[mythtv-users] Playback looks at screensize not at monitor or windowsize

[Michael T. Dean]

On 06/12/2015 05:18 AM, Hika van den Hoven wrote:
> Hoi Michael,
>
> Friday, June 12, 2015, 8:58:25 AM, you wrote:
>
>> On 06/11/2015 08:56 PM, Hika van den Hoven wrote:
>>> Friday, June 12, 2015, 2:00:30 AM, you wrote:
>>>
>>>>    I recently got a new extra monitor for my workcomputer and was
>>>>    experimenting with displaying mythtv on there. The configuration is
>>>>    two monitors (1920x1080 and 1600x1200) in one screen (3520x1200)
>>>>    I have tried both displaying mythtv in a full window on the new
>>>>    screen and in a smaller one 1280x720. Everything goes ok until I try
>>>>    playback, either live or recorded. I get a display with 16:9
>>>>    stretched out to 3520:1200 or 44:15. It seems Mythtv looks at the
>>>>    screen size and not at the monitor or window size.
>>>>    I set up the windowsize in Screen Settings with "Use GUI size for TV
>>>>    playback" checked. Above there I now can select which screen to
>>>>    display on (0, 1 or All) but of cause they are all the same, the
>>>>    monitors are organized in one screen. Also I can select an aspect
>>>>    ratio (16:9, 16:10 and 4:3) bot not 44:15. It actually says there it
>>>>    cannot query a xinerama display and I should specify it, which I can
>>>>    understand. But I cannot, for the right values are missing.
>>>>    Could  this field be split in two or to some running percentage, so
>>>>    you can specify something? The three possibilities are nonsense for a
>>>>    xinerama display, it will always be two or more monitors linked
>>>>    together. Either that or it should look at the GUI setting for the
>>>>    aspect ratio.
>>>>     I can get a somewhat
>>>>    decent display by falsely telling the 16:9 picture is 4:3.
>>> I found the solution. I suddenly remembered you can adjust settings
>>> through mythweb. I set XineramaMonitorAspectRatio to 2.933333
>>> It now shows up like that in The Screen Setting. But you still can not
>>> edit it there. It should be a free fill field.
>> You should use the frontend settings editor to set the Appearance
>> settings properly, and you shouldn't ever insert disallowed values
>> directly into settings with MythWeb's
>> (dangerous/broken-because-it-allows-invalid-values) settings editor.  If
>> you have any kind of Xinerama-type multi-monitor display (including
>> TwinView or what-have-you), you *must* set the 2 Appearance settings:
>> Monitor aspect ratio
>> The aspect ratio of a Xinerama display cannot be queried from the
>> display, so it must be specified.
>> and:
>> Display on screen
>> Run on the specified screen or spanning all screens.
>> and should not (ever--for anyone, even without Xinerama) set the
>> Playback setting:
>> Video aspect override
>> When enabled, these will override the aspect ratio specified by any
>> broadcaster for all video streams.
>> where, if (for anyone at all) it seems like "Video aspect override"
>> needs to be set to get a proper display, you have misconfigured
>> something else (like, for example, your X configuration for
>> DPI/DisplaySize).
> I fully agree with what you say above. Only Nvidia deals with
> multi-monitor in a way impossible with other drivers and MythTV
> doesn't seem able to deal with that. As said One X screen containing
> both monitors. It is like Xinerama but actually incompatible with it.
> MythTV is not the only one not understanding it. Most applications
> that are aware of the two monitors are not properly able to
> distinguish them. Window managers do full-screen to both and Vbox
> also sees two but cannot distinguish them. As said the selection of
> "Display on Screen" does do nothing, because both monitors are on the
> same X screen. It should either forget underlying hardware or look
> deeper, which is possible.
>
>> It seems you're saying you think you need to set "Monitor aspect ratio"
>> to 44:15, but that's not right because neither of your monitors has a
>> 44:15 aspect--one is 16:9 and the other is 4:3 (assuming square pixels,
>> which is almost definitely the case).  Since (I'm pretty sure) you're
>> going to be displaying the video on one or the other monitor (and don't
>> want it stretched across both monitors with some funky stepped
>> letterboxing--not to mention an annoying bezel break in the picture),
>> you simply specify the aspect ratio of the monitor on which you're
>> displaying the video.
> Won't work

...until you configure your system properly :)

>> Since you seem to be saying that it doesn't work when you specify a
>> proper value for "Monitor aspect ratio", I can conclude that you have
>> some other (related) setting misconfigured.  For example, if you do not
>> specify "Display on screen" (or specify it incorrectly), you may get
>> some strange behavior, possibly exactly what you're seeing.  Similarly,
>> if your X configuration for DPI/DisplaySize (for /either/ monitor) is
>> incorrect or incorrectly calculated (if not specified), you'd get broken
>> behavior, such as you're seeing.
> It is all set correctly. Only MythTV and others expect two driver
> instances and two X screens, one for each monitor. This is the only way
> with a none Nvidia driver. The way Nvidia deals with it is actually
> more logical, properly splitting between monitor and screen and really
> creating one screen spanning both monitors.
> MythTV tries to understand it but only comes halfway, while it should
> be simple if, when set, it would only looks at the GUI size settings,
> forgetting the underlying hardware.

You're saying your screen is 3520x1200, so do you actually have to 
scroll to see the top/bottom of the screen on the 1920x1080 screen?  If 
not, your screen isn't 3520x1200.

What do you get from:

xdpyinfo

Mike