[FFmpeg-devel] [PATCH 3/3] lavf/segment: add option to write empty filler segments as needed
Rodger Combs
rodger.combs at gmail.com
Mon Mar 7 03:49:24 CET 2016
---
doc/muxers.texi | 5 +++++
libavformat/segment.c | 8 +++++++-
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/doc/muxers.texi b/doc/muxers.texi
index f2ad7fe..700ec88 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -1224,6 +1224,11 @@ muxers/codecs. It is set to @code{0} by default.
@item initial_offset @var{offset}
Specify timestamp offset to apply to the output packet timestamps. The
argument must be a time duration specification, and defaults to 0.
+
+ at item write_empty_segments @var{1|0}
+If enabled, write an empty segment if there are no packets during the period a
+segment would usually span. Otherwise, the segment will be filled with the next
+packet written. Defaults to @code{0}.
@end table
@subsection Examples
diff --git a/libavformat/segment.c b/libavformat/segment.c
index 6ad991f..df1514f 100644
--- a/libavformat/segment.c
+++ b/libavformat/segment.c
@@ -116,6 +116,7 @@ typedef struct SegmentContext {
char *reference_stream_specifier; ///< reference stream specifier
int reference_stream_index;
int break_non_keyframes;
+ int write_empty;
int use_rename;
char temp_list_filename[1024];
@@ -774,6 +775,7 @@ static int seg_write_packet(AVFormatContext *s, AVPacket *pkt)
if (!seg->avf)
return AVERROR(EINVAL);
+calc_times:
if (seg->times) {
end_pts = seg->segment_count < seg->nb_times ?
seg->times[seg->segment_count] : INT64_MAX;
@@ -805,7 +807,7 @@ static int seg_write_packet(AVFormatContext *s, AVPacket *pkt)
if (pkt->stream_index == seg->reference_stream_index &&
(pkt->flags & AV_PKT_FLAG_KEY || seg->break_non_keyframes) &&
- seg->segment_frame_count > 0 &&
+ (seg->segment_frame_count > 0 || seg->write_empty) &&
(seg->cut_pending || seg->frame_count >= start_frame ||
(pkt->pts != AV_NOPTS_VALUE &&
av_compare_ts(pkt->pts, st->time_base,
@@ -825,6 +827,9 @@ static int seg_write_packet(AVFormatContext *s, AVPacket *pkt)
seg->cur_entry.start_time = (double)pkt->pts * av_q2d(st->time_base);
seg->cur_entry.start_pts = av_rescale_q(pkt->pts, st->time_base, AV_TIME_BASE_Q);
seg->cur_entry.end_time = seg->cur_entry.start_time;
+
+ if (seg->times || (!seg->frames && !seg->use_clocktime) && seg->write_empty)
+ goto calc_times;
}
if (pkt->stream_index == seg->reference_stream_index) {
@@ -956,6 +961,7 @@ static const AVOption options[] = {
{ "write_header_trailer", "write a header to the first segment and a trailer to the last one", OFFSET(write_header_trailer), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, E },
{ "reset_timestamps", "reset timestamps at the begin of each segment", OFFSET(reset_timestamps), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, E },
{ "initial_offset", "set initial timestamp offset", OFFSET(initial_offset), AV_OPT_TYPE_DURATION, {.i64 = 0}, -INT64_MAX, INT64_MAX, E },
+ { "write_empty_segments", "allow writing empty 'filler' segments", OFFSET(write_empty), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, E },
{ NULL },
};
--
2.7.2
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