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segment: introduce segmented chain muxer

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It behaves similarly to image2 muxer
This commit is contained in:
Luca Barbato 2011-10-02 23:05:29 +02:00
parent 1ee5b5e823
commit 02e8f03296
5 changed files with 308 additions and 0 deletions
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1
Changelog
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@ -109,6 +109,7 @@ easier to use. The changes are:
- Dxtory capture format decoder
- v410 QuickTime uncompressed 4:4:4 10-bit encoder and decoder
- OpenMG Audio muxer
- Simple segmenting muxer
version 0.7:

32
doc/muxers.texi
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@ -90,6 +90,7 @@ avconv -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
See also the @ref{crc} muxer.
@anchor{image2}
@section image2
Image file muxer.
@ -267,4 +268,35 @@ For example a 3D WebM clip can be created using the following command line:
avconv -i sample_left_right_clip.mpg -an -c:v libvpx -metadata STEREO_MODE=left_right -y stereo_clip.webm
@end example
@section segment
Basic stream segmenter.
The segmenter muxer outputs streams to a number of separate files of nearly
fixed duration. Output filename pattern can be set in a fashion similar to
@ref{image2}.
Every segment starts with a video keyframe, if a video stream is present.
The segment muxer works best with a single constant frame rate video.
Optionally it can generate a flat list of the created segments, one segment
per line.
@table @option
@item segment_format @var{format}
Override the inner container format, by default it is guessed by the filename
extension.
@item segment_time @var{t}
Set segment duration to @var{t} seconds.
@item segment_list @var{name}
Generate also a listfile named @var{name}.
@item segment_list_size @var{size}
Overwrite the listfile once it reaches @var{size} entries.
@end table
@example
avconv -i in.mkv -c copy -map 0 -f segment -list out.list out%03d.nut
@end example
@c man end MUXERS

1
libavformat/Makefile
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@ -268,6 +268,7 @@ OBJS-$(CONFIG_SAP_DEMUXER) += sapdec.o
OBJS-$(CONFIG_SAP_MUXER) += sapenc.o rtpenc_chain.o
OBJS-$(CONFIG_SDP_DEMUXER) += rtsp.o
OBJS-$(CONFIG_SEGAFILM_DEMUXER) += segafilm.o
OBJS-$(CONFIG_SEGMENT_MUXER) += segment.o
OBJS-$(CONFIG_SHORTEN_DEMUXER) += rawdec.o
OBJS-$(CONFIG_SIFF_DEMUXER) += siff.o
OBJS-$(CONFIG_SMACKER_DEMUXER) += smacker.o

1
libavformat/allformats.c
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@ -197,6 +197,7 @@ void av_register_all(void)
av_register_rdt_dynamic_payload_handlers();
#endif
REGISTER_DEMUXER (SEGAFILM, segafilm);
REGISTER_MUXER (SEGMENT, segment);
REGISTER_DEMUXER (SHORTEN, shorten);
REGISTER_DEMUXER (SIFF, siff);
REGISTER_DEMUXER (SMACKER, smacker);

273
libavformat/segment.c Normal file
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@ -0,0 +1,273 @@
/*
* Generic segmenter
* Copyright (c) 2011, Luca Barbato
*
* 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 <strings.h>
#include <float.h>
#include "avformat.h"
#include "internal.h"
#include "libavutil/log.h"
#include "libavutil/opt.h"
#include "libavutil/avstring.h"
#include "libavutil/parseutils.h"
#include "libavutil/mathematics.h"
typedef struct {
const AVClass *class; /**< Class for private options. */
int number;
AVFormatContext *avf;
char *format; /**< Set by a private option. */
char *list; /**< Set by a private option. */
float time; /**< Set by a private option. */
int size; /**< Set by a private option. */
int64_t offset_time;
int64_t recording_time;
int has_video;
AVIOContext *pb;
} SegmentContext;
static int segment_start(AVFormatContext *s)
{
SegmentContext *c = s->priv_data;
AVFormatContext *oc = c->avf;
int err = 0;
if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
s->filename, c->number++) < 0)
return AVERROR(EINVAL);
if ((err = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
&s->interrupt_callback, NULL)) < 0)
return err;
if (!oc->priv_data && oc->oformat->priv_data_size > 0) {
oc->priv_data = av_mallocz(oc->oformat->priv_data_size);
if (!oc->priv_data) {
avio_close(oc->pb);
return AVERROR(ENOMEM);
}
if (oc->oformat->priv_class) {
*(const AVClass**)oc->priv_data = oc->oformat->priv_class;
av_opt_set_defaults(oc->priv_data);
}
}
if ((err = oc->oformat->write_header(oc)) < 0) {
goto fail;
}
return 0;
fail:
avio_close(oc->pb);
av_freep(&oc->priv_data);
return err;
}
static int segment_end(AVFormatContext *oc)
{
int ret = 0;
if (oc->oformat->write_trailer)
ret = oc->oformat->write_trailer(oc);
avio_close(oc->pb);
if (oc->oformat->priv_class)
av_opt_free(oc->priv_data);
av_freep(&oc->priv_data);
return ret;
}
static int seg_write_header(AVFormatContext *s)
{
SegmentContext *seg = s->priv_data;
AVFormatContext *oc;
int ret, i;
seg->number = 0;
seg->offset_time = 0;
seg->recording_time = seg->time * 1000000;
if (seg->list)
if ((ret = avio_open2(&seg->pb, seg->list, AVIO_FLAG_WRITE,
&s->interrupt_callback, NULL)) < 0)
return ret;
for (i = 0; i< s->nb_streams; i++)
seg->has_video +=
(s->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO);
if (seg->has_video > 1)
av_log(s, AV_LOG_WARNING,
"More than a single video stream present, "
"expect issues decoding it.\n");
oc = avformat_alloc_context();
if (!oc) {
ret = AVERROR(ENOMEM);
goto fail;
}
oc->oformat = av_guess_format(seg->format, s->filename, NULL);
if (!oc->oformat) {
ret = AVERROR_MUXER_NOT_FOUND;
goto fail;
}
if (oc->oformat->flags & AVFMT_NOFILE) {
av_log(s, AV_LOG_ERROR, "format %s not supported.\n",
oc->oformat->name);
ret = AVERROR(EINVAL);
goto fail;
}
seg->avf = oc;
oc->streams = s->streams;
oc->nb_streams = s->nb_streams;
if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
s->filename, seg->number++) < 0) {
ret = AVERROR(EINVAL);
goto fail;
}
if ((ret = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
&s->interrupt_callback, NULL)) < 0)
goto fail;
if ((ret = avformat_write_header(oc, NULL)) < 0) {
avio_close(oc->pb);
goto fail;
}
if (seg->list) {
avio_printf(seg->pb, "%s\n", oc->filename);
avio_flush(seg->pb);
}
fail:
if (ret) {
oc->streams = NULL;
oc->nb_streams = 0;
if (seg->list)
avio_close(seg->pb);
avformat_free_context(oc);
}
return ret;
}
static int seg_write_packet(AVFormatContext *s, AVPacket *pkt)
{
SegmentContext *seg = s->priv_data;
AVFormatContext *oc = seg->avf;
AVStream *st = oc->streams[pkt->stream_index];
int64_t end_pts = seg->recording_time * seg->number;
int ret;
if ((seg->has_video && st->codec->codec_type == AVMEDIA_TYPE_VIDEO) &&
av_compare_ts(pkt->pts, st->time_base,
end_pts, AV_TIME_BASE_Q) >= 0 &&
pkt->flags & AV_PKT_FLAG_KEY) {
av_log(s, AV_LOG_DEBUG, "Next segment starts at %d %"PRId64"\n",
pkt->stream_index, pkt->pts);
ret = segment_end(oc);
if (!ret)
ret = segment_start(s);
if (ret)
goto fail;
if (seg->list) {
avio_printf(seg->pb, "%s\n", oc->filename);
avio_flush(seg->pb);
if (!(seg->number % seg->size)) {
avio_close(seg->pb);
if ((ret = avio_open2(&seg->pb, seg->list, AVIO_FLAG_WRITE,
&s->interrupt_callback, NULL)) < 0)
goto fail;
}
}
}
ret = oc->oformat->write_packet(oc, pkt);
fail:
if (ret < 0) {
oc->streams = NULL;
oc->nb_streams = 0;
if (seg->list)
avio_close(seg->pb);
avformat_free_context(oc);
}
return ret;
}
static int seg_write_trailer(struct AVFormatContext *s)
{
SegmentContext *seg = s->priv_data;
AVFormatContext *oc = seg->avf;
int ret = segment_end(oc);
if (seg->list)
avio_close(seg->pb);
oc->streams = NULL;
oc->nb_streams = 0;
avformat_free_context(oc);
return ret;
}
#define OFFSET(x) offsetof(SegmentContext, x)
#define E AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
{ "segment_format", "container format used for the segments", OFFSET(format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
{ "segment_time", "segment length in seconds", OFFSET(time), AV_OPT_TYPE_FLOAT, {.dbl = 2}, 0, FLT_MAX, E },
{ "segment_list", "output the segment list", OFFSET(list), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
{ "segment_list_size", "maximum number of playlist entries", OFFSET(size), AV_OPT_TYPE_INT, {.dbl = 5}, 0, INT_MAX, E },
{ NULL },
};
static const AVClass seg_class = {
.class_name = "segment muxer",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
AVOutputFormat ff_segment_muxer = {
.name = "segment",
.long_name = NULL_IF_CONFIG_SMALL("segment muxer"),
.priv_data_size = sizeof(SegmentContext),
.flags = AVFMT_GLOBALHEADER | AVFMT_NOFILE,
.write_header = seg_write_header,
.write_packet = seg_write_packet,
.write_trailer = seg_write_trailer,
.priv_class = &seg_class,
};