[FFmpeg-devel] [PATCH] added parameter to dash encoder for start available time

Jan Ekström jeebjp at gmail.com
Thu Mar 18 17:07:03 EET 2021


On Thu, Mar 18, 2021, 17:01 Gyan Doshi <ffmpeg at gyani.pro> wrote:

>
>
> On 2021-03-18 20:12, Jan Ekström wrote:
> > So right now we do have an option in ffmpeg.c called itsoffset. It
> > lets you configure the input offset in time (seconds - such as
> > "1337.123" or time format - such as "00:00:01.123"). The only problem
> > with it right now is that unless you set -copyts it will not get
> > applied for anything else than subtitles, as the offset gets applied
> > before and is not taken into account in the "start from PTS 0"
> > calculation for video/audio streams.
>
> Not the case.
>
>      ffmpeg -f lavfi -itsoffset 3 -i nullsrc=r=1:d=3 -vf showinfo -f null -
>
> gives
>
> [Parsed_showinfo_0 @ 0000019cc1b88540] n:   0 pts:      3 pts_time:3   ...
> [Parsed_showinfo_0 @ 0000019cc1b88540] n:   1 pts:      4 pts_time:4   ...
> [Parsed_showinfo_0 @ 0000019cc1b88540] n:   2 pts:      5 pts_time:5   ...
>
> I've used it many times to adjust sync among streams.
>
> Regards,
> Gyan
>

Very interesting!

I will have to retest, I just recall that the last time I tried it got
applied when there were multiple streams in an input when the start_time
based adjustment was done.

Jan

>


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