[vlc-devel] Over buffering with h.264

David R. Robison david.robison at openroadsconsulting.com
Thu Apr 2 14:15:44 CEST 2015

Yes, of course, but what I meant to ask was where is VLC does the 
decoder thread get created and sent to the OS for execution...

The problem we see seems to be associated with re-buffering when there 
is excessive clock jitter. When this happens (if I understand it 
correctly), EsOutChangePosition is called which tells the decoder thread 
to wait, rests the clock data, and sets the input back into buffering 
mode. Buffering continues until EsOutDecodersStopBuffering is called. 
The current buffering state is checked each time the input calls the 
ES_OUT_SET_PCR routine. What I cannot understand is how, 200ms latter, 
when ES_OUT_SET_PCR is called, that we now have over 6s of video in the 
buffer. I assume, when it is reporting the amount of system time that 
has transpired, it is refering back to the reset clock data from the 
EsOutChangePosition call, but how can it suddenly find 6000ms of data 
having only reset the clocks 200ms ago.

Oddly, we only seem to see this happen with h.264 video.



David R Robison

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On 4/2/2015 2:37 AM, Rémi Denis-Courmont wrote:
> Le 2015-04-01 23:28, David R. Robison a écrit :
>> Hmm... Buffering is controlled in the es_out.c module. Where is the
>> video decoder thread schedule for execution? David
> In the OS kernel code.

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