The present invention relates to a data decoding system and method, a transfer device and method, and a receiving device and method. In particular, the invention relates to a data decoding system and method, a transfer device and method, and a receiving device and method in which in transmitting data via a digital interface a data form is converted, on a transmission or reception side, to a form suitable for a decoder on the reception side.
The DVD (digital versatile disc)-Video (hereinafter referred to simply as "DVD") has been standardized recently and its spread is now expected. Video data is compressed according to the MPEG (Moving Picture Experts Group) scheme and recorded on a DVD. In a DVD player, a DVD is played back by a drive section and the reproduced data is decoded by a decoding section. Resulting data is output to a TV receiver or the like and pictures corresponding to the data are displayed thereon.
DVD data according to the MPEG scheme is recorded as a program stream that is a program consisting of video information, audio information, and associated data.
FIG. 1 shows an example configuration of a DVD player.
In a DVD player 1, among data that is read out from a disc (DVD) 101, presentation data (compressed as a program stream according to the MPEG scheme) consisting of video data, audio data, and sub-picture data that is associated with the video and audio data is supplied to a presentation engine 12. The presentation engine 12 reproduces those data and output resulting data to a display or the like.
On the other hand, navigation data that is read out from the disc 101 and specifies the order of reproduction, the behavior during a reproduction, and other things is supplied to a navigation manager 11. The navigation manager 11 controls the reproduction of data in the presentation engine 12 in accordance with the navigation data.
Further, the navigation manager 11 receives a signal that corresponds to a user's manipulation and is supplied from a given device (not shown), and executes a process corresponding to that signal, i.e., the user's manipulation.
For example, when the user manipulates a reproduction audio selection key (not shown) to change the audio language from Japanese to English, a signal corresponding to that manipulation is supplied to the navigation manager 11. The navigation manager 11 reads a stream number corresponding to an English audio sub-ID from a table showing a relationship between stream numbers and sub-IDs in navigation data, and outputs the acquired information to the presentation engine 12. Upon reception of that information, the presentation engine 12 changes the language from Japanese to English and outputs corresponding audio data.
FIG. 2 shows an example configuration of the navigation manager 11.
General control data, which is part of navigation data read out from the disc 101, is supplied to a general control section 21. The general control data includes general information of a stream such as the kind of compression mode, the kind of broadcast scheme (NTSC, PAL, or the like), and parental information.
The general control section 21 performs in advance the setting of decoders in the presentation engine 12. For example, the general control section 21 checks the general control data and judges an audio compression scheme (in the DVD, one of MPEG-Audio, Dolby AC-3, and Linear PCM) of data to be reproduced.
Entry search data, which is also part of the navigation data, is supplied to an entry search section 22. The entry search data includes an address table that indicates positions on the disc 101 where PGCI (program chain information) indicating a reproduction procedure of data to be reproduced and presentation data are recorded.
The entry search section 22 selects addresses corresponding to PGCI that is designated by parental information supplied from the general control section 21 and the presentation data.
User interface control data, which is also part of the navigation data, is supplied to a user interface control section 24. The user interface control data is data to prescribe, in accordance with the reproduction position, whether a user's manipulation is allowed or prohibited.
When a user's manipulation is allowed, the user interface control section 24 transfers a signal corresponding to a manipulation to a given circuit (not shown).
Navigation control data, which is also part of the navigation data, is PGCI and supplied to a navigation control section 23.
The navigation control section 23 extracts reproduction order and settings from the supplied PGCI, and outputs the extracted information to the presentation engine 12.
As the navigation manager 11 processes the navigation data in the above manner, the presentation engine 122 operates in accordance with settings that are recorded on the disc 101.
FIG. 3 shows an example configuration of the presentation engine 12.
A DEMUX (demultiplexer) section 31 classifies presentation data that is read out from the disc 101 into an audio pack, a video pack, and sub-picture pack in accordance with a stream ID that is written in a packet header of the presentation data, and outputs those data (packs) to an audio decoder 32, a video decoder 33, and a sub-picture decoder 34, respectively, in accordance with the kinds of data.
Each of the audio decoder 32, the video decoder 33, and the sub-picture decoder 34 decodes the supplied data, and outputs a decoded signal to a D/A converter 41 or a superimposing circuit 36.
A highlight decoder 35 designates a highlight position and color based on highlight information that is supplied from the navigation manager 11, and outputs a highlight picture to the superimposing circuit 36.
The superimposing circuit 36 superimposes a video picture supplied from the video decoder 33, a sub-picture (a caption or the like) supplied from the sub-picture decoder 34, and a highlight picture supplied from the highlight decoder 35, and outputs a superimposed picture to a D/A converter 42.
Each of the D/A converters 41 and 42 converts a supplied digital signal into an analog signal and outputs analog audio and video signals.
As described above, in playing back a DVD, navigation data is processed in addition to presentation data.
On the other hand, in an apparatus that receives digital satellite broadcasts, MPEG data that is transmitted from a broadcasting satellite is received and decoded by a built-in decoder, and pictures/information and sound corresponding to the decoded data are displayed or output. Since the MPEG data is transmitted in the form of a transport stream consisting of a plurality of programs, the above apparatus has a decoder suitable for processing of a transport stream.
However, there is a problem that when it is attempted to process data (MPEG data) of a DVD before decoding and to display or output pictures etc. corresponding to the decoded data by using an apparatus that has a decoder suitable for processing of a transport stream like the above-described apparatus, it is difficult to process the data as received because of a difference in data form (program stream vs. transport stream).