Samsung S3C6400X User Manual page 662

MULTI-FORMAT VIDEO CODEC
S3C6400X RISC MICROPROCESSOR
Figure 21.26 highlights the MPEG-4/H.263 transform/quantization process in a macroblock pipeline. In the
encoding process, the quantized coefficients are sent to the inverse quantization module and the coefficient buffer
interface at the same time. The coefficients in the coefficient buffer are processed again in the AC/DC prediction
module.
Note:
The H.263 annex I-advanced intra-coding mode-is supported for the H.263P3 decoding. It is not supported in the
encoding process.
H.264
There are many macroblock types in the H.264 standard such as INTRA_4X4, INTRA_16X16, inter macroblocks
with various block sizes, and I_PCM. The I_PCM macroblock does not have any transform and quantization on its
pixel data. Therefore, in case of I_PCM macroblock, the T/Q module by-passes incoming data to the coefficient
buffer memory and the inverse quantization module without any processing. In case of inter-macroblock and
INTRA_16X16 macroblock, the operation is very similar except transformation of the DC coefficient is performed
for INTRA_16X16. For the H.264 codec, the most complex macroblock type in view point of performance and
control is the INTRA_4X4. Except the INTRA_4X4, all processing such as transform and quantization can be
pipelined efficiently. However, in case of encoding INTRA_4X4-type macroblock, before transform of current 4x4
block, reconstruction of previous 4x4 block has to be finished. This is because the previously reconstructed 4x4
block is used to do intra-prediction of current 4x4 block that is input to residual computation module.
Intra-prediction Intra-prediction
residual residual
Transform/quant. Transform/quant.
Inv. transform/quant. Inv. transform/quant.
reconstruction reconstruction
N-th 4x4 block processing (N+1)-th 4x4 block processing
Figure 21.27 H.264 encoding pipeline
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
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Specifications and information herein are subject to change without notice.