture having the same data size (step ST68). Returning to the process of reading video data (step ST69), the process ends.
[0112]
Note that the data conversion unit 4 increases the interval of the I picture or P picture selected in step ST63 when a special reproduction control signal for performing frame advance reproduction with a frame advance reproduction speed other than the normal speed is input. Adjust the number of repeat pictures. At this time, the data conversion unit 4 performs a process of thinning out the repeat picture replaced in step ST64 or a process of further inserting a repeat picture. Further, the data conversion unit 4 determines the data size of the repeat picture in the same manner as described in step ST24 above.
[0113]
In addition, when a special playback control signal for performing reverse frame-by-frame playback is input, the data conversion unit 4 performs processing for arranging the time direction of the I picture selected in step ST63 in the reverse direction.
[0114]
In such a server device 1, even when special playback video data is transmitted to the decoding terminal 10, the repeat picture is inserted by adjusting the number and data size according to the type of special playback, so that the normal playback video data It is possible to create video data for special playback in the same data format.
[0115]
According to such a data distribution system, even when special reproduction is performed, the special reproduction video data converted by the data conversion unit 4 is converted into the same video data format as that in the normal reproduction. Therefore, special reception processing and decoding processing for special reproduction are not required on the decoding terminal 10 side, and further, a control device for special reproduction is not required on the decoding terminal 10 side.
[0116]
Further, according to the above data distribution system, for example, when ISO / IEC13818-2 is used, the vbv buffer is set when the data conversion unit 4 converts the video data for special reproduction for special reproduction. By performing control processing for outputting video data for special playback that does not fail, the decoding terminal 10 can have a simple configuration that does not require special processing for special playback.
[0117]
Furthermore, according to the server device 1 provided with the data conversion unit 4, since special video playback is converted into the same video data format as that used in normal playback, special playback for special playback is performed. It is not necessary to have a function to make a data format. The server apparatus 1 is a video that does not cause the vbv buffer to fail even when data transmission is performed using the IEEE 1394 cable as the transmission medium 20 with the TS defined in ISO / IEC13818-1 by the method defined in IEC61883, for example. Since it has been converted into data, it can be multiplexed into a TS that satisfies the ISO / IEC13818-1 standard, and data can be transmitted in a data format that meets the IEC61883 standard.
[0118]
Therefore, according to the data distribution system, it is not necessary to combine a special server and a decoding terminal when transmitting data for special reproduction.
[0119]
Furthermore, according to this data distribution system, it is not necessary to perform decoding and re-encoding when transmitting video data by the server device 1, so that the configuration of the data conversion unit 4 can be simplified, and at the time of transmission Processing delay can be reduced, and further, image quality is not deteriorated.
[0120]
【The invention's effect】
According to the present invention, transmission data whose bit occupancy is detected and insertion data whose data size is adjusted are switched and output based on the type of special reproduction included in the special reproduction request received from the outside. Since the transmitted data and the inserted data are transmitted to the playback device, the data transmission side does not need to perform decoding and re-encoding for special playback when sending video data for special playback to the playback device. In addition, the configuration on the data transmission side can be simplified, the processing delay at the time of transmission can be reduced, and the image quality is not deteriorated.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a data distribution system to which the present invention is applied.
FIG. 2 is a diagram showing a locus of bit occupancy of a vbv buffer for video data A;
FIG. 3 is a diagram illustrating a locus of bit occupancy of a vbv buffer for video data B;
FIG. 4 is a diagram illustrating a locus of bit occupancy of a vbv buffer when switching from video data A to video data B;
FIG. 5 is a diagram illustrating a locus of bit occupancy in a vbv buffer when a repeat picture is inserted between video data A and video data B;
FIG. 6 is a diagram for explaining processing when temporary suspension is performed by a data conversion unit of a server device to which the present invention is applied;
FIG. 7 is a flowchart for explaining a processing procedure when the data conversion unit of the server apparatus to which the present invention is applied performs a temporary stop.
FIG. 8 is a diagram for explaining a correction process when the data conversion unit of the server device to which the present invention is applied performs a temporary stop.
FIG. 9 is a diagram for explaining processing when fast-forward playback is performed by the data conversion unit of the server device to which the present invention is applied;
FIG. 10 is a flowchart for explaining a processing procedure when fast-forward playback is performed by the data conversion unit of the server apparatus to which the present invention is applied.
FIG. 11 is a diagram for explaining an example when fast-forward reproduction is performed by the data conversion unit of the server apparatus to which the present invention is applied.
FIG. 12 is a diagram for explaining correction processing when fast-forward reproduction is performed by the data conversion unit of the server device to which the present invention is applied.
FIG. 13 is a diagram for explaining processing when slow reproduction is performed by the data conversion unit of the server device to which the present invention is applied;
FIG. 14 is a flowchart for explaining a processing procedure when performing slow reproduction by the data conversion unit of the server device to which the present invention is applied;
FIG. 15 is a diagram for explaining processing when a jump is performed by a data conversion unit of a server device to which the present invention is applied;
FIG. 16 is a flowchart for explaining a processing procedure when a jump is performed by the data conversion unit of the server device to which the present invention is applied;
FIG. 17 is a diagram for explaining processing when frame-by-frame playback is performed by the data conversion unit of the server apparatus to which the present invention is applied.
FIG. 18 is a flowchart for explaining a processing procedure when frame-by-frame playback is performed by the data conversion unit of the server apparatus to which the present invention is applied.
FIG. 19 is a block diagram showing a conventional data distribution system.
FIG. 20 is a diagram for describing a locus of bit occupancy of a vbv buffer.
FIG. 21 is a diagram for describing a decoder model for decoding TS in ISO / IEC13818-1.
FIG. 22 is a block diagram showing a data distribution system.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Server apparatus, 2 Data storage part, 3 Special reproduction | regeneration control part, 4 Data conversion part, 5 Multiplexing part, 6 Transmission part, 10 Decoding terminal, 11 Reception part, 12 Decoding part, 20 Transmission medium, 21 Reading part, 22 vbv delay detection unit, 23 stuffing insertion unit, 24 switching output unit

Claims (39)

A receiving means for receiving a special reproduction request from the outside;
Data storage means for storing transmission data to be transmitted to the playback device and insertion data to be transmitted to the playback device together with the transmission data;
Reading means for reading transmission data and insertion data from the data storage means based on the received special reproduction request;
A bit occupancy detection means for detecting a bit occupancy with respect to a virtual buffer for code generation amount control of the read transmission data and insertion data;
Insertion data adjustment means for adjusting the data size of the insertion data by adding additional data to the insertion data read by the reading means based on the bit occupation amount detected by the bit occupation amount detection means;
The type of special reproduction included in the special reproduction request received by the receiving means for the transmission data whose bit occupation amount is detected by the bit occupation amount detecting means and the insertion data whose data size has been adjusted by the insertion data adjusting means Switching output means for switching output based on
A data distribution apparatus comprising: transmission means for transmitting transmission data and insertion data output from the switching output means to the reproduction apparatus. The receiving means receives a special reproduction request that specifies pause as the type of special reproduction,
The reading means reads the insertion data from the data storage means as data being paused,
2. The data distribution apparatus according to claim 1, wherein the switching output means outputs the insertion data read from the reading means to the transmission means as temporary stop data. The receiving means receives a special reproduction request that designates fast-forward reproduction as the type of special reproduction,
The reading means reads the transmission data and the insertion data from the data storage means as data during fast-forward playback,
2. The data distribution apparatus according to claim 1, wherein the switching output means outputs data obtained by inserting the insertion data read by the reading means between transmission data to the transmission means as fast-forward reproduction data. 4. The data distribution apparatus according to claim 3, wherein the reading unit selects an intra-frame encoded image or an inter-frame forward prediction encoded image as transmission data constituting the fast-forward reproduction data. The receiving means receives a special reproduction request specifying rewind reproduction as a type of special reproduction,
The reading means reads the transmission data and insertion data as data during rewind reproduction from the data storage means, arranges the read transmission data in the reverse order in the time direction,
2. The data distribution apparatus according to claim 1, wherein the switching output means outputs data obtained by inserting the insertion data read by the reading means between transmission data to the transmission means as rewind reproduction data. . 6. The data distribution apparatus according to claim 5, wherein the reading means selects an intra-frame encoded image as transmission data constituting the rewind reproduction data. The receiving means receives a special reproduction request that specifies slow reproduction as a type of special reproduction,
The reading means reads the transmission data and insertion data from the data storage means as data during slow reproduction,
2. The data distribution apparatus according to claim 1, wherein the switching output means outputs data obtained by inserting the insertion data read by the reading means between transmission data to the transmission means as slow reproduction data. 8. The data distribution according to claim 7, wherein the reading means performs processing for adjusting and reading out the number of frames of the inserted data in accordance with a slow playback speed designated by the special playback request received by the receiving means. apparatus. The receiving means receives a special reproduction request specifying jump reproduction as a type of special reproduction,
The reading means reads the transmission data of the jump source, the transmission data of the jump destination and the insertion data from the data storage means,
The switching output means outputs insertion data read by the reading means between jump source transmission data and jump destination transmission data to the transmission means as jump reproduction data. The data distribution apparatus according to claim 1. The receiving means receives a special reproduction request that designates frame-by-frame reproduction as the type of special reproduction,
The reading means reads the transmission data and insertion data from the data storage means as data during frame-by-frame playback,
2. The data according to claim 1, wherein the switching output means outputs data obtained by replacing a part of the transmission data read by the reading means with insertion data to the transmission means as frame feed reproduction data. Distribution device. 11. The data distribution apparatus according to claim 10, wherein the reading unit selects an intra-frame encoded image or an inter-frame forward prediction encoded image as transmission data constituting the frame advance / playback data. When the transmission data to be replaced by the switching unit is an intra-frame encoded image or an inter-frame forward prediction encoded image, the reading unit reads the inter-frame forward prediction encoded image as insertion data and replaces the transmission data with the switching unit. 11. The data distribution apparatus according to claim 10, wherein when the data is a bi-directional predictive encoded image, the bi-directional predictive encoded image is read as insertion data. The reading means adjusts the time length for each frame selected from the transmission data according to the time interval for each frame in the frame advance reproduction specified by the special reproduction request received by the reception means, and serves as frame advance reproduction data. The data distribution device according to claim 10, wherein the data distribution device is read out. The reading means adjusts the time length for each frame to be selected from the transmission data in accordance with the frame-by-frame playback speed specified by the special playback request received by the receiving means and reads out the frame-by-frame playback data and selects it. The data distribution apparatus according to claim 10, wherein insertion data for replacing between frames is read out. The insertion data adjustment means includes the bit occupation amount detected by the bit occupation amount detection means of the insertion data read by the reading means, and the bit occupation detected by the bit occupation amount detection means of the transmission data read by the readout means. 15. The data distribution apparatus according to claim 14, wherein the additional data is added to the insertion data based on the amount. 2. The data distribution apparatus according to claim 1, wherein the reading means adjusts the reproduction speed by adjusting an interval between frames to be selected from transmission data. The reading means inserts insertion data based on the bit occupancy amount of return destination data when canceling special reproduction in response to the special reproduction request for canceling special reproduction received by the receiving means. The data distribution apparatus according to claim 1. When returning from the special reproduction to the normal reproduction, the reading means reads the insertion data from the data storage means so as to replace the continuous frames from the top of the display order of the reproduction apparatus of the transmission data when returning to the normal reproduction with the insertion data. The data distribution apparatus according to claim 1, wherein the data distribution apparatus reads the data. 19. The data distribution apparatus according to claim 18, wherein the insertion data adjustment unit makes the insertion data read by the reading unit equal to a data size of transmission data before replacement. Receive a special playback request from the outside,
Based on the received special reproduction request, the transmission data to be transmitted to the reproduction device and the insertion data to be transmitted to the reproduction device together with the transmission data are read from the data storage means,
Detect the bit occupancy for the virtual buffer for code generation amount control of the read transmission data and the insertion data,
Based on the detected bit occupancy, add additional data to the read insertion data to adjust the data size of the insertion data,
The transmission data in which the bit occupation amount is detected and the insertion data in which the data size is adjusted are switched and output based on the type of special reproduction included in the received special reproduction request,
A data distribution method, wherein the output transmission data and the insertion data are transmitted to the playback device. The above special playback request specifying pause as the type of special playback is received,
The insertion data is read from the data storage means as temporarily stopped data,
21. The data distribution method according to claim 20, wherein the read insertion data is transmitted as temporary stop data. Receives the above special playback request that specifies fast forward playback as the type of special playback,
Read out the transmission data and the insertion data from the data storage means as data during fast-forward playback,
21. The data distribution method according to claim 20, wherein data obtained by inserting the read insertion data between the transmission data is transmitted as fast-forward reproduction data. The data distribution method according to claim 22, wherein an intra-frame encoded image or an inter-frame forward prediction encoded image is selected as transmission data constituting the fast-forward reproduction data. The above special playback request specifying the rewind playback as the special playback type is received,
Read the transmission data and insertion data as data during rewind playback from the data storage means, arrange the read transmission data in the reverse order in the time direction,
21. The data distribution method according to claim 20, wherein the inserted insertion data that has been read is transmitted as data for rewind reproduction. 25. The data distribution method according to claim 24, wherein an intra-frame encoded image is selected as transmission data constituting the rewind playback data. The above special playback request specifying slow playback as the type of special playback is received,
Read the transmission data and insertion data from the data storage means as data during slow playback,
21. The data distribution method according to claim 20, wherein data obtained by inserting the read insertion data between transmission data is transmitted as slow reproduction data. 27. The data distribution method according to claim 26, wherein a process of adjusting the number of frames of the inserted data and reading from the data storage means is performed according to a slow reproduction speed designated by the received special reproduction request. The above special playback request specifying jump playback as the type of special playback is received,
Read the transmission data of the jump source, the transmission data of the jump destination and the insertion data from the data storage means,
21. The data distribution method according to claim 20, wherein the data inserted between the transmission data of the jump source and the transmission data of the jump destination is transmitted as jump reproduction data. The above special playback request specifying frame-by-frame playback as the type of special playback is received,
Read out the transmission data and insertion data from the data storage means as data during frame-by-frame playback,
21. The data distribution method according to claim 20, wherein data obtained by replacing a part of the read transmission data with the insertion data is transmitted as frame advance reproduction data. 30. The data distribution method according to claim 29, wherein an intra-frame encoded image or an inter-frame forward prediction encoded image is selected and read from the data storage means as the transmission data constituting the frame advance / playback data. . When the replacement transmission data is an intra-frame encoded image or an inter-frame forward prediction encoded image, the inter-frame forward prediction encoded image is read as the insertion data, and the replacement transmission data is a bidirectional prediction encoded image. 30. The data distribution method according to claim 29, wherein a bidirectional predictive encoded image is sometimes read as the insertion data. The time length for each frame selected from the transmission data is adjusted according to the time interval for each frame in the frame advance reproduction specified by the received special reproduction request, and is read as the frame advance reproduction data. 30. A data distribution method according to claim 29. In accordance with the frame-by-frame playback speed specified in the received special playback request, the time length for each frame selected from the transmission data is adjusted and read out as the frame-by-frame playback data, and the selected frames are replaced. 30. The data distribution method according to claim 29, wherein the insertion data is read out. 34. The data distribution method according to claim 33, wherein additional data is added to the insertion data based on the read bit occupation amount of the insertion data and the read bit occupation amount of the transmission data. 21. The data distribution method according to claim 20, wherein a playback speed is adjusted by adjusting an interval between frames selected from the transmission data. 21. The data distribution according to claim 20, wherein the insertion data is inserted based on the bit occupation amount of the return destination data when canceling the special playback in response to the received special playback request for canceling the special playback. Method. When returning from the special playback to the normal playback, the insertion data is read from the data storage means so that the continuous frames from the top of the display order of the playback device of the transmission data when returning to the normal playback are replaced with the insertion data. The data distribution method according to claim 20. 38. The data distribution method according to claim 37, wherein the read insertion data is made equal to a data size of transmission data before replacement. In a data distribution system in which a data distribution device that distributes data and a receiving terminal that receives data from the data distribution device are connected via a transmission medium,
The data distribution apparatus includes: a receiving unit that receives a special reproduction request from a user; a transmission unit that transmits transmission data to the receiving terminal; and a data storage unit that stores insertion data to be transmitted to the receiving terminal together with the transmission data; Read means for reading transmission data and insertion data from the data storage means based on the special reproduction request received by the reception means, and a virtual buffer for controlling the amount of generated code of the transmission data and insertion data read by the read means Bit occupancy detection means for detecting the bit occupancy with respect to the data, and based on the bit occupancy detected by the bit occupancy detection means, additional data is added to the insertion data read by the reading means to insert data The bit occupancy amount by the insertion data adjustment means for adjusting the data size of the data and the bit occupancy amount detection means Switching output means for switching and outputting detected transmission data and insertion data whose data size has been adjusted by the insertion data adjustment means based on the type of special reproduction included in the special reproduction request received by the reception means; and Transmission means for transmitting transmission data and insertion data output from the switching output means to the receiving terminal, and
The receiving terminal includes receiving means for receiving transmission data and insertion data from the transmitting means based on the special reproduction request as special reproduction data, and decoding means for decoding the special reproduction data received by the receiving means. A data distribution system comprising:

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