[Ffmpeg-devel] Bad interation of rc_strategy=1 and qprd

[Loren Merritt]

On Sat, 4 Feb 2006, Nico Sabbi wrote:
> Michael Niedermayer wrote:
>> On Sat, Feb 04, 2006 at 05:47:47PM +0100, Nico Sabbi wrote:
>> 
>>> I wanted to test how the quality of lavc's encodes would differ using 
>>> xvid_rc; the short answer is bad (they look much worse than with 
>>> lavc's rc code), but what
>> 
>> well, you at least have to post 1st pass, 2nd pass stats of lavc, 
>> lavc+xvid_rc
>> and xvid ...
>
> I'm not comparing the two codecs (I prefer lavc much more than xvid):
> I'm only encoding to lavc (mpeg2) with and without vrc_strategy=1 to see if 
> there is any improvement.
> I'll post the psnr figures when I've collected them

But you should compare lavc+xvid_rc against xvid+xvid_rc, otherwise you 
won't know if you've accurately implemented xvid_rc.

First guess for why qprd borks: did you not set lambda appropriately? 
xvid's rc deals only with quantizers.

--Loren Merritt