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122 lines
3.5 KiB
122 lines
3.5 KiB
/* |
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* AST 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/channel_layout.h" |
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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 "ast.h" |
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static int ast_probe(AVProbeData *p) |
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{ |
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if (AV_RL32(p->buf) != MKTAG('S','T','R','M')) |
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return 0; |
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if (!AV_RB16(p->buf + 10) || |
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!AV_RB16(p->buf + 12) || AV_RB16(p->buf + 12) > 256 || |
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!AV_RB32(p->buf + 16) || AV_RB32(p->buf + 16) > 8*48000) |
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return AVPROBE_SCORE_MAX / 8; |
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return AVPROBE_SCORE_MAX / 3 * 2; |
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} |
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static int ast_read_header(AVFormatContext *s) |
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{ |
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int depth; |
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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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avio_skip(s->pb, 8); |
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st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
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st->codec->codec_id = ff_codec_get_id(ff_codec_ast_tags, avio_rb16(s->pb)); |
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depth = avio_rb16(s->pb); |
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if (depth != 16) { |
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avpriv_request_sample(s, "depth %d", depth); |
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return AVERROR_INVALIDDATA; |
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} |
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st->codec->channels = avio_rb16(s->pb); |
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if (!st->codec->channels) |
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return AVERROR_INVALIDDATA; |
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if (st->codec->channels == 2) |
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st->codec->channel_layout = AV_CH_LAYOUT_STEREO; |
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else if (st->codec->channels == 4) |
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st->codec->channel_layout = AV_CH_LAYOUT_4POINT0; |
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avio_skip(s->pb, 2); |
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st->codec->sample_rate = avio_rb32(s->pb); |
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if (st->codec->sample_rate <= 0) |
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return AVERROR_INVALIDDATA; |
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st->start_time = 0; |
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st->duration = avio_rb32(s->pb); |
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avio_skip(s->pb, 40); |
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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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static int ast_read_packet(AVFormatContext *s, AVPacket *pkt) |
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{ |
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uint32_t type, size; |
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int64_t pos; |
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int ret; |
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if (avio_feof(s->pb)) |
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return AVERROR_EOF; |
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pos = avio_tell(s->pb); |
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type = avio_rl32(s->pb); |
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size = avio_rb32(s->pb); |
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if (size > INT_MAX / s->streams[0]->codec->channels) |
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return AVERROR_INVALIDDATA; |
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size *= s->streams[0]->codec->channels; |
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if ((ret = avio_skip(s->pb, 24)) < 0) // padding |
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return ret; |
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if (type == MKTAG('B','L','C','K')) { |
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ret = av_get_packet(s->pb, pkt, size); |
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pkt->stream_index = 0; |
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pkt->pos = pos; |
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} else { |
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av_log(s, AV_LOG_ERROR, "unknown chunk %x\n", type); |
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avio_skip(s->pb, size); |
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ret = AVERROR_INVALIDDATA; |
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} |
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return ret; |
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} |
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AVInputFormat ff_ast_demuxer = { |
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.name = "ast", |
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.long_name = NULL_IF_CONFIG_SMALL("AST (Audio Stream)"), |
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.read_probe = ast_probe, |
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.read_header = ast_read_header, |
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.read_packet = ast_read_packet, |
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.extensions = "ast", |
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.flags = AVFMT_GENERIC_INDEX, |
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.codec_tag = (const AVCodecTag* const []){ff_codec_ast_tags, 0}, |
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};
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