FFmpeg/libavformat/adxdec.c
2012-08-07 16:00:24 +02:00

114 lines
3.2 KiB
C

/*
* Copyright (c) 2011 Justin Ruggles
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* CRI ADX demuxer
*/
#include "libavutil/intreadwrite.h"
#include "libavcodec/adx.h"
#include "avformat.h"
#include "internal.h"
#define BLOCK_SIZE 18
#define BLOCK_SAMPLES 32
typedef struct ADXDemuxerContext {
int header_size;
} ADXDemuxerContext;
static int adx_read_packet(AVFormatContext *s, AVPacket *pkt)
{
ADXDemuxerContext *c = s->priv_data;
AVCodecContext *avctx = s->streams[0]->codec;
int ret, size;
size = BLOCK_SIZE * avctx->channels;
pkt->pos = avio_tell(s->pb);
pkt->stream_index = 0;
ret = av_get_packet(s->pb, pkt, size);
if (ret != size) {
av_free_packet(pkt);
return ret < 0 ? ret : AVERROR(EIO);
}
if (AV_RB16(pkt->data) & 0x8000) {
av_free_packet(pkt);
return AVERROR_EOF;
}
pkt->size = size;
pkt->duration = 1;
pkt->pts = (pkt->pos - c->header_size) / size;
return 0;
}
static int adx_read_header(AVFormatContext *s)
{
ADXDemuxerContext *c = s->priv_data;
AVCodecContext *avctx;
int ret;
AVStream *st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
avctx = s->streams[0]->codec;
if (avio_rb16(s->pb) != 0x8000)
return AVERROR_INVALIDDATA;
c->header_size = avio_rb16(s->pb) + 4;
avio_seek(s->pb, -4, SEEK_CUR);
avctx->extradata = av_mallocz(c->header_size + FF_INPUT_BUFFER_PADDING_SIZE);
if (!avctx->extradata)
return AVERROR(ENOMEM);
if (avio_read(s->pb, avctx->extradata, c->header_size) < c->header_size) {
av_freep(&avctx->extradata);
return AVERROR(EIO);
}
avctx->extradata_size = c->header_size;
ret = avpriv_adx_decode_header(avctx, avctx->extradata,
avctx->extradata_size, &c->header_size,
NULL);
if (ret)
return ret;
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id = s->iformat->raw_codec_id;
avpriv_set_pts_info(st, 64, BLOCK_SAMPLES, avctx->sample_rate);
return 0;
}
AVInputFormat ff_adx_demuxer = {
.name = "adx",
.long_name = NULL_IF_CONFIG_SMALL("CRI ADX"),
.priv_data_size = sizeof(ADXDemuxerContext),
.read_header = adx_read_header,
.read_packet = adx_read_packet,
.extensions = "adx",
.raw_codec_id = AV_CODEC_ID_ADPCM_ADX,
.flags = AVFMT_GENERIC_INDEX,
};