[FFmpeg-devel] [RFC] ratecontrol buffer size magic

Stefano Sabatini stefano.sabatini-lala
Mon Nov 19 11:09:34 CET 2007


On date Tuesday 2007-10-16 22:20:17 +0200, Michael Niedermayer encoded:
> Hi
> 
> On Tue, Oct 16, 2007 at 12:17:26PM +0200, Baptiste Coudurier wrote:
> > Hi Michael,
> > 
> > Michael Niedermayer wrote:
> > > Hi
> > > 
> > > On Tue, Sep 25, 2007 at 12:00:02PM +0200, Baptiste Coudurier wrote:
[...]
> > >> Another try:
> > >>
> > >> /**
> > >>   * Ratecontrol factor applied to vbv buffer free space when limiting QP
> > >> (bits2qp).
> > >>   * With a maximum rate: free space / factor;
> > >>   * With a minimum rate: free space * factor;
> > >>   * - encoding: Set by user.
> > >>   * - decoding: unused
> > >>   */
> > >>   float rc_vbv_to_qp_factor;
> > >>
> > >> {"rc_vbv_to_qp_factor", "ratecontrol vbv buffer free space to qp
> > >> factor", OFFSET(rc_vbv_buf_free_space_to_qp_factor), FF_OPT_TYPE_FLOAT,
> > >> 3.0, FLT_MIN, FLT_MAX, V|E},
> > >>
> > >> Im trying to keep name somewhat short.
> > > 
> > > please split this variable in 2
> > > 2 good names would be:
> > > 
> > > rc_max_available_vbv_use (default 1.0/3)
> > > that is attempt use at maximum 1/3 of what we can use without a underflow
> > > 
> > > rc_min_vbv_overflow_use (default 3)
> > > that attempt to use at least 3 times the amount we must use to prevent
> > > a vbv overflow
> > > 
> > 
> > Patch attached.
> 
> ok

I'm interested in this patch too. Since Michael OKed it could someone
apply it?

I diffed the previous patch against the latest SVN, in order to get a
clean patch.

Best regards.
-- 
Stefano Sabatini
Linux user number 337176 (see http://counter.li.org)
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