[Ffmpeg-devel] Timestamps on Decoding

[Paul Curtis]

Ronald S. Bultje wrote:

> Depends on how you call av_decode_video(). I call it in a loop, like
> this (quasi-code):
> 
> for (;;) {
>   if (output = av_decode_video (ctx, input)) {
>     // do something with output
>   }
> }
> 
> 1) if it's an I frame, then output == input, roughly. Timestamps, all
> are the same. In addition, if ctx->has_b_frames is false, then output ==
> input also. In any case, output.PTS == input.PTS.
> 2) if neither of the above applies, then you probably have a
> backward-reference frame, so output may well represent a frame that you
> fed to the decoder earlier. You'll need to do PTS-calculationing, like I
> showed you in my first email (but there's other reasonable ways to do
> it, also).
> 
> Does this make sense?

Absolutely ... thanks.

Paul