[Ffmpeg-cvslog] CVS: ffmpeg/libavcodec dsputil.c, 1.123, 1.124 dsputil.h, 1.117, 1.118 h264.c, 1.136, 1.137

Loren Merritt lorenm
Fri Jun 17 12:20:44 CEST 2005

On Fri, 17 Jun 2005, [iso-8859-1] M?ns Rullg?rd wrote:
> Loren Merritt <lorenm at u.washington.edu> writes:
>> I won't have time for more lavc development for a while, so if you
>> want to start on custom quant matrices, it won't be a duplication of
>> effort.
> OK.  Have I understood correctly that the dequant[48]_coeff arrays
> should be moved to the SPS/PPS, and calculated from the scaling lists?
> The custom matrixes are different for intra/inter blocks and
> luma/chroma.  Do you have any ideas/opinions on how to best represent
> that?

There should be 8 pointers in each SPS and PPS, which may be populated 
from the stream or from the default matrices (with a bunch of inheritance 
rules). Decoding always uses the pointers from the current PPS; the SPS 
ones are just there in case you have multiple PPSs referencing the same 
luma and chroma are already decoded in different places, just hardcode 
which CQM pointer you need at each one. For intra/inter and U/V, it just 
takes one more index into the list of CQM pointers.

> Does anyone have a sample with a custom quant matrix in the PPS?

maybe at http://ftp3.itu.ch/av-arch/jvt-site/draft_conformance/FRExt/
(But I can't tell you which one; I haven't examined all the streams)

--Loren Merritt

More information about the ffmpeg-cvslog mailing list