[FFmpeg-devel] [PATCH 2/2] webmdashenc: Support for live stream manifests
Vignesh Venkatasubramanian
vigneshv at google.com
Wed Apr 1 01:51:58 CEST 2015
This patch adds support for creating DASH manifests for WebM Live
Streams. It also updates the documentation and adds a fate test to
verify the behavior of the new muxer flag.
Signed-off-by: Vignesh Venkatasubramanian <vigneshv at google.com>
---
doc/muxers.texi | 27 ++++-
libavformat/webmdashenc.c | 187 ++++++++++++++++++++++++++++-----
tests/fate/vpx.mak | 3 +
tests/ref/fate/webm-dash-manifest-live | 26 +++++
4 files changed, 216 insertions(+), 27 deletions(-)
create mode 100644 tests/ref/fate/webm-dash-manifest-live
diff --git a/doc/muxers.texi b/doc/muxers.texi
index a8225fc..089af06 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -1210,7 +1210,11 @@ is the @option{global_header} flag.
WebM DASH Manifest muxer.
-This muxer implements the WebM DASH Manifest specification to generate the DASH manifest XML.
+This muxer implements the WebM DASH Manifest specification to generate the DASH
+manifest XML. It also supports manifest generation for DASH live streams.
+
+WebM DASH Specification: @url{https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification}
+ISO DASH Specification: @url{http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip}
@subsection Options
@@ -1221,6 +1225,27 @@ This muxer supports the following options:
This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the
unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding
audio and video streams. Any number of adaptation sets can be added using this option.
+
+ at item live
+Set this to 1 to create a live stream DASH Manifest. Default: 0.
+
+ at item chunk_start_index
+Start index of the first chunk. This will go in the "startNumber" attribute of
+the "SegmentTemplate" element in the manifest. Default: 0.
+
+ at item chunk_duration_ms
+Duration of each chunk in milliseconds. This will go in the "duration" attribute
+of the "SegmentTemplate" element in the manifest. Default: 1000.
+
+ at item utc_timing_url
+URL of the page that will return the UTC timestamp in ISO format. This will go
+in the "value" attribute of the "UTCTiming" element in the manifest. Default:
+None.
+
+ at item time_shift_buffer_depth
+Smallest time (in seconds) shifting buffer for which any Representation is
+guaranteed to be available. Default: 60.
+
@end table
@subsection Example
diff --git a/libavformat/webmdashenc.c b/libavformat/webmdashenc.c
index 4536b7d..84cc9d8 100644
--- a/libavformat/webmdashenc.c
+++ b/libavformat/webmdashenc.c
@@ -22,10 +22,14 @@
/*
* WebM DASH Specification:
* https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification
+ * ISO DASH Specification:
+ * http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip
*/
+#include <float.h>
#include <stdint.h>
#include <string.h>
+#include <time.h>
#include "avformat.h"
#include "avio_internal.h"
@@ -47,6 +51,12 @@ typedef struct WebMDashMuxContext {
AdaptationSet *as;
int nb_as;
int representation_id;
+ int is_live;
+ int chunk_start_index;
+ int chunk_duration;
+ char *utc_timing_url;
+ double time_shift_buffer_depth;
+ int debug_mode;
} WebMDashMuxContext;
static const char *get_codec_name(int codec_id)
@@ -79,19 +89,42 @@ static double get_duration(AVFormatContext *s)
static void write_header(AVFormatContext *s)
{
+ WebMDashMuxContext *w = s->priv_data;
double min_buffer_time = 1.0;
+ time_t local_time;
+ struct tm* gmt;
+ char* gmt_iso = av_malloc(21);
avio_printf(s->pb, "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
avio_printf(s->pb, "<MPD\n");
avio_printf(s->pb, " xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"\n");
avio_printf(s->pb, " xmlns=\"urn:mpeg:DASH:schema:MPD:2011\"\n");
avio_printf(s->pb, " xsi:schemaLocation=\"urn:mpeg:DASH:schema:MPD:2011\"\n");
- avio_printf(s->pb, " type=\"static\"\n");
- avio_printf(s->pb, " mediaPresentationDuration=\"PT%gS\"\n",
- get_duration(s));
- avio_printf(s->pb, " minBufferTime=\"PT%gS\"\n",
- min_buffer_time);
- avio_printf(s->pb, " profiles=\"urn:webm:dash:profile:webm-on-demand:2012\"");
- avio_printf(s->pb, ">\n");
+ avio_printf(s->pb, " type=\"%s\"\n", w->is_live ? "dynamic" : "static");
+ if (!w->is_live) {
+ avio_printf(s->pb, " mediaPresentationDuration=\"PT%gS\"\n",
+ get_duration(s));
+ }
+ avio_printf(s->pb, " minBufferTime=\"PT%gS\"\n", min_buffer_time);
+ avio_printf(s->pb, " profiles=\"%s\"%s",
+ w->is_live ? "urn:mpeg:dash:profile:isoff-live:2011" : "urn:webm:dash:profile:webm-on-demand:2012",
+ w->is_live ? "\n" : ">\n");
+ time(&local_time);
+ gmt = gmtime(&local_time);
+ strftime(gmt_iso, 21, "%FT%TZ", gmt);
+ if (w->debug_mode) {
+ av_strlcpy(gmt_iso, "", 1);
+ }
+ if (w->is_live) {
+ avio_printf(s->pb, " availabilityStartTime=\"%s\"\n", gmt_iso);
+ avio_printf(s->pb, " timeShiftBufferDepth=\"PT%gS\"", w->time_shift_buffer_depth);
+ avio_printf(s->pb, ">\n");
+ avio_printf(s->pb, "<UTCTiming\n");
+ avio_printf(s->pb, " schemeIdUri=\"%s\"\n",
+ w->utc_timing_url ? "urn:mpeg:dash:utc:http-iso:2014" : "urn:mpeg:dash:utc:direct:2012");
+ avio_printf(s->pb, " value=\"%s\"/>\n",
+ w->utc_timing_url ? w->utc_timing_url : gmt_iso);
+ }
+ av_free(gmt_iso);
}
static void write_footer(AVFormatContext *s)
@@ -137,33 +170,47 @@ static int bitstream_switching(AVFormatContext *s, AdaptationSet *as) {
* Writes a Representation within an Adaptation Set. Returns 0 on success and
* < 0 on failure.
*/
-static int write_representation(AVFormatContext *s, AVStream *stream, int id,
+static int write_representation(AVFormatContext *s, AVStream *stream, char *id,
int output_width, int output_height,
int output_sample_rate) {
+ WebMDashMuxContext *w = s->priv_data;
AVDictionaryEntry *irange = av_dict_get(stream->metadata, INITIALIZATION_RANGE, NULL, 0);
AVDictionaryEntry *cues_start = av_dict_get(stream->metadata, CUES_START, NULL, 0);
AVDictionaryEntry *cues_end = av_dict_get(stream->metadata, CUES_END, NULL, 0);
AVDictionaryEntry *filename = av_dict_get(stream->metadata, FILENAME, NULL, 0);
AVDictionaryEntry *bandwidth = av_dict_get(stream->metadata, BANDWIDTH, NULL, 0);
- if (!irange || cues_start == NULL || cues_end == NULL || filename == NULL ||
- !bandwidth) {
+ if ((w->is_live && (!filename)) ||
+ (!w->is_live && (!irange || !cues_start || !cues_end || !filename || !bandwidth))) {
return -1;
}
- avio_printf(s->pb, "<Representation id=\"%d\"", id);
- avio_printf(s->pb, " bandwidth=\"%s\"", bandwidth->value);
+ avio_printf(s->pb, "<Representation id=\"%s\"", id);
+ // FIXME: For live, This should be obtained from the input file or as an AVOption.
+ avio_printf(s->pb, " bandwidth=\"%s\"",
+ w->is_live ? (stream->codec->codec_type == AVMEDIA_TYPE_AUDIO ? "128000" : "1000000") : bandwidth->value);
if (stream->codec->codec_type == AVMEDIA_TYPE_VIDEO && output_width)
avio_printf(s->pb, " width=\"%d\"", stream->codec->width);
if (stream->codec->codec_type == AVMEDIA_TYPE_VIDEO && output_height)
avio_printf(s->pb, " height=\"%d\"", stream->codec->height);
if (stream->codec->codec_type = AVMEDIA_TYPE_AUDIO && output_sample_rate)
avio_printf(s->pb, " audioSamplingRate=\"%d\"", stream->codec->sample_rate);
- avio_printf(s->pb, ">\n");
- avio_printf(s->pb, "<BaseURL>%s</BaseURL>\n", filename->value);
- avio_printf(s->pb, "<SegmentBase\n");
- avio_printf(s->pb, " indexRange=\"%s-%s\">\n", cues_start->value, cues_end->value);
- avio_printf(s->pb, "<Initialization\n");
- avio_printf(s->pb, " range=\"0-%s\" />\n", irange->value);
- avio_printf(s->pb, "</SegmentBase>\n");
+ if (w->is_live) {
+ // For live streams, Codec and Mime Type always go in the Representation tag.
+ avio_printf(s->pb, " codecs=\"%s\"", get_codec_name(stream->codec->codec_id));
+ avio_printf(s->pb, " mimeType=\"%s/webm\"",
+ stream->codec->codec_type == AVMEDIA_TYPE_VIDEO ? "video" : "audio");
+ // For live streams, subsegments always start with key frames. So this
+ // is always 1.
+ avio_printf(s->pb, " startsWithSAP=\"1\"");
+ avio_printf(s->pb, ">");
+ } else {
+ avio_printf(s->pb, ">\n");
+ avio_printf(s->pb, "<BaseURL>%s</BaseURL>\n", filename->value);
+ avio_printf(s->pb, "<SegmentBase\n");
+ avio_printf(s->pb, " indexRange=\"%s-%s\">\n", cues_start->value, cues_end->value);
+ avio_printf(s->pb, "<Initialization\n");
+ avio_printf(s->pb, " range=\"0-%s\" />\n", irange->value);
+ avio_printf(s->pb, "</SegmentBase>\n");
+ }
avio_printf(s->pb, "</Representation>\n");
return 0;
}
@@ -208,6 +255,53 @@ static int check_matching_sample_rate(AVFormatContext *s, AdaptationSet *as) {
}
/*
+ * Parses a live header filename and computes the representation id,
+ * initialization pattern and the media pattern. Pass NULL if you don't want to
+ * compute any of those 3. Returns 0 on success and non-zero on failure.
+ *
+ * Name of the header file should conform to the following pattern:
+ * <file_description>_<representation_id>.hdr where <file_description> can be
+ * anything. The chunks should be named according to the following pattern:
+ * <file_description>_<representation_id>_<chunk_number>.chk
+ */
+static int parse_filename(char *filename, char **representation_id,
+ char **initialization_pattern, char **media_pattern) {
+ char *filename_str;
+ char *underscore_pos = NULL;
+ char *period_pos = NULL;
+ char *temp_pos = NULL;
+ filename_str = av_mallocz(strlen(filename) + 1);
+ if (!filename_str) return AVERROR(ENOMEM);
+ strncpy(filename_str, filename, strlen(filename));
+ temp_pos = av_stristr(filename_str, "_");
+ while (temp_pos) {
+ underscore_pos = temp_pos + 1;
+ temp_pos = av_stristr(temp_pos + 1, "_");
+ }
+ if (!underscore_pos) return -1;
+ period_pos = av_stristr(underscore_pos, ".");
+ if (!period_pos) return -1;
+ *(underscore_pos - 1) = 0;
+ if (representation_id) {
+ *representation_id = av_malloc(period_pos - underscore_pos + 1);
+ if (!(*representation_id)) return AVERROR(ENOMEM);
+ av_strlcpy(*representation_id, underscore_pos, period_pos - underscore_pos + 1);
+ }
+ if (initialization_pattern) {
+ *initialization_pattern = av_asprintf("%s_$RepresentationID$.hdr",
+ filename_str);
+ if (!(*initialization_pattern)) return AVERROR(ENOMEM);
+ }
+ if (media_pattern) {
+ *media_pattern = av_asprintf("%s_$RepresentationID$_$Number$.chk",
+ filename_str);
+ if (!(*media_pattern)) return AVERROR(ENOMEM);
+ }
+ av_free(filename_str);
+ return 0;
+}
+
+/*
* Writes an Adaptation Set. Returns 0 on success and < 0 on failure.
*/
static int write_adaptation_set(AVFormatContext *s, int as_index)
@@ -222,13 +316,14 @@ static int write_adaptation_set(AVFormatContext *s, int as_index)
// Width, Height and Sample Rate will go in the AdaptationSet tag if they
// are the same for all contained Representations. otherwise, they will go
- // on their respective Representation tag.
+ // on their respective Representation tag. For live streams, they always go
+ // in the Representation tag.
int width_in_as = 1, height_in_as = 1, sample_rate_in_as = 1;
if (codec->codec_type == AVMEDIA_TYPE_VIDEO) {
- width_in_as = check_matching_width(s, as);
- height_in_as = check_matching_height(s, as);
+ width_in_as = !w->is_live && check_matching_width(s, as);
+ height_in_as = !w->is_live && check_matching_height(s, as);
} else {
- sample_rate_in_as = check_matching_sample_rate(s, as);
+ sample_rate_in_as = !w->is_live && check_matching_sample_rate(s, as);
}
avio_printf(s->pb, "<AdaptationSet id=\"%s\"", as->id);
@@ -249,19 +344,53 @@ static int write_adaptation_set(AVFormatContext *s, int as_index)
avio_printf(s->pb, " bitstreamSwitching=\"%s\"",
boolean[bitstream_switching(s, as)]);
avio_printf(s->pb, " subsegmentAlignment=\"%s\"",
- boolean[subsegment_alignment(s, as)]);
+ boolean[w->is_live || subsegment_alignment(s, as)]);
for (i = 0; i < as->nb_streams; i++) {
AVDictionaryEntry *kf = av_dict_get(s->streams[as->streams[i]]->metadata,
CLUSTER_KEYFRAME, NULL, 0);
- if (!kf || !strncmp(kf->value, "0", 1)) subsegmentStartsWithSAP = 0;
+ if (!w->is_live && (!kf || !strncmp(kf->value, "0", 1))) subsegmentStartsWithSAP = 0;
}
avio_printf(s->pb, " subsegmentStartsWithSAP=\"%d\"", subsegmentStartsWithSAP);
avio_printf(s->pb, ">\n");
+ if (w->is_live) {
+ AVDictionaryEntry *filename =
+ av_dict_get(s->streams[as->streams[0]]->metadata, FILENAME, NULL, 0);
+ char *initialization_pattern = NULL;
+ char *media_pattern = NULL;
+ int ret = parse_filename(filename->value, NULL, &initialization_pattern,
+ &media_pattern);
+ if (ret) return ret;
+ avio_printf(s->pb, "<ContentComponent id=\"1\" type=\"%s\"/>\n",
+ codec->codec_type == AVMEDIA_TYPE_VIDEO ? "video" : "audio");
+ avio_printf(s->pb, "<SegmentTemplate");
+ avio_printf(s->pb, " timescale=\"1000\"");
+ avio_printf(s->pb, " duration=\"%d\"", w->chunk_duration);
+ avio_printf(s->pb, " media=\"%s\"", media_pattern);
+ avio_printf(s->pb, " startNumber=\"%d\"", w->chunk_start_index);
+ avio_printf(s->pb, " initialization=\"%s\"", initialization_pattern);
+ avio_printf(s->pb, "/>\n");
+ av_free(initialization_pattern);
+ av_free(media_pattern);
+ }
+
for (i = 0; i < as->nb_streams; i++) {
- write_representation(s, s->streams[as->streams[i]], w->representation_id++,
+ char *representation_id = NULL;
+ if (w->is_live) {
+ AVDictionaryEntry *filename =
+ av_dict_get(s->streams[as->streams[i]]->metadata, FILENAME, NULL, 0);
+ if (!filename ||
+ parse_filename(filename->value, &representation_id, NULL, NULL)) {
+ return -1;
+ }
+ } else {
+ representation_id = av_asprintf("%d", w->representation_id++);
+ if (!representation_id) return -1;
+ }
+ write_representation(s, s->streams[as->streams[i]], representation_id,
!width_in_as, !height_in_as, !sample_rate_in_as);
+ av_free(representation_id);
}
avio_printf(s->pb, "</AdaptationSet>\n");
return 0;
@@ -361,6 +490,12 @@ static int webm_dash_manifest_write_trailer(AVFormatContext *s)
#define OFFSET(x) offsetof(WebMDashMuxContext, x)
static const AVOption options[] = {
{ "adaptation_sets", "Adaptation sets. Syntax: id=0,streams=0,1,2 id=1,streams=3,4 and so on", OFFSET(adaptation_sets), AV_OPT_TYPE_STRING, { 0 }, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },
+ { "debug_mode", "[private option - users should never set this]. set this to 1 to create deterministic output", OFFSET(debug_mode), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM },
+ { "live", "set this to 1 to create a live stream manifest", OFFSET(is_live), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM },
+ { "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 },
+ { "chunk_duration_ms", "duration of each chunk (in milliseconds)", OFFSET(chunk_duration), AV_OPT_TYPE_INT, {.i64 = 1000}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
+ { "utc_timing_url", "URL of the page that will return the UTC timestamp in ISO format", OFFSET(utc_timing_url), AV_OPT_TYPE_STRING, { 0 }, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },
+ { "time_shift_buffer_depth", "Smallest time (in seconds) shifting buffer for which any Representation is guaranteed to be available.", OFFSET(time_shift_buffer_depth), AV_OPT_TYPE_DOUBLE, { .dbl = 60.0 }, 1.0, DBL_MAX, AV_OPT_FLAG_ENCODING_PARAM },
{ NULL },
};
diff --git a/tests/fate/vpx.mak b/tests/fate/vpx.mak
index 83cda9c..5eaf8fb 100644
--- a/tests/fate/vpx.mak
+++ b/tests/fate/vpx.mak
@@ -43,6 +43,9 @@ fate-webm-dash-manifest-unaligned-audio-streams: CMD = run ffmpeg -f webm_dash_m
FATE_VP8-$(call DEMDEC, WEBM_DASH_MANIFEST, VP8) += fate-webm-dash-manifest-representations
fate-webm-dash-manifest-representations: CMD = run ffmpeg -f webm_dash_manifest -i $(TARGET_SAMPLES)/vp8/dash_video1.webm -f webm_dash_manifest -i $(TARGET_SAMPLES)/vp8/dash_video4.webm -c copy -map 0 -map 1 -f webm_dash_manifest -adaptation_sets "id=0,streams=0,1" -
+FATE_VP8-$(call DEMDEC, WEBM_DASH_MANIFEST, VP8) += fate-webm-dash-manifest-live
+fate-webm-dash-manifest-live: CMD = run ffmpeg -f webm_dash_manifest -live 1 -i $(TARGET_SAMPLES)/vp8/dash_live_video_360.hdr -f webm_dash_manifest -live 1 -i $(TARGET_SAMPLES)/vp8/dash_live_audio_171.hdr -c copy -map 0 -map 1 -f webm_dash_manifest -live 1 -adaptation_sets "id=0,streams=0 id=1,streams=1" -chunk_start_index 1 -chunk_duration_ms 5000 -time_shift_buffer_depth 7200 -debug_mode 1 -
+
FATE_SAMPLES_AVCONV += $(FATE_VP6-yes)
fate-vp6: $(FATE_VP6-yes)
diff --git a/tests/ref/fate/webm-dash-manifest-live b/tests/ref/fate/webm-dash-manifest-live
new file mode 100644
index 0000000..797cced
--- /dev/null
+++ b/tests/ref/fate/webm-dash-manifest-live
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<MPD
+ xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+ xmlns="urn:mpeg:DASH:schema:MPD:2011"
+ xsi:schemaLocation="urn:mpeg:DASH:schema:MPD:2011"
+ type="dynamic"
+ minBufferTime="PT1S"
+ profiles="urn:mpeg:dash:profile:isoff-live:2011"
+ availabilityStartTime=""
+ timeShiftBufferDepth="PT7200S">
+<UTCTiming
+ schemeIdUri="urn:mpeg:dash:utc:direct:2012"
+ value=""/>
+<Period id="0" start="PT0S" duration="PT0S" >
+<AdaptationSet id="0" mimeType="video/webm" codecs="vp9" bitstreamSwitching="true" subsegmentAlignment="true" subsegmentStartsWithSAP="1">
+<ContentComponent id="1" type="video"/>
+<SegmentTemplate timescale="1000" duration="5000" media="dash_live_video_$RepresentationID$_$Number$.chk" startNumber="1" initialization="dash_live_video_$RepresentationID$.hdr"/>
+<Representation id="360" bandwidth="1000000" width="640" height="360" codecs="vp9" mimeType="video/webm" startsWithSAP="1"></Representation>
+</AdaptationSet>
+<AdaptationSet id="1" mimeType="audio/webm" codecs="vorbis" bitstreamSwitching="true" subsegmentAlignment="true" subsegmentStartsWithSAP="1">
+<ContentComponent id="1" type="audio"/>
+<SegmentTemplate timescale="1000" duration="5000" media="dash_live_audio_$RepresentationID$_$Number$.chk" startNumber="1" initialization="dash_live_audio_$RepresentationID$.hdr"/>
+<Representation id="171" bandwidth="128000" audioSamplingRate="32000" codecs="vorbis" mimeType="audio/webm" startsWithSAP="1"></Representation>
+</AdaptationSet>
+</Period>
+</MPD>
--
2.2.0.rc0.207.ga3a616c
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