[FFmpeg-cvslog] lavf: Add support for WebM Live Muxing
Vignesh Venkatasubramanian
git at videolan.org
Tue Apr 7 15:37:20 CEST 2015
ffmpeg | branch: master | Vignesh Venkatasubramanian <vigneshv at google.com> | Mon Mar 30 14:46:10 2015 -0700| [6fd300ac6c2c3871736ce0e6df95603255004dc6] | committer: Michael Niedermayer
lavf: Add support for WebM Live Muxing
This patch adds support for WebM Live Muxing by adding a new WebM
Chunk muxer. It writes out live WebM Chunks which can be used for
playback using Live DASH Clients.
Please see muxers.texi for sample usage.
Signed-off-by: Vignesh Venkatasubramanian <vigneshv at google.com>
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=6fd300ac6c2c3871736ce0e6df95603255004dc6
---
Changelog | 1 +
doc/muxers.texi | 43 ++++++++
libavformat/Makefile | 5 +-
libavformat/allformats.c | 1 +
libavformat/matroskaenc.c | 12 ++-
libavformat/version.h | 2 +-
libavformat/webm_chunk.c | 262 +++++++++++++++++++++++++++++++++++++++++++++
7 files changed, 320 insertions(+), 6 deletions(-)
diff --git a/Changelog b/Changelog
index a6a0e2d..4f48261 100644
--- a/Changelog
+++ b/Changelog
@@ -14,6 +14,7 @@ version <next>:
- MMAL-accelerated H.264 decoding
- basic APNG encoder and muxer
- unpack DivX-style packed B-frames in MPEG-4 bitstream filter
+- WebM Live Chunk Muxer
version 2.6:
diff --git a/doc/muxers.texi b/doc/muxers.texi
index f0ca730..335f093 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -1268,4 +1268,47 @@ ffmpeg -f webm_dash_manifest -i video1.webm \
manifest.xml
@end example
+ at section webm_chunk
+
+WebM Live Chunk Muxer.
+
+This muxer writes out WebM headers and chunks as separate files which can be
+consumed by clients that support WebM Live streams via DASH.
+
+ at subsection Options
+
+This muxer supports the following options:
+
+ at table @option
+ at item chunk_start_index
+Index of the first chunk (defaults to 0).
+
+ at item header
+Filename of the header where the initialization data will be written.
+
+ at item audio_chunk_duration
+Duration of each audio chunk in milliseconds (defaults to 5000).
+ at end table
+
+ at subsection Example
+ at example
+ffmpeg -f v4l2 -i /dev/video0 \
+ -f alsa -i hw:0 \
+ -map 0:0 \
+ -c:v libvpx-vp9 \
+ -s 640x360 -keyint_min 30 -g 30 \
+ -f webm_chunk \
+ -header webm_live_video_360.hdr \
+ -chunk_start_index 1 \
+ webm_live_video_360_%d.chk \
+ -map 1:0 \
+ -c:a libvorbis \
+ -b:a 128k \
+ -f webm_chunk \
+ -header webm_live_audio_128.hdr \
+ -chunk_start_index 1 \
+ -audio_chunk_duration 1000 \
+ webm_live_audio_128_%d.chk
+ at end example
+
@c man end MUXERS
diff --git a/libavformat/Makefile b/libavformat/Makefile
index 5082101..8d9a770 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -238,7 +238,7 @@ OBJS-$(CONFIG_MATROSKA_DEMUXER) += matroskadec.o matroska.o \
OBJS-$(CONFIG_MATROSKA_MUXER) += matroskaenc.o matroska.o \
isom.o avc.o hevc.o \
flacenc_header.o avlanguage.o vorbiscomment.o wv.o \
- webmdashenc.o
+ webmdashenc.o webm_chunk.o
OBJS-$(CONFIG_MD5_MUXER) += md5enc.o
OBJS-$(CONFIG_MGSTS_DEMUXER) += mgsts.o
OBJS-$(CONFIG_MICRODVD_DEMUXER) += microdvddec.o subtitles.o
@@ -452,12 +452,13 @@ OBJS-$(CONFIG_WEBM_MUXER) += matroskaenc.o matroska.o \
isom.o avc.o hevc.o \
flacenc_header.o avlanguage.o \
wv.o vorbiscomment.o \
- webmdashenc.o
+ webmdashenc.o webm_chunk.o
OBJS-$(CONFIG_WEBM_DASH_MANIFEST_DEMUXER)+= matroskadec.o matroska.o \
isom.o rmsipr.o flac_picture.o \
oggparsevorbis.o vorbiscomment.o \
flac_picture.o replaygain.o
OBJS-$(CONFIG_WEBM_DASH_MANIFEST_MUXER) += webmdashenc.o matroska.o
+OBJS-$(CONFIG_WEBM_CHUNK_MUXER) += webm_chunk.o matroska.o
OBJS-$(CONFIG_WEBP_MUXER) += webpenc.o
OBJS-$(CONFIG_WEBVTT_DEMUXER) += webvttdec.o subtitles.o
OBJS-$(CONFIG_WEBVTT_MUXER) += webvttenc.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index ca45db8..e6a9d01 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -316,6 +316,7 @@ void av_register_all(void)
REGISTER_DEMUXER (WC3, wc3);
REGISTER_MUXER (WEBM, webm);
REGISTER_MUXDEMUX(WEBM_DASH_MANIFEST, webm_dash_manifest);
+ REGISTER_MUXER (WEBM_CHUNK, webm_chunk);
REGISTER_MUXER (WEBP, webp);
REGISTER_MUXDEMUX(WEBVTT, webvtt);
REGISTER_DEMUXER (WSAUD, wsaud);
diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c
index 5493e3c..6f55c69 100644
--- a/libavformat/matroskaenc.c
+++ b/libavformat/matroskaenc.c
@@ -120,6 +120,7 @@ typedef struct MatroskaMuxContext {
int64_t cluster_time_limit;
int is_dash;
int dash_track_number;
+ int is_live;
uint32_t chapter_id_offset;
int wrote_chapters;
@@ -1412,7 +1413,9 @@ static int mkv_write_header(AVFormatContext *s)
// reserve space for the duration
mkv->duration = 0;
mkv->duration_offset = avio_tell(pb);
- put_ebml_void(pb, 11); // assumes double-precision float to be written
+ if (!mkv->is_live) {
+ put_ebml_void(pb, 11); // assumes double-precision float to be written
+ }
end_ebml_master(pb, segment_info);
ret = mkv_write_tracks(s);
@@ -1436,7 +1439,7 @@ static int mkv_write_header(AVFormatContext *s)
return ret;
}
- if (!s->pb->seekable)
+ if (!s->pb->seekable && !mkv->is_live)
mkv_write_seekhead(pb, mkv->main_seekhead);
mkv->cues = mkv_start_cues(mkv->segment_offset);
@@ -1955,7 +1958,9 @@ static int mkv_write_trailer(AVFormatContext *s)
avio_seek(pb, currentpos, SEEK_SET);
}
- end_ebml_master(pb, mkv->segment);
+ if (!mkv->is_live) {
+ end_ebml_master(pb, mkv->segment);
+ }
av_freep(&mkv->tracks);
av_freep(&mkv->cues->entries);
av_freep(&mkv->cues);
@@ -2019,6 +2024,7 @@ static const AVOption options[] = {
{ "cluster_time_limit", "Store at most the provided number of milliseconds in a cluster.", OFFSET(cluster_time_limit), AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, FLAGS },
{ "dash", "Create a WebM file conforming to WebM DASH specification", OFFSET(is_dash), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, FLAGS },
{ "dash_track_number", "Track number for the DASH stream", OFFSET(dash_track_number), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 127, FLAGS },
+ { "live", "Write files assuming it is a live stream.", OFFSET(is_live), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, FLAGS },
{ "allow_raw_vfw", "allow RAW VFW mode", OFFSET(allow_raw_vfw), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, FLAGS },
{ NULL },
};
diff --git a/libavformat/version.h b/libavformat/version.h
index 1c78df2..55287ae 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -30,7 +30,7 @@
#include "libavutil/version.h"
#define LIBAVFORMAT_VERSION_MAJOR 56
-#define LIBAVFORMAT_VERSION_MINOR 29
+#define LIBAVFORMAT_VERSION_MINOR 30
#define LIBAVFORMAT_VERSION_MICRO 100
#define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
diff --git a/libavformat/webm_chunk.c b/libavformat/webm_chunk.c
new file mode 100644
index 0000000..48ea6f0
--- /dev/null
+++ b/libavformat/webm_chunk.c
@@ -0,0 +1,262 @@
+/*
+ * Copyright (c) 2015, Vignesh Venkatasubramanian
+ *
+ * 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
+ */
+
+/**
+ * @file WebM Chunk Muxer
+ * The chunk muxer enables writing WebM Live chunks where there is a header
+ * chunk, followed by data chunks where each Cluster is written out as a Chunk.
+ */
+
+#include <float.h>
+#include <time.h>
+
+#include "avformat.h"
+#include "avio.h"
+#include "internal.h"
+
+#include "libavutil/avassert.h"
+#include "libavutil/log.h"
+#include "libavutil/opt.h"
+#include "libavutil/avstring.h"
+#include "libavutil/parseutils.h"
+#include "libavutil/mathematics.h"
+#include "libavutil/time.h"
+#include "libavutil/time_internal.h"
+#include "libavutil/timestamp.h"
+
+typedef struct WebMChunkContext {
+ const AVClass *class;
+ int chunk_start_index;
+ char *header_filename;
+ int chunk_duration;
+ int chunk_count;
+ int chunk_index;
+ uint64_t duration_written;
+ int prev_pts;
+ AVOutputFormat *oformat;
+ AVFormatContext *avf;
+} WebMChunkContext;
+
+static int chunk_mux_init(AVFormatContext *s)
+{
+ WebMChunkContext *wc = s->priv_data;
+ AVFormatContext *oc;
+ int ret;
+
+ ret = avformat_alloc_output_context2(&wc->avf, wc->oformat, NULL, NULL);
+ if (ret < 0)
+ return ret;
+ oc = wc->avf;
+
+ oc->interrupt_callback = s->interrupt_callback;
+ oc->max_delay = s->max_delay;
+ av_dict_copy(&oc->metadata, s->metadata, 0);
+
+ oc->priv_data = av_mallocz(oc->oformat->priv_data_size);
+ if (!oc->priv_data) {
+ avio_close(oc->pb);
+ return AVERROR(ENOMEM);
+ }
+ *(const AVClass**)oc->priv_data = oc->oformat->priv_class;
+ av_opt_set_defaults(oc->priv_data);
+ av_opt_set_int(oc->priv_data, "dash", 1, 0);
+ av_opt_set_int(oc->priv_data, "cluster_time_limit", wc->chunk_duration, 0);
+ av_opt_set_int(oc->priv_data, "live", 1, 0);
+
+ oc->streams = s->streams;
+ oc->nb_streams = s->nb_streams;
+
+ return 0;
+}
+
+static int set_chunk_filename(AVFormatContext *s, int is_header)
+{
+ WebMChunkContext *wc = s->priv_data;
+ AVFormatContext *oc = wc->avf;
+ if (is_header) {
+ if (!wc->header_filename) {
+ return AVERROR(EINVAL);
+ }
+ av_strlcpy(oc->filename, wc->header_filename, strlen(wc->header_filename) + 1);
+ } else {
+ if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
+ s->filename, wc->chunk_index) < 0) {
+ av_log(oc, AV_LOG_ERROR, "Invalid chunk filename template '%s'\n", s->filename);
+ return AVERROR(EINVAL);
+ }
+ }
+ return 0;
+}
+
+static int webm_chunk_write_header(AVFormatContext *s)
+{
+ WebMChunkContext *wc = s->priv_data;
+ AVFormatContext *oc = NULL;
+ int ret;
+
+ // DASH Streams can only have either one track per file.
+ if (s->nb_streams != 1) { return AVERROR_INVALIDDATA; }
+
+ wc->chunk_count = 0;
+ wc->chunk_index = wc->chunk_start_index;
+ wc->oformat = av_guess_format("webm", s->filename, "video/webm");
+ if (!wc->oformat)
+ return AVERROR_MUXER_NOT_FOUND;
+
+ ret = chunk_mux_init(s);
+ if (ret < 0)
+ return ret;
+ oc = wc->avf;
+ ret = set_chunk_filename(s, 1);
+ if (ret< 0)
+ return ret;
+ ret = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
+ &s->interrupt_callback, NULL);
+ if (ret < 0)
+ return ret;
+
+ oc->pb->seekable = 0;
+ ret = oc->oformat->write_header(oc);
+ if (ret < 0)
+ return ret;
+ avio_close(oc->pb);
+ return 0;
+}
+
+static int chunk_start(AVFormatContext *s)
+{
+ WebMChunkContext *wc = s->priv_data;
+ AVFormatContext *oc = wc->avf;
+ int ret;
+
+ ret = set_chunk_filename(s, 0);
+ if (ret < 0)
+ return ret;
+ wc->chunk_index++;
+ ret = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
+ &s->interrupt_callback, NULL);
+ if (ret < 0)
+ return ret;
+ oc->pb->seekable = 0;
+ return 0;
+}
+
+static int chunk_end(AVFormatContext *s)
+{
+ WebMChunkContext *wc = s->priv_data;
+ AVFormatContext *oc = wc->avf;
+ int ret;
+
+ if (wc->chunk_start_index == wc->chunk_index)
+ return 0;
+ // Flush the cluster in WebM muxer.
+ oc->oformat->write_packet(oc, NULL);
+ ret = avio_close(oc->pb);
+ if (ret < 0)
+ return ret;
+ wc->chunk_count++;
+ return 0;
+}
+
+static int webm_chunk_write_packet(AVFormatContext *s, AVPacket *pkt)
+{
+ WebMChunkContext *wc = s->priv_data;
+ AVFormatContext *oc = wc->avf;
+ AVStream *st = s->streams[pkt->stream_index];
+ int ret;
+
+ if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
+ wc->duration_written += av_rescale_q(pkt->pts - wc->prev_pts,
+ st->time_base,
+ (AVRational) {1, 1000});
+ wc->prev_pts = pkt->pts;
+ }
+
+ // For video, a new chunk is started only on key frames. For audio, a new
+ // chunk is started based on chunk_duration.
+ if ((st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
+ (pkt->flags & AV_PKT_FLAG_KEY)) ||
+ (st->codec->codec_type == AVMEDIA_TYPE_AUDIO &&
+ (pkt->pts == 0 || wc->duration_written >= wc->chunk_duration))) {
+ wc->duration_written = 0;
+ if ((ret = chunk_end(s)) < 0 || (ret = chunk_start(s)) < 0) {
+ goto fail;
+ }
+ }
+
+ if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO && pkt->pts == 0) {
+ goto fail;
+ }
+ ret = oc->oformat->write_packet(oc, pkt);
+ if (ret < 0)
+ goto fail;
+
+fail:
+ if (ret < 0) {
+ oc->streams = NULL;
+ oc->nb_streams = 0;
+ avformat_free_context(oc);
+ }
+
+ return ret;
+}
+
+static int webm_chunk_write_trailer(AVFormatContext *s)
+{
+ WebMChunkContext *wc = s->priv_data;
+ AVFormatContext *oc = wc->avf;
+ oc->oformat->write_trailer(oc);
+ chunk_end(s);
+ oc->streams = NULL;
+ oc->nb_streams = 0;
+ avformat_free_context(oc);
+ return 0;
+}
+
+#define OFFSET(x) offsetof(WebMChunkContext, x)
+static const AVOption options[] = {
+ { "chunk_start_index", "start index of the chunk", OFFSET(chunk_start_index), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
+ { "header", "filename of the header where the initialization data will be written", OFFSET(header_filename), AV_OPT_TYPE_STRING, { 0 }, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },
+ { "audio_chunk_duration", "duration of each chunk in milliseconds", OFFSET(chunk_duration), AV_OPT_TYPE_INT, {.i64 = 5000}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
+ { NULL },
+};
+
+#if CONFIG_WEBM_CHUNK_MUXER
+static const AVClass webm_chunk_class = {
+ .class_name = "WebM Chunk Muxer",
+ .item_name = av_default_item_name,
+ .option = options,
+ .version = LIBAVUTIL_VERSION_INT,
+};
+
+AVOutputFormat ff_webm_chunk_muxer = {
+ .name = "webm_chunk",
+ .long_name = NULL_IF_CONFIG_SMALL("WebM Chunk Muxer"),
+ .mime_type = "video/webm",
+ .extensions = "chk",
+ .flags = AVFMT_NOFILE | AVFMT_GLOBALHEADER | AVFMT_NEEDNUMBER |
+ AVFMT_TS_NONSTRICT | AVFMT_ALLOW_FLUSH,
+ .priv_data_size = sizeof(WebMChunkContext),
+ .write_header = webm_chunk_write_header,
+ .write_packet = webm_chunk_write_packet,
+ .write_trailer = webm_chunk_write_trailer,
+ .priv_class = &webm_chunk_class,
+};
+#endif
More information about the ffmpeg-cvslog
mailing list