Re: Patch for png_save(), QEMU v8.0

[Валентин]

Thank you! 

Indeed, I haven't took into account big-endian hosts. 

(I tried "PIXMAN_BE_r8g8b8" as in ppm_save(), but didn't fix png header and got broken images). 

 

Your patch should be correct. 

 

Thank you very much! 

With best regards, 

Valentine. 

 

 

 

-------- Исходное сообщение --------

От: Peter Maydell <peter.maydell@linaro.org>

Дата: 02.05.2023 16:59 (GMT+03:00)

Тема: Re: Patch for png_save(), QEMU v8.0

On Tue, 2 May 2023 at 14:48, Валентин via <qemu-devel@nongnu.org> wrote:
>
> Hello!
>
> Currently, png_save() in "console.c" uses "PIXMAN_a8r8g8b8" format when saving png.
>
> ( https://gitlab.com/qemu-project/qemu/-/blob/7c18f2d663521f1b31b821a13358ce38075eaf7d/ui/console.c#L314 )
>
> It should probably use "PIXMAN_a8b8g8r8" (red<>blue exchanged).
> Without it I'm getting PNGs with blue and red channels swapped (QEMU 8.0, qemu-system-x86_64, Arm64 host, libpng 1.6.39).

Ah, I was just working on this this afternoon (it was reported
last week as https://gitlab.com/qemu-project/qemu/-/issues/1622 )
and just sent a patch a minute before I read this email :-)

I think your patch only fixes this problem for little-endian
hosts and leaves big-endian hosts still with the wrong
pixel-data order.

You can see my version of the patch here:
https://patchew.org/QEMU/20230502135548.2451309-1-peter.maydell@linaro.org/

thanks
-- PMM