[FFmpeg-devel] HLS Segmenter and the "hls_time" option

[Steven Liu]

2016-08-26 8:17 GMT+08:00 Ibrahim Tachijian <barhom at netsat.se>:

> Steven, I am not sure you understood me correctly or perhaps I did not
> explain myself optimally.
>
> We still want to split by keyframe in a normal fashion. But, for example,
> would like the first 5 segments to have an "hls_time" of 1s and the rest of
> the segments after the first 5 to have an "hls_time" of 5s.
>
> An made up option would be (hls_time_initial Seconds,Number)
>
>    - "-hls_time_initial 1,5 -hls_time 5"
>
> The output playlist would contain segments (split at keyframes) 5 segments
> of length 1s and then any segment after the initial 5 segment would be 5s.
>
> Is it clear what I am trying to explain?
>
> What do you think? Do you know how this can be achieved?
>
> Thanks,
>
> On Fri, Aug 26, 2016 at 2:06 AM Steven Liu <lingjiujianke at gmail.com>
> wrote:
>
> > 2016-08-26 7:39 GMT+08:00 Ibrahim Tachijian <barhom at netsat.se>:
> >
> > > Hello,
> > >
> > > I've been thinking about an option for "hls_time" that is not currently
> > > supported by FFMpeg and I would like feedback to if some of you may
> think
> > > this is useful or utterly unnecessary.
> > >
> > > I find scenarios where we sometimes want to create an HLS output and
> > would
> > > like the *first couple of segments* to be shorter than the *rest of the
> > > segments.*
> > >
> > > For example starting off with 1s segments up to N segments then switch
> to
> > > 5s segments.
> > >
> > > The reasoning is simply to have the playlist.m3u8 and first segment
> > > available *asap.*
> > >
> > > What do you think? Do you know how this can be achieved?
> > >
> > > Thanks,
> > >
> >
> > ffmpeg split segment use hlsenc by keyframe, if you want to split segment
> > *ASAP*,
> > you can try set your streaming *GOP(Group Of Picture)* shorter,
> > for example: gop_size = 60,  c->time_base = (AVRational){1,60};
> > in command line : -r:v 60 -g 60
> >
> > if can accept split segment at non-keyframe, you can use hls_time and
> > hls_flags split_by_time.
> > _______________________________________________
>
you mean:

segment-0.ts,segment-1.ts,segment-2.ts,segment-3.ts,segment-4.ts  these 5
segments duration is 1s
and
segment-5.ts,segment-6.ts,segment-7.ts ...... these segment duration is 5
or set by hls_time
Is that right i understand?