[FFmpeg-user] Max rtbufsize Via dshow

Gabriel Balaich roderrooder at gmail.com
Wed Sep 19 23:02:38 EEST 2018

> The limits "max signed INT" I believe (2B).
> Anyway this message typically means your system isn't keeping up with
> encoding.  I'd think nvenc would be able to handle it but maybe not?

That actually makes a lot of sense! So I assume when I put it 2147.48M
it's being converted to  2,147,480,000 which is just below the maximum
number an int can hold. So simple, can't believe that didn't cross my

It seems like it would be fairly easy to change the variable to a
unsigned long int... but that doesn't seem very future proof with 8k, 12k,
& 16K just around the corner. Wouldn't it make more sense to use a
double in the 64-Bit version of FFmpeg? Or maybe changing the
conversion... is anyone really setting a buffer lower than 1KB?

As for performance, the encoder is around 60% usage except for when
I start and end recordings in-which there are spikes. I was able to
alleviate the spike when starting a recording by re-arranging my inputs
and outputs... which doesn't make a ton of sense to me. But I haven't
been able to do anything about the spike when ending a recording. It
seems like the entire buffer is being thrown at the encoder at once
when ending a recording or something. I'm just pressing Q to quit, is
there a more "graceful" way?

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