JP2008193227A - Moving picture reproducing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a stream already stored in a buffer from being supplied from a server again when performing fast forward reproduction or reverse fast forward reproduction in a moving picture reproducing apparatus for reproducing moving picture data (stream: MPEG2-TS) supplied through a network. <P>SOLUTION: When the fast forward reproduction or the reverse fast forward reproduction is instructed from a user, the reproduction start time t0, a reproduction start position p0, and the transmission amount sz of one time are respectively set (S1), p0 is set to a parameter ps indicating a transmission start position (S2), (ps+sz-1) is set to a parameter pe indicating a transmission end position, and transmission by the normal reproduction of the stream from ps to pe is requested to a server (S3). The completion of the reception of the stream is waited for (S4), and when it is not the end of the stream (S5), the transmission start position ps is updated to (ps+sz), processes S3-S5 are repeated, and transmission processing is ended when the end of the stream is judged (S5). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a moving image reproducing apparatus that receives and reproduces moving image data from a network-connected server, and particularly efficiently transmits moving image data from the server during fast forward reproduction or reverse fast forward reproduction.

  2. Description of the Related Art In recent years, an environment in which video data distributed via broadcast or the Internet is stored as digital moving image data on a server installed in a home and is played back from a client device in the home via a home network is being prepared. In such an environment, it is desirable for the client to be able to perform various reproductions that have been performed in the stand-alone environment, such as normal reproduction, fast-forward reproduction, and reverse fast-forward reproduction, without being aware of the network. For example, Patent Document 1 has been proposed as a method for realizing various reproductions such as fast-forward reproduction in moving image reproduction in a network-connected environment.

In the technique described in Patent Document 1, the server divides and records moving image data in predetermined time units, and prepares the relationship between the divided file and the reproduction time information as correspondence information. When the server receives the reproduction request from the client, the server transmits correspondence information to the client, and the client requests the server to transmit moving image data based on the correspondence information. For example, in the case of fast-forward playback, transmission of the divided file thinned out in the forward direction is requested, and in the case of reverse fast-forward reproduction, transmission of the divided file thinned out in the reverse direction is requested.
JP 2003-46928 A

  Usually, a moving image reproducing apparatus includes a buffer for accumulating moving image data, and smooth reproduction is realized by reading moving image data from the buffer without interruption. Therefore, the moving image data output from the server and the moving image data decoded by the moving image reproducing device have a difference between the time for transferring from the server to the moving image reproducing device and the time accumulated in the buffer. This is shown in FIG.

  FIG. 12 shows the timing until the moving image data divided into packets is output from the server and decoded by the moving image reproducing apparatus. 12A shows the output timing of the server, FIG. 12B shows the buffer input timing of the video playback device, and FIG. 12C shows the timing of output from the buffer of the video playback device and decoding. (A) and (B) are shifted by the transfer time via the network, and (B) and (C) are shifted by the time accumulated in the buffer. Therefore, for example, at time t4, the video data of packet 4 is output from the buffer for decoding, but the server outputs up to packet 8.

When fast-forward playback is instructed by the user at time t4, the video playback device requests transmission of packets necessary for fast-forward playback after packet 4. If reverse fast-forward playback is instructed, transmission of a packet necessary for reverse fast-forward before packet 4 is requested.
However, packets 1 to 8 have already been transmitted from the server at time t4, and packets in this range need only be stored in the buffer of the video playback device, and need not be transmitted again.
In view of such circumstances, an object of the present invention is to provide a moving image playback apparatus that eliminates unnecessary transmission in fast forward playback and reverse fast forward playback.

  The video playback device of the present invention that solves the above-described problems is connectable to a video transmission device that transmits video data via a network, sends a transmission request to the video transmission device by specifying a transmission range, and receives In the video playback device that plays back the stored video data while storing it in a buffer, the transmission request is a special playback such as fast forward playback or reverse fast forward playback, and the portion of the video data that is not stored in the buffer is It is specified as a transmission range.

  Moreover, the moving image reproducing apparatus of the present invention that solves the above-described problems may specify the transmission range by a relative position from the beginning of the moving image data.

  Alternatively, the moving image data may be divided into blocks of a predetermined size, the transmission range may be designated by the number of blocks from the beginning of the moving image data, or the moving image data may be divided into blocks of a predetermined time unit, and the transmission The range may be specified by the number of blocks from the beginning of the moving image data.

  In the video playback apparatus according to the present invention, in fast forward playback and reverse fast forward playback, video data stored in the built-in buffer is used as it is, and the server requests transmission of video data not stored in the buffer. There is an effect that useless communication data can be effectively utilized without useless moving image data flowing on the road.

  The best mode for carrying out the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to these embodiments, and can be implemented in various modes without departing from the spirit of the present invention.

FIG. 1 illustrates functional blocks of the moving image playback apparatus according to this embodiment. 1 includes a LAN interface 11, a control unit 12, a CPU 13, a buffer 14, a decoder 15, and a user interface 16.
Although not shown, a server storing moving image data is connected to the LAN.
The operation when MPEG2-TS (MPEG2 Transport Stream) is input to the moving picture reproducing apparatus of FIG. 1 will be described below.

  First, when an operation signal is input to the user interface 16 according to a user instruction, the CPU 13 sends an MPEG2-TS transmission request to a server connected via a network. The transmission request is transmitted to the server via the LAN interface 11. It is assumed that the transmission request in the present embodiment is sent to the server using the positional information indicating the transmission position and the information indicating the playback mode in the MPEG2-TS as parameters. FIG. 2 shows parameters in the present embodiment.

  After receiving the transmission request, the server outputs MPEG2-TS and inputs it to the LAN interface 11. In order to transmit on the network, the MPEG2-TS is converted into the IPv4 protocol or the IPv6 protocol and transmitted at the server output, and the MPEG2-TS is reproduced by the LAN interface 11. When the transmission request from the CPU 13 is completed, the LAN interface 11 transmits a completion notification to the CPU 13. The input MPEG2-TS is analyzed by the control unit 12 and separated into audio data, video data, and section data and stored in the buffer 14. The stored MPEG2-TS is read at an appropriate timing, decoded by the decoder 15 and output as a decoded image.

  FIG. 3 is a flowchart showing an operation in which the CPU 13 sends an MPEG2-TS transmission request to the server during normal reproduction. In FIG. 3, first, in step S1, a parameter t0 indicating a reproduction start time is set. The parameter t0 is appropriately set according to an instruction from the user. For example, when the user instructs playback from the beginning of the program, t0 may be set to 0. When playback is instructed from a chapter in the middle, the playback time corresponding to the chapter is set. The parameter p0 indicating the reproduction start position is set by calculating the position of MPEG2-TS corresponding to the parameter t0 from the management data. Here, the reproduction start position is a relative position from the beginning of the MPEG2-TS, specifically, the number of bytes from the beginning. It is assumed that the moving image playback apparatus receives management data such as the size, playback time, and start position information corresponding to a chapter recorded in advance on the server from the server. In step S1, a transmission amount sz from the server is set. The amount of transmission at one time is set to an appropriate value according to the completion of the network. The transmission amount is also specified by the number of bytes. In step S2, p0 is set to the parameter ps indicating the transmission start position. Next, in step S3, (ps + sz-1) is set in the parameter pe indicating the transmission end position, and the server is requested to transmit in the normal reproduction of MPEG2-TS from ps to pe. In step S4, the process waits until the reception of MPEG2-TS is completed. In step S5, it is determined whether the MPEG2-TS is completed. If it is not the end of MPEG2-TS, the transmission start position ps is updated to (ps + sz) in step S6, and steps S3 to S5 are repeated. If it is determined in step S5 that the MPEG2-TS has ended, the transmission process is completed.

  The CPU 13 makes an MPEG2-TS transmission request as described above, and manages the MPEG2-TS stored in the buffer 14. The MPEG2-TS is read at an appropriate timing, supplied to the decoder 15 via the control unit 12, and decoded.

  The MPEG2-TS may be recorded in the buffer 14 as it is, or the header may be removed by the control unit 12 and recorded as a PES (Packetized Elementary Stream) or a section. As for PES, an ES (Elementary Stream) may be recorded by removing the PES header. The control unit 12 and the decoder 15 are configured to appropriately process according to the format of the moving image data recorded in the buffer 14.

Next, FIG. 4 shows a flowchart of an operation in which the CPU 13 sends an MPEG2-TS transmission request to the server when fast-forward playback is performed. In fast forward playback, the video playback device 10 transmits to the server the fast forward playback, the transmission start position of the video data, and the fast forward playback speed. The server selects moving image data necessary for fast-forward playback within a range after the transmission start position, and transmits it to the moving image playback apparatus 10. In FIG. 4, first, in step S11, the rear end position of the moving image data stored in the buffer 14 is set to the parameter be, and the fast-forward playback speed is set to the parameter fsp. Fast forward playback is designated by the user, and the playback speed is set to a preprogrammed value. For example, if the user designates fast-forward playback once, it is set to double speed, and if it is designated twice in succession, it is set to quad speed. Next, in step 12, be is set to the parameter ps indicating the transmission start position. Next, in step S13, a request is made for transmission in fast-forward playback of MPEG2-TS at a speed fsp from the transmission start position ps. In step S14, the process waits until a fast-forward playback end instruction from the user or MPEG2-TS ends.
The CPU 13 requests the MPEG2-TS for fast-forward playback as described above, manages the MPEG2-TS stored in the buffer 14, and controls the decoding process at an appropriate timing.

  Next, FIG. 5 shows a flowchart of an operation in which the CPU 13 sends an MPEG2-TS transmission request to the server when performing reverse fast-forward reproduction. In reverse fast-forward playback, the same operation as fast-forward playback is performed except that reverse fast-forward playback is performed with respect to the server and the moving image data transmission start position is the head position of the moving image data stored in the buffer 14.

  In FIG. 5, first, in step S21, the head position of the moving image data stored in the buffer 14 is set to the parameter bs, and the reverse fast-forward playback speed is set to the parameter bsp. Reverse fast-forward playback is designated by the user, and the playback speed is set to a preprogrammed value. For example, if the user designates reverse fast-forward playback once, the speed is doubled, and if the user designates twice continuously, the speed is quadrupled. In step S22, bs is set in the parameter ps indicating the transmission start position. Next, in step S23, the transmission at the speed bsp is requested from the transmission start position ps at the MPEG2-TS reverse fast forward reproduction. In step S24, the process waits until the end of reverse fast-forward playback from the user or the end of MPEG2-TS.

  The CPU 13 makes a transmission request for MPEG2-TS for reverse fast-forward playback as described above, manages the MPEG2-TS stored in the buffer 14, and controls the decoding process at an appropriate timing.

  In this embodiment, the transmission start position and the transmission amount are designated by the number of bytes, but may be designated by a 2-byte or 4-byte word.

<Embodiment 2>
In the first embodiment, the transmission start position and transmission end position of the moving image data and the amount of transmission at one time are specified by the number of bytes from the beginning of the MPEG2-TS, but in this embodiment, the MPEG2-TS is set to a predetermined value. The block is divided into blocks of a size and designated by the number of blocks from the beginning of MPEG2-TS. The functional blocks of this embodiment are the same as those in FIG.

  FIG. 6 is a flowchart showing an operation in which the CPU 13 sends an MPEG2-TS transmission request to the server during normal reproduction. Also, FIG. 7 shows an operation in which the CPU 13 sends an MPEG2-TS transmission request to the server when fast-forward reproduction is performed, and FIG. 8 shows an operation in which the CPU 13 sends an MPEG2-TS transmission request to the server in the case of reverse fast-forward reproduction. The operation is shown in a flowchart.

  The operation of the CPU 13 shown in FIGS. 6 to 8 is the same as the operation of the CPU 13 shown in FIGS. 3 to 5 except that the transmission start position is designated in units of blocks of a predetermined size. Perform the action. That is, in step S31 of FIG. 6, the MPEG2-TS block number corresponding to the parameter t0 indicating the playback start time is calculated and set in the parameter p0 indicating the playback start block number from the management data, and the transmission amount per transmission is set. The number of transmission blocks at one time is also set in the parameter sz shown. In step S41 of FIG. 7, the rear end block number of the moving image data stored in the buffer 14 is set as the parameter be, and in step S51 of FIG. 8, the first block number of the moving image data stored in the buffer 14 is set as the parameter bs. Otherwise, the same operation as in the best embodiment is performed.

<Embodiment 3>
In this embodiment, the block is divided into moving image data corresponding to a predetermined time as a parameter of the transmission request command, and the time is designated by the number of blocks from the head of MPEG2-TS. The functional blocks of this embodiment are also the same as in FIG.

  FIG. 9 is a flowchart showing an operation in which the CPU 13 sends an MPEG2-TS transmission request to the server during normal reproduction. Further, FIG. 10 shows an operation in which the CPU 13 sends an MPEG2-TS transmission request to the server when fast-forward reproduction is performed, and FIG. 11 shows an operation in which the CPU 13 sends an MPEG2-TS transmission request to the server in the case of reverse fast-forward reproduction. The operation is shown in a flowchart.

  The operation of the CPU 13 shown in FIGS. 9 to 11 is different from the operation of the CPU 13 shown in FIGS. 3 to 5 in that the transmission start position is specified by a block number divided into predetermined time units. The same operation is performed except for.

  That is, in step S61 in FIG. 9, the MPEG2-TS block number corresponding to the parameter t0 indicating the playback start time is calculated from the management data and set in the parameter p0 indicating the playback start block number, and the transmission amount per transmission is set. The number of transmission blocks at one time is also set in the parameter sz shown. In step S71 in FIG. 10, the head block number of the moving image data stored in the buffer 14 is set as the parameter bs. In step S81 in FIG. 11, the head block number of the moving image data stored in the buffer 14 is set as the parameter bs. Otherwise, the same operation as in the best embodiment is performed.

  In the above-described embodiment, an example in which moving image data is received from a server connected to a LAN has been shown. However, the present invention similarly applies to a case where moving image data is received from a server connected to the Internet and played back. It goes without saying that it is available.

It is a figure which shows an example of the functional block of the moving image reproducing apparatus which concerns on embodiment of this invention. It is a figure which shows the reproduction | regeneration mode and parameter of embodiment of this invention. It is a flowchart which shows operation | movement of CPU13 in the normal reproduction | regeneration of embodiment of this invention. It is a flowchart which shows operation | movement of CPU13 in the fast-forward reproduction | regeneration of embodiment of this invention. It is a flowchart which shows operation | movement of CPU13 in the reverse fast-forward reproduction | regeneration of embodiment of this invention. It is a flowchart which shows operation | movement of CPU13 in the normal reproduction | regeneration of Embodiment 2 of this invention. It is a flowchart which shows operation | movement of CPU13 in the fast-forward reproduction | regeneration of Embodiment 2 of this invention. It is a flowchart which shows operation | movement of CPU13 in the reverse fast-forward reproduction | regeneration of Embodiment 2 of this invention. It is a flowchart which shows operation | movement of CPU13 in the normal reproduction | regeneration of Embodiment 3 of this invention. It is a flowchart which shows operation | movement of CPU13 in the fast-forward reproduction | regeneration of Embodiment 3 of this invention. It is a flowchart which shows operation | movement of CPU13 in the reverse fast-forward reproduction | regeneration of Embodiment 3 of this invention. It is a figure which shows the relationship between the input data and output data of a buffer in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Movie reproduction apparatus, 11 ... LAN interface, 12 ... Control part, 13 ... CPU, 14 ... Buffer, 15 ... Decoder, 16 ... User interface.

Claims (4)

  Video playback device that can be connected to a video transmission device that transmits video data via a network, sends a transmission request to the video transmission device by specifying a transmission range, and reproduces the received video data while accumulating it in a buffer The moving image reproducing apparatus according to claim 1, wherein, in the case of special reproduction such as fast forward reproduction and reverse fast forward reproduction, the transmission request designates a portion of the moving image data that is not stored in the buffer as the transmission range.   2. The moving image reproducing apparatus according to claim 1, wherein the transmission range is designated by a relative position from the head of the moving image data.   2. The moving image reproducing apparatus according to claim 1, wherein the moving image data is divided into blocks of a predetermined size, and the transmission range is designated by the number of blocks from the head of the moving image data.   2. The moving image reproducing apparatus according to claim 1, wherein the moving image data is divided into blocks of a predetermined time unit, and the transmission range is designated by the number of blocks from the head of the moving image data.

Images