JP2003046928A - Network video playback method and compressed video data decoding / playback apparatus - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a video reproducing method using a network, for reproducing compressed video data stored in a personal computer (PC) by a TV receiver installed at a position apart from the compressed video data. A device can be configured at low cost without using a large-capacity cache. SOLUTION: A PC 10 analyzes compressed video data in advance and divides the compressed video data into predetermined time units.
The management information on the divided compressed video data is
Send to The decoder device 20 refers to the management information in response to the reproduction request from the user, and requests transmission of the compressed video data to be reproduced to the PC 10 in units of the divided compressed video data. The PC 10 transmits the requested divided compressed video data to the decoder device 20. The decoder device 20 decodes the received divided compressed data to generate a video signal, and outputs the video signal to the video playback device 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television (TV) via a network from a personal computer (hereinafter referred to as a PC) or a home server that stores moving image (MPEG) data connected to a home network, for example.
The present invention relates to a network video reproducing method and a compressed video data decoding / reproducing apparatus for reproducing a moving image on a receiver.

[0002]

2. Description of the Related Art Conventionally, a transport stream (TS) has been used for transmitting MPEG data by broadcasting or network. Since TS considers that the receiver restores the multiplicity of audio and video data and the service to be transmitted without any problem, the decoding procedure is complicated, and the decoder chip is also used for DVD players and the like. It is necessary to have a system compatible with TS, not the cheap one.

[0003] On the other hand, MPEG data such as PCs and DVDs that are prevalent in Japanese homes are program stream (PS) based. In recent years, an application for recording a TV broadcast on a PC using an MPEG capture card is spreading. When viewing a video recorded on a PC, there are many demands for watching it on a TV receiver in the living room rather than on the screen of the PC. Therefore, in order to meet such a demand, a mechanism for transferring and reproducing data from the study PC to the living room TV is required. For example, there is a method of placing a small PC with a video output (with an S terminal) having a soft decoder function next to a TV receiver, and connecting to a study PC by LAN to display and display.

Since the PC has a large memory capacity and has a large-capacity moving picture cache called a hard disk drive (hereinafter referred to as HDD), by caching data while reproducing, special reproduction such as fast-forward and reverse-forward is also possible. is there. However, a small PC capable of reproducing MPEG data is currently priced at about 70,000 to 100,000 yen, which is expensive as a mere decoder box. Therefore, a low-cost decoder device was needed.

Further, in the conventional moving picture reproducing software for PC,
There is also a problem that fast forwarding and reverse forwarding cannot be performed unless all files are cached in the receiving PC once, because the use in the network is not considered. In particular, with regard to reverse feed, there is a problem that image search in the reverse direction is practically impossible because all the files are read once and then reverse feed is performed.

[0006]

In order to solve the above problems, the data stored in the PC encoded by a PC or a dedicated device without storing a large-capacity cache such as an HDD of several GB and stored in the PC is directly displayed on the TV screen. Consider providing an inexpensive system for playback display in.

However, it is only from the PC or home server side that the MPEG data transferred on the network is processed by fast-forwarding and reverse-forwarding while using a small amount of cache such as SDRAM (tens of MB). It is difficult to realize just by transferring data.

Considering the speed of the network, in the case of the normal data transfer only mechanism, 50 times speed, 1
High speed reproduction of 00 times speed is impossible. For example, if an image recorded at an average bit rate of 8 Mbps is
800 when sending at 0x speed and sending to sequential decoder
A transfer rate of Mbps is required.

Therefore, a mechanism for thinning out and transferring scenes to some extent is required on the PC or home server side. In addition, the same mechanism is required when you want to play the video from the middle on the decoder box side or when you want to reverse the video from the end.

The present invention solves the above-mentioned problems, and an MPEG is transmitted from a PC storing image data to a network via a network.
In a system for transmitting data to a decoder device to reproduce a video, a decoder device having only a small capacity cache can perform decoding and reproduction of video data including special reproduction and cacheless reverse feed reproduction. The purpose is to

[0011]

FIG. 1 is a diagram showing an outline of a system assumed in the present invention. An example of using MPEG data as video data will be described below.
Of course, the video data that can be handled by the present invention is MP
It is not limited to EG data.

The PC (or home server) 1 is (M
PEG) decoder device 2 and network 3 such as LAN
Connected by. The decoder device 2 is connected to an image reproduction display device 4 such as a TV and can be used as a so-called set top box. It is also possible to incorporate the decoder device 2 into the housing of the image reproduction display device 4. The decoder device 2 makes a necessary request to the PC 1 through the network 3 by a command from the user. PC1
Transmits MPEG data and the like to the decoder device 2 through the network 3 in accordance with the request from the decoder device 2.

The decoder device 2 includes a control CPU, memory (cache), control ROM, MPEG decoding means, network communication means, user interface means, video signal output means, etc. A large-capacity HDD that caches the video data for one movie) is not installed. This is because the decoder device 2 is inexpensive.

Special reproduction and the like cannot be performed only by sending MPEG data from the PC 1 to the decoder device 2 via the network 3 for reproduction. Conventionally, in order to perform fast-forwarding (scene skipping), reverse fast-forwarding, etc., once the necessary amount of data is cached inside the receiving side device (decoder device), and the video data is once decoded internally and time stamped. I created a table and used the time stamp to perform reverse fast forward. However, the decoder device 2 having only a small capacity (several tens of MB) cache memory cannot perform the processing.

Therefore, the present invention provides a high-speed CPU for the PC1.
By performing load distribution between the PC 1 and the decoder device 2 by using, the special reproduction can be supported even with the configuration of the decoder device 2.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIG. 2 shows a configuration example of a system according to a first embodiment of the present invention. In this system, a PC 10 and a decoder device 20 are connected via a LAN 30, and the decoder device 20 is connected to a video reproducing device 40 such as a TV. MPE for PC10
G video data is stored, and the video data file is transmitted in response to a request from the decoder device 20. The decoder device 20 receives the video data file, performs MPEG decoding, and outputs a video signal to the video reproduction device 40.

The PC 10 for managing and storing the video data is
It has a CPU 11, a controller 12, an HDD 13, an MPEG decoder 14, a memory 15, and a LAN interface 16. A program for performing MPEG data analysis, file division, etc. is read from the HDD 13 or the like and stored in the memory 15. The MPEG decoder 14 is H
The MPEG data of the video stored in the DD is decoded. The LAN interface 16 transmits / receives communication data to / from the decoder device 20 via the LAN 30. The device storing the MPEG data in the PC 10 is the HDD 13 in this example, but may be a DVD or other DASD (Direct Access Storage Device).

The decoder device 20 for decoding the MPEG data sent from the PC 10 includes a CPU 21, RO
M22, SDRAM 23, user interface 24,
MPEG decoder 25, video signal output circuit 26, LAN
It has an interface 27. A program for controlling the decoder device 20 is recorded in the ROM 22. The user interface 24 receives a command or the like from a user using a remote controller or the like. The MPEG decoder 25 decodes video MPEG data. This MPEG decoder has, for example, an OSD function (on-sc
reen display: a mechanism for displaying operation menus and the like on a TV screen or the like). The video signal output circuit 26 sends video data to the video reproduction device 40. L
The AN interface 27 is connected to the PC 1 through the LAN 30.
Communication data with 0 is transmitted and received.

FIG. 3 is a functional block diagram of the system according to the first embodiment of the present invention. With the functional configuration shown in this figure, fast-forward, reverse-forward playback, playback of a video program stream after a predetermined time has passed,
Time skip reproduction is realized between the decoder device 20 and the PC 10.

The PC 10 has a video file 101, a compressed video data analysis unit 102, a time table 103, a video file division unit 104, a division video file 105, a division video file name table 106, and a transmission / reception control unit 107.

The decoder device 20 includes a user command reception unit 201, a request management unit 202, a transmission / reception control unit 203, a divided video file name table 204, a divided video file reception buffer 205, a divided video file decoding unit 206,
It has a video data output unit 207.

On the PC 10, the video file 101
Stores compressed video data such as MPEG data. The file name of the video file 101 is, for example, a video program name such as a title. The compressed video data analysis unit 102 reads the compressed video data of the video file 101, analyzes the compressed video data, and analyzes the timetable 1
Create 03. The time table 103 stores information regarding reproduction time information such as the size (the number of bytes) for each GOP and the number of minutes and seconds after the beginning of the video data.

The video file dividing unit 104 divides the compressed video data of the video file 101 into predetermined time units based on the data stored in the time table 103, and manages the divided video file 105 by the PC 10. It is created on the storage (the HDD 13 in FIG. 2). Further, the video file dividing unit 104 creates a divided video file name table 106 in which the divided video file name and the data stored in the time table 103 are linked.

FIG. 4 shows an example of division of compressed video data according to the first embodiment of the present invention. As shown in FIG. 4, the compressed video data stored in the video file 101 is divided based on the time table 103, and a plurality of divided video files 105 and a divided video file name table 106 are created.

FIG. 5 shows an example of division positions of compressed video data. When dividing the compressed video data as shown in Fig. 5,
The boundary of the division is a GOP unit. FIG. 6 shows an example of the divided video file name table 106. In the divided video file name table 106, for each divided video file 105, the divided video file name, the GOP included in the divided video file, the number of bytes of each GOP, and the reproduction time information (the beginning of the video data is used as a reference). Playback start time) is stored.

The transmission / reception control unit 107 includes a decoder device 20.
Various requests are received from, and the video list (video program / title list), the divided video file name table 106, the divided video file 105, and the like are transmitted to the decoder device 20 via the LAN 30 in response thereto.

In the decoder device 20, the user command receiving section 201 receives a command from the user using a remote controller or the like, and sends it to the request management section 202. The request management unit 202 transmits a request corresponding to the user command from the user command receiving unit 201 to the transmission / reception control unit 203. When a reproduction request is issued to the PC 10, the PC
Since the divided video file name table 106 is sent from 10, the divided video file name table 106 is stored in the memory as the divided video file name table 204, and the necessary request is processed while sequentially referring to the table.

The transmission / reception control unit 203 has a request management unit 202.
The request from the PC 10 is transmitted to the PC 10 via the LAN 30.
Further, when the transmission / reception control unit 203 receives data from the PC 10, the transmission / reception control unit 203 recognizes that the divided video file name table
If it is 6, it is sent to the request management unit 202, and if it is the divided video file 105, it is stored in the divided video file reception buffer 205.

The divided video file decoding unit 206 decodes the compressed video data of the divided video files accumulated in the divided video file reception buffer 205 to generate video data that can be viewed by the video reproducing device 40, and the decoded video data is generated. It is sent to the video data output unit 207. The video data output unit 207
The video data from the divided video file decoding unit 206 is output to the video reproduction device 40.

The decoder device 20 refers to the reproduction time information and the like in the divided video file name table 204 and the PC 10
Sequentially request the necessary divided video files 105. Then, the compressed video data of each divided video file 105 received from the PC 10 is continuously decoded, and the video data output unit 20
Output to 7. The video reproduction device 40 receives the video signal from the video data output unit 207 and reproduces it. Therefore,
It is possible for the user to advance the video data for a desired time or reproduce the video data from the place where the user has returned.

FIG. 7 shows P in the first embodiment of the present invention.
A communication procedure between the C10 and the decoder device 20 is shown. First,
The PC 10 creates the divided video file 105 (procedure (1)). Further, the PC 10 sends a video list in which a list of video programs (titles) is stored to the decoder device 20 (procedure (2)). The decoder device 20 presents the video list to the user. When the user selects a video program and gives an instruction to reproduce the video program, the decoder device 20
A request for reproducing the video program desired by the user is sent to the PC 10 (procedure (3)). Receiving it, the PC 10 transmits the divided video file name table 106 of the video program (procedure (4)). The decoder device 20 requests the PC 10 for the necessary divided video file 105 according to the received divided video file name table (procedure (5)). PC10 is the requested split video file 1
05 is transmitted to the decoder device 20 (procedure (6)), and the decoder device 20 decodes and reproduces the compressed video data of the divided video file 105 (procedure (7)).

FIG. 8 is a processing flowchart of the system according to the first embodiment of the present invention. First, PC10
Analyzes the MPEG data of each video file 101 (step S11) and creates a time table 103 having relation information between each GOP in the MPEG data and reproduction time information (step S12). That timetable 10
The MPEG data is divided based on 3 to create a plurality of divided video files 105 (step S13). Further, the divided video file name table 106 is created (step S14).

When a video list is requested from the decoder device 20 (step S15), the PC 10 transmits the video list of the own video program to the decoder device 20 (step S16). The decoder device 20 sends a playback request for the video program selected by the user from the video list to the PC.
10 (step S17). In contrast, PC10
To the decoder device 20 divided video file name table 1
06 is transmitted (step S18).

The decoder device 20 requests the necessary divided video file 105 from the PC 10 based on the divided video file name table 204 (step S19), and the PC
10 transmits the requested divided video file 105 to the decoder device 20 (step S20). The decoder device 20 performs a process of decoding and reproducing already received compressed video data in parallel with the process of receiving and storing the compressed video data of the divided video file 105 (step S21). The above steps S19 to S21 are repeated until the user makes a reproduction stop request (step S2).
2) If there is a reproduction stop request from the user, the process ends.

[Second Embodiment] FIG. 9 shows a configuration example of a system according to a second embodiment of the present invention. The basic system configuration is the same as in the first embodiment. The difference is that the programs for MPEG analysis, file division, etc. in the memory 15 are changed to the file division management file system programs. This file division management file system is a database type file system for partial reading of files described below.

This database type file system is
The video file is virtually divided (the virtual divided video file is called a virtual divided video file) without changing the position on the storage of the existing compressed video stored in the video file, and the virtual division It is a program that performs a read process for a video file. Therefore, the database type file system acquires the address information of the compressed video data based on the data recorded on the storage and the file table data of the file system of the existing PC 10 and creates a database. Since this file system simply performs a read operation, it is not necessary to perform exclusive control at the time of writing with the conventional file system managed by the system of the PC 10.

FIG. 10 shows an example of division of compressed video data according to the second embodiment of the present invention. In the first embodiment, as shown in FIG. 4, the compressed video data is divided and the divided video file is stored separately from the compressed video data of the original video file. On the other hand, in the second embodiment, as shown in FIG.
As shown in (A), the video file 111 is not actually divided, but is virtually divided by the virtual divided video file name table 115 of FIG. 10B, and the virtually divided file is virtual divided video. Handle as a file. As shown in FIG. 10B, the virtual divided video file name table 115 has correspondence information of the file name of each virtual divided video file, time data of the video, address data on the HDD 13, data size, and the like. . In addition, information about GOP may be held as in the case of FIG. In addition to the virtual divided video file name table 115 shown in FIG.
The present invention can be implemented as long as it is a table that can refer to information such as P data and head sector.

FIG. 11 is a functional block diagram of the system according to the second embodiment of the present invention. With the functional configuration as shown in FIG. 11, fast-forwarding, reverse-forwarding reproduction, reproduction after a predetermined time has passed from the video program, and skipped time reproduction are realized between the decoder device 20 and the PC 10.

The PC 10 has a video file 111, a compressed video data analysis unit 112, a time table 113, a video file virtual division unit 114, a virtual division video file name table 115, and a transmission / reception control unit 116.

The decoder device 20 includes a user command receiving unit 211, a request management unit 212, a transmission / reception control unit 213, a virtual divided video file name table 214, a virtual divided video file reception buffer 215, a virtual divided video file decoding unit 216, and an image. It has a data output unit 217.

On the PC 10, the video file 111
Stores MPEG data. The compressed video data analysis unit 112 reads the MPEG data of the video file 111, analyzes the MPEG data, and creates the time table 113. The timetable 113 is for each GO
Information regarding reproduction time information such as the size (the number of bytes), the number of minutes and seconds after the beginning of the video data for each P, and the address information of the compressed video data in the video file 111 are stored.

The video file virtual dividing unit 114, the data stored in the time table 113, and the PC 10
Based on the address information of the compressed video data on the file system, the compressed video data of the video file 111 is virtually divided in a predetermined time unit, and the virtual divided video file is set.

The virtual divided video file is a video file name (video program title name), a virtual divided video file name, each table data stored in the time table 113, and compression on the file system of the PC 10. It is managed by the virtual divided video file name table 115 which is associated with the address information of the video data.

The transmission / reception control unit 116 includes a decoder device 20.
Various requests from the decoder device 2 are received via the LAN 30 in response to the video list (video program / title list), the virtual divided video file name table 115, the compressed video data of the virtual divided video file, etc.
Send to 0. PC1 is used to send virtual split video files.
0 reads the corresponding portion of the compressed video data based on the information such as the address and size in the virtual divided video file name table 115 on the database type file system,
It is executed by partial transmission.

In the decoder device 20, the user command receiving section 211 receives a command from the user using a remote controller or the like, and sends it to the request management section 212. The request management unit 212 transmits a request corresponding to the user command from the user command reception unit 211 to the transmission / reception control unit 213. When a reproduction request is issued to the PC 10, the PC
Since the virtual divided video file name table 115 is sent from 10, the virtual divided video file name table 115 is stored in the memory as the virtual divided video file name table 214, and thereafter, the processes for the required requests are sequentially performed while sequentially referring to the table.

The transmission / reception control unit 213 has a request management unit 212.
The request from the PC 10 is transmitted to the PC 10 via the LAN 30.
When the transmission / reception control unit 213 receives the data from the PC 10, if it is the virtual divided video file name table 115, it is sent to the request management unit 212, and if it is the virtual divided video file. , Are stored in the buffer 215 for receiving the virtual divided video file.

The virtual divided video file decoding unit 216 decodes the compressed video data stored in the virtual divided video file reception buffer 215 to create video data that can be viewed by the video reproduction device 40, and outputs it. Part 2
Send to 17. The video data output unit 217 outputs the video data from the virtual divided video file decoding unit 216 to the video reproduction device 40.

FIG. 12 is a diagram for explaining a fast-forwarding method according to the second embodiment of the present invention. When the fast forward command is received from the user by operating the remote controller or the like, the decoder device 20 instructs the PC 10 not to be a continuous virtual divided video file but from the virtual divided video file name table 214 at certain intervals. Select a virtual split video file and skip it in ascending order of time to request a virtual split video file.

FIG. 13 is a diagram for explaining the reverse feeding method according to the second embodiment of the present invention. When the reverse command is received from the user, the decoder device 20 causes the PC 10
On the other hand, similarly to the case of fast-forwarding, the virtual divided video file is selected from the virtual divided video file name table 214 so as to be at a certain fixed time interval, and the virtual divided video file is requested by skipping in the order of later time.

FIG. 14 is a diagram for explaining a method of changing the speeds of fast-forward and reverse-feed in the second embodiment of the present invention. In the method shown in FIG. 14A, only the head GOP of each virtual divided video file is selected and reproduced. In addition, in the method shown in FIG.
Similarly, only the I picture at the head of the extracted GOP is selected and reproduced. This makes it possible to perform fast forward and reverse feed at even higher speeds.

These methods can be executed by referring to the GOP information in the virtual divided video file name table 214. As a result, it is possible to perform fast-forwarding and reverse-feeding at various speeds as shown in FIGS.

FIG. 15 shows the division position of compressed video data and M
It is a figure which shows the relationship between a PEG packet, GOP, and a virtual division video file. The same applies to the first embodiment. As shown in the example of FIG. 15, a virtual divided video file has a plurality of G
It consists of OP. In addition, GOP is a multiple MPEG
Composed of packets. Each MPEG packet is composed of a plurality of sectors. Management can be facilitated by making the sector, MPEG packet, GOP, and virtual divided video file have an integral multiple relationship.

FIG. 16 shows a communication procedure in the second embodiment of the present invention. First, the PC 10 creates the virtual divided video file name table 115 (procedure (1)) and sends the video list to the decoder device 20 (procedure (2)). Decoder device 20 which has received a video reproduction command from the user
Transmits a reproduction request of the video program desired by the user to the video PC 10 (procedure (3)), and receives the request, PC 1
0 transmits the virtual divided video file name table 115 of the video program (procedure (4)). The decoder device 20 receives the received virtual divided video file name table 1
According to 15, a required virtual divided video file is requested to the PC 10 (procedure (5)), and the PC 10 transmits the requested virtual divided video file to the decoder device 20 (procedure (6)). On the decoder device 20 side, the compressed video data of the virtual divided video file is decoded and reproduced (procedure (7)).

FIG. 17 is a processing flowchart of the system according to the second embodiment of the present invention. First, PC10
Analyzes compressed video data such as MPEG data (step S31) and creates the timetable 113 (step S32). Next, based on the time table 113, the virtual divided video file name table 115 for virtually dividing the compressed video data on the database type file system is created (step S33).

When there is a video list request from the decoder device 20 (step S34), the PC 10 transmits the video list of the own video program to the decoder device 20 (step S35). Then, when there is a reproduction request from the decoder device 20 (step S36), the PC 10 sends a virtual divided video file name table 115 to the decoder device 20.
Is transmitted (step S37).

The decoder device 20 requests the necessary virtual divided video file from the PC 10 based on the received virtual divided video file name table 214 (step S3).
8), the PC 10 transmits the requested compressed video data of the virtual divided video file to the decoder device 20 (step S39). In parallel with the process of requesting and receiving the compressed divided video file, the decoder device 20 performs a process of decoding and reproducing the compressed video data of the already received virtual divided video file (step S40). The above steps S38 to S40 are repeated until there is a reproduction stop request (step S41), and if there is a reproduction stop request, the process ends.

By using the methods of the first and second embodiments described so far, the decoder device 20 is provided with a large capacity HDD.
Fast forward, reverse rewind (scene skip) of the video data stored in the PC 10, without the pre-reading function.
It becomes possible to perform processing such as reproduction from a predetermined elapsed time. Particularly, in the second embodiment, the files are virtually divided and read without re-copying the divided files to the storage (on the hard disk) of the PC 10,
Since it is not necessary to separately store the divided video files on the disc, the consumption of the disc capacity is not increased.

Furthermore, high-speed fast-forward playback (scene skip)
When performing G, the first G inside the virtual divided video file
By transmitting only the OP data to the decoder device 20, high-speed fast-forwarding can be easily performed. By storing the virtual split video file name, the GOP table inside the virtual split video file, the relationship between the GOP table and the MPEG packet, the relationship between the MPEG packet and the cluster, the sector position, etc. in the database type file system, It enables high-speed access to the MPEG data. Since the database type file system only needs to read quickly, it is possible to use a file system specialized for speeding up reading.

[Third Embodiment] FIG. 18 shows a configuration example of a system according to a third embodiment of the present invention. The third embodiment is a modification of the second embodiment. The PC 10 is provided with an MPEG encoder 17 having a moving picture coding processing function. When a special reproduction request such as 5 × speed or 10 × speed is issued from the decoder device 20, the PC 10 performs special reproduction of the compressed data of the picked up virtual divided video file by the MPEG decoder 14 having the moving picture decoding processing function once. , Which has a moving picture coding function for the reproduced data
The data is re-encoded by the PEG encoder 17 and then transmitted to the decoder device 20.

A specific description will be given with reference to the drawings. FIG. 19 shows
7 shows a data flow on the PC 10 according to the third embodiment of the present invention. First, from the compressed video data stored in the HDD 13, the compressed video data in the virtual divided video file picked up in accordance with the request from the decoder device 20 is read. For example, in the case of fast-forwarding, some required GOPs are appropriately picked up and read. Next, the MPEG decoder 14 sends the read data to the decoder device 2
It is decoded and reproduced in the order of 0, and is passed to the MPEG encoder 17.

The MPEG encoder 17 re-encodes the data passed from the MPEG decoder 14 in a unit that is appropriately collected, and uses the re-encoded data as a virtual divided video file as the LAN interface 16 and the LAN 30.
It transmits to the decoder apparatus 20 via. At this time, data corresponding to the time table in the virtual divided video file name table for the divided video file is attached to the re-encoded data to determine which divided video file is the special reproduction data. To be able to determine.

By using this method, special reproduction can be performed without changing the data transfer rate on the network. Further, as in the other embodiments, the decoder device 20 may not be provided with a large capacity cache. Furthermore, according to the present embodiment, it is possible to transmit as down-converted MPEG video data in correspondence with a network having a narrow band such as when a wireless LAN is used at home.

[Example of Command / Message] Interface (command / message) between the PC 10 and the decoder device 20 in the above-described first and second embodiments (same for the third embodiment).
The example will be described with reference to FIGS. In the first and second embodiments, the interface between the PC 10 and the decoder device 20 is common, and the difference between the first and second embodiments is that the files actually divided by the PC 10 are held or the file system of the PC 10 is different. The difference is that files are managed on another file system as if they were divided. In the first embodiment, a divided file that actually exists on the disk is transferred, and in the second embodiment, a part of one file on another file system is as if it were a divided file. Transfer to.

In the figures described below, the command is R
Although there are notations such as equest-Next-DevideFile, RequestBack-DevideFile, etc., this is a command for requesting transfer of the next or previous divided video file in time. Next refers to the next split video file, and Back refers to the previous split video file. To increase the speed of fast-forward or reverse, specify the decimation number of the split video file to be transferred with the command argument. For example, if the argument is 0, they are transferred in sequence, and if the argument is 1, every other divided video file is transferred.

FIG. 20 shows an example of a command / message transmission / reception sequence between the PC 10 and the decoder device 20 (1).
Indicates. An example of sequentially specifying and transmitting file names in response to a normal reproduction request will be described below with reference to FIG.

First, the decoder device 20 sends a video list sending request command (procedure (1)), and the PC 10 sends a video list sending command (procedure (2)). When there is a reproduction request from the user, the decoder device 20 sends a split video file name table request command for the specified video (procedure (3)). The PC 10 transmits the divided video file name table (procedure (4)), and the decoder device 20
Sends a division video file name table reception notification (procedure (5)).

The decoder device 20 sends a designated split video file request designating the split video file name (procedure (6)). The PC 10 transmits the designated divided video file (procedure (7)), and the decoder device 20
Sends a split video file reception notification (procedure (8)).
Then, steps (6) to (8) are repeated.

When the user issues a stop request during the playback of the specified split video file transmitted from the PC 10 (procedure (9)), the decoder device 20 sends a split video file transmission stop request. Send (procedure (10)).

When there is a reproduction restart request from the user, the decoder device 20 sends a specified split video file request designating a split video file in which the compressed video data at the reproduction restart position is stored (procedure (11)), and the PC 10 , The specified divided video file is transmitted (procedure (12)), and in response thereto, the decoder device 20 transmits a divided video file reception notification (procedure (13)). Then, steps (11) to (13) are repeated in the same manner.

When there is a reverse feed request from the user, the divided video files are requested in the reverse order of time when the designated divided video file is requested from the decoder device 20 in step (6) or step (11). Further, when a fast-forward request is made by the user, the divided video file is skipped at a certain fixed time when the designated divided video file is requested from the decoder device 20 in step (6) or step (11). Request.

FIG. 21 shows an example of a command / message transmission / reception sequence between the PC 10 and the decoder device 20 (2).
Indicates. An example of automatically transmitting the next file in response to a normal reproduction request will be described below with reference to FIG.

In this interface, the decoder device 2
0 requests the divided video file without specifying the divided video file name, and the PC 10 detects and transmits the divided video file that meets the request of the decoder device 20.

First, the decoder device 20 sends a video list sending request command (procedure (1)), and the PC 10 sends a video list sending command (procedure (2)). When there is a reproduction request from the user, the decoder device 20 sends a video file transmission request command (procedure (3)). PC10
Sends the start split video file (procedure (4)),
On the other hand, the decoder device 20 sends a start divided video file reception notification (procedure (5)).

The decoder device 20 sends the next divided video file request (procedure (6)), the PC 10 transmits the next divided video file (procedure (7)), and the decoder device 20 sends the next divided video file request. The divided video file reception notification is sent (procedure (8)). Then, steps (6) to (8) are repeated.

When there is a stop request from the user, the decoder device 20 requests the next divided video file (procedure (6)).
To stop processing without sending. When a reproduction restart request is issued by the user, the decoder device 20 sends a request for the next divided video file (procedure (9)), and the PC 10 transmits the next divided video file (procedure (10)). The decoder device 20 sends the next divided video file reception notification (procedure (11)). Then, from step (9) to step (1
Repeat 1).

Although not shown in the figure, as a method for performing fast-forwarding, a method of specifying a thinning-out number after the command Next can be considered. For example, Request-Next1-
DevideFile interprets it as thinning one divided video file and transmitting it.

FIG. 22 shows an example of a command / message transmission / reception sequence between the PC 10 and the decoder device 20 (3).
Indicates. FIG. 22 shows an example in which the divided video file to be reproduced next is automatically transmitted during reverse feeding. In FIG. 22, the processing procedure from procedure (1) to procedure (8) is the same as that in FIG. 21, so description thereof will be omitted.

The PC 10 manages the file names of the divided video files sequentially transmitted so far. When there is a reverse request from the user, the decoder device 20 sends a request for the previous divided video file (procedure (9)), and the PC 10 transmits the previous divided video file (procedure (10)). Then, the decoder device 20 sends the previous divided video file reception notification (procedure (11)). After that, the procedure (9) to the procedure (11) are repeated until the reverse return stop is requested.

The features of the embodiments of the present invention will be listed below.

(Supplementary Note 1) A first device for holding compressed video data, a video reproduction device, a second device connected to the video reproduction device for decoding compressed video data to generate a video signal, A network video reproducing method in a system including a network connecting a first device and the second device, wherein the first device analyzes the compressed video data in advance and outputs the compressed video data for a predetermined time. The information is divided into units and correspondence information between the divided compressed video data and the reproduction time information is created, and the correspondence information between the divided compressed video data and the reproduction time information is requested by the request from the second device. A unit of the compressed video data which is transmitted to the second device, the second device refers to the correspondence information received from the first device in response to a reproduction request from a user, and is divided. Request to send compressed video data to the first device, the first device sends the divided compressed video data requested from the second device to the second device, and the second device sends the divided compressed video data to the second device. The device is a network video reproduction method, wherein the device decodes the received divided compressed data to generate a video signal and outputs the video signal to the video reproduction device.

(Supplementary Note 2) In the network video reproducing method according to Supplementary Note 1, when the first device divides the compressed video data, the video file storing the compressed video data is divided into a plurality of divided video files. A network video reproducing method characterized by dividing and creating a relation table between a file name of a divided video file and reproduction time information of compressed video data stored in the divided video file as the correspondence information.

(Supplementary Note 3) In the network video reproducing method according to Supplementary Note 1, the first device virtually divides the compressed video data into a video file in which the compressed video data is stored. A network video reproducing method, characterized in that a relationship table between position information of a virtual divided video file in the video file and reproduction time information of compressed video data stored in the virtual divided video file is created as the correspondence information.

(Supplementary Note 4) Supplementary Note 1, Supplementary Note 2 or Supplementary Note 3
In the network video reproduction method described above, the second device refers to the correspondence information in response to a reproduction request of fast-forward or reverse-forward from a user, skips at a predetermined interval, and sequentially or reversely in time. A method for reproducing a network image, comprising requesting the first device for the divided compressed image data.

(Supplementary Note 5) In the network video reproducing method according to any one of Supplementary Notes 1 to 4, the video data is MPEG data, and the video data is divided into a plurality of GOP units. Network video playback method.

(Supplementary Note 6) In the network video reproducing method according to Supplementary Note 5, when a fast-forward or reverse-forward request is made, the first device causes the first G of the divided video data to be separated.
A network video reproducing method characterized by reading out and transmitting only an I picture of an OP or its GOP.

(Supplementary note 7) In the network video reproducing method according to any one of supplementary notes 1 to 6, the first device detects in advance the capacity of the randomly accessible reception buffer of the second device. Then, the network video reproducing method is characterized in that the size of dividing the video data is determined.

(Supplementary Note 8) A first device for holding compressed video data, a video reproducing device, a second device connected to the video reproducing device for decoding compressed video data to generate a video signal, A network video reproducing method in a system including a network connecting a first device and a second device, wherein the first device analyzes compressed video data in advance and outputs the compressed video data in a predetermined time unit. And the correspondence information between the divided compressed video data and the reproduction time information is created, and the correspondence information between the divided compressed video data and the reproduction time information is requested by the request from the second device. Then, the second device refers to the correspondence information received from the first device in response to a reproduction request including special reproduction from the user, and the divided compressed video data is transmitted. Requesting transmission of the compressed video data to the first device in units of data, and the first device transmits the divided compressed video data requested by the second device when the request is normal reproduction. When transmitted to the second device and the request is a special reproduction regarding fast-forward, reverse-feed or slow, the divided compressed video data is decoded in the special reproduction state, re-encoded, and then the encoded compressed video data is encoded. A network video reproducing method, comprising transmitting to the second device, the second device decoding the received divided compressed data to generate a video signal, and outputting the video signal to the video reproducing device.

(Supplementary note 9) In the network video reproducing method according to supplementary note 8, when the first device transmits compressed video data that has been specially reproduced, it transmits compressed video data and divided video data. A network video reproducing method characterized in that data for linking is attached and transmitted.

(Supplementary Note 10) In the network video reproducing method according to Supplementary Note 8 or Supplementary Note 9, in order to eliminate the time difference between the special reproduction and the normal reproduction, the encoding / decoding processing is always performed in the first apparatus to compress the compression. A network video playback method characterized by transmitting video data.

(Supplementary Note 11) Compressed video data decoding / reproduction for connecting to a video data storage control device holding compressed video data via a network and also to a video reproduction device for outputting a video signal to the video reproduction device. A device, a user interface unit for inputting various reproduction requests including special reproduction from a user, and divided compressed video data which the video data storage control device previously analyzed compressed video data and divided into predetermined time units. Reference is made to means for receiving correspondence information with the reproduction time information from the video data storage control device, and correspondence information received from the video data storage control device for various reproduction requests including special reproduction from the user, Means for requesting transmission of compressed video data to the video data storage control device in units of the divided compressed video data; A compressed video data decoding / reproducing apparatus comprising means for receiving divided compressed data from a video data storage control device, decoding the received divided compressed data to generate a video signal, and outputting the video signal to a video reproducing device. .

[0091]

As described above, according to the present invention,
Since the PC side selects and transmits the required video data, it is not necessary to mount a large-capacity storage on the decoder device, and the decoder device is used to create the timetable etc. required for special reproduction on the PC side. A low-speed, low-priced CPU can be adopted. Therefore, the cost of the decoder device can be reduced.

Further, by providing a divided video file name table for making a large video data file accessible in small file units and a read-only database type file system on the PC, it is possible to meet the request from the decoder device side. Thus, it becomes possible to transmit the divided video file according to the arbitrary time.

Further, as in the conventional case where PCs are connected to each other via a LAN and video data files are shared and played back by playback software, it is impossible to reverse-feed from the end of video data without buffering a series of files. At the same time as the problem is solved, image reproduction from an arbitrary position and sudden reverse search at an arbitrary time can be performed.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a system assumed in the present invention.

FIG. 2 is a diagram showing a configuration example of a system according to the first embodiment of the present invention.

FIG. 3 is a functional block diagram of the system according to the first embodiment of the present invention.

FIG. 4 is a diagram showing an example of division of compressed video data according to the first embodiment of the present invention.

FIG. 5 is a diagram showing an example of division positions of compressed video data.

FIG. 6 is a diagram showing an example of a divided video file name table.

FIG. 7 is a diagram showing a communication procedure in the first embodiment of the present invention.

FIG. 8 is a processing flowchart of the system according to the first embodiment of the present invention.

FIG. 9 is a diagram showing a configuration example of a system according to a second embodiment of the present invention.

FIG. 10 is a diagram showing an example of division of compressed video data according to the second embodiment of the present invention.

FIG. 11 is a functional block diagram of a system according to the second embodiment of the present invention.

FIG. 12 is a diagram illustrating a fast-forwarding method according to the second embodiment of the present invention.

FIG. 13 is a diagram illustrating a reverse feeding method according to the second embodiment of the present invention.

FIG. 14 is a diagram illustrating a method of changing speeds for fast-forwarding and reverse-feeding according to the second embodiment of the present invention.

[Fig. 15] Fig. 15 is a diagram illustrating the relationship between the division position of compressed video data and MPEG packets, GOPs, and virtual divided video files.

FIG. 16 is a diagram showing a communication procedure in the second embodiment of the present invention.

FIG. 17 is a processing flowchart of the system according to the second embodiment of the present invention.

FIG. 18 is a diagram showing a configuration example of a system according to a third embodiment of the present invention.

FIG. 19 is a diagram showing a data flow on a PC according to the third embodiment of the present invention.

FIG. 20 is a diagram showing an example (1) of a command / message transmission / reception sequence between a PC and a decoder device.

FIG. 21 is a diagram showing an example (2) of a command / message transmission / reception sequence between a PC and a decoder device.

FIG. 22 is a diagram showing an example (3) of a command / message transmission / reception sequence between a PC and a decoder device.

[Explanation of symbols]

1,10 PC (home server) 2,20 (MPEG) decoder device 3,30 network (LAN) 4 Image reproduction display device 11,21 CPU 12 Control unit 13 HDD 14,25 MPEG decoder 15 memory 16,27 LAN interface 17 MPEG encoder 22 ROM 23 SDRAM 24 User interface (remote control) 26 Video signal output circuit 40 Video playback device 101,111 video files 102, 112 Compressed video data analysis unit 103,113 timetable 104 Video file division 105 split video files 106,204 split video file name table 107, 116 Transmission / reception control unit 114 Video file virtual division 115 Virtual divided video file name table 2011, 211 User command receiver 202,212 Request management unit 203, 213 Transmission / reception control unit 205 Split video file reception buffer 206 Split video file decoding unit 207,217 Video data output section 214 Virtual split video file name table 215 Buffer for receiving virtual divided video file 216 Virtual division video file decoding unit

Claims (5)

[Claims] 1. A first device for holding compressed video data, a video playback device, and a second device connected to the video playback device for decoding compressed video data to generate a video signal.
A network video reproducing method in a system including a network connecting the first device and the second device, wherein the first device analyzes the compressed video data in advance and sets the compressed video data to a predetermined value. Correspondence information between the divided compressed video data and its reproduction time information is generated by requesting from the second device. To the second device, and the second device refers to the correspondence information received from the first device in response to a reproduction request from the user, and the second unit is divided into units of the compressed video data. The first device requests transmission of compressed video data, the first device transmits the divided compressed video data requested by the second device to the second device, and the second device ， It generates a video signal by decoding the divided compressed data signal, the network method of reproducing video and outputting the video reproduction apparatus. 2. The network video reproducing method according to claim 1, wherein the first device divides the compressed video data into a plurality of divided video files in which a video file storing the compressed video data is divided. Then, a network video reproducing method is characterized in that a relation table between the file name of the divided video file and the reproduction time information of the compressed video data stored in the divided video file is created as the correspondence information. 3. The network video reproducing method according to claim 1, wherein the first device virtually divides a video file storing compressed video data in dividing the compressed video data, and A network video reproducing method characterized in that a relationship table between position information of a virtual divided video file in a video file and reproduction time information of compressed video data stored in the virtual divided video file is created as the correspondence information. 4. A first device that holds compressed video data, a video playback device, and a second device that is connected to the video playback device and that decodes the compressed video data to generate a video signal.
A network video reproducing method in a system including a network connecting the first device and the second device, wherein the first device analyzes the compressed video data in advance and outputs the compressed video data for a predetermined time. The information is divided into units and correspondence information between the divided compressed video data and the reproduction time information is created, and the correspondence information between the divided compressed video data and the reproduction time information is requested by the request from the second device. The second device transmits the divided compressed video data by referring to the correspondence information received from the first device in response to a reproduction request including special reproduction from the user. In units of units, the first device is requested to transmit the compressed video data, and when the request is normal reproduction, the first device transmits the divided compressed video data requested by the second device to the second device. Send to the device, the request is fast forward,
In case of special playback related to reverse feed or slow motion,
The divided compressed video data is decoded in a special reproduction state, re-encoded, and then the encoded compressed video data is converted into the second compressed video data.
And the second device decodes the received divided compressed data to generate a video signal and outputs the video signal to the video reproducing device. 5. A compressed video data decoding / reproducing device which is connected to a video data storage control device holding compressed video data via a network and is also connected to a video reproducing device and outputs a video signal to the video reproducing device. Therefore, the user interface means for inputting various reproduction requests including special reproduction from the user, and the divided compressed video data obtained by analyzing the compressed video data in advance by the video data storage control device and dividing the compressed video data by a predetermined time unit and the reproduction thereof. The division is performed by referring to the means for receiving the correspondence information with the time information from the video data storage control device, and the correspondence information received from the video data storage control device in response to various reproduction requests including special reproduction from the user. Means for requesting transmission of compressed video data to the video data storage control device in units of compressed video data; A compressed video data decoding / reproducing device comprising: means for receiving divided compressed data from a storage control device, decoding the received divided compressed data to generate a video signal, and outputting the video signal to a video reproducing device.