[vlc-devel] [PATCH] Send fullscreen video to specific monitor

[Marvin Scholz]

On 7 Oct 2019, at 14:42, Gabriel Luci wrote:

> The Qt option is handled by Qt, yes, but it only works when the video is
> embedded in the interface, which means you can't keep the controls on the
> primary monitor. (I assume that's because a non-embedded video window isn't
> handled by Qt anymore)
>
> I was chatting with Alexandre off-list about this and came to a similar
> conclusion. So I agree this patch can be discarded as I wrote it, and I can
> resubmit with a different approach.
>
> First, in modules/video_output/win32/window.c, I can use the id parameter
> to determine the name of the monitor. I guess that's why the parameter is
> there?
>
> Then another patch would create a new setting with the monitor name and
> pass it into that id parameter from further up the call stack. I think we
> could go further up the call stack than vout_window_SetFullScreen(). When I
> look at the call stack, I see this:
>
>     libwin32_window_plugin.dll!SetFullscreen(vout_window_t * wnd, const
> char * id) (c:\vlc\vlc\modules\video_output\win32\window.c:189)
>     libvlccore.dll!vout_window_SetFullScreen(const char * id, vout_window_t
> * window) (c:\vlc\vlc\include\vlc_vout_window.h:479)
>     libvlccore.dll!vout_ChangeFullscreen(vout_thread_t * vout, const char *
> id) (c:\vlc\vlc\src\video_output\video_output.c:390)
>     libvlccore.dll!FullscreenCallback(vlc_object_t * p_this, const char *
> psz_cmd, vlc_value_t oldval, vlc_value_t newval, void * p_data)
> (c:\vlc\vlc\src\video_output\vout_intf.c:569)
>     libvlccore.dll!TriggerCallback(vlc_object_t * obj, variable_t * var,
> const char * name, vlc_value_t prev) (c:\vlc\vlc\src\misc\variables.c:252)
>     libvlccore.dll!var_SetChecked(vlc_object_t * p_this, const char *
> psz_name, int expected_type, vlc_value_t val)
> (c:\vlc\vlc\src\misc\variables.c:709)
>     libvlccore.dll!vlc_player_vout_SetVar(vlc_player_t * player, const char
> * name, int type, vlc_value_t val) (c:\vlc\vlc\src\player\vout.c:161)
>     libvlccore.dll!vlc_player_vout_SetFullscreen(vlc_player_t * player,
> _Bool enabled) (c:\vlc\vlc\src\player\vout.c:180)
>
> At  vout_intf.c:569 (FullscreenCallback) is where it
> calls vout_ChangeFullscreen(p_vout, NULL); where id is NULL. So that is
> where I'm guessing it could be reading the setting and passing it as the id
> instead of NULL.
>
> Qt has a way to get a list of display devices, and that's already how
> "qt-fullscreen-screennumber" is populated in the preferences window, but we
> can get the name instead of the number by using ->currentText().toUtf8()
> instead of ->currentData().toInt().
>
> Then the only missing piece is to modify the implementations of the other
> OS's to use the value in the id parameter. That's where I can't really
> help. I might be able to help with Linux (I have a Ubuntu machine I can
> test on) but I couldn't help with MacOS.

macOS does not use the Qt UI, so theres no need to worry about that for
now.

>
> Does all that sound reasonable?
>
> On Mon, Oct 7, 2019 at 3:20 AM Steve Lhomme <robux4 at ycbcr.xyz> wrote:
>
>> On 2019-10-03 21:03, Gabriel Luci wrote:
>>> Can you point me to that proper API? I certainly don't mind using a
>>> different method to do it if it makes more sense.
>>
>> I think Remi is talking about the vout_window_SetFullScreen() which can
>> tell which output-identifier should be used. In other words that would
>> be the name of the monitor.
>>
>> Right now we always pass NULL all the time, via
>> vout_window_SetFullScreen(). That's probably where the
>> "qt-fullscreen-screennumber" should be passed, although the name
>> suggests it's Qt specific. It seems that the "screen id" would rather be
>> OS/window manager specific than relying on Qt. It seems the Qt option is
>> already handled fully by Qt, setting in the fullscreen window in the
>> right window. But it may be broken in the current UI.
>>
>>> But the reason I went this route is because the SetFullscreen function
>>> in /modules/video_output/win32/window.c already uses an OS-specific way
>>> to select which monitor to put the video output window on
>>> (MonitorFromWindow). So I assume that code must change if it's going to
>>> put the window on a different monitor. It just needs to be told which
>>> monitor somehow - I just don't know what that "somehow" would be besides
>>> a new configuration setting.
>>>
>>>
>>> On Thu, Oct 3, 2019 at 2:39 PM Rémi Denis-Courmont <remi at remlab.net
>>> <mailto:remi at remlab.net>> wrote:
>>>
>>>     Hello,
>>>
>>>     There is already a proper API defined for this, so clearly adding an
>>>     plugin-
>>>     specific OS-specific setting on top is not the way to go.
>>>
>>>     --
>>>     雷米‧德尼-库尔蒙
>>>     http://www.remlab.net/
>>>
>>>
>>>
>>>     _______________________________________________
>>>     vlc-devel mailing list
>>>     To unsubscribe or modify your subscription options:
>>>     https://mailman.videolan.org/listinfo/vlc-devel
>>>
>>>
>>> _______________________________________________
>>> vlc-devel mailing list
>>> To unsubscribe or modify your subscription options:
>>> https://mailman.videolan.org/listinfo/vlc-devel
>>>
>> _______________________________________________
>> vlc-devel mailing list
>> To unsubscribe or modify your subscription options:
>> https://mailman.videolan.org/listinfo/vlc-devel
> _______________________________________________
> vlc-devel mailing list
> To unsubscribe or modify your subscription options:
> https://mailman.videolan.org/listinfo/vlc-devel