[Ffmpeg-cvslog] CVS: ffmpeg/libavcodec snow.c, 1.68, 1.69 avcodec.h, 1.436, 1.437
Wed Jan 11 05:13:49 CET 2006
On Wed, 28 Dec 2005, Jeff Clagg wrote:
> On Wed, Dec 28, 2005 at 03:32:11PM -0800, Corey Hickey wrote:
>> Besides that, what is *cmp=12? It doesn't seem to be documented.
> Quoth mplayer's DOCS/tech/snow.txt:
> * cmp, subcmp, mbcmp
> Set the comparison function, default: 0 (SAD).
> useful values = 0 (SAD), 1 (SSD), 11 (5/3 wavelet), 12 (9/7 wavelet).
> Experience shows that SSD is the best most of the time, while SAD is
> slightly better the remainder of the time.
> Then, at the end of that document:
> v4mv and the wavelet cmp functions are theoretically good, but in
> practice won't work well until we get OBMC-aware motion estimation.
> In short:
> The best options in almost all cases are
In particular, I hypothesized that v4mv would require obmc-aware block
size decision, and that wavelet cmp funcs would require comparing the
whole area of support at once. Neither of those has been implemented yet.
More information about the ffmpeg-cvslog