Samsung S5PC100, Руководство пользователя

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S5PC100 USER’S MANUAL (REV1.0)
MFC (MULTI FORMAT CODEC)
9.11-11
Under the post filter operation, unfiltered-data for reference frame is written in reconstruction area and edge
filtered-data for display frame is written in display area of frame buffer. Figure 9.11-6 shows the data flow of post
filter. In the case of MPEG4, all I, P and B frames are written in display area regardless of post filter control value.
And I and P frames, frames used for reference, are written in reconstruction area but B frames are not written. In
the case of VC1, H.263 and H.264, all I, P and B frames are written in display area only when the post filter is
turned on
Stream
Processor Transform/
Scal./Quant
Scaling & Inv-
Transform
Intra frame
Prediction
Motion
Compensation
Motion
Estimation
De-blocking
filter
Edge filter
DMA
Bit-stream
Frame Buffer
Recon. area
Stream
Processor
Quant Coeffs
Motion Data
Decoder
Display area
Upper. area
Figure 9.11-5 Data Flow of Post Filter
Block Diagram
Deblocking filter has eight internal buffers (four 1t0x44 buffers for luma coefficients, four 96x44 buffers for chroma
coefficients). Memory word width is 44bits (four pixels unit) to support VC1 overlap smoothing filter. In the case of
VC1, predicted coefficient is not clamped, so the bit width of predicted coefficient is 10. During the overlap
smoothing filter, bit overflow can be happened.
Deblock filter is composed in two stages, one is filtering operation (Stage0) and the other is DMA operation
(Stage1). Predicted coefficients are read from coefficient buffer in prediction block into internal buffers. Preceding
operation block transfers macroblock information through information interface.
H.264 In-loop Filter
A filtering is applied to all 4x4 block edges except the boundary of the picture. For each macroblock, vertical
edges are filtered first from left-hand side to right-hand side of the macroblock, and then horizontal edges are
filtered from top to bottom of the macroblock. Pixel data changed by vertical edges filtering are used as input of
the horizontal edges filtering.
The filter adjusts its strength depending on macroblock mode (Intra or Inter), the quantization parameter, and
motion vector and pixel values. Global parameters for filtering operation such as loop filter disable value, chroma
quantization offset, indexA, and indexB are set by the video stream processor.