| 1 | /* |
| 2 | * CRYO APC audio format demuxer |
| 3 | * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com> |
| 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 <string.h> |
| 23 | |
| 24 | #include "libavutil/channel_layout.h" |
| 25 | #include "avformat.h" |
| 26 | #include "internal.h" |
| 27 | |
| 28 | static int apc_probe(AVProbeData *p) |
| 29 | { |
| 30 | if (!strncmp(p->buf, "CRYO_APC", 8)) |
| 31 | return AVPROBE_SCORE_MAX; |
| 32 | |
| 33 | return 0; |
| 34 | } |
| 35 | |
| 36 | static int apc_read_header(AVFormatContext *s) |
| 37 | { |
| 38 | AVIOContext *pb = s->pb; |
| 39 | AVStream *st; |
| 40 | |
| 41 | avio_rl32(pb); /* CRYO */ |
| 42 | avio_rl32(pb); /* _APC */ |
| 43 | avio_rl32(pb); /* 1.20 */ |
| 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 | st->codec->codec_id = AV_CODEC_ID_ADPCM_IMA_APC; |
| 51 | |
| 52 | avio_rl32(pb); /* number of samples */ |
| 53 | st->codec->sample_rate = avio_rl32(pb); |
| 54 | |
| 55 | /* initial predictor values for adpcm decoder */ |
| 56 | if (ff_get_extradata(st->codec, pb, 2 * 4) < 0) |
| 57 | return AVERROR(ENOMEM); |
| 58 | |
| 59 | if (avio_rl32(pb)) { |
| 60 | st->codec->channels = 2; |
| 61 | st->codec->channel_layout = AV_CH_LAYOUT_STEREO; |
| 62 | } else { |
| 63 | st->codec->channels = 1; |
| 64 | st->codec->channel_layout = AV_CH_LAYOUT_MONO; |
| 65 | } |
| 66 | |
| 67 | st->codec->bits_per_coded_sample = 4; |
| 68 | st->codec->bit_rate = st->codec->bits_per_coded_sample * st->codec->channels |
| 69 | * st->codec->sample_rate; |
| 70 | st->codec->block_align = 1; |
| 71 | |
| 72 | return 0; |
| 73 | } |
| 74 | |
| 75 | #define MAX_READ_SIZE 4096 |
| 76 | |
| 77 | static int apc_read_packet(AVFormatContext *s, AVPacket *pkt) |
| 78 | { |
| 79 | if (av_get_packet(s->pb, pkt, MAX_READ_SIZE) <= 0) |
| 80 | return AVERROR(EIO); |
| 81 | pkt->flags &= ~AV_PKT_FLAG_CORRUPT; |
| 82 | pkt->stream_index = 0; |
| 83 | return 0; |
| 84 | } |
| 85 | |
| 86 | AVInputFormat ff_apc_demuxer = { |
| 87 | .name = "apc", |
| 88 | .long_name = NULL_IF_CONFIG_SMALL("CRYO APC"), |
| 89 | .read_probe = apc_probe, |
| 90 | .read_header = apc_read_header, |
| 91 | .read_packet = apc_read_packet, |
| 92 | }; |