[FFmpeg-devel] [PATCH] Add a gamma flag to exr loader to avoid banding
ggarra13 at gmail.com
Tue Apr 29 01:21:03 CEST 2014
On 28/04/14 17:10, Michael Niedermayer wrote:
> On Mon, Apr 28, 2014 at 09:19:07PM +0200, Reimar Döffinger wrote:
I apologize for being so impatient. Sorry.
>>> First it seems to still have a bug
>>> it fails fate
>>> --- ./tests/ref/fate/exr-slice-raw 2014-04-28 04:14:37.849375679 +0200
>>> +++ tests/data/fate/exr-slice-raw 2014-04-28 19:50:27.430558597 +0200
>>> @@ -1,2 +1,2 @@
>>> #tb 0: 1/25
>>> -0, 0, 0, 1, 3169800, 0x6a356d0d
>>> +0, 0, 0, 1, 3169800, 0x2cfefd25
I am stuck with this bug. Not sure exactly what the numbers mean in the
first place, except that it seems +0 and -0 are misplaced.
The fate test should fail with the exr_patch6.patch since gamma was set
at a default of 2.2. But that's not the case why it is failing. I
removed the powf function from the table lookup and that's not either.
IEEE math is not my strongest suit. Can an IEEE guru take a look at the
code, please (Reimar?)? There is a HACK comment in the exr_flt2uint
function which appears harmless, but not sure.
>> 3) It adds an option that people might rely on but which might be incompatible/require more hacks to support in a better solution. I would suggest marking the option as experimental/unsupported in the meaning we may remove it at any time with only a minor version bump.
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