[FFmpeg-devel] [PATCH] mdec: use correctly permutated quant matrix for dequantization.

[Ronald S. Bultje]

Hi,

On Tue, Jun 20, 2017 at 8:45 PM, Michael Niedermayer <michael at niedermayer.cc
> wrote:

> On Tue, Jun 20, 2017 at 08:18:20PM -0400, Ronald S. Bultje wrote:
> > Hi,
> >
> > On Tue, Jun 20, 2017 at 5:22 PM, Michael Niedermayer
> <michael at niedermayer.cc
> > > wrote:
> >
> > > On Tue, Jun 20, 2017 at 08:47:33AM -0400, Ronald S. Bultje wrote:
> > > > This allows using non-simple (e.g. simplemmx) IDCT implementations.
> > > > The result is not bitexact (which is why the fate test continues to
> > > > use -idct simple), but the PSNR between C/MMX goes from ~35 to ~90.
> > > > ---
> > > >  libavcodec/mdec.c | 14 ++++++++++----
> > > >  1 file changed, 10 insertions(+), 4 deletions(-)
> > > >
> > > [...]
> > >
> > > > @@ -212,9 +213,7 @@ static int decode_frame(AVCodecContext *avctx,
> > > >  static av_cold int decode_init(AVCodecContext *avctx)
> > > >  {
> > > >      MDECContext * const a = avctx->priv_data;
> > > > -
> > > > -    if (avctx->idct_algo == FF_IDCT_AUTO)
> > > > -        avctx->idct_algo = FF_IDCT_SIMPLE;
> > >
> > > iam not sure this should be in this patch
> >
> >
> > Can you be more precise?
>
> > Would you like this in a separate patch?
>
> yes


OK, pushed separately then.

Ronald