Re: [v2 PATCH 3/3] windowscodecs: Add support for palette image formats to PNG encoder.

[Sebastian Lackner]

On 27.01.2017 22:28, Vincent Povirk wrote:
> > -
> >            else
> > -
> >            {
> > -
> >                png_palette[i].red = 0;
> > -
> >                png_palette[i].green = 0;
> > -
> >                png_palette[i].blue = 0;
> > -
> >            }
>
> Why is it necessary to pad the palette in this way? Couldn't you just
> pass the appropriate number of colors?

Clamping to 1 << This->format->bit_depth is necessary (see the comment
about newer libpng versions), but padding the palette probably isn't,
at least I'm not aware of any test for it. It should be fine to
replace

colors = 1 << This->format->bit_depth;

with

colors = min(This->colors, 1 << This->format->bit_depth);

and to remove the else branch.