RELATED APPLICATIONS

This application makes reference to, claims priority to, and claims the benefit of U.S. Provisional Patent Application 60/573,357, filed on May 21, 2004 and entitled â€œMultistandard Video Decoder,â€ the complete subject matter of which is hereby incorporated herein by reference in its entirety.

This application is related to the following applications, each of which is incorporated herein by reference in its entirety for all purposes:

U.S. patent application Ser. No. 10/963,677 filed Oct. 13, 2004;

U.S. patent application Ser. No. 10/985,501 filed Nov. 10, 2004;

U.S. patent application Ser. No. 11/112,632 filed Apr. 22, 2005;

U.S. patent application Ser. No. 10/985,110 filed Nov. 10, 2004;

U.S. patent application Ser. No. 10/981,218 filed Nov. 4, 2004;

U.S. patent application Ser. No. 10/965,172 filed Oct. 13, 2004;

U.S. patent application Ser. No. 10/972,931 filed Oct. 25, 2004;

U.S. patent application Ser. No. 10/974,179 filed Oct. 27, 2004;

U.S. patent application Ser. No. 10/974,872 filed Oct. 27, 2004;

U.S. patent application Ser. No. 10/970,923 filed Oct. 21, 2004;

U.S. patent application Ser. No. 10/963,680 filed Oct. 13, 2004;

U.S. patent application Ser. No. 11/013,768 filed Dec. 16, 2004;

U.S. patent application Ser. No. 11/102,389 filed Apr. 8, 2005;

U.S. patent application Ser. No. 11/135,929 filed May 23, 2005; and

U.S. patent application Ser. No. 11/000,676 filed Dec. 1, 2004.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[Not Applicable]

MICROFICHE/COPYRIGHT REFERENCE

[Not Applicable]

BACKGROUND OF THE INVENTION

During encoding of a video signal, one or more encoding techniques, such as H.261, H.263, H.263+ (Annex J), H.264, SMPTE VC-1, MPEG-1, MPEG-2 and/or MPEG-4, may be utilized to encode the video signal on a macroblock-by-macroblock basis. During encoding of video information, for example, prediction error information may be encoded together with prediction mode information, as well as with other side information necessary for the decoding process. In order to encode the prediction error information, a discrete cosine transformation may be applied to transform the prediction error information into frequency domain coefficients prior to quantization and entropy encoding. During this process, certain information relating to the prediction error, for example, may be lost. As a result of the missing information, the quality of the decoded video signal may be decreased. More specifically, transform blockiness may appear in the decoded video in the form of square grid artifacts, for example. Other artifacts may also appear in the decoded video due to missing video information.

Conventional video decoders are adapted to decode elementary video stream encoded according to a single encoding standard, such as H.264, VC-1, MPEG-1, MPEG-2 and/or MPEG-4 encoding standards. An elementary video stream may be encoded utilizing a single encoding technique. However, an application space may support a stream being encoded using any one of many standards. For example, the Blu-Ray ROM specification for high definition DVD playback allows a video stream to be encoded using MPEG-2, H.264, or VC-1.

However, decoding efficiency in conventional video processing systems is substantially decreased since two or more decoders may need to be utilized for processing/decoding of elementary video streams that may have been encoded according to different encoding standards.

Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of ordinary skill in the art through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.

BRIEF SUMMARY OF THE INVENTION

Certain embodiments of the invention may be found in a method and system for processing an encoded video stream. Aspects of the method may comprise receiving on a chip, packetized data within the encoded video stream. An identifier within the received packetized data may be determined on the chip, where the identifier may define one of a plurality of encoding types associated with packets in the encoded video stream. A decoding process may be selected on the chip from a plurality of decoding processes, based on the determined identifier. A portion of the received packetized data in the encoded video stream may be decoded on the chip utilizing the selected decoding process. A delimiter may be determined within the received packetized data that separates packets within the encoded video stream. A plurality of bytes within the received packetized data may be matched with a determined byte sequence. If the plurality of bytes matches the determined byte sequence, the plurality of bytes may be removed from the received packetized data.

If the determined identifier corresponds to H.264 video encoding, the received packetized data may be decoded utilizing a fixed length coding (FLC) process, a variable length coding (VLC) process and/or a context adaptive binary arithmetic coding (CABAC) process. If the determined identifier corresponds to VC-1, H.261, H.263, H.263+, MPEG-1, MPEG-2 and/or MPEG-4 video encoding, the received packetized data may be decoded utilizing a FLC process and/or a VLC process. The decoded packetized data may comprise decoding process control information and/or prediction error information. A decoded video stream may be generated utilizing the decoded packetized data. The generated decoded video stream may be filtered utilizing an overlapped transform process and/or a deblocking process. For each of the plurality of decoding processes, a portion of the received packetized data may be decoded on the chip utilizing inverse transformation, inverse quantization, and/or motion compensation.

Another embodiment of the invention may provide a machine-readable storage, having stored thereon, a computer program having at least one code section executable by a machine, thereby causing the machine to perform the steps as described above for processing an encoded video stream.

Aspects of the system may comprise at least one processor that receives on a chip, packetized data within the encoded video stream on a chip. The processor may determine on the chip an identifier within the received packetized data that defines one of a plurality of encoding types associated with packets in the encoded video stream. A decoding process may be selected by the processor from a plurality of decoding processes based on the determined identifier. A portion of the received packetized data in the encoded video stream may be decoded by the processor utilizing the selected decoding process. A delimiter within the received packetized data that separates packets within the encoded video stream may be determined by the processor. The processor may match a plurality of bytes within the received packetized data with a determined byte sequence and if the plurality of bytes matches the determined byte sequence, the plurality of bytes may be removed by the processor from the received packetized data.

If the determined identifier corresponds to H.264 video encoding, the received packetized data may be decoded by the processor utilizing a fixed length coding (FLC) process, a variable length coding (VLC) process and/or a context adaptive binary arithmetic coding (CABAC) process. If the determined identifier corresponds to VC-1, H.261, H.263, H.263+, MPEG-1, MPEG-2 and/or MPEG-4 video encoding, the received packetized data may be decoded by the processor utilizing a FLC process and/or a VLC process. The decoded packetized data may comprise decoding process control and/or prediction error information. A decoded video stream may be generated by the processor utilizing the decoded packetized data. The processor may filter the generated decoded video stream utilizing an overlapped transform process and/or a deblocking process.

These and other features and advantages of the present invention may be appreciated from a review of the following detailed description of the present invention, along with the accompanying figures in which like reference numerals refer to like parts throughout.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1

is a block diagram of an encapsulated video payload with a delimiter, in accordance with an embodiment of the invention.

FIG. 2

is a block diagram illustrating byte destuffing within elementary video stream data, in accordance with an embodiment of the invention.

FIG. 3A

is a high level block diagram illustrating a multistandard video decoder, in accordance with an embodiment of the invention.

FIG. 3B

is a high level block diagram illustrating a multistandard video decoder utilizing a single CPU, in accordance with an embodiment of the invention.

FIG. 3C

is a high level block diagram illustrating a multistandard video decoder utilizing a CPU pair, in accordance with an embodiment of the invention.

FIG. 4A

is a block diagram illustrating a multistandard video decoder with hardware assist blocks and a single CPU, in accordance with an embodiment of the invention.

FIG. 4B

is a block diagram illustrating a multistandard video decoder with hardware assist blocks and a CPU pair, in accordance with an embodiment of the invention.

FIG. 5

is a block diagram illustrating operation of the multistandard video decoder of

FIG. 4

when decoding H.264 video data, in accordance with an embodiment of the invention.

FIG. 6

is a block diagram illustrating operation of the multistandard video decoder of

FIG. 4

when decoding VC-1 video data, in accordance with an embodiment of the invention.

FIG. 7

is a block diagram illustrating operation of the multistandard video decoder of

FIG. 4

when decoding MPEG-1 or MPEG-2 video data, in accordance with an embodiment of the invention.

FIG. 8

is a block diagram illustrating operation of the multistandard video decoder of

FIG. 4

when decoding MPEG-4 video data, in accordance with an embodiment of the invention.

FIG. 9

is a flow diagram of an exemplary method for processing an encoded video stream, in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Certain aspects of the invention may be found in a method and system for processing an encoded video stream. During encoding of a video stream, different encoding standards may be utilized to encode data within elementary video streams. In one aspect of the invention, a multistandard video decoder may be adapted to acquire an elementary video stream encoded according to an encoding standards, such as H.261, H.263, H.263+ (Annex J), H.264, VC-1, MPEG-1, MPEG-2 and/or MPEG-4, for example. The multistandard decoder may locate one or more delimiters within the elementary video stream, where the delimiters may separate packetized data within encapsulated video payloads. Each delimiter may comprise a start code information signaling the beginning of a video payload and an encoding type information.

The encoding type information may be associated with a method of encoding utilized by an encoder to encode a corresponding video payload. The multistandard decoder may also destuff, or remove, one or more bytes from the encapsulated video payload, where such bytes were inserted by an encoder to avoid false start codes from being present in the video payload. Depending on the encoding type information, the encapsulated video payload may be decoded on-chip utilizing corresponding decoding modules. For example, temporal or spatial prediction pixels may be generated from decoding process control information in the encapsulated video payload. In addition, prediction errors may also be generated from quantized frequency coefficients within the encoded video payload. A decoded video stream may then be reconstructed utilizing temporal and/or spatial prediction pixels and prediction error information. In one aspect of the invention, the multistandard decoder may utilize a single central processing unit (CPU) to process header information and macroblock information within the packets in the encoded bitstream. In another aspect of the invention, a CPU pair may be utilized, where a first CPU may process future header information while a second CPU may process current macroblock information.

FIG. 1

is a block diagram of an encapsulated video payload 100 with a delimiter, in accordance with an embodiment of the invention. Referring to

FIG. 1

, the encapsulated video payload 100 may comprise a delimiter 104 and elementary video stream data 105. The delimiter 104 may comprise a start code 101 and a start code suffix 103 and may be utilized by a decoder, for example, to locate a starting bit for the encapsulated video payload 100 as well as a starting bit for the elementary video stream data 105. In addition, the delimiter 104 may comprise information relating to the method of encoding utilized to encode the elementary video stream data 105. The elementary video stream data may comprise a plurality of bytes, where each byte may comprise two nibbles.

The start code 101 may comprise a plurality of bytes that may be arranged in a unique combination to signify the beginning of the encapsulated video payload 100 within an encoded video stream. For example, the start code 101 may comprise an exemplary byte sequence â€œ00 00 01.â€ The start code suffix 103 may comprise one or more bytes located after the start code 101 within the encapsulated video payload 100. In one aspect of the invention, the start code suffix 103 may correspond to an encoding method utilized to encode the elementary video stream data 105 within the encapsulated video payload 100. For example, the start code suffix 103 may correspond to H.264, VC-1, MPEG-1, MPEG-2 and/or MPEG-4 as the encoding method utilized to encode the elementary video stream data 105. The start code 101 and the start code suffix 103 may be generated by the encoder prior to communicating the encoded video stream data to a video decoder.

FIG. 2

is a block diagram illustrating byte destuffing within elementary video stream data 200, in accordance with an embodiment of the invention. Referring to

FIG. 2

, the elementary video stream data 200 may comprise elementary video data sequences 201 and 203. The elementary video stream data 200 may be preceded by a delimiter comprising a start code sequence and a start code suffix, as illustrated on

FIG. 1

. During video signal encoding and after an encoder has generated a delimiter for the elementary video stream data 200, the encoder may insert one or more bytes in the elementary video stream data 200 so that a corresponding start code sequence may not be recognized by a decoder within the elementary video stream data 200 during decoding.

For example, during encoding of the elementary video stream data 200, an encoder may utilize a start code comprising the byte sequence â€œ00 00 01.â€ During decoding of the elementary video stream 200, a decoder may incorrectly identify the start code sequence â€œ00 00 01â€ within the elementary stream 200. In order to avoid any such mis-identification of a start code sequence, an encoder may insert one or more extra characters/symbols, or a stuffing byte, so that a start code sequence may not be mis-identified within the elementary video stream 200 during decoding. For example, an extra character string, or a stuffing byte, â€œ03â€ may be inserted within the byte sequence 205 within the elementary video data sequence 201. Similarly, the stuffing byte â€œ03â€ may also be inserted within the byte sequence 207 within the elementary video data sequence 203. In this manner, the decoder may be prevented from recognizing the start code sequence â€œ00 00 01â€ during decoding of the elementary video stream 200.

During decoding of the elementary video stream 200, a video decoder may destuff or remove, any extra characters inserted in the elementary video stream 200 during encoding. Accordingly, the extra character string â€œ03â€ may be removed from the byte sequence 205 within the elementary video data sequence 201, and the extra character â€œ2â€ may be removed from the byte sequence 207 within the elementary video data sequence 207. In this manner, a raw video payload may be generated after removing any extra characters within the elementary video stream 200. The resulting raw video payload may then be decoded by a symbol interpreter, for example.

FIG. 3A

is a high level block diagram illustrating a multistandard video decoder, in accordance with an embodiment of the invention. Referring to

FIG. 3A

, the multistandard video decoder 300 may comprise a memory block 301, a code-in-port (CIP) 305, a stream parser 307, and a processing block 303. The CIP 305 comprises suitable circuitry, logic and/or code and may be adapted to acquire an elementary video stream 309. The CIP 305 may also be adapted to locate start codes and start code suffixes within the elementary video stream 309 and to destuff extra bytes from the elementary video stream 309, thus generating raw elementary video stream.

The multistandard video decoder 300 may utilize the stream parser 307 to process start code information and raw stream information that may be acquired from the CIP 305. For example, the stream parser 307 may be adapted to process header information and/or macroblock information from the raw elementary bitstream generated by the CIP 305. Header information from the raw elementary bitstream may comprise slice information, picture information, GOP/entry point information, and/or sequence information, for example. Slice packets within the raw elementary video stream generated by the CIP 305 may comprise slice header information and macroblock information corresponding to the particular slice. In addition, the stream parser 307 may be adapted to process header and/or macroblock information in the raw elementary stream acquired from the CIP 305, and generate quantized frequency coefficients information and/or additional side information, for example, necessary for decoding of macroblock information in the raw elementary video stream.

The stream parser 307 may comprise one or more decoder assist blocks specific to each mode of encoding that may be utilized to decode the raw elementary stream. The output signal from the stream parser 307 may be communicated to the processing block 303 via the bus 311. The bus 311 may be implemented within the multistandard video decoder 300 as a one-way bus communicating information to the processing block 303 to increase processing efficiency and simplicity of implementation. Temporary information generated during decoding of the raw elementary video stream may be stored by the stream parser 307 and/or by the CIP 305 in the memory module 301. The memory module 301 may comprise DRAM, for example.

In an exemplary aspect of the invention, the stream parser 307 may be implemented utilizing a single CPU and a single corresponding symbol interpreter (SI). The single CPU/SI configuration may be utilized to process the entire video elementary stream, including start codes/suffixes, header information, and/or macroblock information. In another aspect of the invention, the stream parser 307 may be implemented utilizing two separate CPUs and symbol interpreters for increased processing efficiency. For example, in the exemplary dual-CPU/SI configuration, a first CPU and a first SI may be utilized to process header information within the elementary video stream, and a second CPU with a corresponding second SI may be utilized to process macroblock information from the elementary bitstream. In this regard, subsequent header information may be processed by the first CPU and the first SI, while the second CPU and the second SI may simultaneously process current macroblock information.

The processing block 303 may utilize the processing information generated by the stream parser 307 to generate a decoded video stream 313. The processing block 303 comprises suitable circuitry, logic and/or code and may be adapted to perform one or more of the following processing tasks: spatial prediction, motion compensation, inverse quantization and transformation, macroblock reconstruction, in-loop macroblock filtering, and/or macroblock post processing. Each of the processing tasks within the processing block 303 may utilize one or more assist blocks corresponding to a specific encoding method that may have been utilized to encode the elementary video stream 309. In this regard, the processing block 303 may be adapted to decode an elementary video stream that may have been encoded utilizing one of a plurality of encoding methods, such as H.261, H.263, H.263+ (Annex J), H.264, VC-1, MPEG-1, MPEG-2 and/or MPEG-4, for example.

FIG. 3B

is a high level block diagram illustrating a multistandard video decoder 320 utilizing a single CPU, in accordance with an embodiment of the invention. Referring to

FIG. 3B

, the multistandard video decoder 320 may comprise a memory block 321, a code-in-port (CIP) 329, an inner loop central processing unit (ILCPU) 325, an inner loop symbol interpreter (ILSI) 327, and a processing block 323. The CIP 329 comprises suitable circuitry, logic and/or code and may be adapted to acquire an elementary video stream 331. The CIP 329 may also be adapted to locate start codes and/or start code suffixes within the elementary video stream 331 and to destuff extra bytes from the elementary video stream 331, thus generating raw elementary video stream.

In an exemplary embodiment of the invention, the multistandard video decoder 320 may utilize the ILCPU 325 and the ILSI 327 to process header information and/or macroblock information from the raw elementary bitstream generated by the CIP 329. Header information from the raw elementary bitstream may comprise slice information, picture information, GOP/entry point information, and/or sequence information, for example. Slice packets within the raw elementary video stream generated by the CIP 329 may comprise slice header information and/or macroblock information corresponding to the particular slice.

The ILSI 327 comprises suitable circuitry, logic and/or code and may be adapted to process header and/or macroblock information in the raw elementary stream acquired from the CIP 329, and generate quantized frequency coefficients information and/or additional side information, for example, necessary for decoding of macroblock information in the raw elementary video stream. The ILSI 327 may comprise one or more decoder assist blocks specific to each mode of encoding that may be utilized to decode the raw elementary stream.

The ILCPU 325 may be adapted to sequence the ILSI 327 by, for example, providing decoding instructions to the ILSI 327 via the bus 333. The bus 333 may be implemented within the multistandard video decoder 320 as a one-way bus communicating information to the processing block 323 to increase processing efficiency and simplicity of implementation. Temporary information generated during decoding of the raw elementary video stream may be stored by the ILCPU 325, the CIP 329, and/or the ILSI 327 in the memory module 321. The memory module 321 may comprise DRAM, for example.

In operation, the incoming elementary video stream 331 may comprise video data encoded according to one of a plurality of encoding standards, such as H.261, H.263, H.263+ (Annex J), H.264, VC-1, MPEG-1, MPEG-2, and/or MPEG-4, for example. The CIP 329 may be adapted to detect one or more start codes and start code suffixes, which may correspond to the mode of encoding of the elementary video stream 331. The CIP 329 may also be adapted to generate a raw elementary video stream comprising header and/or macroblock information. The start codes and the raw elementary stream may be communicated, via the memory 321, to the ILCPU 325 and the ILSI 327 for further processing. The ILSI 327, utilizing instructions from the ILCPU 325, may be adapted to process the header and/or macroblock information communicated by the CIP 329. The ILSI 327 may then generate an output signal that may comprise acquired macroblock type information, slice type information, prediction mode information, motion vector information, and/or quantized frequency coefficients, for example. The output signal may be communicated via the bus 333 to the processing block 323 for use during macroblock decoding.

The processing block 323 may utilize the processing information generated by the ILSI 327 to generate a decoded video stream 335. The processing block 323 comprises suitable circuitry, logic and/or code and may be adapted to perform one or more of the following processing tasks: spatial prediction, motion compensation, inverse quantization and transformation, macroblock reconstruction, in-loop macroblock filtering, and/or macroblock post processing. Each of the processing tasks within the processing block 323 may utilize one or more assist blocks corresponding to a specific encoding method that may have been utilized to encode the elementary video stream 331. In this regard, the processing block 323 may be adapted to decode an elementary video stream that may have been encoded utilizing one of a plurality of encoding methods, such as H.261, H.263, H.263+ (Annex J), H.264, VC-1, MPEG-1, MPEG-2, and/or MPEG-4, for example.

FIG. 3C

is a high level block diagram illustrating a multistandard video decoder 340 utilizing a CPU pair, in accordance with an embodiment of the invention. Referring to

FIG. 3C

, the multistandard video decoder 340 may comprise a memory block 341, an outer loop central processing unit (OLCPU) 349, a code-in-port (CIP) 351, an outer loop symbol interpreter (OLSI) 353, an inner loop central processing unit (ILCPU) 345, an inner loop symbol interpreter (ILSI) 347, and a processing block 343. The CIP 351 comprises suitable circuitry, logic and/or code and may be adapted to acquire an elementary video stream 355. The CIP 351 may also be adapted to locate start codes and start code suffixes within the elementary video stream 355 and to destuff extra bytes from the elementary video stream 355, thus generating raw elementary video stream.

In an exemplary embodiment of the invention, the multistandard video decoder 340 may utilize a CPU pair, such as ILCPU 345 and OLCPU 349, with corresponding ILSI 347 and OLSI 353, to separately process header information and macroblock information from the raw elementary bitstream generated by the CIP 351. Header information from the raw elementary bitstream may comprise slice information, picture information, GOP/entry point information, and/or sequence information, for example. Slice packets within the raw elementary video stream generated by the CIP 351 may comprise slice header information and macroblock information corresponding to the particular slice. For example, the OLCPU 349 and the OLSI 353 may be adapted to process header information from the raw elementary bitstream generated by the CIP 351. In addition, the ILCPU 345 and the ILSI 347 may be adapted to process macroblock information from the raw elementary bitstream generated by the CIP 351. In this manner, parallel processing may be achieved within the multistandard video decoder 340 as the OLCPU 349 and the OLSI 353 may process future header information, while the ILCPU 345 and the ILSI 347 may process current macroblock information.

The ILSI 347 comprises suitable circuitry, logic and/or code and may be adapted to process macroblock information in the raw elementary stream acquired from the CIP 351, and generate quantized frequency coefficients information and/or additional side information, for example, necessary for decoding of macroblock information in the raw elementary video stream. The ILSI 347 may comprise one or more decoder assist blocks specific to each mode of encoding that may be utilized to decode the raw elementary stream. The OLSI 353 comprises suitable circuitry, logic and/or code and may be adapted to process header information in the raw elementary stream acquired from the CIP 351.

The ILCPU 345 may be adapted to sequence the ILSI 347 by, for example, providing decoding instructions to the ILSI 347 via the bus 357. The bus 357 may be implemented within the multistandard video decoder 340 as a one-way bus communicating information to the processing block 343 to increase processing efficiency and simplicity of implementation. Temporary information generated during decoding of the raw elementary video stream may be stored by the ILCPU 345, the OLCPU 349, the OLSI 353, the CIP 351, and/or the ILSI 347 in the memory module 341. The memory module 341 may comprise DRAM, for example.

In operation, the incoming elementary video stream 355 may comprise video data encoded according to one of a plurality of encoding standards, such as H.261, H.263, H.263+ (Annex J), H.264, VC-1, MPEG-1, MPEG-2, and/or MPEG-4, for example. The CIP 351 may be adapted to detect one or more start codes and start code suffixes, which may correspond to the mode of encoding of the elementary video stream 355. The CIP 351 may also be adapted to generate a raw elementary video stream comprising header and/or macroblock information. Header information within the raw elementary stream generated by the CIP 351 may be communicated to the OLCPU 349 and the OLSI 353 for further processing. The start codes and macroblock information within the raw elementary stream may be communicated, via the memory 341, to the ILCPU 345 and the ILSI 347 for further processing. In an exemplary aspect of the invention, the OLCPU 349 and the OLSI 353 may be adapted to process subsequent, or future, header information, while the ILCPU 345 and the ILSI 347 may process current macroblock information.

The ILSI 347, utilizing instructions from the ILCPU 345, may be adapted to process the macroblock information in the raw elementary stream communicated by the CIP 351. The ILSI 347 may then generate an output signal that may comprise acquired macroblock type information, slice type information, prediction mode information, motion vector information, and/or quantized frequency coefficients, for example. The output signal may be communicated via the bus 357 to the processing block 343 for use during macroblock decoding.

The processing block 343 may utilize the processing information generated by the ILSI 347 to generate a decoded video stream 361. The processing block 343 comprises suitable circuitry, logic and/or code and may be adapted to perform one or more of the following processing tasks: spatial prediction, motion compensation, inverse quantization and transformation, macroblock reconstruction, in-loop macroblock filtering, and/or macroblock post processing. Each of the processing tasks within the processing block 343 may utilize one or more assist blocks corresponding to a specific encoding method that may have been utilized to encode the elementary video stream 355. In this regard, the processing block 343 may be adapted to decode an elementary video stream that may have been encoded utilizing one of a plurality of encoding methods, such as H.261, H.263, H.263+ (Annex J), H.264, VC-1, MPEG-1, MPEG-2 and/or MPEG-4, for example.

FIG. 4A

is a block diagram illustrating a multistandard video decoder with hardware assist blocks and a single CPU, in accordance with an embodiment of the invention. Referring to

FIG. 4A

, the multistandard video decoder 400 may comprise a code-in-port (CIP) 403, a symbol interpreter 405, a central processing unit (CPU) 407, a spatial prediction block 409, an inverse quantization and transformation (IQT) block 411, a motion compensation block 413, a reconstructor 415, an in-loop filter 417, a frame buffer 419 and a post-processing block 421.

The CIP 403 comprises suitable circuitry, logic and/or code and may be adapted to receive video elementary code stream 401 and generate start codes, start code suffixes and raw elementary stream. The CIP 403 may comprise a start code finding block 423 and a byte destuffing block 425. The start code finding block 423 may be adapted to locate start codes and start code suffixes, as illustrated in

FIG. 1

. The byte destuffing block 425 may be adapted to destuff extra bytes from the video elementary codestream 401 and generate raw elementary stream data, as illustrated in

FIG. 2

. After the start codes, start code suffixes and raw elementary stream are generated within the CIP 403, the start code suffixes 426 may be communicated to the CPU 407 and the raw elementary stream may be communicated to the symbol interpreter 405 for further processing.

In an exemplary embodiment of the invention, the multistandard video decoder 400 may utilize the CPU 407 and the symbol interpreter 405 to process header information and/or macroblock information from the raw elementary bitstream generated by the CIP 403. Header information from the raw elementary bitstream may comprise slice information, picture information, GOP/entry point information, and/or sequence information, for example. Slice packets within the raw elementary video stream generated by the CIP 403 may comprise slice header information and macroblock information corresponding to the particular slice.

The symbol interpreter 405 comprises suitable circuitry, logic and/or code and may be adapted to interpret raw elementary stream 424 acquired from the CIP 403 to obtain quantized frequency coefficients information and/or additional side information necessary for decoding of the raw elementary video stream 424. The symbol interpreter 405 may also communicate to the CPU 407, video information on subsequent macroblock and/or frame within the raw elementary video stream 424 via the connection 406. After the CPU 407 acquires start code suffixes 426 from the CIP 403, the CPU 407 may generate one or more decoding instructions for the symbol interpreter 405 based on the encoding method associated with the acquired start code suffixes 426. The CPU 407 may be adapted to sequence the symbol interpreter 405 by providing such decoding instructions to the symbol interpreter 405 via the connection 408. The CPU 407 may also communicate decoding instructions to the symbol interpreter 405 based on received video information on a subsequent macroblock and/or frame via the connection 406.

In one aspect of the invention, the incoming elementary video stream 401 may comprise video data encoded according to one of a plurality of encoding standards, such as H.261, H.263, H.263+ (Annex J), H.264, VC-1, MPEG-1, MPEG-2 and/or MPEG-4, for example. The symbol interpreter 405, utilizing instructions from the CPU 407, may be adapted to decode one or more symbols and/or additional processing information, such as header and/or macroblock information, that may be utilized to complete decoding of the raw elementary stream 424 received from the CIP 403. The symbol interpreter 405 may comprise a plurality of decoder assist blocks specific to each mode of encoding that may be utilized to decode the raw elementary stream 424.

In an illustrative embodiment of the invention, the symbol interpreter 405 may comprise a fixed length coding (FLC) block 427, a variable length coding (VLC) block 429, a context adaptive binary arithmetic coding (CABAC) block 433, a coefficient construction block 435, and a vector construction block 437. The decoder assist blocks within the symbol interpreter 405 may be utilized during decoding depending on encoding method information that may be obtained from a start code suffix 426 generated by the CIP 403 and communicated to the CPU 407. The FLC block 427, the VLC block 429 and the CABAC block 433 may be utilized by the symbol interpreter 405 to decode/interpret single syntax elements from the raw elementary stream 424 that were encoded utilizing fixed length coding, variable length coding or CABAC coding techniques, respectively.

The coefficient construction block 435 may be adapted to generate one or more quantized frequency coefficients from the raw elementary stream 424. Quantized frequency coefficients generated by the coefficient construction block 435 may be subsequently utilized within the multistandard video decoder 400 to generate prediction error information utilized during reconstruction of one or more macroblocks. The generated quantized frequency coefficients may be communicated by the symbol interpreter 405 to the IQT block 411 for further processing.

Similarly, the vector construction block 437 may be adapted to generate one or more motion vectors from the raw elementary stream 424. The motion vectors generated by the vector construction block 437 may be utilized within the multistandard video decoder 400 to generate prediction pixels utilized during reconstruction of one or more macroblocks. The generated motion vector information may be communicated by the symbol interpreter 405 to the motion compensation block 413 for further processing.

The spatial prediction block 409 comprises suitable circuitry, logic and/or code and may be adapted to generate prediction pixels used by the reconstruction block 415 to generate a decoded macroblock. The spatial prediction block 409 may be adapted to acquire macroblock type information, slice type information and/or prediction mode information, for example, from the symbol interpreter 405. The spatial prediction block 409 may then utilize the acquired macroblock type information, slice type information and/or prediction mode information to generate prediction pixels for spatially predicted macroblocks.

The motion compensation block 413 comprises suitable circuitry, logic and/or code and may be adapted to generate prediction pixels utilizing motion vector information received from the symbol interpreter 405. For example, the motion compensation block 413 may generate prediction pixels for temporally predicted macroblocks, which may be associated with motion compensation vectors in frames/fields neighboring a current frame/field. The motion compensation block 413 may acquire previous and/or subsequent frames/fields from the frame buffer 419 and utilize the acquired previous and/or subsequent frames/fields for predicting temporally encoded pixels within a current macroblock.

The motion compensation block 413 may comprise a plurality of motion compensation assist blocks that may be utilized to generate the prediction pixels depending on the method utilized to encode the raw elementary stream data 424. For example, the motion compensation block 413 may comprise a range remap block 447, an intensity compensation block 449, an interpolation block 451, a variable block sizing module 453, and bidirectional prediction block 455. The interpolation block 451 may be adapted to interpolate one or more prediction pixels within a current frame utilizing motion vector information received from the symbol interpreter 405, as well as one or more reference frames that are temporally adjacent to the current frame.

If prediction pixels are interpolated utilizing only one reference frame, the interpolation block 451 may be utilized to generate the prediction pixels. However, if more than one prediction reference frames are utilized during temporal prediction of a current pixel, the bidirectional prediction block 455 may be utilized by the motion compensation block 413 to generate the prediction pixels. For example, if several reference frames are utilized for prediction of a current pixel, the bidirectional prediction block 455 may determine the current prediction pixel as an average of the prediction pixels in the reference frames.

The range remap block 447 may be utilized by the motion compensation block 413 during decoding of a VC-1 encoded raw elementary stream. More specifically, the range remap block 447 may be utilized to remap the dynamic range of a reference frame prior to interpolation by the interpolation block 451. The intensity compensation block 449 may be utilized by the motion compensation block 413 to adjust the intensity level of a reference frame to the intensity level of a current frame prior to interpolation by the interpolation block 451.

The variable block sizing module 453 may be utilized by the motion compensation block 413 to control utilization of reference frames acquired from the frame buffer 419. For example, the variable block sizing module 453 may fetch a 16Ã—16, 16Ã—8 and/or 4Ã—4 pixel size macroblock from the frame buffer 419 for use during temporal prediction of pixels within a current macroblock. Other macroblock and/or frame sizes may also be supported by the frame buffer 419, as may be required during motion compensation prediction within the motion compensation block 413.

The IQT block 411 comprises suitable circuitry, logic and/or code and may be adapted to transform quantized frequency coefficients received from the symbol interpreter 405 into one or more prediction errors. More specifically, the IQT block 411 may be adapted to utilize the inverse quantization block 443 and the inverse transformation block 445 to transform the quantized frequency coefficients back to spatial domain, thus generating prediction error information. The prediction error information generated by the IQT block 411 may then be communicated to the reconstructor 415 for further processing during reconstruction of a macroblock.

The inverse zigzag block 439 may be utilized by the IQT block 411 to rearrange the quantized frequency coefficients received from the symbol interpreter 405 prior to inverse transformation by the inverse transformation block 445. Quantized frequency coefficients generated by the symbol interpreter 405 may have been arranged in a zigzag scan order to facilitate encoding. Accordingly, the inverse zigzag block 439 may utilize one or more look-up tables to arrange the quantized frequency coefficients in sequential order, for example.

Depending on the encoding method of the raw elementary stream 424, the IQT block 411 may utilize an AC/DC prediction block 441 during decoding of the prediction error information. For example, quantized frequency coefficients may be encoded within the raw elementary stream 424 utilizing prediction residuals and prediction errors from neighboring pixels. Further, DC prediction within the AC/DC prediction block 441 may correspond to zero frequency coefficients utilized for generating prediction error information. AC prediction within the AC/DC prediction block 441 may correspond to low frequency coefficients utilized for generating prediction error information. Additional information on the operation of a symbol interpreter, motion compensation block, spatial prediction block and inverse quantization and transformation block is more fully disclosed in U.S. patent application Ser. No. 10/963,677 filed Oct. 13, 2004, which is incorporated herein by reference in its entirety.

The reconstructor 415 may be adapted to acquire spatial prediction pixels or temporal prediction pixels from the spatial prediction block 409 or the motion compensation block 413, respectively. In addition, the reconstructor 415 may be adapted to acquire prediction error information generated by the IQT block 411. The reconstructor 415 may then reconstruct a current macroblock utilizing prediction pixels and prediction error information. The reconstructed macroblock may be communicated to the in-loop filter 417 for further processing.

The in-loop filter 417 comprises suitable circuitry, logic and/or code and may be adapted to further filter a decoded/reconstructed macroblock that may be acquired from the reconstructor 415. Depending on the encoding method of the raw elementary stream 424, the in-loop filter 417 may comprise an overlapped transformation block 457 and a deblocking module 459. The overlapped transformation block 457 may be utilized during filtering of a macroblock generated from a VC-1 encoded raw elementary stream 424. More specifically the overlapped transformation block 457 may apply an overlapped transformation to a reconstructed macroblock in order to reduce edge artifacts along one or more edges of the reconstructed macroblock. Similarly, the deblocking module 459 may also be utilized by the in-loop filter 417 to reduce edge artifacts and transform blockiness effects along one or more edges of a reconstructed macroblock. Additional information on deblocking and deblocking memory utilization within a decoder is more fully disclosed in U.S. patent application Ser. No. 10/965,172 filed Oct. 13, 2004 and U.S. patent application Ser. No. 10/972,931 filed Oct. 25, 2004, which are incorporated herein by reference in their entirety.

After a reconstructed macroblock is filtered by the in-loop filter 417, additional post-processing may be performed by the post-processing block 421. Depending on the encoding method of the raw elementary stream 424, the post-processing block may utilize one or more of the following post-processing assist blocks: a range remapping block 461, a resizing block 463, a deblocking module 465 and/or a deringing block 467. The range remapping block 461 may be utilized by the post-processing block 421 if during a VC-1 encoding process, the dynamic range of a macroblock, or a series of macroblocks, was changed. In this manner, all decoded macroblocks 469 that are communicated to a display postprocessor are characterized by the same dynamic range.

The resizing block 463 may be utilized by the post-processing block 421 to rescale/resize a macroblock that may have been upscaled or downscaled during encoding. By utilizing the resizing block 463, the post-processing block 421 may generate decoded macroblocks 469 with the same resolution. The deringing block 467 may be utilized to attenuate â€œmosquito noiseâ€ within a reconstructed macroblock that may have been generated by overly quantized AC coefficients. The deblocking module 465 is similar to the deblocking module 459 within the in-loop filter 417, and may be utilized to further reduce edge artifacts and transform blockiness effects along one or more edges of a reconstructed macroblock prior to communication of the macroblock to a display post-processor, for example.

FIG. 4B

is a block diagram illustrating a multistandard video decoder with hardware assist blocks and a CPU pair, in accordance with an embodiment of the invention. Referring to

FIG. 4B

, the multistandard video decoder 470 may comprise a code in port (CIP) 471, an outer loop CPU (OLCPU) 473, an outer loop symbol interpreter (OLSI) 475, an inner loop CPU (ILCPU) 477, and an inner loop symbol interpreter (ILCPU) 479. The multistandard video decoder 470 may also comprise a spatial prediction block, an inverse quantization and transformation block, a motion compensation block, a reconstruction block, an in-loop filtering block, frame buffers block, and/or a post-processing block (not pictured in

FIG. 4B

), as illustrated and described in detail with regard to the multistandard video decoder 400 in

FIG. 4A

In an exemplary embodiment of the invention, the multistandard decoder 470 may utilize the OLCPU 473 and OLSI 475 to process header information from the video elementary bitstream 480. The ILCPU 477 and ILSI 479 may be utilized to process macroblock information from the video elementary bitstream 480. In this manner, parallel processing may be achieved within the multistandard video decoder 470 as OLCPU 473 and OLSI 475 may be processing future header information while ILCPU 477 and ILSI 479 may be processing current macroblock information. Header information from the elementary bitstream 480 may comprise slice information, picture information, GOP/entry point information, and/or sequence information, for example.

In operation, the CIP 471 may receive video elementary code stream 480 and generate start codes and start code suffixes 481 and raw elementary stream 482. The start codes and start code suffixes 481 may be communicated for processing to the OL CPU 473 and the raw packets information 482 may be communicated for processing to the OLSI 475. The OLCPU 473 and the OLSI 475 may be adapted to process only header information from the start codes and start code suffixes 481 and the raw elementary stream 482. The OLCPU 473 may interface with an off-chip video processing system, for example, via the system communications port 483.

The OLSI 475 may comprise a variable-length coding (VLC) block 484 and a fixed length coding (FLC) block 472. The VLC block 484 and the FLC block 472 may be utilized to decode header information from the raw packets information 482 received from the CIP 471. For example, header information 485 may be extracted from the raw packets information 482, thus generating an output bitstream 486. The output bitstream 486 may comprise macroblock-related information and may be communicated to the ILSI 479 for further processing. After OLCPU 473 processes header information from the start codes and start code suffixes information 481, the resulting processing control information 476 may be communicated for further processing to the ILCPU 477. The processing control information 476 may comprise control information corresponding to packets containing macroblock information, such as packets in the output bitstream 486.

The ILCPU 477 and the ILSI 479 may be adapted to simultaneously process macroblock-related information for a current macroblock while the OLCPU 473 and the OLSI 475 may be processing subsequent header information. The ILSI 479, similarly to the symbol interpreter 405 in

FIG. 4A

, may be adapted to generate an output signal 487. The output signal 487 may comprise acquired macroblock type information, slice type information, prediction mode information, motion vector information, and/or quantized frequency coefficients, for example. The acquired macroblock type information, slice type information and/or prediction mode information 488 may be communicated to a spatial prediction block (not pictured), such as the spatial prediction block 409 in

FIG. 4A

, for further processing and generation of prediction pixels for spatially predicted macroblocks.

The motion vector information 490 may be communicated to a motion compensation block (not pictured), such as the motion compensation block 413 in

FIG. 4A

, for further processing and generation of prediction pixels for temporally predicted macroblocks. The quantized frequency coefficients 489 may be communicated to an inverse quantization and transformation block (not pictured), such as the inverse quantization and transformation block 411 in

FIG. 4A

, for further processing and generation of prediction errors utilized during macroblock decoding.

FIG. 5

is a block diagram illustrating operation of the multistandard video decoder 500 of

FIG. 4

when decoding H.264 video data, in accordance with an embodiment of the invention. Referring to

FIG. 5

, the multistandard video decoder 500 may be adapted to process video elementary codestream 401 that was encoded utilizing H.264 encoding techniques. The CIP 403 may utilize the start code finding block 423 to locate start codes and start code suffixes, as well as the byte destuffing block 425 to remove extra bytes from the H.264 encoded video elementary codestream 401.

The symbol interpreter 405 may be adapted to interpret the H.264 raw elementary stream 424 acquired from the CIP 403 to obtain quantized frequency coefficients information and/or additional side information, such as macroblock type information, slice type information, prediction mode information, and/or motion vectors information, necessary for decoding of the H.264 raw elementary video stream 424. During generation of the quantized frequency coefficients and/or the side information, the symbol interpreter 405 may receive instructions by the CPU 407 and provide subsequent symbol information to the CPU 407. In addition, the symbol interpreter may utilize one or more of the following assist blocks: the FLC block 427, the VLC block 429, the CABAC block 433, the coefficient construction block 435, and/or the vector construction block 437.

Inverse quantized frequency coefficients may be communicated from the symbol interpreter block 405 to the IQT block 411, which may generate prediction error information. The IQT block 411 may utilize the inverse zigzag block 439, the inverse quantization block 443 and/or the inverse transformation block 445 to generate the prediction error information. Side information from the symbol interpreter 405 may be communicated to either the spatial prediction block 409 or the motion compensation block 413 to generate prediction pixels. The motion compensation block 413 may utilize the frame buffer 419 together with the intensity compensation block 449, the interpolation block 451, the variable block sizing module 453 and/or the bi-directional prediction module 455 to generate temporally predicted pixels.

The reconstructor 415 may then be utilized by the multistandard decoder 500 to reconstruct a current macroblock utilizing prediction pixel information acquired from either the spatial prediction block 409 or the motion compensation block 413, respectively, as well as prediction error information acquired from the IQT block 411. A reconstructed macroblock may be filtered by the in-loop filter 417, utilizing the deblocking module 459. The filtered macroblock may be further processed by the post-processing block 421. The post-processing block 421 may utilize the deringing block 467 to generate the decoded macroblock 469. The decoded macroblock 469 may then be communicated to a display post-processor, for example.

FIG. 6

is a block diagram illustrating operation of the multistandard video decoder 600 of

FIG. 4

when decoding VC-1 video data, in accordance with an embodiment of the invention. Referring to

FIG. 6

, the multistandard video decoder 600 may be adapted to process video elementary codestream 401 that was encoded utilizing VC-1 encoding techniques. The CIP 403 may utilize the start code finding block 423 to locate start codes and start code suffixes, as well as the byte destuffing block 425 to remove extra bytes from the VC-1 encoded video elementary codestream 401.

The symbol interpreter 405 may be adapted to interpret the VC-1 raw elementary stream 424 acquired from the CIP 403 to obtain quantized frequency coefficients information and/or additional side information, such as macroblock type information, slice type information, prediction mode information, and/or motion vectors information, necessary for decoding the VC-1 raw elementary video stream 424. During generation of the quantized frequency coefficients and/or the side information, the symbol interpreter 405 may receive instructions by the CPU 407 and provide subsequent symbol information to the CPU 407. In addition, the symbol interpreter may utilize one or more of the following assist blocks: the FLC block 427, the VLC block 429, the coefficient construction block 435, and/or the vector construction block 437.

Inverse quantized frequency coefficients may be communicated from the symbol interpreter block 405 to the IQT block 411, which may generate prediction error information. The IQT block 411 may utilize the inverse zigzag block 439, the AC/DC prediction block 441, the inverse quantization block 443 and/or the inverse transformation block 445 to generate the prediction error information. Side information from the symbol interpreter 405 may be communicated to the motion compensation block 413 to generate prediction pixels. The motion compensation block 413 may utilize the frame buffer 419 together with the intensity compensation block 449, the range remapping block 447, the interpolation block 451, the variable block sizing module 453 and/or the bi-directional prediction module 455 to generate temporally predicted pixels. The frame buffer 419 may be adapted to store and provide at least two reference frames/pictures to the motion compensation