ffmpeg/libavformat/rawdec.c

219 lines
6.3 KiB
C

/*
* RAW demuxers
* Copyright (c) 2001 Fabrice Bellard
* Copyright (c) 2005 Alex Beregszaszi
*
* 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
*/
#include "avformat.h"
#include "internal.h"
#include "avio_internal.h"
#include "rawdec.h"
#include "libavutil/opt.h"
#include "libavutil/parseutils.h"
#include "libavutil/pixdesc.h"
#include "libavutil/intreadwrite.h"
#define RAW_PACKET_SIZE 1024
int ff_raw_read_partial_packet(AVFormatContext *s, AVPacket *pkt)
{
int ret, size;
size = RAW_PACKET_SIZE;
if (av_new_packet(pkt, size) < 0)
return AVERROR(ENOMEM);
pkt->pos= avio_tell(s->pb);
pkt->stream_index = 0;
ret = ffio_read_partial(s->pb, pkt->data, size);
if (ret < 0) {
av_free_packet(pkt);
return ret;
} else if (ret < size) {
/* initialize end of packet for partial reads to avoid reading
* uninitialized data on allowed overreads */
memset(pkt->data + ret, 0, FF_INPUT_BUFFER_PADDING_SIZE);
}
pkt->size = ret;
return ret;
}
int ff_raw_audio_read_header(AVFormatContext *s)
{
AVStream *st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id = s->iformat->raw_codec_id;
st->need_parsing = AVSTREAM_PARSE_FULL;
st->start_time = 0;
/* the parameters will be extracted from the compressed bitstream */
return 0;
}
/* MPEG-1/H.263 input */
int ff_raw_video_read_header(AVFormatContext *s)
{
AVStream *st;
FFRawVideoDemuxerContext *s1 = s->priv_data;
AVRational framerate;
int ret = 0;
st = avformat_new_stream(s, NULL);
if (!st) {
ret = AVERROR(ENOMEM);
goto fail;
}
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
st->codec->codec_id = s->iformat->raw_codec_id;
st->need_parsing = AVSTREAM_PARSE_FULL;
if ((ret = av_parse_video_rate(&framerate, s1->framerate)) < 0) {
av_log(s, AV_LOG_ERROR, "Could not parse framerate: %s.\n", s1->framerate);
goto fail;
}
st->avg_frame_rate = framerate;
avpriv_set_pts_info(st, 64, framerate.den, framerate.num);
fail:
return ret;
}
/* Note: Do not forget to add new entries to the Makefile as well. */
#define OFFSET(x) offsetof(FFRawVideoDemuxerContext, x)
#define DEC AV_OPT_FLAG_DECODING_PARAM
const AVOption ff_rawvideo_options[] = {
{ "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0, DEC},
{ NULL },
};
#if CONFIG_LATM_DEMUXER
#define LOAS_SYNC_WORD 0x2b7
static int latm_read_probe(AVProbeData *p)
{
int max_frames = 0, first_frames = 0;
int fsize, frames;
uint8_t *buf0 = p->buf;
uint8_t *buf2;
uint8_t *buf;
uint8_t *end = buf0 + p->buf_size - 3;
buf = buf0;
for (; buf < end; buf = buf2 + 1) {
buf2 = buf;
for (frames = 0; buf2 < end; frames++) {
uint32_t header = AV_RB24(buf2);
if ((header >> 13) != LOAS_SYNC_WORD) {
if (buf != buf0) {
// Found something that isn't a LOAS header, starting
// from a position other than the start of the buffer.
// Discard the count we've accumulated so far since it
// probably was a false positive.
frames = 0;
}
break;
}
fsize = (header & 0x1FFF) + 3;
if (fsize < 7)
break;
buf2 += fsize;
}
max_frames = FFMAX(max_frames, frames);
if (buf == buf0)
first_frames = frames;
}
if (first_frames >= 3)
return AVPROBE_SCORE_EXTENSION + 1;
else if (max_frames > 100)
return AVPROBE_SCORE_EXTENSION;
else if (max_frames >= 3)
return AVPROBE_SCORE_EXTENSION / 2;
else if (max_frames > 1)
return 1;
else
return 0;
}
AVInputFormat ff_latm_demuxer = {
.name = "latm",
.long_name = NULL_IF_CONFIG_SMALL("raw LOAS/LATM"),
.read_probe = latm_read_probe,
.read_header = ff_raw_audio_read_header,
.read_packet = ff_raw_read_partial_packet,
.flags = AVFMT_GENERIC_INDEX,
.extensions = "latm",
.raw_codec_id = AV_CODEC_ID_AAC_LATM,
};
#endif
#if CONFIG_MJPEG_DEMUXER
FF_DEF_RAWVIDEO_DEMUXER(mjpeg, "raw MJPEG video", NULL, "mjpg,mjpeg", AV_CODEC_ID_MJPEG)
#endif
#if CONFIG_MLP_DEMUXER
AVInputFormat ff_mlp_demuxer = {
.name = "mlp",
.long_name = NULL_IF_CONFIG_SMALL("raw MLP"),
.read_header = ff_raw_audio_read_header,
.read_packet = ff_raw_read_partial_packet,
.flags = AVFMT_GENERIC_INDEX,
.extensions = "mlp",
.raw_codec_id = AV_CODEC_ID_MLP,
};
#endif
#if CONFIG_TRUEHD_DEMUXER
AVInputFormat ff_truehd_demuxer = {
.name = "truehd",
.long_name = NULL_IF_CONFIG_SMALL("raw TrueHD"),
.read_header = ff_raw_audio_read_header,
.read_packet = ff_raw_read_partial_packet,
.flags = AVFMT_GENERIC_INDEX,
.extensions = "thd",
.raw_codec_id = AV_CODEC_ID_TRUEHD,
};
#endif
#if CONFIG_SHORTEN_DEMUXER
AVInputFormat ff_shorten_demuxer = {
.name = "shn",
.long_name = NULL_IF_CONFIG_SMALL("raw Shorten"),
.read_header = ff_raw_audio_read_header,
.read_packet = ff_raw_read_partial_packet,
.flags = AVFMT_NOBINSEARCH | AVFMT_NOGENSEARCH | AVFMT_NO_BYTE_SEEK,
.extensions = "shn",
.raw_codec_id = AV_CODEC_ID_SHORTEN,
};
#endif
#if CONFIG_VC1_DEMUXER
FF_DEF_RAWVIDEO_DEMUXER(vc1, "raw VC-1", NULL, "vc1", AV_CODEC_ID_VC1)
#endif