Multiformat transport stream demultiplexor

• US 6,731,657 B1
• Filed: 03/14/2000
• Issued: 05/04/2004
• Est. Priority Date: 03/14/2000
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Anderson, Richard E., Lloyd, Bryan J., Foster, Eric M.
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US09/525,156
• Time in Patent Office: 1,512 Days
• Field of Search: 370/412, 370/389, 370/516, 370/536, 370/395, 370/601, 370/466, 370/468, 370/498, 370/535, 370/543, 370/487, 370/486, 370/537, 714/746
• US Class Current: 370/536
• CPC Class Codes: H04N 21/23614 Multiplexing of additional data and video streams arrangements for simultaneous broadcast of plural pieces of information H04H20/28
• CPC Class Codes: H04N 21/4305 Synchronising client clock from received content stream, e.g. locking decoder clock with encoder clock, extraction of the PCR packets arrangements for synchronising receiver with transmitter by comparing receiver clock with transmitter clock H04L7/0012; arrangements for synchronising receiver with transmitter wherein the receiver takes measures against momentary loss of synchronisation H04L7/0083
• CPC Class Codes: H04N 21/434 Disassembling of a multiplex stream, e.g. demultiplexing audio and video streams, extraction of additional data from a video stream; Remultiplexing of multiplex streams; Extraction or processing of SI; Disassembling of packetised elementary stream demultiplexing of data packets for data networks, e.g. RTP/UDP H04L65/00
• CPC Class Codes: H04N 21/4341 Demultiplexing of audio and video streams
• CPC Class Codes: H04N 21/4348 Demultiplexing of additional data and video streams
• CPC Class Codes: H04N 21/435 Processing of additional data, e.g. decrypting of additional data, reconstructing software from modules extracted from the transport stream
• CPC Class Codes: H04N 21/8126 involving additional data, e.g. news, sports, stocks, weather forecasts

Abstract

The preferred embodiment of the present invention provides an improved receiver that can receive and process many different data types in addition to decoding MPEG-2 transport streams. The preferred embodiment minimizes hardware complexity by using the same loaders for both MPEG-2 and alternative stream data. The preferred embodiment utilizes a bypassable synchronizer and a bypassable packet parser to allow alternative data streams to be sent to system memory for decoding by a the host processor. When receiving MPEG-2 transport streams, the bypassable synchronizer and bypassable packet parser are used to synchronize and filter the MPEG-2 transport stream. The parsed MPEG-2 streams are then loaded into a packet buffer and passed to the video and audio decoders. When non-MPEG-2 stream data is provided, the bypassable synchronizer and bypassable packet parser instead forward the data to the packet buffer without performing synchronization or filtering. There, the non-MPEG-2 stream data is loaded into system memory. In memory, the non-MPEG-2 data can be decoded by the CPU and then passed onto the video and audio decoders. Thus, by selectively bypassing synchronizer and packet parser, the preferred embodiment allows the receiver to decode non-MPEG-2 data streams while maintaining the ability to perform real time decoding of MPEG-2 streams. Additionally, the preferred embodiment facilitates this dual purpose while minimizing device complexity.

Claims

1. A transport demultiplexor, the transport demultiplexor selectively receiving a first type transport stream and second type transport stream, the transport demultiplexor delivering first type transport stream system data to a data unloader, first type transport stream video data to a video unloader, and first type transport audio data to an audio unloader, the transport demultiplexor delivering second type transport stream data to the data unloader, the data unloader delivering the second type transport stream data to the data unloader, the data unloader delivering the second type transport stream data to system memory for processing, the transport demultiplexor including a bypassable synchronizer, the bypassable synchronizer receiving the first and second type of transport stream and synchronizing the first type transport stream before passing said first type transport stream, the bypassable synchronizer passing said second type of transport stream without regard to synchronization.

2. The transport demultiplexor of claim 1 wherein the transport demultiplexor includes a bypassable packet parser and a packet buffer, the bypassable packet parser receiving the first and second type transport stream from the bypassable synchronizer, the bypassable packet parser filtering the first type transport stream data before passing to the packet buffer, the bypassable packet parser delivering second type transport stream data to the packet buffer without filtering.

3. The transport demultiplexor of claim 2 wherein the bypassable packet parser includes a filter, the filter comparing packet identifications for first type transport stream data to a selected packet identification.

4. The transport demultiplexor of claim 1 further comprising a packet buffer, the packet buffer buffering the first type transport stream and the second type transport stream.

5. The transport demultiplexor of claim 4 further comprising buffer control, wherein the buffer control includes a packet manager, the packet manager selectively receiving first type transport stream video data from the packet buffer when requested by the video unloader, the packet manager selectively retrieving first type transport audio data from the packet buffer when requested by the audio unloader, the packet manager selectively receiving said first type transport stream system data and second type transport stream data from the packet buffer when requested by the data unloader.

6. The transport demultiplexor of claim 1 wherein the first type of transport stream comprises an MPEG-2 transport stream, and wherein the second type of transport stream comprises a non-MPEG-2 transport stream.

7. The transport demultiplexor of claim 2 wherein the bypassable packet parser appends packet identification information to the first type transport stream packets and to the second type transport stream packets according to the respective types of the first type transport stream and the second type transport stream, and wherein the appended packet identification is used by the transport demultiplexor to selectively route the first type transport stream and the second type transport stream to the video unloader, the audio unloader, and the data unloader.

8. A transport demultiplexor for receiving a first and second type of transport stream, the transport demultiplexor comprising:

a) front end logic;

b) a packet buffer;

c) a video unloader;

d) a data unloader; and

e) an audio unloader;

said front end logic receiver transport stream input packets, and delivering said transport stream packets to the packet buffer, and said packet buffer delivering first type transport stream system data to the data unloader, first type transport stream video data to the video unloader, and first type transport audio data to the audio loader, said packet buffer delivering second type transport stream data to the data unloader for delivering the second type transport stream data to system memory for processing, the front end logic including a bypassable synchronizer, the bypassable synchronizer receiving the first and second type of transport stream and synchronizing the first type transport stream into first type transport stream packets on predefined packet boundaries before passing said first type transport stream, the bypassable synchronizer passing second type of transport stream packets without regard to predefined packet boundaries.

9. The transport demultiplexor of claim 8 wherein the front end logic includes a bypassable packet parser, the bypassable packets parser receiving the first and second type of transport stream from the bypassable synchronizer, the bypassable parser filtering the first type transport stream data before passing to the packet buffer, the bypassable packet parser delivering second type transport stream data to the packet without filtering.

10. The transport demultiplexor of claim 9 wherein the bypassable packet parser retrieves identification information from first type transport stream packets, and wherein the bypassable packet parser appends packet identification to the first type transport stream packets from the retrieved identification information, the appended packet identification used identify the first type transport packets as video packets, audio packets or system data packets, and wherein the packet parser appends identification information to the second type transport stream packets to identify the second type transport stream packets.

11. The transport demultiplexor of claim 10 wherein first type transport stream appended packet identification is used to selectively route the first type transport stream packets to the video unloader, the audio unloader, and the data unloader, and wherein the second type transport stream appended packet identification is used to route the second type transport packets to the data unloader.

12. The transport demultiplexor of claim 8 wherein the buffer control includes a packet manager, the packet manager selectively retrieving first type transport stream video data when requested by the video unloader, the packet manager selectively retrieving first type transport audio data when requested by the audio unloader, the packet manager selectively retrieving said first type transport stream system data and second type transport stream data from the packet buffer when requested by the data unloader.

13. The transport demultiplexor of claim 8 wherein the data unloader includes a queue control, said queue control controlling storage location of said first transport stream system data in system memory.

14. A transport demultiplexor for receiving a first and second type of transport stream, the transport demultiplexor comprising:

a) front end logic;

b) a packet buffer;

c) a video unloader;

d) a data unloader; and

e) an audio unloader;

said front end logic receiver transport stream input packets, and delivering said transport stream packets to the packet buffer, and said packet buffer delivering first type transport stream system data to the data unloader, first type transport stream video data to the video unloader, and first type transport audio data to the audio loader, said packet buffer delivering second type transport stream data to the data unloader for delivering the second type transport stream data to system memory for processing, wherein the first type of transport stream comprises an MPEG-2 transport stream, and wherein the second type of transport stream comprises a non-MPEG-2 transport stream.

15. The transport demultiplexor of claim 14 wherein the front end logic includes a bypassable packet parser, the bypassable packer parser receiving the list and second type of transport stream from the bypassable synchronizer, the bypassable packet parser filtering the first type transport stream data before passing to the packet buffer, the bypassable packet parser delivering second type transport stream data to the packet buffer without filtering.

16. The transport demultiplexor claim 15 wherein the bypassable packet parser retrieves identification information from first type transport stream packets, and wherein the bypassable packet parser appends packet identification to the first type transport stream packets from the retrieved identification information, the appended packet identification use identify the first type transport stream packets as video packets, audio packets or system data packets, and wherein the packet parser appends identification information to the second type transport stream packets to identify the second type transport stream packets.

17. The transport demultiplexor of claim 16 wherein first type transport stream appended packet identification is used to selectively route the first type transport stream packets to the video unloader, the audio unloader, and the data unloader, and wherein the second type transport stream appended packet identification is used to route the second type transport packets to the data unloader.

18. The transport demultiplexor of claim 14 wherein the buffer control includes a packet manager, the packet manager selectively retrieving first type stream video data when requested by the video unloader, the packet manager selectively retrieving first type transport audio data when requested by the audio unloader, the packet manager selectively retrieving said first type transport stream system data and second type transport stream data from the packet buffer when requested by the data unloader.

19. The transport demultiplexor of claim 14 wherein the data unloader includes a queue control, said queue control controlling storage location of said first transport stream system data in system memory.

20. A transport demultiplexor for receiving MPEG-2 transport stream and alternative transport stream, the transport demultiplexor comprising:

a) packet buffer;

b) front end logic, the front end logic selectively receiving the MPEG-2 transport stream and the alternative transport stream, the front end logic comprising;

i) a bypassable synchronizer, the bypassable synchronizer receiving the MPEG-2 transport stream and the alternative transport stream, and synchronizing the MPEG-2 transport stream on MPEG-2 packet boundaries, the bypassable synchronizer passing said alternative transport stream without regard to predefined packet boundaries;

ii) a bypassable packet parser, the bypassable packet parser selectively receiving the MPEG-2 transport stream and the alternative transport stream, wherein the bypassable packet parser wherein the bypassable packet parser retrieves identification information from first type transport stream packets, and wherein the bypassable packet parser retrieves identification information from the MPEG-2 transport stream and appends packet identification from the retrieved identification information to the MPEG-2 transport packets, the appended packet identification used identify the MPEG-2 transport stream packets as video packets, audio packets or system data packets, and wherein the packet parser appends identification information to the second type transport stream packets to identify the second type transport stream packets, and wherein the bypassable packet parser filters the MPEG-2 transport stream data before passing appended MPEG-2 transport stream packets to the packet buffer, and wherein the bypassable packet parser passes appended alternative transport stream packets to the packet buffer without filtering;

c) a video unloader, the video unloader receiving MPEG-2 video packets from the packet buffer;

d) an audio unloader, the audio unloader receiving MPEG-2 audio packets from the packet buffer, and

e) data unloader, the data receiving MPEG-2 system data packets and receiving alternative transport stream packets, the data unloader delivering the alternative transport stream packets to system memory for processing.