third_party_ffmpeg/libavformat/rawdec.c

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/*
* RAW demuxers
* Copyright (c) 2001 Fabrice Bellard
* Copyright (c) 2005 Alex Beregszaszi
*
* 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 "config_components.h"
#include "avformat.h"
#include "internal.h"
#include "avio_internal.h"
#include "rawdec.h"
#include "libavutil/opt.h"
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#include "libavutil/parseutils.h"
#include "libavutil/pixdesc.h"
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#include "libavutil/intreadwrite.h"
#define RAW_PACKET_SIZE 1024
int ff_raw_read_partial_packet(AVFormatContext *s, AVPacket *pkt)
{
FFRawDemuxerContext *raw = s->priv_data;
int ret, size;
size = raw->raw_packet_size;
if ((ret = av_new_packet(pkt, size)) < 0)
return ret;
pkt->pos= avio_tell(s->pb);
pkt->stream_index = 0;
ret = avio_read_partial(s->pb, pkt->data, size);
if (ret < 0) {
av_packet_unref(pkt);
return ret;
}
av_shrink_packet(pkt, ret);
return ret;
}
int ff_raw_audio_read_header(AVFormatContext *s)
{
AVStream *st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
lavf: replace AVStream.codec with AVStream.codecpar Currently, AVStream contains an embedded AVCodecContext instance, which is used by demuxers to export stream parameters to the caller and by muxers to receive stream parameters from the caller. It is also used internally as the codec context that is passed to parsers. In addition, it is also widely used by the callers as the decoding (when demuxer) or encoding (when muxing) context, though this has been officially discouraged since Libav 11. There are multiple important problems with this approach: - the fields in AVCodecContext are in general one of * stream parameters * codec options * codec state However, it's not clear which ones are which. It is consequently unclear which fields are a demuxer allowed to set or a muxer allowed to read. This leads to erratic behaviour depending on whether decoding or encoding is being performed or not (and whether it uses the AVStream embedded codec context). - various synchronization issues arising from the fact that the same context is used by several different APIs (muxers/demuxers, parsers, bitstream filters and encoders/decoders) simultaneously, with there being no clear rules for who can modify what and the different processes being typically delayed with respect to each other. - avformat_find_stream_info() making it necessary to support opening and closing a single codec context multiple times, thus complicating the semantics of freeing various allocated objects in the codec context. Those problems are resolved by replacing the AVStream embedded codec context with a newly added AVCodecParameters instance, which stores only the stream parameters exported by the demuxers or read by the muxers.
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st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_id = s->iformat->raw_codec_id;
ffstream(st)->need_parsing = AVSTREAM_PARSE_FULL_RAW;
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;
FFStream *sti;
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FFRawVideoDemuxerContext *s1 = s->priv_data;
int ret = 0;
st = avformat_new_stream(s, NULL);
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if (!st) {
ret = AVERROR(ENOMEM);
goto fail;
}
sti = ffstream(st);
lavf: replace AVStream.codec with AVStream.codecpar Currently, AVStream contains an embedded AVCodecContext instance, which is used by demuxers to export stream parameters to the caller and by muxers to receive stream parameters from the caller. It is also used internally as the codec context that is passed to parsers. In addition, it is also widely used by the callers as the decoding (when demuxer) or encoding (when muxing) context, though this has been officially discouraged since Libav 11. There are multiple important problems with this approach: - the fields in AVCodecContext are in general one of * stream parameters * codec options * codec state However, it's not clear which ones are which. It is consequently unclear which fields are a demuxer allowed to set or a muxer allowed to read. This leads to erratic behaviour depending on whether decoding or encoding is being performed or not (and whether it uses the AVStream embedded codec context). - various synchronization issues arising from the fact that the same context is used by several different APIs (muxers/demuxers, parsers, bitstream filters and encoders/decoders) simultaneously, with there being no clear rules for who can modify what and the different processes being typically delayed with respect to each other. - avformat_find_stream_info() making it necessary to support opening and closing a single codec context multiple times, thus complicating the semantics of freeing various allocated objects in the codec context. Those problems are resolved by replacing the AVStream embedded codec context with a newly added AVCodecParameters instance, which stores only the stream parameters exported by the demuxers or read by the muxers.
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st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->codec_id = s->iformat->raw_codec_id;
sti->need_parsing = AVSTREAM_PARSE_FULL_RAW;
sti->avctx->framerate = s1->framerate;
avpriv_set_pts_info(st, 64, 1, 1200000);
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fail:
return ret;
}
int ff_raw_subtitle_read_header(AVFormatContext *s)
{
AVStream *st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
st->codecpar->codec_id = s->iformat->raw_codec_id;
st->start_time = 0;
return 0;
}
static int raw_data_read_header(AVFormatContext *s)
{
AVStream *st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_DATA;
st->codecpar->codec_id = s->iformat->raw_codec_id;
st->start_time = 0;
return 0;
}
/* Note: Do not forget to add new entries to the Makefile as well. */
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#define OFFSET(x) offsetof(FFRawVideoDemuxerContext, x)
#define DEC AV_OPT_FLAG_DECODING_PARAM
static const AVOption rawvideo_options[] = {
{ "framerate", "", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, INT_MAX, DEC},
{ "raw_packet_size", "", OFFSET(raw_packet_size), AV_OPT_TYPE_INT, {.i64 = RAW_PACKET_SIZE }, 1, INT_MAX, DEC},
{ NULL },
};
#undef OFFSET
const AVClass ff_rawvideo_demuxer_class = {
.class_name = "generic raw video demuxer",
.item_name = av_default_item_name,
.option = rawvideo_options,
.version = LIBAVUTIL_VERSION_INT,
};
#define OFFSET(x) offsetof(FFRawDemuxerContext, x)
const AVOption ff_raw_options[] = {
{ "raw_packet_size", "", OFFSET(raw_packet_size), AV_OPT_TYPE_INT, {.i64 = RAW_PACKET_SIZE }, 1, INT_MAX, DEC},
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{ NULL },
};
const AVClass ff_raw_demuxer_class = {
.class_name = "generic raw demuxer",
.item_name = av_default_item_name,
.option = ff_raw_options,
.version = LIBAVUTIL_VERSION_INT,
};
#if CONFIG_DATA_DEMUXER
const AVInputFormat ff_data_demuxer = {
.name = "data",
.long_name = NULL_IF_CONFIG_SMALL("raw data"),
.read_header = raw_data_read_header,
.read_packet = ff_raw_read_partial_packet,
.raw_codec_id = AV_CODEC_ID_NONE,
.flags = AVFMT_NOTIMESTAMPS,
.priv_data_size = sizeof(FFRawDemuxerContext),\
.priv_class = &ff_raw_demuxer_class,
};
#endif
#if CONFIG_MJPEG_DEMUXER
static int mjpeg_probe(const AVProbeData *p)
{
int i;
int state = -1;
int nb_invalid = 0;
int nb_frames = 0;
for (i = 0; i < p->buf_size - 1; i++) {
int c;
if (p->buf[i] != 0xFF)
continue;
c = p->buf[i+1];
switch (c) {
case 0xD8:
state = 0xD8;
break;
case 0xC0:
case 0xC1:
case 0xC2:
case 0xC3:
case 0xC5:
case 0xC6:
case 0xC7:
case 0xF7:
if (state == 0xD8) {
state = 0xC0;
} else
nb_invalid++;
break;
case 0xDA:
if (state == 0xC0) {
state = 0xDA;
} else
nb_invalid++;
break;
case 0xD9:
if (state == 0xDA) {
state = 0xD9;
nb_frames++;
} else
nb_invalid++;
break;
default:
if ( (c >= 0x02 && c <= 0xBF)
|| c == 0xC8) {
nb_invalid++;
}
}
}
if (nb_invalid*4 + 1 < nb_frames) {
static const char ct_jpeg[] = "\r\nContent-Type: image/jpeg\r\n";
int i;
for (i=0; i<FFMIN(p->buf_size - (int)sizeof(ct_jpeg), 100); i++)
if (!memcmp(p->buf + i, ct_jpeg, sizeof(ct_jpeg) - 1))
return AVPROBE_SCORE_EXTENSION;
if (nb_invalid == 0 && nb_frames > 2)
return AVPROBE_SCORE_EXTENSION / 2;
return AVPROBE_SCORE_EXTENSION / 4;
}
if (!nb_invalid && nb_frames)
return AVPROBE_SCORE_EXTENSION / 4;
return 0;
}
FF_DEF_RAWVIDEO_DEMUXER2(mjpeg, "raw MJPEG video", mjpeg_probe, "mjpg,mjpeg,mpo", AV_CODEC_ID_MJPEG, AVFMT_GENERIC_INDEX|AVFMT_NOTIMESTAMPS)
#endif