[FFmpeg-devel] NUT and no PTS

Luca Barbato lu_zero
Tue Oct 12 12:09:18 CEST 2010

On 10/12/2010 11:57 AM, Michael Niedermayer wrote:
> There is code on the demuxer side that fills in pts that are not stored in the
> file based on what the mpeg specs say. For mpeg this is exact and calling it
> guessing feels insulting its not any more guessing than the IDCT is guessing
> the output. If the code ends up used for non mpeg it of course can mess up

I wasn't using the demuxer at all, still it's nice to know =)

> On the muxer side there is only code that fills in pts for videos that dont do
> frame reordering. (this of course can mess up if you do not set the values
> that muxers needs to know about frame reordering, they need them for other
> reasons as well)

That was my case ^^

> The reason why this code is there is historic ABI/API IIRC, its definitly needed
> to supply the muxer with timestamps. nut needs pts, mpeg-ps/ts need dts for
> their buffering models, mov/mp4 need both, some formats like raw need none.

That explains everything.



Luca Barbato

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