id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc 1234,Spec/SW mismatch: long start codes (B.2.2),fbossen,,"The spec appears to mandate long start codes for APS NAL units: When one or more of the following conditions are true, the zero_byte syntax element shall be present: – The nal_unit_type within the nal_unit( ) syntax structure is equal to DCI_NUT, VPS_NUT, SPS_NUT, PPS_NUT, PREFIX_APS_NUT, or SUFFIX_APS_NUT. – The byte stream NAL unit syntax structure contains the first NAL unit of an AU in decoding order, as specified in subclause 7.4.2.4.4. However, the software doesn't do that: {{{ if (it == au.begin() || nalu.m_nalUnitType == NAL_UNIT_DCI || nalu.m_nalUnitType == NAL_UNIT_SPS || nalu.m_nalUnitType == NAL_UNIT_VPS || nalu.m_nalUnitType == NAL_UNIT_PPS) { /* From AVC, When any of the following conditions are fulfilled, the * zero_byte syntax element shall be present: * - the nal_unit_type within the nal_unit() is equal to 7 (sequence * parameter set) or 8 (picture parameter set), * - the byte stream NAL unit syntax structure contains the first NAL * unit of an access unit in decoding order, as specified by subclause * 7.4.1.2.3. */ out.write(reinterpret_cast(start_code_prefix), 4); size += 4; } else { out.write(reinterpret_cast(start_code_prefix+1), 3); size += 3; } }}} I don't know which one is correct. (Except for the comment in the software which definitely looks outdated...) ",defect,closed,minor,VTM-10.0,VTM,VTM-9.3,fixed,,ksuehring bbross XiangLi fbossen jvet@…