@@ -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:

@@ -1268,4 +1268,47 @@ ffmpeg -f webm_dash_manifest -i video1.webm \

        manifest.xml

 @end example

+@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.

+

+@subsection Options

+

+This muxer supports the following options:

+

+@table @option

+@item chunk_start_index

+Index of the first chunk (defaults to 0).

+

+@item header

+Filename of the header where the initialization data will be written.

+

+@item audio_chunk_duration

+Duration of each audio chunk in milliseconds (defaults to 5000).

+@end table

+

+@subsection Example

+@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

+@end example

+

 @c man end MUXERS

@@ -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

@@ -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);

@@ -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 },

 };

@@ -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, \

new file mode 100644

@@ -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