[MPlayer-dev-eng] [PATCH] mplayer has broken Letterboxing with xv Video Output on i3wm

[Reimar Döffinger]

> On 21 May 2022, at 23:06, Erik Auerswald <auerswal at unix-ag.uni-kl.de> wrote:
> On 21.05.22 22:38, Reimar Döffinger wrote:
>>> On 6 May 2022, at 23:49, Tobias Girstmair <t-mplayer at girst.at> wrote:
>>> Solution:
>>>  Remove the `if ( vo_fs )` gate in `void vo_xv_draw_colorkey(...)` in
>>>  libvo/x11_common.c:2361.
>>>  Since this function assumed the window is screen sized, it now draws
>>>  oversized boxes. I modified it to use window width/height instead, so
>>>  it only draw the pixels needed.
>> FYI one important case that needs testing is that resizing works, smoothly and flicker-free.
> 
> I've just tested that: this works just fine with -vo xv.  It
> actually works much better with -vo xv and this patch than
> it does with -vo gl.  I do not see a difference between before
> and after this patch regarding flickering when resizing.
> 
> I think this is fine.

Do you have hardware using actual XVideo overlay hardware?
It seems I might not (I'll try and look again - probably next week), and you wouldn't see the colorkey flicker with non-colorkey XVideo.
(colorkey XVideo you can recognize because if you use -colorkey 0 and move a black window over the video, you incorrectly see the video shine through still as if there was no window on top)
I'll admit that if nobody can find hardware using it, maybe we can ignore the issues, especially if it's just flicker during move/resize (though I seem to remember it also caused flicker when moving another window along the borders of the MPlayer window).

>> That has been the reason why in the past it was not fixed, breaking tiling window managers seemed preferable of breaking resizing with non-tiling window managers.
> 
> For what it's worth, resizing with -vo gl has lots of flicker.

Hm, I think that might be due to something (compositing?) doing bad buggy stuff.
I notice it gets much better with -nodouble, which suggests something is ignoring that double buffering was requested, and displays things that should not be visible.
Also need to double-check if that's specific drivers/compositors we should detect and enable workarounds for.

> I'm not sure what you mean with "bad" flickering.  But I am
> quite sure that this patch does not introduce it.  At least
> it did not do so for me on Ubuntu GNU/Linux with Intel
> integrated grafics.

Yeah, for Intel integrated I can confirm, but it does not use XVideo hardware, it's software emulated.
As said, it might be time to re-consider, but I'd be curious to try it out on some old hardware.

Best regards,
Reimar