yading@11: /* yading@11: * RAW AC-3 and E-AC-3 demuxer yading@11: * Copyright (c) 2007 Justin Ruggles yading@11: * yading@11: * This file is part of FFmpeg. yading@11: * yading@11: * FFmpeg is free software; you can redistribute it and/or yading@11: * modify it under the terms of the GNU Lesser General Public yading@11: * License as published by the Free Software Foundation; either yading@11: * version 2.1 of the License, or (at your option) any later version. yading@11: * yading@11: * FFmpeg is distributed in the hope that it will be useful, yading@11: * but WITHOUT ANY WARRANTY; without even the implied warranty of yading@11: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU yading@11: * Lesser General Public License for more details. yading@11: * yading@11: * You should have received a copy of the GNU Lesser General Public yading@11: * License along with FFmpeg; if not, write to the Free Software yading@11: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA yading@11: */ yading@11: yading@11: #include "libavutil/crc.h" yading@11: #include "libavcodec/ac3_parser.h" yading@11: #include "avformat.h" yading@11: #include "rawdec.h" yading@11: yading@11: static int ac3_eac3_probe(AVProbeData *p, enum AVCodecID expected_codec_id) yading@11: { yading@11: int max_frames, first_frames = 0, frames; yading@11: const uint8_t *buf, *buf2, *end; yading@11: AC3HeaderInfo hdr; yading@11: GetBitContext gbc; yading@11: enum AVCodecID codec_id = AV_CODEC_ID_AC3; yading@11: yading@11: max_frames = 0; yading@11: buf = p->buf; yading@11: end = buf + p->buf_size; yading@11: yading@11: for(; buf < end; buf++) { yading@11: if(buf > p->buf && !(buf[0] == 0x0B && buf[1] == 0x77) yading@11: && !(buf[0] == 0x77 && buf[1] == 0x0B) ) yading@11: continue; yading@11: buf2 = buf; yading@11: yading@11: for(frames = 0; buf2 < end; frames++) { yading@11: uint8_t buf3[4096]; yading@11: int i; yading@11: if(!memcmp(buf2, "\x1\x10\0\0\0\0\0\0", 8)) yading@11: buf2+=16; yading@11: if (buf[0] == 0x77 && buf[1] == 0x0B) { yading@11: for(i=0; i<8; i+=2) { yading@11: buf3[i ] = buf[i+1]; yading@11: buf3[i+1] = buf[i ]; yading@11: } yading@11: init_get_bits(&gbc, buf3, 54); yading@11: }else yading@11: init_get_bits(&gbc, buf2, 54); yading@11: if(avpriv_ac3_parse_header(&gbc, &hdr) < 0) yading@11: break; yading@11: if(buf2 + hdr.frame_size > end) yading@11: break; yading@11: if (buf[0] == 0x77 && buf[1] == 0x0B) { yading@11: av_assert0(hdr.frame_size <= sizeof(buf3)); yading@11: for(i=8; i 10) yading@11: codec_id = AV_CODEC_ID_EAC3; yading@11: buf2 += hdr.frame_size; yading@11: } yading@11: max_frames = FFMAX(max_frames, frames); yading@11: if(buf == p->buf) yading@11: first_frames = frames; yading@11: } yading@11: if(codec_id != expected_codec_id) return 0; yading@11: // keep this in sync with mp3 probe, both need to avoid yading@11: // issues with MPEG-files! yading@11: if (first_frames>=4) return AVPROBE_SCORE_MAX/2+1; yading@11: else if(max_frames>200)return AVPROBE_SCORE_MAX/2; yading@11: else if(max_frames>=4) return AVPROBE_SCORE_MAX/4; yading@11: else if(max_frames>=1) return 1; yading@11: else return 0; yading@11: } yading@11: yading@11: #if CONFIG_AC3_DEMUXER yading@11: static int ac3_probe(AVProbeData *p) yading@11: { yading@11: return ac3_eac3_probe(p, AV_CODEC_ID_AC3); yading@11: } yading@11: yading@11: AVInputFormat ff_ac3_demuxer = { yading@11: .name = "ac3", yading@11: .long_name = NULL_IF_CONFIG_SMALL("raw AC-3"), yading@11: .read_probe = ac3_probe, yading@11: .read_header = ff_raw_audio_read_header, yading@11: .read_packet = ff_raw_read_partial_packet, yading@11: .flags= AVFMT_GENERIC_INDEX, yading@11: .extensions = "ac3", yading@11: .raw_codec_id = AV_CODEC_ID_AC3, yading@11: }; yading@11: #endif yading@11: yading@11: #if CONFIG_EAC3_DEMUXER yading@11: static int eac3_probe(AVProbeData *p) yading@11: { yading@11: return ac3_eac3_probe(p, AV_CODEC_ID_EAC3); yading@11: } yading@11: yading@11: AVInputFormat ff_eac3_demuxer = { yading@11: .name = "eac3", yading@11: .long_name = NULL_IF_CONFIG_SMALL("raw E-AC-3"), yading@11: .read_probe = eac3_probe, yading@11: .read_header = ff_raw_audio_read_header, yading@11: .read_packet = ff_raw_read_partial_packet, yading@11: .flags = AVFMT_GENERIC_INDEX, yading@11: .extensions = "eac3", yading@11: .raw_codec_id = AV_CODEC_ID_EAC3, yading@11: }; yading@11: #endif