"zhilizhao(赵志立)" <quinkbl...@foxmail.com> 于2022年3月21日周一 11:55写道: > > > > > On Mar 18, 2022, at 8:20 PM, Steven Liu <l...@chinaffmpeg.org> wrote: > > > > From: Steven Liu <liuq...@kuaishou.com> > > > > There have some video stream usually cannot get precise duration, > > for example: > > > > command: > > ffmpeg -i input.mp4 -c copy -copyts -f hls -hls_time 5 -hls_list_size 0 > > -hls_segment_type mpegts -t 20 a.m3u8 > > > > the first segment should split at 5.133333, > > because 5.133333 - 0.133333 is 5.0000, > > pkt->pts = [5.133333] vs->end_pts = 0.133333, flags = [1] > > but the second segment will cannot split at 10.133322, > > because 10.133322 - 5.133333 is 4.999989, it small than hls_time, > > It doesn’t looks like an issue. > > Firstly, user can specify a smaller ‘hls_time'. '-hls_time 4.9' > is the same as '-hls_time 5 -hls_time_delta 0.1', right? 4.9 is set by user, and 5.0 is set by user to, but user can set a time_delta to control the approximation. the file number will get more then 5.0 if they set 4.9 than 5.0
eg. 50/4.9 10 50%4.9 1.0 50/5.0 10 50%5.0 0 > > Secondly, if user want to have precise segment durations, they > need to control the timestamp of input packets, with fixed FPS. That's not fixed FPS, just input files precise problem from one format to the other format: ----test case---- (base) liuqi05:ufbuild liuqi$ ffmpeg -v quiet -i input.mp4 -c:v copy -an -y out.ts ffmpeg(47154,0x1090e7600) malloc: nano zone abandoned due to inability to preallocate reserved vm space. (base) liuqi05:ufbuild liuqi$ ffprobe -hide_banner -select_streams v -show_packets -show_entries packet=pts,dts,flags -of xml out.ts |grep "flags=\"K" | head -n 5 ffprobe(47254,0x10f8e3600) malloc: nano zone abandoned due to inability to preallocate reserved vm space. Input #0, mpegts, from 'out.ts': Duration: 00:04:00.70, start: 1.533333, bitrate: 1595 kb/s Program 1 Metadata: service_name : Service01 service_provider: FFmpeg Stream #0:0[0x100]: Video: hevc (Main) (HEVC / 0x43564548), yuvj420p(pc, bt470bg/unknown/unknown), 1600x670 [SAR 1:1 DAR 160:67], 30 fps, 30 tbr, 90k tbn, 30 tbc <packet pts="138000" dts="126000" flags="K_"> <packet pts="588000" dts="576000" flags="K_"> <packet pts="1037999" dts="1025999" flags="K_"> <packet pts="1487999" dts="1475999" flags="K_"> <packet pts="1496999" dts="1484999" flags="K_"> (base) liuqi05:ufbuild liuqi$ ffprobe -hide_banner -select_streams v -show_packets -show_entries packet=pts,dts,flags -of xml input.mp4 |grep "flags=\"K" | head -n 5 ffprobe(47477,0x1149d1600) malloc: nano zone abandoned due to inability to preallocate reserved vm space. Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4': Metadata: major_brand : isom minor_version : 512 compatible_brands: isomiso2mp41 encoder : Lavf58.29.100 Duration: 00:04:00.70, start: 0.000000, bitrate: 1504 kb/s Stream #0:0(und): Video: hevc (Main) (hvc1 / 0x31637668), yuvj420p(pc, bt470bg/unknown/unknown, progressive), 1600x670 [SAR 1:1 DAR 160:67], 1500 kb/s, 30 fps, 30 tbr, 1000k tbn, 30 tbc (default) Metadata: handler_name : VideoHandler vendor_id : [0][0][0][0] <packet pts="0" dts="-133333" flags="K_"/> <packet pts="4999995" dts="4866662" flags="K_"/> <packet pts="9999990" dts="9866657" flags="K_"/> <packet pts="14999985" dts="14866652" flags="K_"/> <packet pts="15099984" dts="14966651" flags="K_"/> (base) liuqi05:ufbuild liuqi$ --- end --- > > > pkt->pts = [10.133322] vs->end_pts = 5.133333, flags = [1] > > so add hls_time_delta for approximation value to hls_time. > > > > Signed-off-by: Steven Liu <liuq...@kuaishou.com> > > --- > > doc/muxers.texi | 8 ++++++++ > > libavformat/hlsenc.c | 4 +++- > > 2 files changed, 11 insertions(+), 1 deletion(-) > > > > diff --git a/doc/muxers.texi b/doc/muxers.texi > > index 1af603b7f6..c91a7a9216 100644 > > --- a/doc/muxers.texi > > +++ b/doc/muxers.texi > > @@ -778,6 +778,14 @@ Segment will be cut on the next key frame after this > > time has passed on the firs > > After the initial playlist is filled @command{ffmpeg} will cut segments > > at duration equal to @code{hls_time} > > > > +@item hls_time_delta @var{duration} > > +Set approximation value used for the segment duration. Default value is > > @var{0}. > > + > > +@var{duration} must be a time duration specification, > > +see @ref{time duration syntax,,the Time duration section in the > > ffmpeg-utils(1) manual,ffmpeg-utils}. > > + > > +Segment will be cut on the key frame before @code{hls_time_delta} to > > @code{hls_time}. > > + > > @item hls_time @var{duration} > > Set the target segment length. Default value is 2. > > > > diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c > > index 14eb7c4530..56cde7dd70 100644 > > --- a/libavformat/hlsenc.c > > +++ b/libavformat/hlsenc.c > > @@ -200,6 +200,7 @@ typedef struct HLSContext { > > > > int64_t time; // Set by a private option. > > int64_t init_time; // Set by a private option. > > + int64_t time_delta; > > int max_nb_segments; // Set by a private option. > > int hls_delete_threshold; // Set by a private option. > > uint32_t flags; // enum HLSFlags > > @@ -2489,7 +2490,7 @@ static int hls_write_packet(AVFormatContext *s, > > AVPacket *pkt) > > > > can_split = can_split && (pkt->pts - vs->end_pts > 0); > > if (vs->packets_written && can_split && av_compare_ts(pkt->pts - > > vs->start_pts, st->time_base, > > - end_pts, > > AV_TIME_BASE_Q) >= 0) { > > + end_pts - > > hls->time_delta, AV_TIME_BASE_Q) >= 0) { > > int64_t new_start_pos; > > int byterange_mode = (hls->flags & HLS_SINGLE_FILE) || > > (hls->max_seg_size > 0); > > > > @@ -3101,6 +3102,7 @@ static const AVOption options[] = { > > {"start_number", "set first number in the sequence", > > OFFSET(start_sequence),AV_OPT_TYPE_INT64, {.i64 = 0}, 0, INT64_MAX, E}, > > {"hls_time", "set segment length", > > OFFSET(time), AV_OPT_TYPE_DURATION, {.i64 = 2000000}, 0, > > INT64_MAX, E}, > > {"hls_init_time", "set segment length at init list", > > OFFSET(init_time), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, > > INT64_MAX, E}, > > + {"hls_time_delta", "set approximation value used for the segment > > duration", OFFSET(time_delta), AV_OPT_TYPE_DURATION, {.i64 = > > 0}, 0, INT64_MAX, E}, > > {"hls_list_size", "set maximum number of playlist entries", > > OFFSET(max_nb_segments), AV_OPT_TYPE_INT, {.i64 = 5}, 0, INT_MAX, > > E}, > > {"hls_delete_threshold", "set number of unreferenced segments to keep > > before deleting", OFFSET(hls_delete_threshold), AV_OPT_TYPE_INT, > > {.i64 = 1}, 1, INT_MAX, E}, > > #if FF_HLS_TS_OPTIONS > > -- > > 2.25.0 > > > > _______________________________________________ > > ffmpeg-devel mailing list > > ffmpeg-devel@ffmpeg.org > > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > > > To unsubscribe, visit link above, or email > > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". Thanks Steven _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".