| /* |
| * CRYO APC audio format demuxer |
| * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com> |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include <string.h> |
| #include "avformat.h" |
| |
| static int apc_probe(AVProbeData *p) |
| { |
| if (!strncmp(p->buf, "CRYO_APC", 8)) |
| return AVPROBE_SCORE_MAX; |
| |
| return 0; |
| } |
| |
| static int apc_read_header(AVFormatContext *s, AVFormatParameters *ap) |
| { |
| AVIOContext *pb = s->pb; |
| AVStream *st; |
| |
| avio_rl32(pb); /* CRYO */ |
| avio_rl32(pb); /* _APC */ |
| avio_rl32(pb); /* 1.20 */ |
| |
| st = av_new_stream(s, 0); |
| if (!st) |
| return AVERROR(ENOMEM); |
| |
| st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
| st->codec->codec_id = CODEC_ID_ADPCM_IMA_WS; |
| |
| avio_rl32(pb); /* number of samples */ |
| st->codec->sample_rate = avio_rl32(pb); |
| |
| st->codec->extradata_size = 2 * 4; |
| st->codec->extradata = av_malloc(st->codec->extradata_size + |
| FF_INPUT_BUFFER_PADDING_SIZE); |
| if (!st->codec->extradata) |
| return AVERROR(ENOMEM); |
| |
| /* initial predictor values for adpcm decoder */ |
| avio_read(pb, st->codec->extradata, 2 * 4); |
| |
| st->codec->channels = 1; |
| if (avio_rl32(pb)) |
| st->codec->channels = 2; |
| |
| st->codec->bits_per_coded_sample = 4; |
| st->codec->bit_rate = st->codec->bits_per_coded_sample * st->codec->channels |
| * st->codec->sample_rate; |
| st->codec->block_align = 1; |
| |
| return 0; |
| } |
| |
| #define MAX_READ_SIZE 4096 |
| |
| static int apc_read_packet(AVFormatContext *s, AVPacket *pkt) |
| { |
| if (av_get_packet(s->pb, pkt, MAX_READ_SIZE) <= 0) |
| return AVERROR(EIO); |
| pkt->stream_index = 0; |
| return 0; |
| } |
| |
| AVInputFormat ff_apc_demuxer = { |
| "apc", |
| NULL_IF_CONFIG_SMALL("CRYO APC format"), |
| 0, |
| apc_probe, |
| apc_read_header, |
| apc_read_packet, |
| }; |