[FFmpeg-devel] [PATCH 10/11] avfilter/vf_ssim: use log10 instead of log()/log(10)
gajjanag at mit.edu
Thu Oct 29 19:07:38 CET 2015
On Thu, Oct 29, 2015 at 1:37 PM, Michael Niedermayer
<michael at niedermayer.cc> wrote:
> On Thu, Oct 29, 2015 at 12:20:08AM -0400, Ganesh Ajjanagadde wrote:
>> This is likely more precise and conveys the intent better.
>> Signed-off-by: Ganesh Ajjanagadde <gajjanagadde at gmail.com>
>> libavfilter/vf_ssim.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>> diff --git a/libavfilter/vf_ssim.c b/libavfilter/vf_ssim.c
>> index ce1e3db..6b2a8d7 100644
>> --- a/libavfilter/vf_ssim.c
>> +++ b/libavfilter/vf_ssim.c
>> @@ -176,7 +176,7 @@ static float ssim_plane(SSIMDSPContext *dsp,
>> static double ssim_db(double ssim, double weight)
>> - return 10 * (log(weight) / log(10) - log(weight - ssim) / log(10));
>> + return 10 * (log10(weight) - log10(weight - ssim));
> note, this can be simplified further but thats maybe off topic in
> relation to switching to log10
I did note that you can rewrite as log10(weight/(weight-ssim)), but
avoided it deliberately as I did not know what people want with
respect to it. Since you brought it up and think it may be good, I
will change it.
I personally don't consider it too off topic, and prefer this over
sending a separate patch for the simplification and dealing with
another wm4 rant about it.
Will push all later, once everything is reviewed and ok'ed.
> Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
> You can kill me, but you cannot change the truth.
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