[FFmpeg-cvslog] segment: introduce segmented chain muxer
Luca Barbato
git at videolan.org
Tue Dec 20 04:18:11 CET 2011
ffmpeg | branch: master | Luca Barbato <lu_zero at gentoo.org> | Sun Oct 2 23:05:29 2011 +0200| [02e8f03296d29949a7cffc8fa3e704b0efa66f17] | committer: Luca Barbato
segment: introduce segmented chain muxer
It behaves similarly to image2 muxer
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=02e8f03296d29949a7cffc8fa3e704b0efa66f17
---
Changelog | 1 +
doc/muxers.texi | 32 ++++++
libavformat/Makefile | 1 +
libavformat/allformats.c | 1 +
libavformat/segment.c | 273 ++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 308 insertions(+), 0 deletions(-)
diff --git a/Changelog b/Changelog
index 5f5154a..58568c2 100644
--- a/Changelog
+++ b/Changelog
@@ -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:
diff --git a/doc/muxers.texi b/doc/muxers.texi
index 17b1de3..5a609c8 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.
+ at 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
+ at 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
+ at 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.
+
+ at table @option
+ at item segment_format @var{format}
+Override the inner container format, by default it is guessed by the filename
+extension.
+ at item segment_time @var{t}
+Set segment duration to @var{t} seconds.
+ at item segment_list @var{name}
+Generate also a listfile named @var{name}.
+ at item segment_list_size @var{size}
+Overwrite the listfile once it reaches @var{size} entries.
+ at end table
+
+ at example
+avconv -i in.mkv -c copy -map 0 -f segment -list out.list out%03d.nut
+ at end example
+
+
@c man end MUXERS
diff --git a/libavformat/Makefile b/libavformat/Makefile
index ff6140b..c3a4c0d 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -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
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index c75f1ba..083ee08 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..89ae62d
--- /dev/null
+++ b/libavformat/segment.c
@@ -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,
+};
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