View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0000363 | JVT JM H.264/AVC reference software | decoder | public | 2018-10-09 14:44 | 2018-10-09 14:44 |
| Reporter | Sergey Y | Assigned To | |||
| Priority | normal | Severity | minor | Reproducibility | always |
| Status | new | Resolution | open | ||
| Product Version | JM 18.6 | ||||
| Summary | 0000363: The vertical motion vector component range | ||||
| Description | Hallo. I have interlaced stream in bitstream_1080i.h264 file. To decode, I run the command: ldecod.exe -i bitstream_1080i.h264 The decoding have following warnings: WARNING! Vertical motion vector -1600 is out of allowed range {-1024, 1023} in picture 1, macroblock 763 WARNING! Vertical motion vector -1680 is out of allowed range {-1024, 1023} in picture 1, macroblock 2077 WARNING! Vertical motion vector -1696 is out of allowed range {-1024, 1023} in picture 1, macroblock 2423 WARNING! Vertical motion vector -1333 is out of allowed range {-1024, 1023} in picture 1, macroblock 3330 WARNING! Vertical motion vector -2048 is out of allowed range {-1024, 1023} in picture 1, macroblock 3422 The maximum absolute value of a decoded vertical or horizontal motion vector component is constrained by profile and level limits as specified in Annex A of the ITU-T Specification. The vertical motion vector component range for level 4.0 does not exceed -512, +511.75 in units of luma frame samples, which is equal -2048, +2047 in 1/4 units. In set_chroma_vector function in mb_prediction.c file, the maximum range is reduced from -2048, +2047 to -1024, +1023 for interlaced stream: currSlice->max_mb_vmv_r = (currSlice->structure != FRAME || ( currMB->mb_field )) ? p_Vid->max_vmv_r >> 1 : p_Vid->max_vmv_r; I did not find in the ITU-T Specification any information about the reduction of the maximum range for vertical motion vectors for interlaced streams. Maybe this line is incorrect? And to avoid WARNINGS, just need to change it to: currSlice->max_mb_vmv_r = p_Vid->max_vmv_r; Best Regards, Sergey | ||||
| Tags | motion estimation | ||||
