static int ac3_eac3_probe(AVProbeData *p, enum CodecID expected_codec_id) { int max_frames, first_frames = 0, frames; uint8_t *buf, *buf2, *end; AC3HeaderInfo hdr; GetBitContext gbc; enum CodecID codec_id = CODEC_ID_AC3; max_frames = 0; buf = p->buf; end = buf + p->buf_size; for(; buf < end; buf++) { buf2 = buf; for(frames = 0; buf2 < end; frames++) { init_get_bits(&gbc, buf2, 54); if(avpriv_ac3_parse_header(&gbc, &hdr) < 0) break; if(buf2 + hdr.frame_size > end || av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, buf2 + 2, hdr.frame_size - 2)) break; if (hdr.bitstream_id > 10) codec_id = CODEC_ID_EAC3; buf2 += hdr.frame_size; } max_frames = FFMAX(max_frames, frames); if(buf == p->buf) first_frames = frames; } if(codec_id != expected_codec_id) return 0; // keep this in sync with mp3 probe, both need to avoid // issues with MPEG-files! if (first_frames>=4) return AVPROBE_SCORE_MAX/2+1; else if(max_frames>500)return AVPROBE_SCORE_MAX/2; else if(max_frames>=4) return AVPROBE_SCORE_MAX/4; else if(max_frames>=1) return 1; else return 0; }