blob: f7954956c017ff315dfb5b8228f0b39e784e399e
| 1 | /* |
| 2 | * MD STUDIO audio demuxer |
| 3 | * |
| 4 | * Copyright (c) 2009 Benjamin Larsson |
| 5 | * |
| 6 | * This file is part of FFmpeg. |
| 7 | * |
| 8 | * FFmpeg is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU Lesser General Public |
| 10 | * License as published by the Free Software Foundation; either |
| 11 | * version 2.1 of the License, or (at your option) any later version. |
| 12 | * |
| 13 | * FFmpeg is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | * Lesser General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU Lesser General Public |
| 19 | * License along with FFmpeg; if not, write to the Free Software |
| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 21 | */ |
| 22 | |
| 23 | #include "libavutil/channel_layout.h" |
| 24 | #include "libavutil/intreadwrite.h" |
| 25 | #include "avformat.h" |
| 26 | #include "pcm.h" |
| 27 | |
| 28 | #define AT1_SU_SIZE 212 |
| 29 | |
| 30 | static int aea_read_probe(AVProbeData *p) |
| 31 | { |
| 32 | if (p->buf_size <= 2048+212) |
| 33 | return 0; |
| 34 | |
| 35 | /* Magic is '00 08 00 00' in little-endian*/ |
| 36 | if (AV_RL32(p->buf)==0x800) { |
| 37 | int ch, i; |
| 38 | ch = p->buf[264]; |
| 39 | |
| 40 | if (ch != 1 && ch != 2) |
| 41 | return 0; |
| 42 | |
| 43 | /* Check so that the redundant bsm bytes and info bytes are valid |
| 44 | * the block size mode bytes have to be the same |
| 45 | * the info bytes have to be the same |
| 46 | */ |
| 47 | for (i = 2048; i + 211 < p->buf_size; i+= 212) { |
| 48 | int bsm_s, bsm_e, inb_s, inb_e; |
| 49 | bsm_s = p->buf[0]; |
| 50 | inb_s = p->buf[1]; |
| 51 | inb_e = p->buf[210]; |
| 52 | bsm_e = p->buf[211]; |
| 53 | |
| 54 | if (bsm_s != bsm_e || inb_s != inb_e) |
| 55 | return 0; |
| 56 | } |
| 57 | return AVPROBE_SCORE_MAX / 4 + 1; |
| 58 | } |
| 59 | return 0; |
| 60 | } |
| 61 | |
| 62 | static int aea_read_header(AVFormatContext *s) |
| 63 | { |
| 64 | AVStream *st = avformat_new_stream(s, NULL); |
| 65 | if (!st) |
| 66 | return AVERROR(ENOMEM); |
| 67 | |
| 68 | /* Parse the amount of channels and skip to pos 2048(0x800) */ |
| 69 | avio_skip(s->pb, 264); |
| 70 | st->codecpar->channels = avio_r8(s->pb); |
| 71 | avio_skip(s->pb, 1783); |
| 72 | |
| 73 | |
| 74 | st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
| 75 | st->codecpar->codec_id = AV_CODEC_ID_ATRAC1; |
| 76 | st->codecpar->sample_rate = 44100; |
| 77 | st->codecpar->bit_rate = 292000; |
| 78 | |
| 79 | if (st->codecpar->channels != 1 && st->codecpar->channels != 2) { |
| 80 | av_log(s, AV_LOG_ERROR, "Channels %d not supported!\n", st->codecpar->channels); |
| 81 | return AVERROR_INVALIDDATA; |
| 82 | } |
| 83 | |
| 84 | st->codecpar->channel_layout = (st->codecpar->channels == 1) ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO; |
| 85 | |
| 86 | st->codecpar->block_align = AT1_SU_SIZE * st->codecpar->channels; |
| 87 | return 0; |
| 88 | } |
| 89 | |
| 90 | static int aea_read_packet(AVFormatContext *s, AVPacket *pkt) |
| 91 | { |
| 92 | int ret = av_get_packet(s->pb, pkt, s->streams[0]->codecpar->block_align); |
| 93 | |
| 94 | pkt->stream_index = 0; |
| 95 | if (ret <= 0) |
| 96 | return AVERROR(EIO); |
| 97 | |
| 98 | return ret; |
| 99 | } |
| 100 | |
| 101 | AVInputFormat ff_aea_demuxer = { |
| 102 | .name = "aea", |
| 103 | .long_name = NULL_IF_CONFIG_SMALL("MD STUDIO audio"), |
| 104 | .read_probe = aea_read_probe, |
| 105 | .read_header = aea_read_header, |
| 106 | .read_packet = aea_read_packet, |
| 107 | .read_seek = ff_pcm_read_seek, |
| 108 | .flags = AVFMT_GENERIC_INDEX, |
| 109 | .extensions = "aea", |
| 110 | }; |
| 111 |