[FFmpeg-user] Multithreaded multioutput problem

Deron deron at pagestream.org
Mon Apr 20 22:15:57 CEST 2015

On 4/20/15 1:48 PM, Marton Balint wrote:
> On Mon, 20 Apr 2015, Deron wrote:
>> Another user has contacted me with the exact same problem hoping that 
>> I stumbled on a solution for the below problem. I did not, so I am 
>> adding some more extensive log output in hopes that someone might 
>> recongize the source of the problem.
> I have also experienced this problem. Depending on your use case you 
> can face a similar situation with only one input and one output as 
> well and a few cores. There is no buffering between the various stages 
> of the ffmpeg encoder/filter/decoder pipeline, so even if the stages 
> by themselves are multi threaded, you won't be able to scale up, 
> because passing data between the stages is done in a single thread.
> Or at least that is what I think is going on. So as far as I know you 
> can only scale up properly by running multiple ffmpeg instances. E.g: 
> create a multicast and encode that.
> Regards,
> Marton

What would be the best way to solve this then? I'm not sure I understand 
what you mean by multicast. Having multiple ffmpeg's decoding the same 
original mpegts input would be pretty slow. Is there some way to have 
ffmpeg output a multicast that is in a faster/raw format?

Seems like more overhead and more ways for it to go wrong.

Thanks for your input,


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