Method and/or apparatus for transcoding between H.264 CABAC and CAVLC entropy coding modes
View Patent ↗An apparatus comprising a first circuit, a second circuit and an output circuit. The first circuit may be configured to generate (i) one of a first set of entropy coded input signals or a second set of entropy coded input signals and (ii) a data path signal. The second circuit may be configured to generate (i) a first set of entropy encoded output signals in response to decoding the second set of entropy coded input signals, or (ii) a second set of entropy coded output signals in response to decoding the first set of entropy coded input signals. The second circuit may provide real time decoding and encoding on a macroblock basis. The output circuit may be configured to present an output signal in response to (i) one of the first set of entropy coded output signals or the second set of entropy coded output signals and (ii) the data path signal.
1. An apparatus comprising:
a first circuit configured to present (i) one of a first set of entropy coded input signals or a second set of entropy coded input signals, and (ii) a data path signal;
a second circuit configured to generate (i) a first set of entropy coded output signals in response to decoding said second set of entropy coded input signals, or (ii) a second set of entropy coded output signals in response to decoding said first set of entropy coded input signals, wherein said second circuit provides real time decoding and encoding on a macroblock basis; and
an output circuit configured to present an output signal in response to (i) one of said first set of entropy coded output signals or said second set of entropy coded output signals and (ii) said data path signal.
2. The apparatus according to claim 1 , wherein said first set of entropy coded input signals comprise context adaptive binary arithmetic coding (CABAC) input bits and said first set of entropy coded output signals comprise CABAC output bits.
3. The apparatus according to claim 2 , wherein said second set of entropy coded input signal comprise context adaptive variable length coding (CAVLC) input bits and said second set of entropy coded output signals comprising CAVLC output bits.
4. The apparatus according to claim 3 , wherein said second circuit comprises a CABAC context and processing circuit configured to (i) generate CABAC input bins in response to receiving said CABAC input bits and (ii) generate said CABAC output bits in response to encoding CABAC output bins.
5. The apparatus according to claim 4 , wherein said second circuit comprises an input parsing circuit configured to generated decoded integers in response to parsing said CAVLC input bits or said CABAC input bins.
6. The apparatus according to claim 5 , wherein said second circuit comprises an output encoding circuit configured to generate said CABAC output bins or said CAVLC output bits.
7. The apparatus according to claim 5 , wherein said input parsing circuit is configured to operate at a minimum rate of 1 bit or bin per cycle.
8. The apparatus according to claim 6 , wherein said output encoding circuit is configured to produce encoded data at a minimum rate of 1 bit or bin per cycle.
9. The apparatus according to claim 5 , wherein said CABAC context and processing circuit is configured to encode CABAC output bins at a minimum rate of one bin per cycle.
10. The apparatus according to claim 1 , wherein said apparatus further comprises:
a memory configured to store (i) one or more previous macroblock rows for above context information, (ii) a pre-determined number of picture parameter sets and (iii) a pre-determined number of sequence parameter sets.
11. The apparatus according to claim 1 , wherein said second circuit comprises a register configured to provide neighbor context information to be made available for CABAC and CAVLC context selection.
12. The apparatus according to claim 1 , wherein said data path signal comprises direct copies that are used for unprocessed network abstraction layer (NAL) types or pulse code modulation (PCM) coded macroblocks.
13. The apparatus according to claim 1 , wherein said output signal comprises an entropy coding mode flag, wherein said entropy coding mode flag (i) produces a 0 to indicate that said output signal comprises encoded CAVLC data or (ii) produces a 1 to indicate that said output signal comprises encoded CABAC data.
14. The apparatus according to claim 1 , wherein said output circuit further comprises:
a compliant H.264 decoder configured to (i) decode said output signal and (ii) generate video data, wherein said output signal comprises said second set of entropy coded output signals.
15. The apparatus according to claim 1 , wherein said first circuit further comprises a first encoder configured to generate said second set of entropy coded input signals in real time in response to encoding video data.
16. A method for transcoding between different entropy codes, comprising the steps of:
(A) generating (i) one of a first set of entropy coded input signals or a second set of entropy coded input signals and (ii) a data path signal;
(B) decoding said first set of entropy coded input signals to (i) produce a second set of entropy coded output signals and (ii) allow real time decode of said first set of entropy coded input signals on a macroblock basis;
(C) decoding said second set of entropy coded input signals to (i) produce a first set of entropy coded output signals and (ii) allow real time encode of said first set of entropy coded input signal on a macroblock basis; and
(D) generating an output signal in response to (i) one of said first set of entropy coded output signals or said second set of entropy coded output signals and (ii) said data path signal.
17. A computer readable medium configured to execute the steps of claim 16 .
18. An apparatus comprising:
a first circuit configured to (i) encode video data into a first set of context adaptive variable length coding (CAVLC) coded data and (ii) produce a first set of context adaptive binary arithmetic coding (CABAC) data; and
a second circuit configured to (i) encode said first set of CABAC data, (ii) generate a second set of CAVLC data, (iii) decode said second set of CAVLC data and (iv) generate said video data in response to decoding said second set of CAVLC data.
19. The apparatus according to claim 18 , wherein said first circuit comprises (i) a first encoder configured to encode said video data in real time to produce said first set of CAVLC data and (ii) a first entropy processor configured to produce said first set of CABAC data in response to receiving said first set of CAVLC data.
20. The apparatus according to claim 18 , wherein said second circuit comprises (i) a second entropy processor configured to produce said second set of CAVLC data in response to receiving said first set of CABAC data and (ii) a first decoder configured to decode said second set of CAVLC data in real time to produce said video data.