static void vc1_extract_headers(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t *buf, int buf_size) { VC1ParseContext *vpc = s->priv_data; GetBitContext gb; const uint8_t *start, *end, *next; uint8_t *buf2 = av_mallocz(buf_size + FF_INPUT_BUFFER_PADDING_SIZE); vpc->v.s.avctx = avctx; vpc->v.parse_only = 1; vpc->v.first_pic_header_flag = 1; next = buf; s->repeat_pict = 0; for(start = buf, end = buf + buf_size; next < end; start = next){ int buf2_size, size; next = find_next_marker(start + 4, end); size = next - start - 4; buf2_size = vc1_unescape_buffer(start + 4, size, buf2); init_get_bits(&gb, buf2, buf2_size * 8); if(size <= 0) continue; switch(AV_RB32(start)){ case VC1_CODE_SEQHDR: ff_vc1_decode_sequence_header(avctx, &vpc->v, &gb); break; case VC1_CODE_ENTRYPOINT: ff_vc1_decode_entry_point(avctx, &vpc->v, &gb); break; case VC1_CODE_FRAME: if(vpc->v.profile < PROFILE_ADVANCED) ff_vc1_parse_frame_header (&vpc->v, &gb); else ff_vc1_parse_frame_header_adv(&vpc->v, &gb); /* keep AV_PICTURE_TYPE_BI internal to VC1 */ if (vpc->v.s.pict_type == AV_PICTURE_TYPE_BI) s->pict_type = AV_PICTURE_TYPE_B; else s->pict_type = vpc->v.s.pict_type; if (avctx->ticks_per_frame > 1){ // process pulldown flags s->repeat_pict = 1; // Pulldown flags are only valid when 'broadcast' has been set. // So ticks_per_frame will be 2 if (vpc->v.rff){ // repeat field s->repeat_pict = 2; }else if (vpc->v.rptfrm){ // repeat frames s->repeat_pict = vpc->v.rptfrm * 2 + 1; } } if (vpc->v.broadcast && vpc->v.interlace && !vpc->v.psf) s->field_order = vpc->v.tff ? AV_FIELD_TT : AV_FIELD_BB; else s->field_order = AV_FIELD_PROGRESSIVE; break; } } av_free(buf2); }