[FFmpeg-user] Overlay one subtitle stream and copy another

[Hans Carlson]

On Mon, 7 Mar 2016, Carl Eugen Hoyos wrote:

> Hans Carlson <forbyta <at> inbox.com> writes:
>
>> Buffer queue overflow, dropping.
>
> You can use the fifo filter to avoid these, it will
> increase memory usage.

Probably I'm doing something wrong, but adding the fifo filter didn't 
help.  I'm not exactly sure how/where I should be using it.

I changed my original command to use this filter_complex:

   -filter_complex 'fifo; [0:v][0:3]overlay'

I still see the buffer overflow warnings.  But the problem isn't just that 
I see these warnings, the problem is the resulting video doesn't play 
correctly.  At a couple points, the video stalls and the audio continues 
for several seconds, then the video skips ahead.