Memory Format - 1.0 English

H.264/H.265 Video Decode Unit Solutions LogiCORE IP Product Guide (PG414)

Document ID
PG414
Release Date
2022-07-08
Version
1.0 English

The decoded picture buffer contains the decoded pixels. It contains two parts: luminance pixels (Luma) followed by chrominance pixels (Chroma). Luma pixels are stored in pixel raster scan order. Chroma pixels are stored in U/V-interleaved pixel raster scan order; hence, the Chroma part is half the size of the Luma part when using a 4:2:0 format and the same size as the Luma part when using a 4:2:2 format. The decoded picture buffer must be one contiguous memory region.

Note: Decoder output buffers width are in multiples of 256 bytes. Height is in multiples of 64. For example: Decoder output is 2048*1088 for 1920*1080 resolution.

Two packing formats are supported in external memory: eight bits per component or 10 bits per component, shown in the following tables, respectively. The 8-bit format can only be used for an 8-bit component depth and the 10-bit format can only be used for a 10- bit component depth. The following tables show the raster scan format supported by the decoder block for 8-bit and 10-bit color depth.

255 248 ... 31 24 23 16 15 8 7 0
Yx+31,y ... Yx+3,y Yx+2,y Yx+1,y Yx,y
...(all Luma in pixel raster scan order)...
255 248 247 240 ... 31 24 23 16 15 8 7 0
Vx+15,y Ux+15,y ... Vx+1,y Ux+1,y Vx,y Ux,y
...(all interleaved Chroma in pixel raster scan order)...
255 254 253 244   31 30 29 20 19 10 9 0
0 0 Vx+23,y   0 0 Yx+2,y Yx+1,y Yx,y
...(all Luma in pixel raster scan order)...
255 254 253 244 ... 63 62 61 52 51 42 41 32 31 30 29 20 19 10 9 0
0 0 Vx+11,y ... 0 0 Vx+2,y Ux+2,y Vx+1,y 0 0 Ux+1,y Vx,y Ux,y
...(all interleaved Chroma in pixel raster scan order)...

The frame buffer width (pitch) may be larger than the frame width so that there are (pitch - width) ignored values between consecutive pixel lines.