[FFmpeg-devel] H264 encoding and RTP muxing - calculating pts and dts

[Vladimir Pantelic]

Reimar D?ffinger wrote:
> On Tue, Jul 20, 2010 at 03:33:02PM +0200, Vladimir Pantelic wrote:
>>  Alexandre Ferrieux wrote:
>>
>>  >Side question: what is the behavior of ffmpeg when such a VFR input (assuming the grabbing rate is somehow irregular) is
>>  >converted to a CFR container and codec like TS/mpeg2 ?
>>  >
>>  >Suppose an input timeline with frames F1...Fn. Dots indicate time:
>>  >
>>  >     F1.....F2....................F3....F4................F5
>>  >
>>  >and a regular output timeline for mpeg2ts:
>>  >
>>  >     G1.......G2.......G3.......G4.......G5.......G6.......G7
>>  >
>>  >What is G4:
>>  >
>>  >      - F2 (latest) ?
>>  >      - F3 (closest, non-causal) ?
>>  >      - F4 (one-to-one) ?
>>
>>  F4
>
> Never looked at the code, but are you sure?

now, not any more :)

> After all the -async etc. options must be there for some purpose,
> if your answer is correct I can't see what purpose they'd have...
> Ah, I realize that you are probably talking about using libavcodec/
> libavformat directly, then that's probably true, but not for ffmpeg
> as in the command-line program...

yes, I was thinking about lavf/lavc.