[Ffmpeg-devel] output_example - "buffer underflow" messages on Darwin/PPC

[Adam Nohejl]

2005/12/30 v 13:40, Adam Nohejl:

> Hello,
>
> I'm writing a tool that uses libavcodec/libavformat for its output.  
> I've used the output_example as a starting point (BTW, thanks a lot  
> for this piece of code, Fabrice, I'd be lost without it). Both my  
> program based on it and the example tool itself constantly reports  
> buffer underflows when encoding an MPEG (see below), but the output  
> seems to be perfectly OK.
>
> I'm testing on Mac OS X 10.4.3 / PowerPC G4 and I have the CVS  
> source from 14 Dec, because I wasn't able to build the up-to-date  
> ones (errors during compilations).
>
> This is what I get:
>
> $ output_example out.mpeg
> Output #0, mpeg, to '/out.mpg':
>   Stream #0.0,   nan fps: Video: mpeg1video (hq), yuv420p, 352x288,  
> q=2-31, 400 kb/s
>   Stream #0.1: Audio: mp2, 44100 Hz, stereo, 64 kb/s
> [mpeg @ 0x45fbfc]buffer underflow
> [mpeg @ 0x45fbfc]buffer underflow
> (...)
>
> That's quite annoying. What does it mean? Is there any way I can  
> help to fix it?

Today I've built the up-to-date CVS sources and the result is much  
the same, the framerate is displayed correctly but the buffer  
underflows remain:

   Stream #0.0, 25.00 fps(c): Video: mpeg1video (hq), yuv420p,  
352x288, q=2-31, 400 kb/s
   Stream #0.1: Audio: mp2, 44100 Hz, stereo, 64 kb/s
[mpeg @ 0x232f68]buffer underflow
[mpeg @ 0x232f68]buffer underflow
(...)

I've searched the archives and I found out that it has already been  
reported, but I didn't find any explanations. I'm new to ffmpeg, but  
I'd expect that if there's a buffer underflow reported by example  
code, then there must be something wrong. Or did I miss anything?

I'd be grateful for any help or suggestions.

-- 
Adam Nohejl
Loki Software
mailto:adam at lokisw.com
http://lokisw.com