[vlc-devel] Subtitles synchronization : identified a bug cause that breaks audio output under linux / need help

Rémi Denis-Courmont remi at remlab.net
Sat Apr 27 14:32:39 CEST 2013

Le samedi 27 avril 2013 15:02:45, Pascal Thomet a écrit :
> But what I do not understand is : why would applying a simple subtitle
> delay require the jitter to be corrected?

Indeed, the inter-arrival delay variance, a.k.a. jitter, should not be affected 
by manual change of inter-track delay. But then again, it does affect the 
overall buffering requirements.

This may not be a problem for a separate subtitle track file, but it is obvious 
when tracks come interleaved from the same file. Suddenly audio or text data is 
going to arrive much earlier or much latter than video data. That is why the 
pts_delay value is partly dependent on the subtitle and audio delay. And thus 
the SetJitter() call.

Rémi Denis-Courmont

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