Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-03 Thread Ganesh Ajjanagadde
On Tue, Nov 3, 2015 at 12:45 AM, Timothy Gu wrote: > On Mon, Nov 2, 2015 at 8:23 PM Rostislav Pehlivanov > wrote: > >> >if one removes the crippling >> >-fno-tree-vectorize >> Yes, I think a config option to turn this flag on (like the unsafe >>

Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-03 Thread Hendrik Leppkes
On Tue, Nov 3, 2015 at 1:08 PM, Ganesh Ajjanagadde wrote: > On Tue, Nov 3, 2015 at 2:17 AM, Clément Bœsch wrote: >> On Mon, Nov 02, 2015 at 10:10:33PM -0500, Ganesh Ajjanagadde wrote: >>> On Mon, Nov 2, 2015 at 9:32 PM, Ganesh Ajjanagadde wrote:

Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-03 Thread Ganesh Ajjanagadde
On Tue, Nov 3, 2015 at 2:17 AM, Clément Bœsch wrote: > On Mon, Nov 02, 2015 at 10:10:33PM -0500, Ganesh Ajjanagadde wrote: >> On Mon, Nov 2, 2015 at 9:32 PM, Ganesh Ajjanagadde wrote: >> > On Mon, Nov 2, 2015 at 6:49 PM, Ganesh Ajjanagadde >> >

Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-03 Thread Ganesh Ajjanagadde
On Tue, Nov 3, 2015 at 11:53 AM, Timothy Gu wrote: > On Tue, Nov 3, 2015 at 4:47 AM Ganesh Ajjanagadde > - GCC vectorization > slows down compilation A LOT in all versions. The newer > >> > the worse. >> >> A ~ 20% slowdown on a build for a ~ 20% improvement in an overall

Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-03 Thread Timothy Gu
On Tue, Nov 3, 2015 at 4:47 AM Ganesh Ajjanagadde > - GCC vectorization slows down compilation A LOT in all versions. The newer > > the worse. > > A ~ 20% slowdown on a build for a ~ 20% improvement in an overall FATE > bench - sounds like a win to me especially with ccache. Of course, but

Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-03 Thread Clément Bœsch
On Tue, Nov 03, 2015 at 07:20:39AM -0500, Ganesh Ajjanagadde wrote: [...] > This is an opinion, so I will state mine here: if you are developing > use ccache + GCC > ccache + clang > clang = gcc. Reason for the first > is due to the terrible interaction ccache has with clang. I'm curious; what

Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-03 Thread Ganesh Ajjanagadde
On Tue, Nov 3, 2015 at 8:36 AM, Clément Bœsch wrote: > On Tue, Nov 03, 2015 at 07:20:39AM -0500, Ganesh Ajjanagadde wrote: > [...] >> This is an opinion, so I will state mine here: if you are developing >> use ccache + GCC > ccache + clang > clang = gcc. Reason for the first >> is

Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-03 Thread Ganesh Ajjanagadde
On Tue, Nov 3, 2015 at 8:16 AM, Hendrik Leppkes wrote: > On Tue, Nov 3, 2015 at 1:08 PM, Ganesh Ajjanagadde wrote: >> On Tue, Nov 3, 2015 at 2:17 AM, Clément Bœsch wrote: >>> On Mon, Nov 02, 2015 at 10:10:33PM -0500, Ganesh Ajjanagadde wrote:

Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-03 Thread Ganesh Ajjanagadde
On Tue, Nov 3, 2015 at 8:43 AM, Clément Bœsch wrote: > On Tue, Nov 03, 2015 at 08:41:33AM -0500, Ganesh Ajjanagadde wrote: >> On Tue, Nov 3, 2015 at 8:36 AM, Clément Bœsch wrote: >> > On Tue, Nov 03, 2015 at 07:20:39AM -0500, Ganesh Ajjanagadde wrote: >> > [...] >> >>

Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-03 Thread Clément Bœsch
On Tue, Nov 03, 2015 at 08:41:33AM -0500, Ganesh Ajjanagadde wrote: > On Tue, Nov 3, 2015 at 8:36 AM, Clément Bœsch wrote: > > On Tue, Nov 03, 2015 at 07:20:39AM -0500, Ganesh Ajjanagadde wrote: > > [...] > >> This is an opinion, so I will state mine here: if you are developing > >>

Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-02 Thread Clément Bœsch
On Mon, Nov 02, 2015 at 10:10:33PM -0500, Ganesh Ajjanagadde wrote: > On Mon, Nov 2, 2015 at 9:32 PM, Ganesh Ajjanagadde wrote: > > On Mon, Nov 2, 2015 at 6:49 PM, Ganesh Ajjanagadde wrote: > >> On Mon, Nov 2, 2015 at 6:37 PM, wm4

[FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-02 Thread Ganesh Ajjanagadde
This improves accuracy for the bessel function, and this in turn should improve the quality of the Kaiser window. The algorithm is taken from the Boost project, who have done a detailed investigation of the accuracy of their method, as compared with e.g the GNU Scientific Library (GSL):

Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-02 Thread Timothy Gu
On Mon, Nov 2, 2015 at 8:23 PM Rostislav Pehlivanov wrote: > >if one removes the crippling > >-fno-tree-vectorize > Yes, I think a config option to turn this flag on (like the unsafe > bitstream reader) would be good. Defaulting to off by default if it doesn't > break

Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-02 Thread wm4
On Mon, 2 Nov 2015 14:49:54 -0500 Ganesh Ajjanagadde wrote: > This improves accuracy for the bessel function, and this in turn should > improve the quality of the Kaiser window. "Should"? Does it or does it not? If you don't know, why the patch?

Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-02 Thread Ganesh Ajjanagadde
On Mon, Nov 2, 2015 at 6:37 PM, wm4 wrote: > On Mon, 2 Nov 2015 14:49:54 -0500 > Ganesh Ajjanagadde wrote: > >> This improves accuracy for the bessel function, and this in turn should >> improve the quality of the Kaiser window. > > > "Should"?

Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-02 Thread Michael Niedermayer
On Mon, Nov 02, 2015 at 09:32:13PM -0500, Ganesh Ajjanagadde wrote: > On Mon, Nov 2, 2015 at 6:49 PM, Ganesh Ajjanagadde wrote: > > On Mon, Nov 2, 2015 at 6:37 PM, wm4 wrote: > >> On Mon, 2 Nov 2015 14:49:54 -0500 > >> Ganesh Ajjanagadde

Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-02 Thread Rostislav Pehlivanov
>if one removes the crippling >-fno-tree-vectorize Yes, I think a config option to turn this flag on (like the unsafe bitstream reader) would be good. Defaulting to off by default if it doesn't break anything for at least a few people (and compilers) who test it. It's not a big performance impact

Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-02 Thread Ganesh Ajjanagadde
On Mon, Nov 2, 2015 at 9:32 PM, Ganesh Ajjanagadde wrote: > On Mon, Nov 2, 2015 at 6:49 PM, Ganesh Ajjanagadde wrote: >> On Mon, Nov 2, 2015 at 6:37 PM, wm4 wrote: >>> On Mon, 2 Nov 2015 14:49:54 -0500 >>> Ganesh Ajjanagadde

Re: [FFmpeg-devel] [PATCH] swresample/resample: improve bessel function accuracy

2015-11-02 Thread Ganesh Ajjanagadde
On Mon, Nov 2, 2015 at 6:49 PM, Ganesh Ajjanagadde wrote: > On Mon, Nov 2, 2015 at 6:37 PM, wm4 wrote: >> On Mon, 2 Nov 2015 14:49:54 -0500 >> Ganesh Ajjanagadde wrote: >> >>> This improves accuracy for the bessel function, and