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#include "avformat.h" 24 25static int apc_probe(AVProbeData *p) 26{ 27 if (!strncmp(p->buf, "CRYO_APC", 8)) 28 return AVPROBE_SCORE_MAX; 29 30 return 0; 31} 32 33static int apc_read_header(AVFormatContext *s, AVFormatParameters *ap) 34{ 35 ByteIOContext *pb = s->pb; 36 AVStream *st; 37 38 get_le32(pb); /* CRYO */ 39 get_le32(pb); /* _APC */ 40 get_le32(pb); /* 1.20 */ 41 42 st = av_new_stream(s, 0); 43 if (!st) 44 return AVERROR(ENOMEM); 45 46 st->codec->codec_type = AVMEDIA_TYPE_AUDIO; 47 st->codec->codec_id = CODEC_ID_ADPCM_IMA_WS; 48 49 get_le32(pb); /* number of samples */ 50 st->codec->sample_rate = get_le32(pb); 51 52 st->codec->extradata_size = 2 * 4; 53 st->codec->extradata = av_malloc(st->codec->extradata_size + 54 FF_INPUT_BUFFER_PADDING_SIZE); 55 if (!st->codec->extradata) 56 return AVERROR(ENOMEM); 57 58 /* initial predictor values for adpcm decoder */ 59 get_buffer(pb, st->codec->extradata, 2 * 4); 60 61 st->codec->channels = 1; 62 if (get_le32(pb)) 63 st->codec->channels = 2; 64 65 st->codec->bits_per_coded_sample = 4; 66 st->codec->bit_rate = st->codec->bits_per_coded_sample * st->codec->channels 67 * st->codec->sample_rate; 68 st->codec->block_align = 1; 69 70 return 0; 71} 72 73#define MAX_READ_SIZE 4096 74 75static int apc_read_packet(AVFormatContext *s, AVPacket *pkt) 76{ 77 if (av_get_packet(s->pb, pkt, MAX_READ_SIZE) <= 0) 78 return AVERROR(EIO); 79 pkt->stream_index = 0; 80 return 0; 81} 82 83AVInputFormat apc_demuxer = { 84 "apc", 85 NULL_IF_CONFIG_SMALL("CRYO APC format"), 86 0, 87 apc_probe, 88 apc_read_header, 89 apc_read_packet, 90}; 91