[FFmpeg-devel] [PATCH v2] lavf/dashenc: add dash SegmentBase manifest generator
David Martin
davimdo at gmail.com
Thu Mar 12 21:01:26 EET 2020
Support to generate dash SegmentBase manifests, by adding
"use_segmentbase" option to dash muxer. SegmentBase manifest
is defined in ISO DASH Specification section 5.3.9.2 and has as
prerequisite the option "global_sidx" as players will use this
box to have a reference to all fragments in the media.
Signed-off-by: David Martin <davimdo at gmail.com>
---
doc/muxers.texi | 5 +++++
libavformat/dashenc.c | 16 ++++++++++++++++
2 files changed, 21 insertions(+)
diff --git a/doc/muxers.texi b/doc/muxers.texi
index d304181671..fbaa357f2d 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -309,6 +309,11 @@ escaped.
@item global_sidx @var{global_sidx}
Write global SIDX atom. Applicable only for single file, mp4 output, non-streaming mode.
+ at item use_segmentbase @var{use_segmentbase}
+Generates a dash SegmentBase manifest as defined in section 5.3.9.2 of the ISO
+DASH specification. Only applicable when global sidx is enabled since the player
+uses it to have a reference of all the segments in the media
+
@item dash_segment_type @var{dash_segment_type}
Possible values:
@table @option
diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
index 94d463972a..39286e9e11 100644
--- a/libavformat/dashenc.c
+++ b/libavformat/dashenc.c
@@ -193,6 +193,8 @@ typedef struct DASHContext {
int profile;
int64_t target_latency;
int target_latency_refid;
+ int use_segmentbase;
+ int64_t sidx_size;
} DASHContext;
static struct codec_string {
@@ -694,6 +696,12 @@ static void output_segment_list(OutputStream *os, AVIOContext *out, AVFormatCont
avio_printf(out, "\t\t\t\t\t</SegmentTimeline>\n");
}
avio_printf(out, "\t\t\t\t</SegmentTemplate>\n");
+ } else if (c->single_file && c->use_segmentbase && final) {
+ avio_printf(out, "\t\t\t\t<BaseURL>%s</BaseURL>\n", os->initfile);
+ int64_t init_segment_size = os->init_start_pos + os->init_range_length;
+ avio_printf(out, "\t\t\t\t<SegmentBase indexRange=\"%"PRId64"-%"PRId64"\" timescale=\"%d\">\n", init_segment_size - c->sidx_size, init_segment_size - 1, AV_TIME_BASE);
+ avio_printf(out, "\t\t\t\t\t<Initialization range=\"%"PRId64"-%"PRId64"\" />\n", os->init_start_pos, init_segment_size - c->sidx_size - 1);
+ avio_printf(out, "\t\t\t\t</SegmentBase>\n");
} else if (c->single_file) {
avio_printf(out, "\t\t\t\t<BaseURL>%s</BaseURL>\n", os->initfile);
avio_printf(out, "\t\t\t\t<SegmentList timescale=\"%d\" duration=\"%"PRId64"\" startNumber=\"%d\">\n", AV_TIME_BASE, FFMIN(os->seg_duration, os->last_duration), start_number);
@@ -1389,6 +1397,12 @@ static int dash_init(AVFormatContext *s)
av_log(s, AV_LOG_WARNING, "Global SIDX option will be ignored as streaming is enabled\n");
c->global_sidx = 0;
}
+
+ if (c->use_segmentbase && !c->global_sidx) {
+ av_log(s, AV_LOG_WARNING, "SegmentBase manifest signaling option will be ignored as global SIDX is not enabled\n");
+ c->use_segmentbase = 0;
+ }
+
if (c->frag_type == FRAG_TYPE_NONE && c->streaming) {
av_log(s, AV_LOG_VERBOSE, "Changing frag_type from none to every_frame as streaming is enabled\n");
c->frag_type = FRAG_TYPE_EVERY_FRAME;
@@ -1981,6 +1995,7 @@ static int dash_flush(AVFormatContext *s, int final, int stream)
if (c->global_sidx) {
int j, start_index, start_number;
int64_t sidx_size = avio_tell(os->ctx->pb) - file_size;
+ c->sidx_size = sidx_size;
get_start_index_number(os, c, &start_index, &start_number);
if (start_index >= os->nb_segments ||
os->segment_type != SEGMENT_TYPE_MP4)
@@ -2350,6 +2365,7 @@ static const AVOption options[] = {
{ "index_correction", "Enable/Disable segment index correction logic", OFFSET(index_correction), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, E },
{ "format_options","set list of options for the container format (mp4/webm) used for dash", OFFSET(format_options), AV_OPT_TYPE_DICT, {.str = NULL}, 0, 0, E},
{ "global_sidx", "Write global SIDX atom. Applicable only for single file, mp4 output, non-streaming mode", OFFSET(global_sidx), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, E },
+ { "use_segmentbase", "Use SegmentBase in Representation", OFFSET(use_segmentbase), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, E },
{ "dash_segment_type", "set dash segment files type", OFFSET(segment_type_option), AV_OPT_TYPE_INT, {.i64 = SEGMENT_TYPE_AUTO }, 0, SEGMENT_TYPE_NB - 1, E, "segment_type"},
{ "auto", "select segment file format based on codec", 0, AV_OPT_TYPE_CONST, {.i64 = SEGMENT_TYPE_AUTO }, 0, UINT_MAX, E, "segment_type"},
{ "mp4", "make segment file in ISOBMFF format", 0, AV_OPT_TYPE_CONST, {.i64 = SEGMENT_TYPE_MP4 }, 0, UINT_MAX, E, "segment_type"},
--
2.25.1
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