[FFmpeg-devel] [PATCH] avformat/segment: add option min_seg_duration
Gyan Doshi
ffmpeg at gyani.pro
Wed Dec 28 05:56:53 EET 2022
Plan to push tomorrow.
On 2022-12-25 11:54 pm, Gyan Doshi wrote:
>
>
> On 2022-12-21 09:08 pm, Gyan Doshi wrote:
>> New option can be used to avoid creating very short segments with inputs
>> whose GOP size is variable or unharmonic with segment_time.
>>
>> Only effective with segment_time.
> Comments?
>
>> ---
>> doc/muxers.texi | 5 +++++
>> libavformat/segment.c | 12 +++++++++++-
>> 2 files changed, 16 insertions(+), 1 deletion(-)
>>
>> diff --git a/doc/muxers.texi b/doc/muxers.texi
>> index 4edbb22b00..ed5341be39 100644
>> --- a/doc/muxers.texi
>> +++ b/doc/muxers.texi
>> @@ -2369,6 +2369,11 @@ Note that splitting may not be accurate,
>> unless you force the
>> reference stream key-frames at the given time. See the introductory
>> notice and the examples below.
>> + at item min_seg_duration @var{time}
>> +Set minimum segment duration to @var{time}, the value must be a
>> duration
>> +specification. This prevents the muxer ending segments at a duration
>> below
>> +this value. Only effective with @code{segment_time}. Default value
>> is "0".
>> +
>> @item segment_atclocktime @var{1|0}
>> If set to "1" split at regular clock time intervals starting from
>> 00:00
>> o'clock. The @var{time} value specified in @option{segment_time} is
>> diff --git a/libavformat/segment.c b/libavformat/segment.c
>> index c904e20708..c19c2a94ae 100644
>> --- a/libavformat/segment.c
>> +++ b/libavformat/segment.c
>> @@ -93,6 +93,7 @@ typedef struct SegmentContext {
>> int list_type; ///< set the list type
>> AVIOContext *list_pb; ///< list file put-byte context
>> int64_t time; ///< segment duration
>> + int64_t min_seg_duration; ///< minimum segment duration
>> int use_strftime; ///< flag to expand filename with strftime
>> int increment_tc; ///< flag to increment timecode if found
>> @@ -710,6 +711,10 @@ static int seg_init(AVFormatContext *s)
>> }
>> seg->clocktime_offset = seg->time -
>> (seg->clocktime_offset % seg->time);
>> }
>> + if (seg->min_seg_duration > seg->time) {
>> + av_log(s, AV_LOG_ERROR, "min_seg_duration cannot be
>> greater than segment_time\n");
>> + return AVERROR(EINVAL);
>> + }
>> }
>> if (seg->list) {
>> @@ -839,7 +844,7 @@ static int seg_write_packet(AVFormatContext *s,
>> AVPacket *pkt)
>> {
>> SegmentContext *seg = s->priv_data;
>> AVStream *st = s->streams[pkt->stream_index];
>> - int64_t end_pts = INT64_MAX, offset;
>> + int64_t end_pts = INT64_MAX, offset, pkt_pts_avtb;
>> int start_frame = INT_MAX;
>> int ret;
>> struct tm ti;
>> @@ -890,11 +895,15 @@ calc_times:
>> pkt->flags & AV_PKT_FLAG_KEY,
>> pkt->stream_index == seg->reference_stream_index ?
>> seg->frame_count : -1);
>> + if (pkt->pts != AV_NOPTS_VALUE)
>> + pkt_pts_avtb = av_rescale_q(pkt->pts, st->time_base,
>> AV_TIME_BASE_Q);
>> +
>> if (pkt->stream_index == seg->reference_stream_index &&
>> (pkt->flags & AV_PKT_FLAG_KEY || seg->break_non_keyframes) &&
>> (seg->segment_frame_count > 0 || seg->write_empty) &&
>> (seg->cut_pending || seg->frame_count >= start_frame ||
>> (pkt->pts != AV_NOPTS_VALUE &&
>> + pkt_pts_avtb - seg->cur_entry.start_pts >=
>> seg->min_seg_duration &&
>> av_compare_ts(pkt->pts, st->time_base,
>> end_pts - seg->time_delta, AV_TIME_BASE_Q)
>> >= 0))) {
>> /* sanitize end time in case last packet didn't have a
>> defined duration */
>> @@ -1031,6 +1040,7 @@ static const AVOption options[] = {
>> { "segment_clocktime_wrap_duration", "set segment clocktime
>> wrapping duration", OFFSET(clocktime_wrap_duration),
>> AV_OPT_TYPE_DURATION, {.i64 = INT64_MAX}, 0, INT64_MAX, E},
>> { "segment_time", "set segment duration",
>> OFFSET(time),AV_OPT_TYPE_DURATION, {.i64 = 2000000}, INT64_MIN,
>> INT64_MAX, E },
>> { "segment_time_delta","set approximation value used for the
>> segment times", OFFSET(time_delta), AV_OPT_TYPE_DURATION, {.i64 = 0},
>> 0, INT64_MAX, E },
>> + { "min_seg_duration", "set minimum segment
>> duration", OFFSET(min_seg_duration),
>> AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, E },
>> { "segment_times", "set segment split time
>> points", OFFSET(times_str),AV_OPT_TYPE_STRING,{.str =
>> NULL}, 0, 0, E },
>> { "segment_frames", "set segment split frame
>> numbers", OFFSET(frames_str),AV_OPT_TYPE_STRING,{.str =
>> NULL}, 0, 0, E },
>> { "segment_wrap", "set number after which the index
>> wraps", OFFSET(segment_idx_wrap), AV_OPT_TYPE_INT, {.i64 = 0}, 0,
>> INT_MAX, E },
>
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