JP6464647B2 - Moving image processing method, moving image transmission apparatus, moving image processing system, and moving image processing program - Google Patents

Description

  Embodiments referred to in this specification relate to a moving image processing method, a moving image processing system, and a moving image processing program.

  In recent years, for example, WiFi tuners that transmit (transmit) television broadcasts such as digital terrestrial broadcasts to terminal devices such as smartphones and tablets via wireless LAN (Local Area Network) such as WiFi (Wireless Fidelity) have been put into practical use. Yes.

  Further, such a WiFi tuner is integrated with a wireless router and is also commercialized as a mobile WiFi router. Further, the television broadcast to be transmitted is not limited to the terrestrial digital broadcast, but may be a BS (broadcasting satellite) broadcast, a CS (Communication Satellite) broadcast, a local broadcast, or the like.

  In this specification, a WiFi tuner is described as an example of a moving image processing apparatus. However, the present invention is not limited to transmitting data using WiFi, and may use other various wireless systems. In addition, data may be transmitted by wire.

  By the way, terrestrial digital broadcasting is broadcast as digital data by, for example, MPEG-2 (Moving Picture Experts Group phase 2). When this is viewed on a general television receiver (for example, a dedicated television), the broadcast wave is received by the tuner, the MPEG-2 digital data is taken out, and the video ( Play video and audio (audio).

  Specifically, for example, in the case of television broadcasting in Japan, a band for transmission is secured such as 16 Mbps for terrestrial digital broadcasting and 25 Mbps for BS digital broadcasting.

  On the other hand, techniques for securing bandwidth in Internet-based networks (lines), including wireless LANs, have also been proposed, but normal data transmission uses Best Effort type lines, The transmission band (transmission capability) is not guaranteed.

  Therefore, if the average transmission capability of the network is sufficiently higher than, for example, 16 Mbps for terrestrial digital broadcasting or 25 Mbps for BS digital broadcasting, transmission is possible even with a wireless LAN or the like. It becomes difficult.

  Therefore, for example, a product such as a WiFi tuner receives, for example, a broadcast wave by a tuner and takes out digital data of MPEG-2, and then again H.264. It is re-encoded (transcoded) by a method with a higher compression ratio such as H.264, and then the television broadcast is transmitted.

  That is, products such as WiFi tuners transmit data that is sufficiently compressed to a network such as WiFi (wireless LAN), and are decoded by a terminal device such as a tablet at the transmission destination to reproduce video and audio.

  MPEG-2 digital data is converted to H.264. Transcoding to H.264 is merely an example. H.264 high-quality data is the same as H.264. Even in the H.264 standard, deterioration in image quality is allowed and transcoding may be performed at a higher compression rate.

  By the way, conventionally, various types of moving image processing methods, moving image processing systems, and moving image processing programs have been proposed.

International Publication No. 09/017084 JP 2010-062629 A JP 2008-227719 A JP 2012-222511 A

  As described above, for example, the WiFi tuner transmits digital terrestrial broadcasting or the like to the terminal device using a line whose transmission band is not guaranteed, and thus stably transmits data even when the transmission band changes. Therefore, a large-capacity buffer is provided on the transmission and reception sides.

  By the way, when a user views digital terrestrial broadcasting or the like with a terminal device via the above-described WiFi tuner and wireless LAN, a delay in display start is a serious problem. This delay in display start is caused not only by the time required for switching the channel of digital broadcasting, but also by a large-capacity buffer on the transmission and reception sides. As a result, for example, each time a user performs a channel switching operation, the user is expected to wait for a long time.

According to an embodiment, there is provided a moving image processing method in which a transmitting device transmits first image data generated based on moving image data to a terminal device via a best effort type line. The transmission device generates dummy data after transmitting the first image data to the terminal device, and transmits the dummy data to the terminal device. The dummy data corresponds to at least the capacity of the reception buffer in the terminal device , and the dummy data is not display target data in the terminal device.

  The disclosed moving image processing method, moving image processing system, and moving image processing program have an effect of reducing the waiting time until the first image is displayed.

FIG. 1 is a diagram schematically illustrating an example of a moving image processing system to which a moving image processing apparatus is applied. FIG. 2 is a diagram for explaining an example of the moving image processing system shown in FIG. 1 and its operation. FIG. 3 is a diagram for explaining the transition of the transmission capability of the network and the data amount in the moving image processing system shown in FIG. FIG. 4 is a diagram illustrating an example of a transcoder and a stream in an example of a related-art moving image processing apparatus. FIG. 5 is a block diagram showing an example of a multiplexer unit in the transcoder shown in FIG. FIG. 6 is a diagram (No. 1) for explaining the operation at the time of channel switching when the transcoder shown in FIGS. 4 and 5 is applied. FIG. 7 is a diagram (No. 2) for explaining the operation at the time of channel switching when the transcoder shown in FIGS. 4 and 5 is applied. FIG. 8 is a diagram for explaining the transition of the data amount at the time of channel switching shown in FIG. 6 and FIG. FIG. 9 is a flowchart for explaining an example of overall control processing by the overall controller of the transcoder shown in FIGS. 4 and 5. FIG. 10 is a flowchart for explaining an example of video decoding processing by the decoder unit of the transcoder shown in FIGS. 4 and 5. FIG. 11 is a flowchart for explaining an example of audio decoding processing by the decoder unit of the transcoder shown in FIGS. 4 and 5. FIG. 12 is a flowchart for explaining an example of video transcoding processing by the encoder unit of the transcoder shown in FIGS. 4 and 5. FIG. 13 is a flowchart for explaining an example of audio transcoding processing by the encoder unit of the transcoder shown in FIGS. 4 and 5. FIG. 14 is a flowchart for explaining an example of multiplexing processing by the multiplexer unit in the transcoder shown in FIGS. 4 and 5. FIG. 15 is a diagram illustrating an example of a transcoder and a stream in the moving image processing system (moving image processing apparatus) according to the present embodiment. FIG. 16 is a block diagram showing an example of a multiplexer unit in the transcoder shown in FIG. FIG. 17 is a diagram for explaining the operation at the time of channel switching when the transcoder shown in FIGS. 15 and 16 is applied. FIG. 18 is a diagram for explaining the transition of the data amount at the time of channel switching shown in FIG. FIG. 19 is a flowchart for explaining an example of video decoding processing by the decoder unit of the transcoder shown in FIGS. 15 and 16. FIG. 20 is a flowchart for explaining an example of video transcoding processing by the encoder unit of the transcoder shown in FIGS. 15 and 16. FIG. 21 is a flowchart for explaining an example of multiplexing processing by the multiplexer unit in the transcoder shown in FIGS. 15 and 16.

  First, before detailed description of the moving image processing method, moving image processing system, and moving image processing program of the present embodiment, referring to FIGS. 1 to 14, the moving image processing system to which the moving image processing apparatus is applied. An example and an operation thereof, an example of a moving image processing method, a moving image processing system and a moving image processing program, and problems thereof will be described.

  FIG. 1 is a diagram schematically illustrating an example of a moving image processing system to which a moving image processing apparatus is applied. As shown in FIG. 1, the moving image processing system includes a WiFi tuner 1 (transmission device), a wireless LAN (WiFi) 2, a terminal device such as a tablet 3, a router 4, and an antenna 5.

  As described above, the WiFi tuner 1 receives, for example, the BS broadcast, the terrestrial digital broadcast, and the like via the antenna 5 and transmits them to the terminal device 3 such as a smartphone or a tablet. In other words, the WiFi tuner 1 is, for example, H.264 having a higher compression rate for broadcasting digitalized by MPEG-2. The digital data such as H.264 is transcoded and transmitted to the terminal device 3 via the wireless LAN 2 such as WiFi.

  The WiFi tuner 1 is connected to the Internet 6 via the router 4. For example, the WiFi tuner 1 downloads video data from a video site such as YouTube (registered trademark) or Niconico video (registered trademark), and the terminal device 3. Can be sent to.

  By the way, a wireless LAN (wireless line) 2 such as WiFi is usually a best-effort line (network), the transmission band is not guaranteed, and the transmission capability (transmission band) is large depending on the state of the line. Change.

  FIG. 2 is a diagram for explaining an example of the moving image processing system shown in FIG. 1 and its operation, and FIG. 2 (a) shows the overall configuration of the moving image processing system. FIG. 2 (b) is for explaining the operation of the moving image processing system shown in FIG. 2 (a) in a state where transmission (transmission) is stable. FIG. 2 (c) This is for explaining the operation when the transmission capability of the network is temporarily lowered.

  As shown in FIG. 2A, in the moving image processing system, the WiFi tuner 1 includes a tuner 11, a transcoder 12, a transmission buffer 13, and a LAN (transmission) 14. The terminal device 3 includes a LAN (reception) 31, a reception buffer 32, a decoder 33 and a display (display device) 34.

  The tuner 11 receives, for example, a BS broadcast or a terrestrial digital broadcast via the antenna 5, for example, reproduces a broadcast converted into digital data by MPEG-2 and outputs it to the transcoder 12.

  The transcoder 12 converts the MPEG-2 digital data from the tuner 11 into, for example, an H.264 having a higher compression rate. It is transcoded to digital data such as H.264 and outputted to the transmission buffer 13.

  When the transmission capability of the wireless LAN (network) 2 is temporarily lowered and the data input from the transcoder 12 cannot be transmitted at a constant bit rate, the transmission buffer 13 receives data until the transmission capability of the network 2 is restored. It is for temporarily storing.

  The LAN (transmission) 14 is for transmitting data from the transmission buffer 13 to the LAN (reception) 31 of the terminal device 3 via the network 2. For example, the LAN (transmission) 14 is also transmitted from the Internet (6) via the router 4. Video data can be downloaded and transmitted. The LAN (reception) 31 shows a state in which data is received using the reception function of a wireless LAN device such as WiFi that can be transmitted and received.

  The reception buffer 32 can store data for a certain period of time, and even if the transmission capability of the network 2 is temporarily reduced and data is not transmitted, the reproduction of video and audio is continued for a certain period of time. It is for doing so. If the transmission capability of the network 2 is restored and data is transmitted during the predetermined time, the video and audio are continuously reproduced without interruption.

  The decoder 33 receives data (for example, digital data such as H.264) from the reception buffer 32, decodes video and audio, displays the video on the display 34, and outputs audio from a speaker (not shown). .

  Here, for example, when the video data is downloaded and viewed from a video site such as YouTube (registered trademark) on a personal computer (PC), the reception buffer 32 is initially set to a certain buffer so that the video data can be smoothly played back. It is similar to performing a ring.

  However, even if the network does not have sufficient transmission capacity and the next data cannot be filled in time for the buffered data to be played back, if it is a video site or the like, the buffer is refilled and played back. The That is, even when the buffer data is depleted and playback stops, playback is continued from the stopped image.

  This is because, in the service provided by the video site, if the content is stored in advance on the server side and the data transmission to the PC side is stagnant, the data transmission from the server is simply stopped and the network is restored. This is because it is only necessary to resume data transmission from the next.

  On the other hand, in applications such as the WiFi tuner 1, even if data transmission is delayed, TV broadcast data from the tuner 11 continues to flow and data by the transcoder 12 continues to be generated. For this reason, for example, as in the service of a moving image site such as YouTube (registered trademark), a simple response such as simply stopping data transmission causes a problem.

  If the transcoding process by the transcoder 12 is temporarily stopped to cope with it, even if the data transmission is recovered and the transcoding process is resumed, an actual time interruption between them will occur. Therefore, in order to avoid the occurrence of such interruption as much as possible, the transmission side (WiFi tuner 1) is also provided with a buffer (transmission buffer 13) for a certain period of time.

  First, as shown in FIG. 2B, in a state where transmission is stable (normal operation state), for example, MPEG-2 digital data from the tuner 11 is further compressed by the transcoder 12. High H.H. It is transcoded to H.264 digital data.

  Further, digital data (H.264) from the transcoder 12 is output to the network 2 via the transmission buffer 13 and the LAN (transmission) 14. Here, in a normal operation state, the transmission buffer 13 operates in an empty (empty) manner.

  Further, digital data (H.264) from the network 2 is input to the decoder 33 via the LAN (reception) 31 and the reception buffer 32, and the decoded video and audio are output from the display 34 or the like. Here, in a normal operation state, the reception buffer 32 operates in a full (full) manner.

  That is, in FIG. 2B, the width of the hatched portion of the arrow indicates the data transmission capability, and the hatched area in the transmission buffer 13 and the reception buffer 32 indicates the amount of buffered (stored) data. . The size of the whole (box) of the transmission buffer 13 and the reception buffer 32 indicates the maximum buffer amount that can store data.

  On the other hand, as shown in FIG. 2C, the amount of data in the network 2 and the amount of data from the LAN 31 to the reception buffer 32 are small (the hatched portion is narrow). At this time, the data stored in the transmission buffer 13 increases, and conversely, the data stored in the reception buffer 32 decreases.

  FIG. 3 is a diagram for explaining the transition of the transmission capacity and data amount of the network 2 in the moving image processing system shown in FIG. 2, where time is taken on the horizontal axis and data amount is taken on the vertical axis. It shows an example of transition of the input / output data amount and the data amount in the buffer.

  FIG. 3 shows a state in which the transmission capability of the network is temporarily lowered in the period P12 from the period P11 in a state where the network (wireless LAN, line) 2 can stably transmit data (steady state), and then in the period P12. A state is shown in which the state returns to the original stable state (transient state) in the period P13.

  That is, when the transmission capacity of the network 2 is temporarily lowered from the period P11 to the period P12, the amount of data (LAN (transmission) that can be transmitted to the network is larger than the amount of data output from the transcoder 12 per unit time. ) 14 transmission data amount) is reduced.

  At this time, data that cannot be transmitted is temporarily accumulated in the transmission buffer 13 on the transmission side (WiFi tuner 1 side), so that the data amount in the transmission buffer 13 gradually increases in the period P12. .

  On the other hand, on the receiving side (terminal device 3 side), the amount of data received from the network 2 (the amount of data received on the LAN (reception) 31) decreases, so that the amount of data stored in the reception buffer 32 during the period P12 is Decrease gradually.

  Here, while the amount of input data received by the decoder 33 per unit time is maintained by the reception buffer 32, the decoder 33 can reproduce a moving image without interruption.

  The example of FIG. 3 shows a case where the transmission capacity of the network 2 returns to the steady state before the data amount in the transmission buffer 13 overflows or the data amount in the reception buffer 32 is exhausted.

  Therefore, when the period P12 is changed to the period P13, the transmission capacity of the network 2 temporarily decreases and data that cannot be transferred is transmitted over the network 2 more than usual, and the data amount in the transmission buffer 13 gradually decreases (reception buffer The amount of data in 32 gradually increases).

  Here, since the network 2 is a best-effort line, the transmission data amount of the LAN (transmission) 14 and the reception data amount of the LAN (reception) 31 in the period P13 are larger than the data amount in the period P11. Perform data transmission.

  When the data amounts of the transmission buffer 13 and the reception buffer 32 return to the original state, the data amounts of the LAN (transmission) 14 and the LAN (reception) 31 also return to the steady state of the period P11.

  If the transmission capacity of the network 2 continues to decrease for a long time and the data in the reception buffer 32 is exhausted, input data to be decoded is not given to the decoder 33, and reproduction (moving image) is interrupted. Also, when the transmission buffer 13 becomes full (constant capacity), the operation of the transcoder 12 is temporarily stopped or data is discarded, and the moving image is also interrupted during reproduction.

  In order to avoid such interruption of moving images, it is preferable to set the capacities of the reception buffer 32 and the transmission buffer 13 large. Although the network traffic varies depending on the operation status, the reception buffer 32 and the transmission buffer 13 usually have a capacity capable of holding moving image data of, for example, about several seconds to several tens of seconds.

  Furthermore, for example, when the average transmission capacity declines over a long period of time, it is difficult to cope with any buffer capacity. For this reason, the bit rate of the transcoder 12 can be reduced according to the transmission capacity. Will do.

  However, because the buffering is performed in various processes in the transcoder 12, the actual data is reduced in response to the generated bit rate change instruction because, for example, it takes several seconds, the transmission buffer 13 Furthermore, it has a capacity of about several seconds or more.

  By the way, in recent years, it has been regarded as a problem that the channel switching takes time from analog TV (television broadcasting) to digital TV. Further, when the terminal device 3 reproduces the broadcast from the WiFi tuner 1 via the network 2, the terminal device 3 further waits until data accumulates in the reception buffer 32 described above.

  That is, when the channel is switched from the first channel to the second channel by the terminal device 3, for example, a new second channel image is not displayed until the data amount in the reception buffer 32 reaches a certain amount, You will have to wait.

  Specifically, when a digital TV is viewed via the WiFi tuner 1 and the network 2, when the channel is switched by the terminal device 3, for example, in addition to the time required for switching a normal digital TV, in addition, about several seconds to several tens of seconds Will be waited for.

  In the time waited at the time of channel switching, for example, a black screen is displayed on the display 34 of the terminal device 3, or the last screen before the channel switching remains.

  Alternatively, a screen for feedback to the user that a channel switching instruction has been accepted may be displayed by displaying a display during channel switching or separately acquired program information of the switching destination together with an hourglass animation or the like. Conceivable. However, also in this case, it takes about several seconds to several tens of seconds until the screen is displayed after the channel is switched.

  FIG. 4 is a diagram illustrating an example of a transcoder and a stream in an example of a related-art moving image processing apparatus. 4A shows details of an example of the transcoder 12 together with the tuner 11 and the transmission buffer 13, and FIG. 4B shows a stream output from the transcoder 12 (transport stream: TS (Transport Stream). )) An example is shown.

  As shown in FIG. 4A, the transcoder 12 includes an overall control unit (arithmetic processing unit) 121, a demultiplexer unit (DEMUX) 122, a decoder unit 123, a memory 124, an encoder unit 125, and a multiplexer unit (MUX). 126.

  The demultiplexer unit 122 includes a PSI (Program Specific Information) analysis unit 20, the decoder unit 123 includes a video processing unit 31 ′ and an audio processing unit 32 ′, and the encoder unit 125 includes the video processing unit 51 and the audio processing unit 32 ′. A processing unit 52 is included.

  The overall control unit 121 controls the demultiplexer unit 122 and the decoder unit 123, for example, extracts image data and audio data from MPEG-2 digital data from the tuner 11 and stores them in the memory 124.

  In addition, the overall control unit 121 controls the encoder unit 125 and the multiplexer unit 126 to convert the image data and audio data read from the memory 124 into H.264 having a higher compression rate than MPEG-2, for example. The data is converted to H.264 digital data and output to the transmission buffer 13.

  That is, the transcoder 12 compresses MPEG-2 digital data from the tuner 11 with a higher compression rate that can be transmitted through the network 2 such as WiFi. It is converted into digital data such as H.264 and output to the network 2.

  As shown in FIG. 4B, the stream from the transcoder 12 includes, for example, a PAT (Program Association Table), a PMT (Program Map Table), a PCR (Program Clock Reference), a PAT, a PMT, a PCR, an I- It is arranged as pic (Intra-coded Picture), ...

  Furthermore, the stream is arranged in, for example,..., PCR, B-pic (Bidirectionally predictive-coded picture), B-pic, P-pic (Predictive-coded picture), B-pic, B-pic,.

  For example, when the terminal device 3 receives the data shown in FIG. 4B, the leading I-picture (I-pic) is passed to the decoder 33 of the terminal device 3, for example, the reception buffer 32 of the terminal device 3. After the data corresponding to the size (constant capacity) is transmitted.

  Therefore, when the channel is switched by the terminal device 3, the image (I-picture) of the new channel is not input to the decoder 33 until the data amount of the reception buffer 32 reaches a certain amount, and the image of the new channel is not displayed. You will have to wait for a long time to display.

  Here, for example, when the channel is switched from the first channel to the second channel, after the first I-picture is stored in the reception buffer 32, for example, the data of the second channel processed by the transcoder 12 Are input at a predetermined transfer rate.

  That is, even when data is transmitted from the WiFi tuner 1 to the terminal device 3 via the best effort type network (line) 2, for example, the transcoder 12 that converts MPEG-2 into H, 264 is used. A data amount of data based on the output is transmitted.

  FIG. 5 is a block diagram illustrating an example of a multiplexer unit in the transcoder illustrated in FIG. 4, and illustrates the multiplexer unit 126 together with the encoder unit 125. As shown in FIG. 5, the multiplexer unit 126 includes FIFO (First-In First-Out) buffers 61 and 62, an STC (System Time Clock) counter 63, a video TS (Transport Stream) packet generator 64, and an audio TS. A packet generator 65 is included.

  Further, the multiplexer unit 126 includes a PAT generation unit 66, a PMT generation unit 67, a PCR generation unit 68, a null (NULL) packet generation unit 69, a multiplexing target determination unit 70, and a multiplexing target selection unit 71.

  The video TS packet generation unit 64 includes a video TS multiplexing time counter 640, and performs packet division, TS header addition, and multiplexing time calculation in video data. The audio TS packet generation unit 65 includes an audio TS multiplexing time counter 650, and performs packet division, TS header addition, and multiplexing time calculation in audio data.

  The PAT generation unit 66 includes a PAT multiplexing time counter 660, and the PMT generation unit 67 includes a PMT multiplexing time counter 670. The PCR generation unit 68 includes a PCR multiplexing time counter 680, and the NULL packet generation unit 69 includes a null packet multiplexing time counter 690.

  The STC counter 63 is a counter that receives the multiplexed master clock CLKmm, and counts up with, for example, a 27 MHz multiplexed master clock CLKmm after setting an initial value. The output signal of the STC counter 63 is input to the multiplexing time counters 640, 650,..., 690 of each generation unit, and the system time is given.

  The video TS packet generation unit 64 receives video PES (Packetized Elementary Stream) data (VD-PES) from the video processing unit 51 of the encoder 125 input via the FIFO buffer 61.

  The video TS multiplexing time counter 640 uses the multiplexing start time information in units of video PES sent from the video processing unit 51 as an initial value, and multiplexes each TS packet when the video PES is decomposed into TS packets. Manage the start time. As a result, the video TS (VD-TS) generated by the video TS packet generator 64 becomes a value corresponding to the video bit rate on the basis of the count-up amount of 27 MHz.

  Specifically, if the video bit rate is 20 Mbps, the data amount of the payload of the TS packet is 184 bytes, so the number of TS packets per second is 20 M [bps] / (184 [byte] × 8 [bit]) ≈ It becomes 13586.9 [pieces].

  That is, the period of each TS packet when viewed in units of 27 MHz is 27M [Hz] ÷ 13586.9≈1987.2 [cycle], which is the count-up amount. Actually, since it is difficult to handle the decimal point or less, for example, it is managed and counted up in the form of a numerator and a denominator.

  The audio TS packet generator 65 receives audio PES data (AD-PES) from the audio processor 52 of the encoder 125 input via the FIFO buffer 62.

  The audio TS multiplexing time counter 650 uses the audio PES unit multiplexing start time information sent from the audio processing unit 52 as an initial value, and multiplexes for each TS packet when the audio PES is disassembled into TS packets. Manage the start time. As a result, the audio TS (AD-TS) generated by the audio TS packet generator 65 becomes a value corresponding to the audio bit rate on the basis of the count-up amount of 27 MHz.

  Note that the PAT multiplexing time counter 660, the PMT multiplexing time counter 670, and the PCR multiplexing time counter 680 are values according to the insertion period of each TS packet (100 msec or less in the standard) after setting the initial values. Is the count-up amount. Specifically, if the period is 99 msec, the count is incremented by 99 m [sec] / (1/27 M [Hz]) ≈2673000 [cycle].

  In addition, the null packet multiplexing time counter 690 sets a value corresponding to the TS system rate after the initial value is set. Specifically, if the TS system rate is 25 Mbps, the data amount of the TS packet is 188 bytes, so 27 M [Hz] ÷ (25 M [bps] ÷ (188 [byte] × 8 [bit])) ≈1624.32. cycle].

  Then, the video TS packet generator 64, the audio TS packet generator 65, the PAT generator 66, the PMT generator 67, the PCR generator 68 and the NULL packet generator 69 generate respective TS packets and select the multiplexing target. To the unit 71.

  At this time, each of the generating units 64 to 69 calculates the multiplexing start time of the corresponding TS packet by using the respective multiplexing time counters 640 to 690. The calculated multiplexing start time is compared with the system time output from the STC counter 63, and when the system time becomes equal to or greater than the multiplexing start time, the multiplexing request signal is validated (Valid).

  The multiplexing target determining unit 70 checks the request signals from the other generating units (packet generating units) 64 to 68 every time the request signal (multiplexing request signal) from the NULL packet generating unit 69 becomes valid.

  Here, in addition to the valid request signal from the NULL packet generation unit 69, if the request signals from the plurality of generation units 64 to 68 are valid, one of the generation units is selected according to the priority order. Then, the multiplexing target selection signal SSmo is designated to select the generation unit.

  As an example of the priority order, the PCR generation unit 68 has the highest priority. Hereinafter, the PSI information of the PMT generation unit 67, the PAT generation unit 68, etc., the video TS packet generation unit 64, and the audio TS packet generation unit 65 It can be considered in order.

  On the other hand, if only the request signal from the NULL packet generation unit 69 is valid and all the request signals from the other generation units 64 to 68 are invalid (invalid), multiplexing is performed in the NULL packet insertion mode. A NULL packet is selected as the target selection signal SSmo. In addition, since nothing is multiplexed unless the NULL packet insertion mode is selected, packet invalidity is selected as the multiplexing target selection signal SSmo.

  If the request signals of the generation units 64 to 68 other than the NULL packet generation unit 69 are valid, the packet output of the generation unit is selected. Here, whether or not it is the NULL packet insertion mode is designated by, for example, a NULL packet insertion mode designation signal MSnp input to the NULL packet generation unit 69.

  The result selected by the multiplexing target determination unit 70 is output to the multiplexing target selection unit 71 as a multiplexing target selection signal SSmo, and a valid pulse is output as a multiplexing acknowledge signal (ACK) for the selected generation units 64-68. To do. However, a valid pulse is output as a multiplexed acknowledge signal to the NULL packet generator 69 regardless of whether or not a NULL packet is selected.

  When each of the generation units 64 to 68 receives a valid pulse of the multiplexed acknowledge signal, it makes the multiplexing request signal invalid and counts up the multiplexing time counters 640 to 680 provided in the generation unit.

  Note that the PCR generation unit 68 captures the system time value from the STC counter 63 at the time when the valid pulse of the multiplexed acknowledge signal is received in order to enter an accurate time in the PCR field of the TS packet, and the TS packet Write to the PCR field.

  6 and 7 are diagrams for explaining the operation at the time of channel switching when the transcoder shown in FIGS. 4 and 5 is applied. Here, FIG. 6A is a diagram for explaining a situation in which the user of the terminal device (WiFi tuner receiving device) 3 is viewing in a steady state.

  FIG. 6B is a diagram for explaining a situation in which the user has instructed channel switching. FIG. 6C is a diagram for explaining the situation immediately after the user has instructed channel switching. FIG.

  Further, FIGS. 7 (a), 7 (b) and 7 (c) are diagrams for explaining the situation following FIG. 6 (c) immediately after the user instructs the channel switching. (d) is a figure for demonstrating the condition where the user is watching in a steady state by the channel after switching. In FIG. 6 (a) to FIG. 7 (d), reference symbols F (n), F (n + 1), F (n + 2), F (n + 3),. m) indicates data corresponding to each encoded video frame.

  In the following description, the order of encoded data corresponding to the time order of video display is the same. However, in actual encoding, for example, reorder processing is performed, and the order of video display and the order of streams are changed. Sometimes.

  First, as shown in FIG. 6A, when the user is watching a television broadcast of a predetermined channel (first channel) via the display 34 of the terminal device 3, the transmission buffer 13 is empty. Operating, the reception buffer 32 is operating at full potential.

  That is, the display 34 displays the video (moving image) sequentially output from the reception buffer 32 and decoded by the decoder 33, and the user views the first channel television broadcast.

  Next, as illustrated in FIG. 6B, when the user switches the channel to be viewed by operating the terminal device 3 from the first channel to the second channel, the user, for example, controls the control unit 35 of the terminal device 3. Instructs channel switching via.

  In the terminal device 3, the control unit 35 controls the LAN (reception) 31, the reception buffer 32, and the display 34, and also controls the control unit of the WiFi tuner 1 through the network (line: WiFi) 2.

  That is, the control unit 35 issues a channel switching instruction to each part of the terminal device 3 and a clear instruction to the reception buffer 32, and further issues a channel switching instruction to each part of the WiFi tuner 1 and a clear instruction to the transmission buffer 13. Receiving this, each part of the WiFi tuner 1 and the terminal device 3 starts preparation for data processing after switching from the first channel to the second channel.

  Here, for example, when the channel is switched by controlling only the tuner 11 without clearing the transmission buffer 13 and the reception buffer 32, for example, in the reception buffer 32, several seconds to several tens of seconds related to the first channel. Is stored.

  Therefore, even though the user has instructed switching to the second channel, the broadcast of the first channel before switching was displayed on the display for several seconds to several tens of seconds, and the switching instruction was not accepted for the user. It will give you worries.

  Therefore, when the user gives an instruction to switch from the first channel to the second channel, the data stored in the transmission buffer 13 and the reception buffer 32 is discarded and new data is buffered. Note that, for example, the black screen or the last screen of the first channel is displayed on the display 34 until the moving image of the second channel is displayed.

  After that, when the transmission buffer 13 and the reception buffer 32 are cleared and channel switching is performed by the tuner 11, data on the new second channel is processed and stored in the transmission buffer 13 and the reception buffer 32.

  That is, as shown in FIG. 6 (c), data relating to the second channel is input from the tuner 11 to the transcoder 12, and the encoded data F (1) for the first effective video (image) of the television broadcast of the second channel. ) Is sent to the reception buffer 32 via the network 2.

  However, since the reception buffer 32 is empty at this time, even if the encoded data F (1) arrives, the data F (1) is not immediately output to the decoder 33, but a certain amount of data is stored. After (buffering), the data F (1) is output to the decoder 33.

  That is, as shown in FIGS. 7A to 7D, the reception buffer 32 has data F (2), F (3),..., F (m) following the data F (1). ,...) Are sequentially input and buffered. When valid data is accumulated in the reception buffer 32 by a certain amount (for example, several seconds to several tens of seconds: F (2), F (3),..., F (m), F (m + 1)), Data F (1) is pushed out and inputted to the decoder 33.

  Thereafter, similarly to FIG. 7D (FIG. 6A), data F (2), F (3),... Temporarily stored in the reception buffer 32 are sequentially output to the display 34. The video is decoded by the decoder 33 and the video of the second channel television broadcast is displayed on the display 34.

  As shown in FIGS. 6A and 7D, when the user is watching a television broadcast of a predetermined channel via the display 34 of the terminal device 3, the transmission buffer 13 is empty. The reception buffer 32 operates in a full manner.

  FIG. 8 is a diagram for explaining the transition of the data amount at the time of channel switching shown in FIGS. 6 and 7, where time is taken on the horizontal axis and data amount is taken on the vertical axis, and the input / output data amount of each part. 4 shows an example of the transition of the data amount in the buffer.

  That is, FIG. 8 shows, for example, the change in the amount of data when the user switches from the steady state period P21 in which the user watches the first channel TV broadcast using the terminal device 3 to another second channel in the period P22. Show.

  Here, the period P21 in FIG. 8 corresponds to FIG. 6A described above, the period P22 corresponds to FIG. 6B, and the period P23 corresponds to FIG. 6C and FIG. This corresponds to FIG. 7D, and the period P24 corresponds to FIG.

  As shown in FIG. 8, for example, when the user switches the channel to be viewed by operating the terminal device 3 from the first channel to the second channel in the period P22 (first timing of the period P22), the user It is difficult to immediately confirm the image of the second channel.

  For example, the user can view the TV broadcast of the second channel because the buffer is cleared by switching the channel, and after a period P23 in which a certain amount of data is accumulated in the reception buffer 32, the decoder 33 starts operating in the period P24. After that.

  For example, when the channel is switched, it is waited until a certain amount of data (several seconds to several tens of seconds) is accumulated in the reception buffer 32, and then the data is input to the decoder 33 to start the operation. The contents of the channel are displayed on the display 34.

  For this reason, for example, a user who views a television broadcast by the WiFi tuner 1 via the terminal device 3 becomes a digital broadcast and the response to channel switching becomes slow. You will have to wait for the time.

  As a result, the user waits for several seconds to several tens of seconds, for example, until the user can watch the broadcast of the new channel after performing the channel switching operation. In order to reduce the user's feeling of waiting, it may be possible to display information such as an hourglass icon or an EPG (Electronic program guide). It is not.

  Also, if there are no programs that you want to watch clearly and you switch between several channels, or if there are programs that you are watching, there are programs that are interested in other channels when switching to CM (Commercial Message) An act called zapping to confirm is often performed.

  At this time, if the time required for channel switching is short, channel switching can be performed one after another to perform zapping and the like lightly. However, in the reception of a television broadcast by the WiFi tuner as described above, it is necessary to wait several seconds to several tens of seconds every time the channel is switched.

  By the way, at the time of channel switching, if the intention to view the switching destination channel is clear, there is little sense of burden even if waiting for a certain period of time before playback. However, when performing zapping, etc., each time the channel is switched, the user waits for several seconds to several tens of seconds. Further, if the content after the wait is uninteresting is broadcast, there is a great sense of labor. It becomes practically difficult.

  Next, referring to FIGS. 9 to 14, each process (overall control processing, video decoding processing, audio decoding processing, video transcoding processing, audio transcoding processing and multiplexing in the transcoder shown in FIGS. 4 and 5 is performed. An example of processing will be described.

  FIG. 9 is a flowchart for explaining an example of overall control processing by the overall controller of the transcoder shown in FIGS. 4 and 5. As shown in FIG. 9, when the overall control process by the overall control unit 121 is started, the internal state of each unit is initialized in step ST10, and the process proceeds to step ST11 where the demultiplexer unit 122 starts operation (stream capture is performed). Start.

  Further, the process proceeds to step ST12, waits for the completion of the PSI analysis processing by the PSI analysis processing unit 20 of the demultiplexer unit 122, proceeds to step ST13, and determines whether or not the video PID (packet identifier) is confirmed.

  If it is determined in step ST13 that the video PID has been confirmed (YES), the process proceeds to step ST17, where the video processing by the video processing unit 31 ′ of the decoder unit 123 is started and the processing of the multiplexer unit 126 is started, and step ST14 is started. Proceed to If it is determined in step ST13 that the video PID has not been determined (NO), the process proceeds directly to step ST14 to determine whether or not the audio PID has been determined.

  If it is determined in step ST14 that the audio PID has been confirmed (YES), the process proceeds to step ST18, where the audio processing by the audio processing unit 32 ′ of the decoder unit 123 is started, and the process proceeds to step ST15. If it is determined in step ST14 that the audio PID has not been determined (NO), the process proceeds to step ST15 and waits for an action by the next user.

  Then, the process proceeds to step ST16, where it is determined whether or not the action by the user is channel switching. When it is determined that the channel is switched (YES), the process proceeds to step ST19, and each processing unit is forcibly stopped. Returning to step ST10, the same processing is performed. If it is determined in step ST16 that the user action is not channel switching (NO), the process is not described because it is not related to the present embodiment.

  FIG. 10 is a flowchart for explaining an example of video decoding processing by the decoder unit of the transcoder shown in FIGS. 4 and 5. As shown in FIG. 10, when the video decoding process by the decoder unit 123 (video processing unit 31 ′) is started, in step ST20, the video processing unit 31 ′ is initialized to initialize the internal state. move on.

  In step ST21, the capturing of the video stream from the demultiplexer unit 122 is checked, and the process proceeds to step ST22 to determine whether or not the capturing of the stream (data) for one picture is completed.

  If it is determined in step ST22 that the capture of the stream for one picture has not been completed (NO), the process returns to step ST21 to check, and the same processing is performed until it is determined that the capture of the stream for one picture has been completed. repeat.

  In step ST22, if it is determined that the fetch of the stream for one picture is completed (YES), the process proceeds to step ST23, and the stream decoding process for one picture is executed. Furthermore, it progresses to step ST24 and it is determined whether the decoded picture was an I-picture.

  If it is determined in step ST24 that the decoded picture is not an I-picture (NO), the process returns to step ST20 and the same processing is repeated. If it is determined that the decoded picture is an I-picture (YES), the process proceeds to step ST25. Set the video head discovery flag.

  Further, in step ST26, the decoded image data of the first I-picture is sent to the encoder unit 125 to start the transcoding process. Then, the process proceeds to step ST27, where the video stream capturing check is performed, and the process proceeds to step ST28. .

  In step ST28, as in step ST22 described above, it is determined whether or not the fetch of the stream for one picture has been completed. If it is determined in step ST28 that the fetching of the stream for one picture is not completed (NO), the process returns to step ST27 and the same processing is repeated, and the fetching of the stream for one picture is completed (YES). If determined, the process proceeds to step ST29.

  In step ST29, the decoding process of the stream for one picture is executed, and the process proceeds to step ST30, where it is determined whether or not the decoded picture is a closed B-picture, I-picture or P-picture. Here, the closed B-picture is a B-picture that does not refer to the front.

  If it is determined in step ST30 that the decoded picture is not a closed B-picture, I-picture, or P-picture (NO), the process proceeds to step ST31. In step ST31, the decoded image data of the leading I-picture is sent to the encoder unit 125 to perform transcoding processing, and the processing returns to step ST27 and the same processing is repeated.

  On the other hand, if it is determined in step ST30 that the decoded picture is a closed B-picture, I-picture, or P-picture (YES), the process proceeds to step ST35. In step ST35, the decoded image data is sent to the encoder unit 125 to execute transcoding processing. Then, the process proceeds to step ST32, the video stream from the demultiplexer unit 122 is checked, and the process proceeds to step ST33.

  If it is determined in step ST33 that the fetching of the stream for one picture is not completed (NO), the process returns to step ST32 and the same processing is repeated until it is determined that the fetching of the stream for one picture is completed.

  If it is determined in step ST33 that the fetching of the stream for one picture is completed (YES), the process proceeds to step ST34, and the decoding process of the stream for one picture is executed. Furthermore, it progresses to step ST35 mentioned above, the same process is repeated, and a video decoding process (video transcode process) is continued.

  FIG. 11 is a flowchart for explaining an example of audio decoding processing by the decoder unit of the transcoder shown in FIGS. 4 and 5. As shown in FIG. 11, when the audio decoding process by the decoder unit 123 (audio processing unit 32 ′) is started, in step ST40, the audio processing unit 32 ′ is initialized to initialize the internal state, and the process proceeds to step ST41. move on.

  In step ST41, the audio stream acquisition from the demultiplexer unit 122 is checked, and the process proceeds to step ST42 to determine whether or not the acquisition of the stream (data) for 1 AAU (Audio Access Unit: audio decoding unit) has been completed. To do.

  If it is determined in step ST42 that the capture of the stream for 1 AAU is not completed (NO), the process returns to step ST41 and the same process is repeated until it is determined that the capture of the stream for 1 AAU is completed. .

  In step ST42, if it is determined that the capture of the stream for one AAU is completed (YES), the process proceeds to step ST43, the video head discovery flag is checked, and the process proceeds to step ST44 to determine whether the video head has been found. judge.

  If it is determined in step ST44 that the video head has not been found (NO), the process proceeds to step ST47, the captured data for 1 AAU is discarded, and the process returns to step ST41 to determine that the video head has been found. Repeat the same process until.

  On the other hand, if it is determined in step ST44 that the beginning of the video has been found (YES), the process proceeds to step ST45, after decoding for 1 AAU, the process proceeds to step ST46, and the decoded audio data is sent to the encoder unit 125. To start transcoding.

  Further, the process proceeds to step ST48, and after checking the audio stream capturing, it is determined in step ST49 whether or not the capturing of the stream for one AAU is completed.

  If it is determined in step ST49 that the capture of the stream for 1 AAU has not been completed (NO), the process returns to step ST48 to check, and the same processing is repeated until it is determined that the capture of the stream for 1 AAU is completed. .

  Further, if it is determined in step ST49 that the capture of the stream for 1 AAU is completed (YES), the process proceeds to step ST50, the decoding process for 1 AAU is executed, and the process proceeds to step ST51.

  In step ST51, the decoded audio data is sent to the encoder unit 125 to execute the transcoding process, and the process returns to the above-described step ST48 to continue the audio decoding process (audio transcoding process).

  FIG. 12 is a flowchart for explaining an example of video transcoding processing by the encoder unit of the transcoder shown in FIGS. 4 and 5. As shown in FIG. 12, when video transcoding processing by the encoder unit 125 (video processing unit 51) starts, in step ST60, the video processing unit 51 is initialized to initialize the internal state, and the process proceeds to step ST61. .

  In step ST61, the image data is checked, and the process proceeds to step ST62 to determine whether there is image data. If it is determined in step ST62 that there is no image data (NO), the process returns to step ST61 to check, and the same processing is repeated until it is determined that there is image data.

  On the other hand, if it is determined in step ST62 that there is image data (YES), the process proceeds to step ST63, video encoding (transcoding) of the image data is executed, and the process further proceeds to step ST64.

  In step ST64, after the transcoded video stream is sent to the multiplexer unit 126, the process returns to step ST61 and the same processing is repeated to continue the video transcoding processing.

  FIG. 13 is a flowchart for explaining an example of audio transcoding processing by the encoder unit of the transcoder shown in FIGS. 4 and 5. As shown in FIG. 13, when the audio transcoding process by the encoder unit 125 (audio processing unit 52) is started, in step ST70, the audio processing unit 52 is initialized to initialize the internal state, and the process proceeds to step ST71. .

  In step ST71, the audio data is checked, and the process proceeds to step ST72 to determine whether there is audio data. If it is determined in step ST72 that there is no audio data (NO), the process returns to step ST71 to check, and the same processing is repeated until it is determined that there is audio data.

  On the other hand, if it is determined in step ST72 that there is audio data (YES), the process proceeds to step ST73, audio encoding (transcoding) of the audio data is executed, and the process further proceeds to step ST74.

  In step ST74, after the transcoded audio stream is sent to the multiplexer unit 126, the process returns to step ST71 and the same process is repeated to continue the audio transcoding process.

  FIG. 14 is a flowchart for explaining an example of multiplexing processing by the multiplexer unit in the transcoder shown in FIGS. 4 and 5. As shown in FIG. 14, when the multiplexing process by the multiplexer unit 126 is started, the video head discovery flag is checked in step ST80, and the process proceeds to step ST81 to determine whether or not the video head has been found.

  If it is determined in step ST81 that the video head has not been found (NO), the process returns to step ST80, and the same processing is repeated until it is determined that the video head has been found. If it is determined in step ST81 that the beginning of the video has been found (YES), the process proceeds to step ST82, and after checking the transcoded data, the process proceeds to step ST83 to determine whether there is data. .

  If it is determined in step ST83 that there is no data (NO), the process returns to step ST82, and the same processing is repeated until it is determined that there is data. If it is determined in step ST83 that there is data (YES), the process proceeds to step ST84 to determine whether the data is video stream data.

  If it is determined in step ST84 that the data is not video stream data (NO), the process proceeds to step ST87, the transcoded data is discarded, the process returns to step ST82, and the same processing is repeated.

  On the other hand, if it is determined in step ST84 that the data is video stream data (YES), the process proceeds to step ST85, where the PTS (Presentation Time Stamp) and DTS (Decode Time Stamp) of the leading picture are captured, and the multiplexing of the leading picture is started. Calculate the time. Further, in step ST85, the calculated multiplexing start time of the first picture is set to STC (System Time Clock), and counting of the STC counter 63 is started.

  Then, the process proceeds to step ST86, and multiplexing of the video stream, the audio stream, and the PSI (Program Specific Information) stream is started according to the STC. In addition, since the process after step ST86 has little relation with a present Example, the description is abbreviate | omitted.

  Embodiments of a moving image processing method, a moving image processing system, and a moving image processing program will be described in detail below with reference to the accompanying drawings. FIG. 15 is a diagram illustrating an example of a transcoder and a stream in the moving image processing system (moving image processing apparatus) according to the present embodiment. 15A shows details of an embodiment of the transcoder 12 together with the tuner 11 and the transmission buffer 13, and FIG. 15B shows an example of a stream (transport stream) output from the transcoder 12. Indicates.

  As apparent from the comparison between FIG. 15A and FIG. 4A described above, the transcoder 12 in the moving image processing apparatus of the present embodiment includes the multiplexer unit (MUX) 126, the forced NULL generation unit (dummy data). Generating section) 60.

  For example, after the channel is switched and an I-picture is generated at the head of the moving image data of the channel after the switching, the forced NULL generation unit 60 determines whether the NULL data (dummy) is based on the maximum transmission capability of the line (network) 2. Data) is forcibly generated. Details will be described later.

  The overall control unit 121, the demultiplexer unit (DEMUX) 122, the decoder unit 123, the memory 124, and the encoder unit 125 substantially correspond to those described with reference to FIG.

  That is, the demultiplexer unit 122 includes the PSI analysis unit 20, the decoder unit 123 includes the video processing unit 31 ′ and the audio processing unit 32 ′, and the encoder unit 125 includes the video processing unit 51 and the audio processing unit 52. including.

  The overall control unit 121 controls the demultiplexer unit 122 and the decoder unit 123, for example, extracts image data and audio data from MPEG-2 digital data from the tuner 11 and stores them in the memory 124.

  In addition, the overall control unit 121 controls the encoder unit 125 and the multiplexer unit 126 to convert the image data and audio data read from the memory 124 into H.264 having a higher compression rate than MPEG-2, for example. The data is converted to H.264 digital data and output to the transmission buffer 13.

  That is, the transcoder 12 compresses MPEG-2 digital data from the tuner 11 with a higher compression rate that can be transmitted through the network 2 such as WiFi. It is converted into digital data such as H.264 and output to the network 2.

  As shown in FIG. 15B, the stream from the transcoder 12 is, for example, PAT, PMT, PCR, PAT, PMT, PCR, I-pic, PCR, P-pic,..., P-pic, NULL. (Null data, dummy data), I-pic, B-pic, B-pic,...

  The moving image processing apparatus (transcoder 12) of the present embodiment generates, for example, a NULL packet (dummy data) after the first I-picture after channel switching by the forced NULL generation unit 60 provided in the multiplexer unit 126. And output.

  That is, as shown in FIG. 15B, the transcoder 12 inserts PAT, PMT, and PCR twice or more so that the PID analysis is correctly performed on the receiving side (the (decoder 33) of the terminal device 3). I have to.

  Here, the transcoder 12 outputs the leading I-picture (leading I-pic) so as to be reproduced without reordering as DTS = PTS. That is, by performing reorder processing, it is possible to increase the compression rate and reduce the amount of data, but in this embodiment, the terminal device 3 can immediately reproduce the first I-pic image. Reorder processing is not performed. Specifically, as the PCR (PTS), the reproduction start time is reached after the head I-pic.

  That is, for example, H.I. In video compression such as H.264, a bi-prediction technique (referred to as bidirectional prediction in MPEG) is used to increase compression efficiency. Therefore, the order of the pictures is changed by reorder processing in order to improve the compression rate. As a result, the arrangement order of the pictures in the compressed data does not necessarily match the arrangement order of the pictures at the time of display.

  In the present embodiment, for example, since the first I-pic image after the channel switching is displayed in the shortest time, the decoder 33 does not apply the reordering process even if the compression rate is somewhat reduced. When it receives -pic, it decodes it immediately so that the image can be displayed.

  Further, a plurality of P-pictures (P-pics) that only refer to the I-pic are inserted after the first I-pic data. The number of P-pics to be inserted is set in advance, for example, about 1 second (30 pictures).

  The number of P-pics to be inserted depends on the capacity of the transmission buffer 13 and the reception buffer 32 applied to the system, for example, the number increases when the capacity is large, and the number when the capacity is small. Adjustment may be performed to reduce Alternatively, the number of inserted P-pics can be adjusted based on the reorder number of the original stream (the number of B-pictures (B-pic)), the difference between the PCR and I-pic PTS, and the like.

  Then, by inserting a NULL packet corresponding to the capacity of the receiving side (receiving buffer 32), the leading I-pic is quickly passed from the receiving buffer 32 to the decoder 33.

  In this way, as shown in FIG. 15B, the transcoder 12 of the present embodiment uses a P that is only pre-referenced after the first I-picture (first I-pic) at the start of transcoding. -Insert multiple pictures. Then, the NULL packet generated by the forced NULL generation unit 60 is transmitted (transmitted) to the terminal device 3 based on the maximum transmission capability of the line (network).

  As a result, the reception buffer 32 in the terminal device 3 is filled with a NULL packet, and the first I-picture data is input to the decoder 33 in a short time, and the display 34 of the terminal device 3 is displayed in a short time. An image will be displayed.

  That is, for example, in the moving image processing apparatus described with reference to FIGS. 4A and 4B, data (picture stream) after the first I-picture is generated according to the set bit rate.

  Therefore, it takes time of the size of the reception buffer (several seconds to several tens of seconds) until the reception buffer 32 becomes full (constant capacity) and the first I-pic is sent to the decoder. According to this embodiment, NULL is used. The reception buffer 32 can be forcibly set to a full state by the packet.

  As a result, the leading I-pic is sent to the decoder 33 in a short time, and the leading I-pic is quickly displayed. That is, the waiting time until the first image is displayed can be shortened.

  After the second I-pic, data transcoded as usual is accumulated in the reception buffer 32. Therefore, it takes a time corresponding to the size of the reception buffer 32 until the image after the second I-pic is displayed. However, since the first picture is displayed, the feeling of waiting is greatly increased. To be relaxed.

  Here, the image displayed on the display 34 is, for example, the first I-pic (still image) of the broadcast in the channel after switching. For example, when zapping is performed, the still image after switching the channel is confirmed. In many cases, this is sufficient.

  Furthermore, since the application of the moving image processing apparatus (moving image processing system) of the present embodiment does not require new improvements or changes to the terminal apparatus 3 itself, the terminal apparatus 3 can be used as it is. Become. That is, according to the present embodiment, the waiting time until the first image is displayed can be shortened without changing the configuration of the terminal device.

  FIG. 16 is a block diagram showing an example of a multiplexer unit in the transcoder shown in FIG. As is clear from the comparison between FIG. 16 and FIG. 5 described above, the transcoder 12 in this embodiment includes an OR gate 127.

  The OR gate 127 receives a NULL packet insertion mode designating signal MSnp for designating whether or not a NULL packet insertion mode and a NULL packet forcible insertion mode designating signal MSic for designating a NULL packet forced insertion mode, and outputs a logical sum signal thereof.

  Here, the output signal of the OR gate 127 is input to the null packet generating unit 69, and the NULL packet forced insertion mode designating signal MSic is also input to the STC counter 63 ′. That is, the STC counter 63 ′ has a high-speed mode function based on the NULL packet forced insertion mode designation signal MSic, as will be described in detail later.

  The configurations and operations of the FIFO buffers 61 and 62, the video TS packet generator 64, the audio TS packet generator 65, and the PAT generator 66 are the same as those described with reference to FIG. The configurations and operations of the PMT generation unit 67, the PCR generation unit 68, the multiplexing target determination unit 70, and the multiplexing target selection unit 71 are the same as those described with reference to FIG.

  In the multiplexer unit 126 of the present embodiment, when a NULL packet forced insertion mode designation signal MSic is input, the NULL packet generation unit 69 forcibly inserts a NULL packet regardless of the NULL packet insertion mode designation signal MSnp. ing. Note that the configuration and operation of the NULL packet generation unit 69 are the same as those shown in FIG.

  The STC counter 63 ′ has a high-speed mode function. When the forced NULL packet insertion mode is designated (signal MSic is input), the STC counter 63 ′ has a higher speed than the normal operation. It becomes a high-speed mode in which operation is possible.

  That is, the STC counter 63 ′ in this embodiment counts, for example, a normal mode in which system time (STC: System Time Clock) is generated by counting up by one and a preset number (count up value). Has a high speed mode to up.

  Here, the count-up value is set based on, for example, the capacities of the transmission buffer 13 and the reception buffer 32 and how long the leading picture and the subsequent skip (Skip-) P-picture are sent.

  Specifically, when data corresponding to a time of 5 seconds is sent to the transmission buffer 13 and the reception buffer 32 with a frame time of 33 msec, 5 sec / 33 msec≈151.5 is taken, and the count-up value is, for example, 151. It should be set to 5 etc.

  In the above, the transcoder shown in FIG. 15 and FIG. 16 is merely an example, and the transcoder to which the present embodiment is applied is not limited to that shown in FIG. 15 and FIG. Needless to say, changes are possible.

  FIG. 17 is a diagram for explaining the operation at the time of channel switching when the transcoder shown in FIGS. 15 and 16 is applied, and corresponds to FIG. 7 described above. The situation in which the user of the terminal device (WiFi tuner receiving device) 3 is viewing in a steady state is the same as described with reference to FIG.

  Further, the situation in which the user has instructed to switch channels and the situation immediately after the user has instructed to switch channels are the same as described with reference to FIGS. 6B and 6C.

  That is, FIG. 17A, FIG. 17B, and FIG. 17C show FIG. 6C immediately after the user instructs switching of the channel by the moving image processing apparatus (transcoder) of the present embodiment. This is to explain the situation that follows. Note that the situation in which the user is viewing in a steady state by the channel after switching is the same as described with reference to FIG.

  17 (a) to 17 (c), reference codes F (1), F (2), and F (3) in the reception buffer 32 indicate data corresponding to each encoded video frame. NULL indicates a null packet of the transport stream.

  Note that F (1) is the first effective video (first I-picture: first head) of the second channel television broadcast after switching, for example, when the user gives an instruction to switch from the first channel to the second channel. Corresponds to encoded data for I-pic).

  In addition, as described above, in this embodiment, the first I-pic of the second channel TV broadcast after switching is displayed in the first I-pic in order to be able to be displayed on the display 34 of the terminal device 3 in a short time. On the other hand, reorder processing is not performed.

  First, as shown in FIG. 6C described above, for example, encoded data F (1) for the leading I-pic of the second channel television broadcast is sent to the reception buffer 32 via the network 2. Thereafter, as shown in FIG. 17A, the transcoder 12 forcibly generates a null packet (dummy data) NULL and transmits it to the reception buffer 32 via the network 2.

  Note that, as described with reference to FIG. 15B, the transcoder 12 stops, for example, the terminal device 3 with the head I-pic after the head I-pic (data F (1)). A plurality of P-pics for continuing image display are generated and transmitted to the reception buffer 32.

  For example, if a null packet NULL to be forcibly inserted and a voice packet whose time stamp is adjusted are transmitted to the reception buffer 32 via the network 2, a still image is displayed on the terminal device 3 (display 34). You can also output audio while you are.

  Next, as shown in FIG. 17B, when the reception buffer 32 is filled with the null packet NULL, the head I-pic data F (1) is pushed out to the decoder 33.

  Then, as shown in FIG. 17 (c), for example, when the processing of the data F (1) is completed by the decoder 33, an image based on the head I-pic is displayed on the display 34, and the user Can be confirmed. As shown in FIGS. 17A to 17C, the transmission buffer 13 operates in an empty (empty) manner.

  Here, the transmission amount (transmission amount) of the null packet NULL is set based on the maximum transmission capability of the network 2, for example. That is, since the null packet NULL generated by the transcoder 12 is much larger than the data transcoded as usual, the reception buffer 32 can be fully (full) in a short time according to the maximum transmission capability of the network 2. It becomes a state.

  In addition, it takes time corresponding to the size of the reception buffer 32 until the image after the second I-pic data F (2) is displayed, but the display of the image (still image) by the first I-pic is required. The feeling of being awaited is greatly relieved.

  The null packet NULL stored in the reception buffer 32 is input to the decoder 33, but the decoder 33 simply discards the NULL data and does not cause any problem.

  Furthermore, if the content after the channel change is not what is desired, for example, in a CM, the still image by the head I-pic can be confirmed within a short time without waiting for several seconds to several tens of seconds. Therefore, zapping and the like can be easily performed.

  FIG. 18 is a diagram for explaining the transition of the data amount at the time of channel switching shown in FIG. 17. The horizontal axis represents time, the vertical axis represents the data amount, the input / output data amount of each part, and the buffer contents It shows an example of the transition of the data amount.

  That is, FIG. 18 shows, for example, the change in the amount of data when the user switches from the steady state period P31 in which the user watches the first channel television broadcast using the terminal device 3 to another second channel in the period P32. Show. In FIG. 18, cross hatching indicates a null packet NULL (dummy data).

  Here, the period P31 in FIG. 18 corresponds to FIG. 6A described above, the period P32 corresponds to FIG. 6B, the period P33 corresponds to FIG. 6C, and the period P34 corresponds to FIG. 17 corresponds to FIG. 17A and FIG. 17B described above, and the period P35 corresponds to FIG. 17C.

  As illustrated in FIG. 18, for example, when the user switches the channel to be viewed by operating the terminal device 3 from the first channel to the second channel in the period P32 (first timing of the period P32), It is difficult to immediately confirm the image of the second channel.

  For example, the user can view the television broadcast of the second channel because the buffer is cleared by switching the channel, and the decoder 33 operates in the period P35 after the periods P33 and P34 in which a certain amount of data is accumulated in the reception buffer 32. It is after starting. Here, in the present embodiment, for example, data can be stored in the reception buffer 32 with a transmission amount based on the maximum transmission capability of the network 2 by a null packet NULL.

  That is, in the example of FIG. 8, for example, data given in a predetermined amount such as television broadcasting is transcoded in units of pictures and output to the network 2, so that data accumulates in the reception buffer 32 due to an intermittent operation. Requires several seconds to several tens of seconds.

  On the other hand, as shown in FIG. 18, in the present embodiment, the data amount of the second channel is small after performing data transmission by the first I-pic and a plurality of P-pics in the period P33. In addition, data can be stored in the reception buffer 32 using the null packet NULL.

  For example, if the maximum transmission capacity (data amount) TDm of the network 2 is 10 times the data amount of a normal stream, by transmitting a null packet NULL based on the maximum transmission capacity, the time can be reduced to 1/10. The reception buffer 32 can be full.

  As a result, the head I-pic data F (1) is pushed out from the reception buffer 32, and the user can confirm the image of the head I-pic in a short waiting time. That is, as is clear from the comparison between the periods P33 and P34 in FIG. 18 and the period P23 in FIG. 8, according to the present embodiment, it is possible to significantly reduce the time until data is accumulated in the reception buffer 32. I understand.

  In the above, the dummy data in this embodiment is discarded without affecting the decoding process by the decoder 33 such as a transport stream (TS) NULL packet and TS packets having PIDs not subject to decoding. Anything is acceptable. In the above description, the TS packet is used. However, the data is not limited to the TS packet as long as the data is discarded without affecting the processing on the decoder 33 side.

  Next, an example of each process (video decoding process, video transcoding process, and multiplexing process) in the transcoder shown in FIG. 16 will be described with reference to FIGS. The overall control process in the transcoder 12, the audio decoding process in the decoder unit 123, and the audio transcoding process in the encoder unit 125 are the same as those described with reference to FIGS. 9, 11, and 13, respectively. Description is omitted.

  FIG. 19 is a flowchart for explaining an example of video decoding processing by the decoder unit of the transcoder shown in FIGS. 15 and 16, and corresponds to FIG. 10 described above.

  Here, as is clear from the comparison between FIG. 19 and FIG. 10 described above, in FIG. 19, steps ST20 to ST24 and steps ST27 to ST35 perform the same processing as in FIG.

  That is, as shown in FIG. 19, if it is determined in step ST24 that the decoded picture is an I-picture (YES), the process proceeds to step ST200 instead of step ST25 in FIG.

  In step ST200, the video head discovery flag is set, and the original PTS and DTS of the head I-picture are saved in the internal registers orgPTS and orgDTS (PTS: = orgPTS, DTS: = orgDTS), and the process proceeds to step ST201.

  In Step ST201, the original PTS and DTS of the first I-picture are changed by PreTime (time stamp is changed), the decoded image data is sent to the encoder unit 125, and transcoding is started (PTS: DTS: = OrgPTS-PreTime).

  Here, the value of PreTime is preferably set in advance in a register as a parameter in consideration of, for example, a delay time assumed from the capacity of the reception buffer 32. However, a mechanism for feeding back the display start timing (timing for displaying the first I-picture) from the terminal device 3 to the WiFi tuner 1 (transmission device: transcoder 12) is introduced to calibrate the delay amount. It may be.

  Further, the process proceeds to step ST202, the PTS and DTS of the leading I-picture are returned to the original PTS and DTS, the decoded image data is sent to the encoder unit 125, transcoding is performed, and the process proceeds to step ST27. The processes after step ST27 are the same as those described with reference to FIG.

  FIG. 20 is a flowchart for explaining an example of video transcoding processing by the encoder unit of the transcoder shown in FIGS. 15 and 16, and corresponds to FIG. 12 described above.

  Here, as is clear from the comparison between FIG. 20 and FIG. 12 described above, in FIG. 20, steps ST60 and ST61 to ST64 (ST61 ′ to ST64 ′) are the same processes as steps ST60 and ST61 to ST64 in FIG. Is to do.

  That is, as shown in FIG. 20, after the transcoded video stream is sent to the multiplexer unit 126 in step ST64, the process proceeds to step ST600 instead of returning to step ST61.

  In Step ST600, PTS and DTS are set to addTime: = 33.3 msec. (PTS: = DTS: = PTS + 33.3 msec., Count = 33.3 msec.), The process proceeds to step ST601.

  In step ST601, PTS and DTS are updated (offsetTime: = offsetTime + addTime, PTS: = DTS: = PTS + offsetTime), and the process proceeds to step ST602.

  In step ST602, it is determined whether offsetTime <PreTime is satisfied. If it is determined in step ST602 that offsetTime <PreTime is satisfied (YES), the process proceeds to step ST603.

  In step ST603, the skip-P-picture video stream is sent to the multiplexer 126 using the updated PTS and DTS, and then the process returns to step ST601. On the other hand, if it is determined in step ST602 that offsetTime <PreTime is not satisfied (NO), the process proceeds to step ST61 ′. The processes in steps ST61 ′ to ST64 ′ are the same as the processes in steps ST61 to ST64.

  That is, in step ST61 ′, the image data is checked, and the process proceeds to step ST62 ′ to determine whether there is image data. If it is determined in step ST62 ′ that there is no image data (NO), the process returns to step ST61 ′ for checking, and the same processing is repeated until it is determined that there is image data.

  On the other hand, if it is determined in step ST62 ′ that there is image data (YES), the process proceeds to step ST63 ′, video encoding (transcoding) of the image data is executed, and the process further proceeds to step ST64 ′.

  In step ST64 ′, the transcoded video stream is sent to the multiplexer unit 126, and then the process returns to step ST61 ′ to repeat the same processing and continue the video transcoding processing.

  FIG. 21 is a flowchart for explaining an example of multiplexing processing by the multiplexer unit in the transcoder shown in FIGS. 15 and 16, and corresponds to FIG. 14 described above. Here, as is clear from the comparison between FIG. 21 and FIG. 14 described above, in FIG. 21, steps ST80 to ST85 and ST86 perform the same processing as in FIG.

  That is, as shown in FIG. 21, in step ST85, the PTS and DTS of the leading picture are taken in, the multiplexing start time of the leading picture is calculated, the multiplexing start time of the leading picture is set in the STC, and the STC counter Start counting 63. And it progresses to step ST800 instead of progressing to step ST86 in FIG.

  In Step ST800, a NULL forced insertion mode is set, multiplexing of the video stream, audio stream, and PSI stream is started, and the process proceeds to Step ST801 to check completion of full multiplexing of the video head and skip-P-picture. To do.

  Furthermore, it progresses to step ST802 and it is determined whether multiplexing was completed. If it is determined in step ST802 that multiplexing has not been completed (NO), the process returns to step ST801, and the processing is repeated until it is determined that multiplexing has been completed.

  If it is determined in step ST802 that multiplexing has been completed (YES), the process proceeds to step ST803, the transmission buffer 13 is checked, and the process proceeds to step ST804 to determine whether the transmission buffer 13 is full.

  If it is determined in step ST804 that the transmission buffer 13 is not full (NO), the process proceeds to step ST803, and the process is repeated until it is determined that the transmission buffer 13 is full.

  If it is determined in step ST804 that the transmission buffer 13 is full (YES), the process proceeds to step ST805, where the normal mode is set, and normal multiplexing of the video stream, audio stream, and PSI stream is resumed. In addition, since the process after step ST805 has little relation with a present Example, the description is abbreviate | omitted.

  Although the embodiment has been described above, all examples and conditions described herein are described for the purpose of helping understanding of the concept of the invention applied to the invention and the technology. It is not intended to limit the scope of the invention. Nor does such a description of the specification indicate an advantage or disadvantage of the invention. Although embodiments of the invention have been described in detail, it should be understood that various changes, substitutions and modifications can be made without departing from the spirit and scope of the invention.

Regarding the embodiment including the above examples, the following supplementary notes are further disclosed.
(Appendix 1)
The transmitting device transmits the first image data generated based on the moving image data to the terminal device via a best effort type line,
The transmission device generates dummy data after transmitting the first image data to the terminal device and transmits the dummy data to the terminal device,
The terminal device stores the first image data and the dummy data transmitted from the transmission device in a reception buffer, and displays them on the display device in the order of storage in the reception buffer.
And a moving image processing method.

(Appendix 2)
The transmission amount of the dummy data is defined based on the maximum transmission capacity of the line.
The moving image processing method according to appendix 1, wherein:

(Appendix 3)
The transmitting device is
After transmitting the first image data and the dummy data to the terminal device, generating second image data following the first image data based on the moving image data, and transmitting the second image data to the terminal device;
The moving image processing method according to Supplementary Note 1 or Supplementary Note 2, wherein:

(Appendix 4)
The display device
Until the moving image based on the second image data is displayed, the still image based on the first image data is continuously displayed.
The moving image processing method according to Supplementary Note 3, wherein:

(Appendix 5)
The moving image data is video data of a television broadcast,
The transmission device transmits the first image data to the terminal device when the terminal device switches the first channel in the television broadcast to the second channel.
The moving image processing method according to any one of Supplementary Note 1 to Supplementary Note 4, wherein

(Appendix 6)
The moving image data includes an I-picture, a P-picture, and a B-picture,
The transmitting device generates the first image data based on a leading I-picture of video data related to the second channel;
The moving image processing method according to supplementary note 5, wherein

(Appendix 7)
The transmitting apparatus transmits a plurality of P-pictures referring to the first I-picture to the terminal apparatus after transmitting the first image data.
The moving image processing method according to appendix 6, wherein:

(Appendix 8)
When the first channel is switched to the second channel, the transmission device generates the first image data in response to receiving the first I-picture of video data related to the second channel.
The moving image processing method according to Supplementary Note 5 or Supplementary Note 6, wherein:

(Appendix 9)
The line is a wireless line;
9. The moving image processing method according to any one of appendices 1 to 8, characterized in that:

(Appendix 10)
The dummy data is a null packet of a transport stream,
The moving image processing method according to any one of Supplementary Note 1 to Supplementary Note 9, wherein

(Appendix 11)
Transmission that generates first image data based on moving image data, transmits the first image data via a best-effort line, and generates and transmits dummy data after transmitting the first image data. Equipment,
A terminal device that stores the first image data and the dummy data transmitted from the transmission device in a reception buffer, and displays the data stored in the reception buffer on a display device in the order of storage,
A moving image processing system.

(Appendix 12)
The transmitter is
An image generation unit for generating the first image data based on the moving image data;
Including a dummy data generation unit for generating the dummy data,
The moving image processing system according to appendix 11, wherein

(Appendix 13)
The terminal device
A reception buffer for storing the first image data and the dummy data transmitted from the transmission device;
A display device that displays the data stored in the reception buffer in the order in which they are stored,
13. The moving image processing system according to appendix 11 or appendix 12, characterized in that.

(Appendix 14)
The moving image data is video data of a television broadcast,
The transmission device transmits the first image data to the terminal device when the terminal device switches the first channel in the television broadcast to the second channel.
14. The moving image processing system according to any one of Supplementary Note 11 to Supplementary Note 13, wherein:

(Appendix 15)
The moving image data includes an I-picture, a P-picture, and a B-picture,
The transmitting device generates the first image data based on a leading I-picture of video data related to the second channel;
15. The moving image processing system according to appendix 14, wherein

(Appendix 16)
The transmitting apparatus transmits a plurality of P-pictures referring to the first I-picture to the terminal apparatus after transmitting the first image data.
The moving image processing system according to supplementary note 15, wherein

(Appendix 17)
When the first channel is switched to the second channel, the transmission device generates the first image data in response to receiving the first I-picture of video data related to the second channel.
The moving image processing system according to Supplementary Note 15 or Supplementary Note 16, wherein

(Appendix 18)
The line is a wireless line;
18. The moving image processing system according to any one of appendix 11 to appendix 17, characterized in that.

(Appendix 19)
The dummy data is a null packet of a transport stream,
The moving image processing system according to any one of Supplementary Note 11 to Supplementary Note 18, which is characterized in that.

(Appendix 20)
In the arithmetic processing unit,
The transmitting device transmits the first image data generated based on the moving image data to the terminal device via a best effort type line,
The transmission device generates dummy data after transmitting the first image data to the terminal device and transmits the dummy data to the terminal device,
The terminal device stores the first image data and the dummy data transmitted from the transmission device in a reception buffer, and displays them on a display device in the order stored in the reception buffer.
A moving image processing program.

1 WiFi tuner (transmitter)
2 lines (network, wireless LAN, WiFi)
3 Terminal device (receiving device)
4 router 5 antenna 6 internet 11 tuner 12 transcoder 13 transmission buffer 14 LAN (transmission)
31 LAN (Reception)
32 reception buffer 33 decoder 34 display (display device)
60 Forced NULL generator (dummy data generator)
61, 62 FIFO buffer 63 STC counter 64 Video TS packet generation unit 65 Audio TS packet generation unit 66 PAT generation unit 67 PMT generation unit 68 PCR generation unit 69 Null packet generation unit 70 Multiplexing object determination unit 71 Multiplexing object selection unit 121 Overall control unit 122 Demultiplexer unit (DEMUX)
123 Decoder unit 124 Memory 125 Encoder unit 126 Multiplexer unit (MUX)

Claims (16)

The transmitting device transmits the first image data generated based on the moving image data to the terminal device via a best effort type line,
The transmission device generates dummy data after transmitting the first image data to the terminal device and transmits the dummy data to the terminal device,
The dummy data corresponds to at least a capacity of a reception buffer in the terminal device , and the dummy data is not display target data in the terminal device.
And a moving image processing method. The transmitting device transmits the first image data generated based on the moving image data to the terminal device via a best effort type line,
The transmission device generates dummy data after transmitting the first image data to the terminal device and transmits the dummy data to the terminal device,
The dummy data is not display target data in the terminal device,
The transmission amount of the dummy data is defined based on the maximum transmission capacity of the line.
And a moving image processing method. The terminal device receives the transmitted dummy data, so that the time from when the first image data is transmitted from the transmission device to when the first image data is displayed on the terminal device is Controlled to be shorter than the case of not receiving dummy data,
The moving image processing method according to claim 1, wherein the moving image processing method is performed. The transmitting device is
After transmitting the first image data and the dummy data to the terminal device, generating second image data following the first image data based on the moving image data, and transmitting the second image data to the terminal device;
The moving image processing method according to claim 1, wherein the moving image processing method is performed. The moving image data is video data of a television broadcast,
The transmission device transmits the first image data to the terminal device when the terminal device switches the first channel in the television broadcast to the second channel.
5. The moving image processing method according to claim 1, wherein the moving image processing method is performed. The moving image data includes an I-picture, a P-picture, and a B-picture,
The transmitting device generates the first image data based on a leading I-picture of video data related to the second channel;
The moving image processing method according to claim 5. When the first channel is switched to the second channel, the transmission device generates the first image data in response to receiving the first I-picture of video data related to the second channel.
The moving image processing method according to claim 6. The terminal device receives the first image data and the dummy data transmitted from the transmission device via the line;
The moving image processing method according to claim 1, wherein: First image data is generated based on moving image data, the first image data is transmitted to a terminal device via a best effort type line, and dummy data is generated after transmitting the first image data. A transmitting device for moving images to be transmitted to the terminal device,
The dummy data corresponds to at least a capacity of a reception buffer in the terminal device , and the dummy data is not display target data in the terminal device.
A transmission apparatus characterized by the above. First image data is generated based on moving image data, the first image data is transmitted to a terminal device via a best effort type line, and dummy data is generated after transmitting the first image data. A transmission device for transmitting to the terminal device,
The dummy data is not display target data in the terminal device,
The transmission amount of the dummy data is defined based on the maximum transmission capacity of the line.
A transmission apparatus characterized by the above. The terminal device receives the transmitted dummy data, so that the time from when the first image data is transmitted from the transmission device to when the first image data is displayed on the terminal device is Controlled to be shorter than the case of not receiving dummy data,
The transmission device according to claim 9 or 10, wherein The transmitter is
An image generation unit for generating the first image data based on the moving image data;
Including a dummy data generation unit for generating the dummy data,
12. The transmission apparatus according to claim 9, wherein the transmission apparatus is any one of claims 9 to 11. A transmission device according to any one of claims 9 to 12,
A terminal device that stores the first image data and the dummy data transmitted from the transmission device in a reception buffer, and displays the data stored in the reception buffer on a display device in the order of storage,
A moving image processing system. The terminal device
A reception buffer for storing the first image data and the dummy data transmitted from the transmission device;
Including a display device which is displayed in the order in which data stored in the reception buffer is stored,
The moving image processing system according to claim 13. In the arithmetic processing unit,
The transmitting device transmits the first image data generated based on the moving image data to the terminal device via a best effort type line,
The transmission device generates dummy data after transmitting the first image data to the terminal device and transmits the dummy data to the terminal device;
The dummy data corresponds to at least a capacity of a reception buffer in the terminal device , and the dummy data is not display target data in the terminal device.
A moving image processing program. In the arithmetic processing unit,
The transmitting device transmits the first image data generated based on the moving image data to the terminal device via a best effort type line,
The transmission device generates dummy data after transmitting the first image data to the terminal device and transmits the dummy data to the terminal device;
The dummy data is not display target data in the terminal device,
The transmission amount of the dummy data is defined based on the maximum transmission capacity of the line.
A moving image processing program.

Images