[FFmpeg-devel] [PATCH]Sanitize VBR setting for libfdk-aac

Carl Eugen Hoyos cehoyos at ag.or.at
Wed Sep 12 19:00:53 CEST 2012

Derek Buitenhuis <derek.buitenhuis <at> gmail.com> writes:

> On 11/09/2012 4:46 PM, Carl Eugen Hoyos wrote:
> >>> -        int mode = avctx->global_quality;
> >>> +        int mode = avctx->global_quality / FF_QP2LAMBDA;
> >>
> >> I'm not really sure how this can be right.
> > 
> > Please elaborate how this is supposed to be done.
> This doesn't make it better in any way.

I wonder what makes you think so...

> Nothing that uses global_quality uses
> the same scale anyway, 

> and libfdk-aac uses a discrete set of values from it. 

> Using FF_QP2LAMBDA will only complicate and/or break this functionality.

Given that the functionality is broken now and the patch fixes it here, 
I would appreciate it if you could elaborate.

Carl Eugen

More information about the ffmpeg-devel mailing list