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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4349 | Serge | 1 | /* |
| 2 | * AST demuxer |
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| 3 | * Copyright (c) 2012 Paul B Mahol |
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| 4 | * |
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| 5 | * This file is part of FFmpeg. |
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| 6 | * |
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| 7 | * FFmpeg is free software; you can redistribute it and/or |
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| 8 | * modify it under the terms of the GNU Lesser General Public |
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| 9 | * License as published by the Free Software Foundation; either |
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| 10 | * version 2.1 of the License, or (at your option) any later version. |
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| 11 | * |
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| 12 | * FFmpeg is distributed in the hope that it will be useful, |
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| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 15 | * Lesser General Public License for more details. |
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| 16 | * |
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| 17 | * You should have received a copy of the GNU Lesser General Public |
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| 18 | * License along with FFmpeg; if not, write to the Free Software |
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| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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| 20 | */ |
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| 21 | |||
| 22 | #include "libavutil/channel_layout.h" |
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| 23 | #include "libavutil/intreadwrite.h" |
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| 24 | #include "avformat.h" |
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| 25 | #include "internal.h" |
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| 26 | #include "ast.h" |
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| 27 | |||
| 28 | static int ast_probe(AVProbeData *p) |
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| 29 | { |
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| 30 | if (AV_RL32(p->buf) == MKTAG('S','T','R','M') && |
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| 31 | AV_RB16(p->buf + 10) && |
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| 32 | AV_RB16(p->buf + 12) && |
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| 33 | AV_RB32(p->buf + 16)) |
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| 34 | return AVPROBE_SCORE_MAX / 3 * 2; |
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| 35 | return 0; |
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| 36 | } |
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| 37 | |||
| 38 | static int ast_read_header(AVFormatContext *s) |
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| 39 | { |
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| 40 | int depth; |
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| 41 | AVStream *st; |
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| 42 | |||
| 43 | st = avformat_new_stream(s, NULL); |
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| 44 | if (!st) |
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| 45 | return AVERROR(ENOMEM); |
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| 46 | |||
| 47 | avio_skip(s->pb, 8); |
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| 48 | st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
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| 49 | st->codec->codec_id = ff_codec_get_id(ff_codec_ast_tags, avio_rb16(s->pb)); |
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| 50 | |||
| 51 | depth = avio_rb16(s->pb); |
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| 52 | if (depth != 16) { |
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| 53 | avpriv_request_sample(s, "depth %d", depth); |
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| 54 | return AVERROR_INVALIDDATA; |
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| 55 | } |
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| 56 | |||
| 57 | st->codec->channels = avio_rb16(s->pb); |
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| 58 | if (!st->codec->channels) |
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| 59 | return AVERROR_INVALIDDATA; |
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| 60 | |||
| 61 | if (st->codec->channels == 2) |
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| 62 | st->codec->channel_layout = AV_CH_LAYOUT_STEREO; |
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| 63 | else if (st->codec->channels == 4) |
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| 64 | st->codec->channel_layout = AV_CH_LAYOUT_4POINT0; |
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| 65 | |||
| 66 | avio_skip(s->pb, 2); |
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| 67 | st->codec->sample_rate = avio_rb32(s->pb); |
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| 68 | if (st->codec->sample_rate <= 0) |
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| 69 | return AVERROR_INVALIDDATA; |
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| 70 | st->start_time = 0; |
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| 71 | st->duration = avio_rb32(s->pb); |
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| 72 | avio_skip(s->pb, 40); |
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| 73 | avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate); |
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| 74 | |||
| 75 | return 0; |
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| 76 | } |
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| 77 | |||
| 78 | static int ast_read_packet(AVFormatContext *s, AVPacket *pkt) |
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| 79 | { |
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| 80 | uint32_t type, size; |
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| 81 | int64_t pos; |
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| 82 | int ret; |
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| 83 | |||
| 84 | if (url_feof(s->pb)) |
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| 85 | return AVERROR_EOF; |
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| 86 | |||
| 87 | pos = avio_tell(s->pb); |
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| 88 | type = avio_rl32(s->pb); |
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| 89 | size = avio_rb32(s->pb); |
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| 90 | if (size > INT_MAX / s->streams[0]->codec->channels) |
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| 91 | return AVERROR_INVALIDDATA; |
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| 92 | |||
| 93 | size *= s->streams[0]->codec->channels; |
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| 94 | if ((ret = avio_skip(s->pb, 24)) < 0) // padding |
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| 95 | return ret; |
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| 96 | |||
| 97 | if (type == MKTAG('B','L','C','K')) { |
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| 98 | ret = av_get_packet(s->pb, pkt, size); |
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| 99 | pkt->stream_index = 0; |
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| 100 | pkt->pos = pos; |
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| 101 | } else { |
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| 102 | av_log(s, AV_LOG_ERROR, "unknown chunk %x\n", type); |
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| 103 | avio_skip(s->pb, size); |
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| 104 | ret = AVERROR_INVALIDDATA; |
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| 105 | } |
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| 106 | |||
| 107 | return ret; |
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| 108 | } |
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| 109 | |||
| 110 | AVInputFormat ff_ast_demuxer = { |
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| 111 | .name = "ast", |
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| 112 | .long_name = NULL_IF_CONFIG_SMALL("AST (Audio Stream)"), |
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| 113 | .read_probe = ast_probe, |
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| 114 | .read_header = ast_read_header, |
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| 115 | .read_packet = ast_read_packet, |
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| 116 | .extensions = "ast", |
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| 117 | .flags = AVFMT_GENERIC_INDEX, |
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| 118 | .codec_tag = (const AVCodecTag* const []){ff_codec_ast_tags, 0}, |
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| 119 | }; |