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100 lines
2.9 KiB
100 lines
2.9 KiB
/* |
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* AVR demuxer |
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* Copyright (c) 2012 Paul B Mahol |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#include "libavutil/intreadwrite.h" |
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#include "avformat.h" |
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#include "internal.h" |
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#include "pcm.h" |
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static int avr_probe(AVProbeData *p) |
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{ |
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if (AV_RL32(p->buf) == MKTAG('2', 'B', 'I', 'T')) |
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return AVPROBE_SCORE_MAX / 2; |
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return 0; |
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} |
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static int avr_read_header(AVFormatContext *s) |
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{ |
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uint16_t chan, sign, bps; |
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AVStream *st; |
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st = avformat_new_stream(s, NULL); |
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if (!st) |
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return AVERROR(ENOMEM); |
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st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
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avio_skip(s->pb, 4); // magic |
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avio_skip(s->pb, 8); // sample_name |
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chan = avio_rb16(s->pb); |
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if (!chan) { |
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st->codec->channels = 1; |
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} else if (chan == 0xFFFFu) { |
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st->codec->channels = 2; |
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} else { |
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av_log_ask_for_sample(s, "unknown number of channels\n"); |
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return AVERROR_PATCHWELCOME; |
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} |
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st->codec->bits_per_coded_sample = bps = avio_rb16(s->pb); |
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sign = avio_rb16(s->pb); |
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avio_skip(s->pb, 2); // loop |
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avio_skip(s->pb, 2); // midi |
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avio_skip(s->pb, 1); // replay speed |
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st->codec->sample_rate = avio_rb24(s->pb); |
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avio_skip(s->pb, 4 * 3); |
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avio_skip(s->pb, 2 * 3); |
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avio_skip(s->pb, 20); |
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avio_skip(s->pb, 64); |
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if (!sign && bps == 8) { |
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st->codec->codec_id = AV_CODEC_ID_PCM_U8; |
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} else if (!sign && bps == 16) { |
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st->codec->codec_id = AV_CODEC_ID_PCM_U16BE; |
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} else if (sign == 0xFFFFu && bps == 8) { |
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st->codec->codec_id = AV_CODEC_ID_PCM_S8; |
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} else if (sign == 0xFFFFu && bps == 16) { |
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st->codec->codec_id = AV_CODEC_ID_PCM_S16BE; |
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} else { |
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av_log_ask_for_sample(s, "unknown bits per sample\n"); |
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return AVERROR_PATCHWELCOME; |
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} |
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st->codec->block_align = bps * st->codec->channels / 8; |
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avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate); |
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return 0; |
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} |
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AVInputFormat ff_avr_demuxer = { |
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.name = "avr", |
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.long_name = NULL_IF_CONFIG_SMALL("AVR (Audio Visual Research)"), |
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.read_probe = avr_probe, |
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.read_header = avr_read_header, |
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.read_packet = ff_pcm_read_packet, |
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.read_seek = ff_pcm_read_seek, |
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.extensions = "avr", |
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.flags = AVFMT_GENERIC_INDEX, |
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};
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