JP2000134237A - Digital av data reproduction method and digital av data reproduction device for home network - Google Patents

Abstract

PROBLEM TO BE SOLVED: To share decoder resources between equipment for constituting a home network. SOLUTION: A decoder library box(DLB) 17 holds plural software decoders #1-#N for decoding digital AV data encoded to a prescribed stream form to be transmitted on an IEEE1394 bus 18. At the time of receiving MPEG2-TS from a CS digital tuner 13, a TV 12 or a PC 11 downloads an MPEG2 software decoder from the decoder library box(DLB) 17 prior to it. Then, in the TV 12 or the PC 11, by using the downloaded MPEG2 software decoder, the MPEG 2-TS received from the CS digital tuner 13 is decoded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a digital AV data reproducing method and a digital AV data reproducing apparatus for a home network.

[0002]

2. Description of the Related Art In recent years, with the market expansion of digital audio-visual equipment (hereinafter, referred to as digital AV equipment), digital AV equipment, personal computers (hereinafter, referred to as PCs), PC peripheral equipment, and the like are connected to a specific bus. A home network has been developed in which connections are made using a line, and digital audio, digital video, data, and the like are exchanged between the devices.

[0003] Techniques related to the home network include "The HAVI Architecture:
Specification of the Home
Audio / Video Interoperabi
LITY (HAVI) Architecture "is known.

[0004] This "HAVI Architectural"
e ”, digital AV equipment and PCs are IEEE1394
It is conceived that they are connected to each other by a cable based on the standard, and can provide services such as video, audio and data to each other. In addition, a function of controlling a specific device in a network to control another device is provided, and a user can control operations of a digital VTR, a tuner, and the like using a TV or a PC.

By the way, in such a home network, a bus line such as IEEE1394 has
Video, audio, and data in various stream formats will flow.

For example, from a tuner that has received a CS digital broadcast, a transport stream in the form of MPEG2 (hereinafter referred to as MPEG2_TS) is sent out on a bus line and transmitted to a playback-side device such as a TV or PC. Is done. In a TV or a PC, the MPEG2_TS is decoded, converted back to the original video and audio signals, and reproduced.

The digital A flowing on the bus line as described above
Since the V data is encoded in a predetermined stream format, it is necessary to individually provide a decoder for a device on the reproduction side that outputs video and outputs audio, such as a TV or a PC.

For decoding different streams, dedicated decoders are required. For example, in a video stream, in addition to MPEG2, MPEG1
There are also stream formats such as MPEG4, MPEG4, and DV format, and PCM,
There are various stream formats such as MD and AC-3. It is necessary that each device on the reproduction side has a built-in decoder corresponding to all of these stream formats.

[0009]

As described above, since video and audio in various stream formats flow on the bus line of the home network, the playback side that displays video and outputs audio like a TV or PC. It was necessary to provide a decoder corresponding to each of these various stream formats individually. Therefore, a redundant configuration in which the same type of decoder is built in or added to a plurality of devices is inevitable, and this causes a problem of increasing the cost of the home network.

[0010] The present invention has been made in view of the above points, and a digital AV data reproducing method capable of sharing a decoder resource between devices in a home network and inexpensively constructing a home network. And a digital AV data reproducing apparatus.

[0011]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention relates to a digital AV data reproducing method applied to a home network in which a plurality of devices handling digital AV data are connected via a bus line. When digital AV data encoded in a predetermined stream format transmitted on the bus line is reproduced by a predetermined device in the home network, a decoder program for decoding the stream is stored in the home network. The digital AV data is downloaded from the other device to the reproducing device, and the digital AV data is decoded using the downloaded decoder program.

In this digital AV data reproducing method, a reproducing device that decodes a stream downloads a decoder program from another device connected to the home network into its own device and uses it. Several kinds of decoder programs may be prepared in a dedicated decoder library device in advance, or instead of preparing such a dedicated device, an AV device or the like having a downloadable decoder program may read the decoder program. It is also possible to download. Further, a decoder program can be downloaded from an external network such as the Internet and used. By sharing the software decoder among the devices in the home network in this way, it is not necessary to mount a decoder function in each device, and it is possible to construct a home network at low cost.

The digital A transmitted on the bus line
By combining a mechanism for inquiring the device on the sending side about the stream format of the V data, it becomes possible to recognize a decoder program corresponding to the stream format to be reproduced, and it is possible to handle various stream formats efficiently.

Furthermore, the number of downloads of the decoder program can be reduced by caching and holding the once downloaded decoder program in the reproducing apparatus. Further, since the decoder is software, it is possible to respond to version upgrades and future function expansion.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows the configuration of a system according to a first embodiment of the present invention. This system uses digital audiovisual equipment, PCs, PC peripheral devices, etc.
It is used as a home network interconnected by using a specific bus line such as a cable based on the 394 standard. In FIG. 1, PC11, TV1
2, CS digital tuner 13, digital audio equipment 15, digital video recorder (DVTR) 16, and decoder library box (DLB) 17,
IEEE1 which is a cable based on the IEEE1394 standard
A configuration in which the components are interconnected by a 394 bus 18 is illustrated. This home network is based on the aforementioned "HAVIArc
TV12 and PC
Reference numeral 11 functions as a control device for controlling the operation of other devices on the network, that is, the CS digital tuner 13, digital audio device 15, digital video recorder (DVTR) 16, and decoder library box (DLB) 17.

Decoder library box (DLB) 1
Reference numeral 7 denotes a software decoder, which is a computer program for decoding digital AV data (digital audio, digital video, or multiplexed data thereof) encoded in a predetermined stream format transmitted on the IEEE 1394 bus 18. And a plurality of software decoders # 1 to # 4 corresponding to a plurality of stream formats, respectively.
#N is registered. The decoder library box (DLB) 17 can be realized by a storage device or the like having an interface with the IEEE 1394 bus.

The stream format transmitted on the IEEE 1394 bus 18 is Y for video data.
In addition to UV and RGB, MPEG1, MPEG2, MPEG
4, DV format (DVC), etc., and audio data is not only PCM, but also MPEG1,
MD, AC-3, DTS, and the like.

The signal received by the CS antenna 14 is transmitted to a channel selector 131, a demodulator 132, an error corrector 133, and a descrambler 134 of the CS digital tuner 13, as shown in FIG. After being corrected and descrambled, the MPEG1 transport stream (MPEG2_TS) is used as an IEEE1
It is output on the 394 bus 18. In the case where a TV is directly connected to the CS digital tuner 13 to view video / audio, after the descrambling, a decoding process is further performed by the bucket decoder 135 and the MPEG2 decoder 136, and the decoded data is input to the TV.

The MPEG2_TS output from the CS digital tuner 13 is transmitted to the IEEE 1394 bus 18 at the request of a control device such as the TV 12 or the PC 11.
Is input to the TV 12 or the PC 11 via the. Here, when viewing video / audio on the TV 12 or the PC 11, an MPEG2 decoder is required for each.

In this embodiment, the TV 12 or the PC 1
1 does not have a built-in MPEG2 decoder.
2 or MP from DLB17 upon request of PC11
A method of downloading and using a software decoder of EG2 is used.

This series of operations is shown in the flowchart of FIG. That is, first, the TV 12 or the PC 11
Based on the operation instruction from the user, the CS digital tuner 13 is requested to transmit a stream of digital AV data (step S101). This request includes an inquiry about the stream format of the digital AV data. The CS digital tuner 13 detects the format of the stream using stream type information and the like included in the stream, and replies to the control device of the TV 12 or the PC 11 that the stream format of the digital AV data to be transmitted is MPEG2. (Step S10
2).

The control device of the TV 12 or the PC 11
When recognizing that the stream sent from the CS digital tuner 13 is MPEG2, it controls the DLB 17 to change the software decoder (MPEG2 software decoder) corresponding to the MPEG2 stream to IEEE.
The data is downloaded from the DLB 17 via the 1394 bus 18 (step S103). Thereafter, transmission of MPEG2_TS by the CS digital tuner 13 is started, and T
The control device of V12 or PC11 receives it (step S104). T that received MPEG2_TS
The control device of the V12 or the PC 11 executes the downloaded MPEG2 software decoder and executes the MPEG2 software decoder.
2_TS is decoded and reproduced (step S10)
5). The execution of the MPEG2 software decoder is performed on a PC
11 is performed by the CPU.
The process 2 is performed by a DSP or the like built in the TV 12. For this reason, it is preferable to use a software decoder to be downloaded that is described in a script language corresponding to various platforms.

When the decoding operation is completed and the decoder is no longer needed, the decoder may be returned to the DLB 17, or the device on the reproducing side, that is, the TV 12 or the storage device in the PC 11 may be kept as it is if there is room. You can keep it.

As described above, if necessary, the decoder can be connected to the DL.
Since it can be downloaded from B17 and used, TV1
It is not necessary to incorporate a decoder in the PC 2 or the PC 11, respectively. The TV 12 and the PC 11 require a minimum storage device (such as an inexpensive semiconductor memory) that can be downloaded by the software decoder and a processor (such as a DSP) for executing the storage device.

Further, even if the number of playback devices requiring decoders increases in the future, the data can be downloaded from the DLB 17 and used, so that the cost of the entire system can be reduced. FIG. 4 shows a series of operation procedures when the downloaded software decoder is cached and stored in the storage device in the TV 12 or the PC 11.

First, the TV 12 or the PC 11 operates the CS digital tuner 13 based on an operation instruction from the user.
Is requested to transmit a stream (step S20).
1). The CS digital tuner 13 replies to the control device of the TV 12 or the PC 11 that the stream format of the digital AV data to be transmitted is MPEG2 (step S202).

The control device of the TV 12 or the PC 11 is as follows.
When recognizing that the stream sent from the CS digital tuner 13 is MPEG2, the storage device (cache) in the own device is searched, and whether or not the MPEG2 software decoder has already been downloaded, that is, whether or not it has been cached (Step S20)
3, S204). DLB1 if cached
7 does not execute the download of the MPEG2 software decoder.
The MPEG2 software decoder is downloaded from B17 (step S205).

Thereafter, the transmission of the MPEG2_TS by the CS digital tuner 13 is started, and the control device of the TV 12 or the PC 11 receives it (step S20).
6). TV12 or P that received MPEG2_TS
The control device of C11 executes the MPEG2 software decoder to decode and reproduce the MPEG2_TS (step S207).

In the first embodiment, the decoder library box (DLB) 17 is provided as a dedicated device for holding a plurality of types of software decoders. Of the software decoder, and in response to a request from the TV 12 or the like, the software decoder is
You can also distribute to.

(Second Embodiment) FIG. 5 shows a system configuration according to a second embodiment of the present invention. Here, only the differences from the first embodiment will be described.

In the second embodiment, the control device (the PC 11 in FIG. 5) that requires the software decoder inquires of all devices in the home network whether the required software decoder is possessed or not. This is a method for downloading a software decoder from a device that is running. In such a case, the TV 12 or P
The control device such as C11 downloads and uses the software decoder from the device that owns the software decoder before transmitting the stream from the stream transmission device. This series of operation procedure is shown in the flowchart of FIG.

First, the TV 12 or the PC 11 operates the CS digital tuner 13 based on an operation instruction from the user.
Is requested to transmit a digital AV data stream (step S301). This request includes digital AV
Includes data stream format queries.
The CS digital tuner 13 detects the format of the stream using stream type information and the like included in the stream, and replies to the control device of the TV 12 or the PC 11 that the stream format of the digital AV data to be transmitted is MPEG2. (Step S30
2).

The control devices of the TV 12 or the PC 11 are as follows:
When recognizing that the stream sent from the CS digital tuner 13 is MPEG2, it inquires of all devices connected in the home network whether or not they have a downloadable MPEG2 software decoder (step S303). . A device having a downloadable MPEG2 software decoder (CS digital tuner in FIG. 5) responds to this inquiry (step S304).

The control device of the TV 12 or the PC 11 is as follows.
The MPEG2 software decoder is downloaded from a device having the MPEG2 software decoder (step S305). Thereafter, transmission of MPEG2_TS by the CS digital tuner 13 is started, and T
The control device of V12 or PC11 receives it (step S306). T that received MPEG2_TS
The control device of the V12 or the PC 11 executes the downloaded MPEG2 software decoder and executes the MPEG2 software decoder.
2_TS is decoded and reproduced (step S30)
7).

FIG. 7 shows a series of operation procedures when the downloaded software decoder is cached and stored in the storage device in the TV 12 or the PC 11. First, the TV 12 or the PC 11 requests the CS digital tuner 13 to transmit a stream based on an operation instruction from a user (step 401). The CS digital tuner 13 is a digital AV
TV that the data stream format is MPEG2
A reply is made to the control device of the PC 12 or the PC 11 (step S402).

The control devices of the TV 12 or the PC 11 are as follows:
When recognizing that the stream sent from the CS digital tuner 13 is MPEG2, the storage device (cache) in the own device is searched, and whether or not the MPEG2 software decoder has already been downloaded, that is, whether or not it has been cached (Step S40)
3, S404). If the data is cached, the download operation of the MPEG2 software decoder from another device is not executed, and only when the data is not cached, the following download processing is performed.

That is, when the control device of the TV 12 or the PC 11 recognizes that the stream transmitted from the CS digital tuner 13 is MPEG2, the MPEG2 software decoder that can be downloaded to all the devices connected in the home network. It is inquired as to whether or not it is possessed (step S405).
In response to this inquiry, downloadable MPEG2
Equipment that has a software decoder (in FIG. 5,
The CS digital tuner answers (step S40)
6). The control device of TV12 or PC11 is MPE
The MPEG2 software decoder is downloaded from a device having the G2 software decoder (step S407).

Thereafter, the transmission of the MPEG2_TS by the CS digital tuner 13 is started, and the control device of the TV 12 or the PC 11 receives it (step S40).
8). TV12 or P that received MPEG2_TS
The control device of C11 executes the MPEG2 software decoder to decode and reproduce the MPEG2_TS (step S409).

(Third Embodiment) FIG. 8 shows a system configuration according to a third embodiment of the present invention. Here, only the differences from the first embodiment will be described.

In the third embodiment, the above-described DLB 17 is connected to the external network 20 via a telephone line or the like, so that the software decoder can be downloaded from the external network. The external network may be the Internet or the like. D
FIG. 9 shows an example of the operation procedure of the LB 17.

That is, when a download request is made by the TV 12 or the control device of the PC 11, the DLB 17 checks whether or not the software decoder holding the download request is held (step S 501).
If the software decoder is not stored, the software decoder is downloaded from a predetermined server via an external network such as the Internet and stored (step S502). And TV12 or PC
The software decoder requested to be downloaded by the control device 11 is sent to the control device (step S50).
3).

The DLB 17 may periodically access the server to update the software decoder, or the server may automatically distribute the latest software decoder to the DLB 17 using a push-type service. .

The operation procedure in each of the above-described embodiments can be controlled by a computer program, and this can be introduced into the PC 11 through a recording medium, or a device such as a TV equipped with a processor such as a DSP. The same effects as in the present embodiment can be realized by introducing the program as a built-in program for a ROM or the like.

[0044]

As described above, according to the present invention,
Decoder resources can be shared between devices in the home network, and a home network can be constructed at low cost.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a system configuration of a home network according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a CS digital tuner used in the first embodiment.

FIG. 3 is an exemplary flowchart showing an operation procedure when reproducing the AV data in the system of the first embodiment;

FIG. 4 is an exemplary flowchart showing a second example of the operation procedure when reproducing the AV data in the system according to the first embodiment;

FIG. 5 is a block diagram showing a system configuration of a home network according to a second embodiment of the present invention.

FIG. 6 is an exemplary flowchart showing an operation procedure when reproducing AV data in the system according to the second embodiment;

FIG. 7 is an exemplary flowchart showing a second example of the operation procedure when reproducing AV data in the system according to the second embodiment;

FIG. 8 is a block diagram showing a system configuration of a home network according to a third embodiment of the present invention.

FIG. 9 is an exemplary flowchart showing an operation procedure for downloading a software decoder from an external network in the system according to the third embodiment;

[Explanation of symbols]

11 PC, 12 TV, 13 CS digital tuner, 14 CS antenna, 15 digital audio equipment, 16 digital VTR (DVTR), 17 decoder library box (DLB).

Claims (9)

[Claims] 1. A digital AV data reproducing method applied to a home network in which a plurality of devices handling digital AV data are connected via a bus line, wherein the digital AV data reproducing method is a method for reproducing a predetermined stream format transmitted on the bus line. When the encoded digital AV data is played back by a predetermined device in the home network, a decoder program for decoding the stream is downloaded from another device in the home network to a playback-side device. And reproducing the digital AV data by using the decoded decoder program. 2. A decoder program corresponding to a stream format of the digital AV data obtained by inquiring about a stream format of the digital AV data to a device on a transmitting side for transmitting the digital AV data to be reproduced onto the bus line. 2. The digital AV data reproducing method according to claim 1, wherein the program is downloaded from another device in the home network to a reproducing device. 3. A decoder library means for centrally managing a plurality of types of decoder programs respectively corresponding to a plurality of types of stream formats is connected in the home network, and a predetermined stream transmitted on the bus line is provided. When digital AV data encoded in a format is reproduced by a predetermined device in the home network, a decoder program for decoding the stream is downloaded from the decoder library means to the reproducing device. The digital AV data reproducing method according to claim 1. 4. The digital library according to claim 3, wherein the decoder library device is connected to an external network, and a decoder program downloaded from the outside via the external network is held in the decoder library device. AV data playback method. 5. When reproducing digital AV data encoded in a predetermined stream format transmitted on the bus line by a predetermined device in the home network,
It detects whether or not a device holding a decoder program for decoding the stream exists in the home network, and when a device holding the decoder program is detected, the device reads from the device. 2. The digital AV data reproducing method according to claim 1, wherein said decoder program is downloaded to said device. 6. The downloaded decoder program is cached in a storage device in a playback device, and the download of the decoder program is performed in a stream format corresponding to the decoder program cached in the storage device in the playback device. 2. The digital AV data reproducing method according to claim 1, wherein the method is executed when reproducing digital AV data in a stream format other than the above. 7. A digital AV data reproducing apparatus for reproducing digital AV data encoded in a predetermined stream format, wherein a plurality of devices handling digital AV data are used in a home network connected via a bus line. A decoder download unit for downloading a decoder program for decoding a target stream from another device in the home network via the bus line; and the digital AV using the decoder program downloaded by the decoder download unit. A digital AV data reproducing apparatus, comprising: decoding means for decoding data. 8. An apparatus for inquiring about a stream format of the digital AV data with respect to a sending-side device for sending the digital AV data to be reproduced onto the bus line, wherein the stream format obtained by the inquiry is provided. 8. The digital AV data reproducing apparatus according to claim 7, wherein a decoder program corresponding to the above is downloaded by said decoder download means. 9. A cache unit for caching the downloaded decoder program, wherein the download of the decoder program by the decoder download unit is performed in a stream other than the stream format corresponding to the decoder program cached by the cache unit. 8. The digital AV data reproducing apparatus according to claim 7, wherein the apparatus is executed when reproducing digital AV data in a format.