On Wed, Dec 07, 2011 at 01:06:43AM +0100, Luca Barbato wrote:
> It behaves similarly to image2 muxer
> ---
> doc/muxers.texi | 27 +++++
> libavformat/Makefile | 1 +
> libavformat/allformats.c | 1 +
> libavformat/segment.c | 249
> ++++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 278 insertions(+), 0 deletions(-)
> create mode 100644 libavformat/segment.c
>
> diff --git a/doc/muxers.texi b/doc/muxers.texi
> index f6b17a1..6584cdf 100644
> --- a/doc/muxers.texi
> +++ b/doc/muxers.texi
> @@ -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 +268,30 @@ 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 splits the streams in a number of separate files of
> nearly fixed duration in a fashion similar to @ref{image2}.
> +Each segment starts from a video I frame.
I'd rephrase that. Like:
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.
> +The segment muxer works best with constant frame rate video.
> +
> +@table @option
> +@item container_format @var{format}
> +Override the inner container format, by default it is guessed by the filename
> +extension.
> +@item segment_time @var{t}
> +Split the streams every @var{t} seconds.
maybe: set segment duration to @var{t} seconds.
Splitting streams sounds more like what MPEG-TS demuxer does.
> +@item list @var{name}
> +Generate also a listfile named @var{name}.
> +@item list_size @var{size}
> +Reset the listfile once it reaches @var{size} entries.
Reset? Maybe overwrite or clean?
> +@end table
> +
> +@example
> +avconv -i in.mkv -c copy -map 0 -f segment -list out.list out%d.nut
> +@end example
> +
> +
> @c man end MUXERS
> diff --git a/libavformat/Makefile b/libavformat/Makefile
> index fccb5f3..9367212 100644
> --- a/libavformat/Makefile
> +++ b/libavformat/Makefile
> @@ -266,6 +266,7 @@ 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-$(CONFIG_SEGMENT_MUXER) += segment.o
tabs inside?
> OBJS-$(CONFIG_SHORTEN_DEMUXER) += rawdec.o
> OBJS-$(CONFIG_SIFF_DEMUXER) += siff.o
> OBJS-$(CONFIG_SMACKER_DEMUXER) += smacker.o
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index fe775f4..2e06f81 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -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);
> diff --git a/libavformat/segment.c b/libavformat/segment.c
> new file mode 100644
> index 0000000..d53ca36
> --- /dev/null
> +++ b/libavformat/segment.c
> @@ -0,0 +1,249 @@
> +/*
> + * Generic Segmenter
segmenter, it's not a newspaper headline
> + * 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 "libavutil/avstring.h"
> +#include "libavutil/log.h"
> +#include "libavutil/opt.h"
> +#include "libavutil/mathematics.h"
> +#include "libavutil/parseutils.h"
> +#include "avformat.h"
> +#include "internal.h"
> +#include <strings.h>
> +#include <float.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;
> +} SegmentContext;
> +
> +#if CONFIG_SEGMENT_MUXER
> +
> +static int segment_header(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_open(&oc->pb, oc->filename, AVIO_FLAG_WRITE)) < 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 ((err = oc->oformat->write_header(oc)) < 0) {
> + avio_close(oc->pb);
> + av_freep(&oc->priv_data);
> + }
> +
> + return err;
> +}
> +
> +static int segment_trailer(AVFormatContext *oc)
> +{
> + int ret = 0;
> +
> + if (oc->oformat->write_trailer)
> + ret = oc->oformat->write_trailer(oc);
> +
> + avio_close(oc->pb);
> + av_freep(&oc->priv_data);
> +
> + return ret;
> +}
> +
> +static int seg_write_header(AVFormatContext *s)
> +{
> + SegmentContext *seg = s->priv_data;
> + AVFormatContext *oc;
> + int ret;
> +
> + seg->number = 0;
> + seg->recording_time = seg->time*1000000;
> + seg->offset_time = 0;
> +
> + if (seg->list) {
> + if ((ret = avio_open(&s->pb, seg->list, AVIO_FLAG_WRITE)) < 0) {
> + return ret;
> + }
> + }
> +
> + if (!seg->format) {
> + char *t = strrchr(s->filename, '.');
> + if (t && ++t)
> + seg->format = strdup(t);
Looks like a memleak (also don't we have av_strdup() ?).
> + else
> + return AVERROR_MUXER_NOT_FOUND;
> + }
> +
> + oc = avformat_alloc_context();
> +
> + if (!oc) {
> + return AVERROR(ENOMEM);
> + }
> +
> + oc->oformat = av_guess_format(seg->format, NULL, NULL);
> +
> + if (!oc->oformat) {
> + ret = AVERROR_MUXER_NOT_FOUND;
> + 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_open(&oc->pb, oc->filename, AVIO_FLAG_WRITE)) < 0) {
> + goto fail;
> + }
> +
> + if ((ret = avformat_write_header(oc, NULL)) < 0) {
> + avio_close(oc->pb);
> + goto fail;
> + }
> +
> + if (seg->list) {
> + avio_printf(s->pb, "%s\n", oc->filename);
> + avio_flush(s->pb);
> + }
> +
> + fail:
> +
> + if (ret) {
> + oc->streams = NULL;
> + oc->nb_streams = 0;
> + 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 (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, "I'd reset at %d %"PRId64"\n",
> + pkt->stream_index, pkt->pts);
Maybe "next segment start at ..."? Remember, even modern computer cases are
mostly shy to have a reset button, let alone anything portable.
> + ret = segment_trailer(oc);
> + if (!ret)
> + ret = segment_header(s);
> +
> + if (ret)
> + goto fail;
> +
> + if (seg->list) {
> + avio_printf(s->pb, "%s\n", oc->filename);
> + avio_flush(s->pb);
> + if (!(seg->number % seg->size)) {
> + avio_close(s->pb);
> + if ((ret = avio_open(&s->pb, seg->list,
> + AVIO_FLAG_WRITE)) < 0) {
> + goto fail;
> + }
> + }
> + }
> + }
> +
> + ret = oc->oformat->write_packet(oc, pkt);
> +
> + fail:
> + if (ret < 0) {
> + oc->streams = NULL;
> + oc->nb_streams = 0;
> + avformat_free_context(oc);
> + }
> +
> + return ret;
> +}
> +
> +static int seg_write_trailer(struct AVFormatContext *s)
> +{
> + SegmentContext *seg = s->priv_data;
> + AVFormatContext *oc = seg->avf;
> +
> + return segment_trailer(oc);
> +}
> +
> +#endif /* CONFIG_SEGMENT_MUXER */
> +
> +#define OFFSET(x) offsetof(SegmentContext, x)
> +#define E AV_OPT_FLAG_ENCODING_PARAM
nit: you could define whole SEG_OPTION(name, description, field, type, defval)
here instead
> +static const AVOption options[] = {
> + { "container_format", "container format used for the segments",
> OFFSET(format), FF_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
> + { "segment_time", "segment lenght in seconds",
> OFFSET(time), FF_OPT_TYPE_FLOAT, {.dbl = 2}, 0, FLT_MAX, E },
> + { "list", "output the segment list",
> OFFSET(list), FF_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
> + { "list_size", "maximum number of entry in the playlist",
> OFFSET(size), FF_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,
> +};
> +
> +/* output */
> +#if CONFIG_SEGMENT_MUXER
> +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,
> +};
> +#endif
> --
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