Multistandard video decoder and decompression system for processing encoded bit streams including start code detection and methods relating thereto

• US 7,711,938 B2
• Filed: 01/26/2001
• Issued: 05/04/2010
• Est. Priority Date: 06/30/1992
• Status: Expired due to Fees

• Current Assignee: Coases Investments Bros LLC (Intellectual Ventures LLC)
• Original Assignee: Coases Investments Bros LLC (Intellectual Ventures LLC)
• Inventors: Robbins, William P, Wise, Adrian P, Boyd, Kevin J, Jones, Anthony M, Sotheran, Martin W, Claydon, Anthony Peter J, Finch, Helen R
• Primary Examiner(s): Nguyen; Dustin
• Application Number:
  US09/770,157
• Publication Number:
  US 20040025000A1
• Time in Patent Office: 3,385 Days
• Field of Search: 382/27, 382/303, 382/235, 382/304, 382/233, 711/169, 712/27, 714/30, 341/67, 348/400.1
• US Class Current: 712/300
• CPC Class Codes: G06F 12/0207 with multidimensional access, e.g. row/column, matrix
• CPC Class Codes: G06F 12/04 Addressing variable-length words or parts of words
• CPC Class Codes: G06F 12/0607 Interleaved addressing
• CPC Class Codes: G06F 13/16 for access to memory bus G06F13/28 takes precedence
• CPC Class Codes: G06F 13/1673 using buffers
• CPC Class Codes: G06F 13/1689 Synchronisation and timing concerns synchronisation on a memory bus G06F13/4234
• CPC Class Codes: G06F 13/28 using burst mode transfer, e.g. direct memory access DMA, cycle steal G06F13/32 takes precedence
• CPC Class Codes: G06F 9/3867 using instruction pipelines
• CPC Class Codes: G06F 9/4494 data driven
• CPC Class Codes: H04N 19/13 Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC]
• CPC Class Codes: H04N 19/42 characterised by implementation details or hardware specially adapted for video compression or decompression, e.g. dedicated software implementation H04N19/635 takes precedence
• CPC Class Codes: H04N 19/423 characterised by memory arrangements H04N19/433 takes precedence
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/91 Entropy coding, e.g. variable length coding [VLC] or arithmetic coding

Abstract

A pipeline video decoder and decompression system handles a plurality of separately encoded bit streams arranged as a single serial bit stream of digital bits and having separately encoded pairs of control codes and corresponding data carried in the serial bit stream. The pipeline system employs a plurality of interconnected stages to decode and decompress the single bit stream, including a start code detector. When in a search mode, the start code detector searches for a specific start code corresponding to one of multiple compression standards. The start code detector responding to the single serial bit stream generates control tokens and data tokens. A respective one of the tokens includes a plurality of data words. Each data word has an extension bit which indicates a presence of additional words therein. The data words are thereby unlimited in number. A token decode circuit positioned in certain of the stages recognizes certain of the tokens as control tokens pertinent to that stage and passes unrecognized control tokens to a succeeding stage. A reconfigurable decode and parser processing means positioned in certain of the stages is responsive to a recognized control token and reconfigures a particular stage to handle an identified data token. Methods relating to the decoder and decompression system include processing steps relating thereto.

Claims

1. A processing apparatus for decompressing video data, comprising:

a start code detector configured to receive a stream of video data comprising video data encoded in a first format and video data encoded in a second format and configured to convert a portion of the stream of video data into at least a stream of data tokens in response to detecting a start code sequence in the stream of video data wherein the stream of data tokens comprise a first plurality of data tokens that are associated with video data encoded in the first format and a second plurality of data tokens that are associated with video data encoded in the second format; and

a pipeline comprising stages that decode the video data in the first and second formats, the start code detector being coupled to send the data tokens to the pipeline.

2. The apparatus of claim 1, wherein a plurality of the stages of the pipeline have operating modes responsive to the formats of the data tokens.

3. The apparatus of claim 1, further comprising an inserter of search mode tokens to transmit search mode tokens into the stream of video data.

4. The apparatus of claim 1, wherein the start code detector is capable of searching for video start codes complying with different formats.

5. The apparatus of claim 4, wherein the formats include formats complying with at least two of the video standards selected from the group consisting of JPEG, MPEG, and H.261.

6. The apparatus of claim 3, wherein the start code detector ignores video data until a video start code is found in response to receiving one of the search mode tokens.

7. The apparatus of claim 1, further comprising:

two-wire interfaces coupling the consecutive stages of the pipeline.

8. The apparatus of claim 7, wherein the two-wire interfaces transmit data valid and data acceptance signals.

9. The apparatus of claim 1, wherein the start code detector is adapted to introduce new tokens into the stream of video data at detected start code sequences.

10. The apparatus of claim 2, wherein a portion of the stages of the pipeline reconfigure themselves to process data in response to receiving predetermined types of tokens.

11. The apparatus of claim 9, wherein the start code detector introduces picture end tokens into the stream of video data.

12. The apparatus of claim 1, wherein the start code detector is a hardware device.

13. The apparatus of claim 1, wherein the pipeline includes:

a Huffman decoder coupled to receive data from the start code detector;

a token formatter coupled to data from the Huffman decoder;

an inverse modeler coupled to receive data from the token formatter; and

an inverse quantizer coupled to receive data from the inverse modeler.

14. A method for decoding encoded video data, comprising:

detecting a search mode token in a video data stream comprising video data encoded with a first format and video data encoded with a second format; and

searching for a start code token in the video data stream in response to detecting the search mode token, wherein the start code token is associated with one of at least two different video encoding formats,

wherein the detecting and searching are performed by a computing system.

15. The method of claim 14, further comprising:

making a random access into the data stream to receive the portion of the video stream; and

wherein the search mode token is inserted in response to making the random access.

16. The method of claim 15, wherein the random access results from one of an error and a channel switch.

17. The method of claim 15, further comprising:

reconfiguring stages of a decoder to decode video data in response to detecting the start code token.

18. The method of claim 17 wherein searching recognizes start code tokens corresponding to video data encoded according to one of the standards MPEG, JPEG, and H.261.

19. An apparatus for processing encoded video data, comprising:

means for receiving video data having a plurality of stages for receiving and decoding a portion of a video data stream, the video data stream comprising video data encoded with a first format and video data encoded with a second format; and

means for detecting start code tokens in the video data stream in response to detecting a search mode token, wherein the start code tokens are associated with at least two different video encoding formats.

20. The apparatus of claim 19, further comprising a means for inserting that inserts a search mode token into the data stream in response to making a random access into the video data stream.

21. The apparatus of claim 20, wherein the random access results from one of an error and a channel switch.

22. The apparatus of claim 20, wherein a plurality of the stages reconfigure themselves to decode video data in response a start code token.

23. The apparatus of claim 22, wherein the start code token corresponds to video data encoded according to one of the standards MPEG, JPEG, and H.261.

24. The apparatus of claim 20, further comprising:

a semiconductor substrate, wherein the means for inserting and the means for detecting start code tokens are located on the substrate.

25. A processing system including memory, the processing system, comprising:

a start code detector to search for a start code sequence in a stream of video data in response to detecting a search mode token therein and to convert a portion of the stream of video data into data tokens in response to detecting a start code sequence in the stream of video data, wherein the stream of video data comprises video data encoded with a first standard and video data encoded with a second standard, and wherein a first plurality of the data tokens are associated with the first standard and wherein a second plurality of the data tokens associated with the second standard; and

decoder coupled to receive the data tokens from the start code detector and to decode the received data tokens into picture frames, the decoder configured to decode the first and second standards.

26. The system of claim 25, further comprising an inserter of search mode tokens coupled to insert search mode tokens into the stream of video data.

27. The system of claim 25, wherein the standards include two of JPEG, MPEG, and H.261.

28. The system of claim 25, wherein the decoder further comprises:

a Huffman decoder

an inverse quantizer coupled to the Huffman decoder; and

an inverse discrete cosine transformer coupled to the inverse quantizer.

29. The system of claim 25, wherein the decoder is a hardware device.