1/* 2 * AVR demuxer 3 * Copyright (c) 2012 Paul B Mahol 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22#include "libavutil/intreadwrite.h" 23#include "avformat.h" 24#include "internal.h" 25#include "pcm.h" 26 27static int avr_probe(AVProbeData *p) 28{ 29 if (AV_RL32(p->buf) != MKTAG('2', 'B', 'I', 'T')) 30 return 0; 31 32 if (!AV_RB16(p->buf+12) || AV_RB16(p->buf+12) > 256) // channels 33 return AVPROBE_SCORE_EXTENSION/2; 34 if (AV_RB16(p->buf+14) > 256) // bps 35 return AVPROBE_SCORE_EXTENSION/2; 36 37 return AVPROBE_SCORE_EXTENSION; 38} 39 40static int avr_read_header(AVFormatContext *s) 41{ 42 uint16_t chan, sign, bps; 43 AVStream *st; 44 45 st = avformat_new_stream(s, NULL); 46 if (!st) 47 return AVERROR(ENOMEM); 48 49 st->codec->codec_type = AVMEDIA_TYPE_AUDIO; 50 51 avio_skip(s->pb, 4); // magic 52 avio_skip(s->pb, 8); // sample_name 53 54 chan = avio_rb16(s->pb); 55 if (!chan) { 56 st->codec->channels = 1; 57 } else if (chan == 0xFFFFu) { 58 st->codec->channels = 2; 59 } else { 60 avpriv_request_sample(s, "chan %d", chan); 61 return AVERROR_PATCHWELCOME; 62 } 63 64 st->codec->bits_per_coded_sample = bps = avio_rb16(s->pb); 65 66 sign = avio_rb16(s->pb); 67 68 avio_skip(s->pb, 2); // loop 69 avio_skip(s->pb, 2); // midi 70 avio_skip(s->pb, 1); // replay speed 71 72 st->codec->sample_rate = avio_rb24(s->pb); 73 avio_skip(s->pb, 4 * 3); 74 avio_skip(s->pb, 2 * 3); 75 avio_skip(s->pb, 20); 76 avio_skip(s->pb, 64); 77 78 st->codec->codec_id = ff_get_pcm_codec_id(bps, 0, 1, sign); 79 if (st->codec->codec_id == AV_CODEC_ID_NONE) { 80 avpriv_request_sample(s, "Bps %d and sign %d", bps, sign); 81 return AVERROR_PATCHWELCOME; 82 } 83 84 st->codec->block_align = bps * st->codec->channels / 8; 85 86 avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate); 87 return 0; 88} 89 90AVInputFormat ff_avr_demuxer = { 91 .name = "avr", 92 .long_name = NULL_IF_CONFIG_SMALL("AVR (Audio Visual Research)"), 93 .read_probe = avr_probe, 94 .read_header = avr_read_header, 95 .read_packet = ff_pcm_read_packet, 96 .read_seek = ff_pcm_read_seek, 97 .extensions = "avr", 98 .flags = AVFMT_GENERIC_INDEX, 99}; 100