[FFmpeg-devel] [PATCH 1/2] huffyuvdec: implement trick

Michael Niedermayer michaelni at gmx.at
Wed Jun 4 13:25:04 CEST 2014


On Wed, Jun 04, 2014 at 08:14:42AM +0200, Christophe Gisquet wrote:
> Hi,
> 
> 2014-06-03 23:19 GMT+02:00 Michael Niedermayer <michaelni at gmx.at>:
> >> On a 1000-frames YUV4:2:0 video, before:
> >> 362851 decicycles in 422, 262094 runs, 50 skips
> >> 346800 decicycles in 422, 262079 runs, 65 skips
> >> Object size: 23584
> >> Overall time: 8.377
> >>
> >> After:
> >> 182488 decicycles in gray, 262087 runs, 57 skips
> >> 168197 decicycles in gray, 262077 runs, 67 skips
> >> Object size: 23188
> >> Overall time: 7.878
> 
> AND... I forgot to refresh patch on the third and last rebase...
> 
> > you write YUV420 but the "Before" scores say "in 422" and the after
> > "in gray"
> > iam confused
> 
> 422 comes from the confusingly named function, decode_422_bitstream.
> Actually, it decodes chroma. huffyuv stores YV12/I420 as NV12 (a plane
> for luma and a plane for interleaved chroma).
> 
> Hence, decode_gray_bitstream refers to the luma. I suspect you could
> entirely replace it with the decode_plane_bitstream (I don't have
> samples using it), but that's another story.
> 
> Yet another story is that keeping the native NV12 format might be more
> efficient.
>
> > can you confirm these are the correct scores ?
> 
> So the numbers are correct, but they were swapped in yet another
> incorrect way. The attached patch should be ok.
> 
> -- 
> Christophe

>  huffyuvdec.c |   71 +++++++++++++++++++++++++++++++++++++++++++++++------------
>  1 file changed, 57 insertions(+), 14 deletions(-)
> 83d442ed8ff76bd580106ef8468e7aef9bc5854d  0001-huffyuvdec-implement-trick.patch
> From 1db3868998a3d447d3c6386e06dd4bd99c616814 Mon Sep 17 00:00:00 2001
> From: Christophe Gisquet <christophe.gisquet at gmail.com>
> Date: Tue, 3 Jun 2014 16:38:36 +0200
> Subject: [PATCH 1/2] huffyuvdec: implement trick

applied

thanks

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

While the State exists there can be no freedom; when there is freedom there
will be no State. -- Vladimir Lenin
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