[FFmpeg-user] Decklink with ffmpeg audio desync

Dpto. Datos Television Costa Blanca datos at tvt-datos.es
Mon May 16 19:23:41 CEST 2016

El 14/05/2016 a las 2:44, Marton Balint escribió:
>> I've removed -re from the command, but if that doesnt help, how can I
>> fix the desync? I have no way of "not having" the NO INPUT SIGNAL ->
>> Also, when the signal interrupts I see in the stream the colour bars. Do
>> they come from ffmpeg or from the decklink card?
> Bars are coming from ffmpeg, when no input is detected. Apparently
> your inputs are not synchornized... Can you try to feed synchronized
> signal to ffmpeg to rule out this, as a probable source of A-V desync?
The quick answer is no, I cant feed with sync. One of the sources is a 
complex PC VGA to S-VIDEO to SDI (Yes, 3 converters, dont ask) and they 
dont have sync in/out.

We have a blackmagic SDI to Analog A/V that works perfectly (Never get 
desync), but with the quality loss of the Analog A/V so is a discarded 

While Im looking on how to sync the inputs, is there any other way to 
fix this? Maybe telling ffmpeg to ignore any time code and just encode 
whatever get in?



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