Re: [transcode-users] rc buffer underflow with ffmpeg

[Phil Ehrens <phil@xxxxxxxx>]

Andrew Church wrote:
> >Using ffmpeg in two-pass mode with mencoder for ripping
> >dvd's produces absolutely brilliant results. How is it
> >that the rate control is not broken when using ffmpeg
> >via mencoder? Or is it spcifically mpeg2 rate control that
> >is borken?
> 
>      Rate control is only used when three things are set: minimum rate,
> maximum rate, and buffer size.  IIRC, mencoder never sets buffer size, so
> the rate control code is never used in the first place (and hence you have
> no control over the peak data rate).

Ah, I see. I am a little skeptical about "minimum rate"
however... since that should always be 0, no? Also, the
buffer size is then buffer size for the encoder, isn't
it? And shouldn't it be possible to always have that be
as large as necessary? I am asking these questions because
I am thinking about having a crack at the rate control
myself. How can a buffer underflow occur at all? If the
condition can be detected, it can be handled. Certainly
I will find out that I am very naive, I am sure.

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