[mythtv-users] HDPVR HD Recordings are in 4:3 format

Karl Newman newmank1 at asme.org
Sat Dec 14 06:37:05 UTC 2013


On Fri, Dec 13, 2013 at 10:19 AM, Karl Newman <newmank1 at asme.org> wrote:

> On Fri, Dec 13, 2013 at 9:06 AM, Michael T. Dean <mtdean at thirdcontact.com>wrote:
>
>> On 12/13/2013 11:25 AM, Karl Newman wrote:
>>
>>> On Fri, Dec 13, 2013 at 5:41 AM, Michael T. Dean wrote:
>>>
>> ...
>>
>>> Sorry, I just realized that I wasn't clear. When I say I switched
>>> hardware,
>>> I meant my motherboard died and had to be replaced, and I lost my
>>> built-in
>>> TV out (new MB has HDMI&  VGA only). There has been no change to the STB
>>>
>>> feeding the PVR-500. The converter changes the HDMI output of my computer
>>> to the composite input of my TV.
>>>
>>>  Anyway, it's strictly a display issue because it
>>>> happens with old recordings as well.
>>>>
>>>>
>>>  Well, if that's the case, then you have X misconfigured and you're
>>>> abusing
>>>> the "Video aspect override" setting to make it appear correctly--the 2
>>>> wrongs to make a right approach.  See
>>>> http://www.mythtv.org/wiki/Display_Size  (Or you have Xinerama enabled
>>>> and your "Monitor aspect ratio" setting is incorrect.)
>>>>
>>>>  It's entirely possible that X is misconfigured, but I fought with it
>>> for
>>> quite a while and even to get it to stay in 720p I have to issue a xrandr
>>> command in my .xsession script because I couldn't force the preferred
>>> mode
>>> in my xorg.conf (it used to stick, but an update to X broke it). Hmm... I
>>> just looked up man page for xrandr and I see there's a --fbmm option that
>>> can set the display size, so I'll look into that. Maybe if I set that I
>>> can
>>> get rid of the override and have everything work right.
>>>
>> ...
>>
>>  The "Video aspect override" setting shouldn't exist and only provides a
>>>> way for people with broken configurations to make it seem like things
>>>> aren't broken without actually fixing the brokenness.  It only adds to
>>>> confusion when users are configuring their systems, especially when it
>>>> makes a broken configuration seem to work.
>>>>
>>>>  Yep. The "brokenness" in this case is primarily due to my
>>> HDMI->Composite
>>> converter, but I'm able to get it to work well enough for now. There
>>> comes
>>> a point where you've fought enough with arcane config files and arbitrary
>>> package changes and you just want it to fricking work.
>>>
>>>
>> Sounds like you're using 1280x720 output on your HDMI that's going to an
>> HDMI->Composite converter, which outputs NTSC Composite (which is assumed
>> by your TV to be 4:3).  If that's the case, you simply need to tell your X
>> the proper DisplaySize to use.  (While nvidia drivers allow you to specify
>> a DPI value, doing so would require doing more math, so I'm giving examples
>> using DisplaySize--which presumes that you did *not* specify DPI to the
>> nvidia drivers--if you are using nvidia drivers.)
>>
>> If you have a 16:9 (physical aspect ratio--as in comparing the physical
>> width/height of the) TV, you simply need to specify a 16:9 aspect ratio on
>> the DisplaySize, such as:
>>
>> DisplaySize 325 182
>>
>> in the Monitor section of the X config file.
>>
>> If you have a 4:3 TV, you need to specify a 4:3 aspect:
>>
>> DisplaySize 325 243
>>
>> I'm guessing you need the former. Just make sure in your Xorg.log, you
>> see something on the order of:
>>
>> (**) Dec 10 18:16:47 NVIDIA(0): DPI set to (100, 100); computed from
>> "DisplaySize" Monitor
>>
>> (though you may well have different DPI--the important part is that it
>> was computed from the DisplaySize, rather than from some (broken) --dpi
>> setting on the X command line that your distro decided to create havoc by
>> including or similar).  Also, FWIW, your needing to use xrandr to force the
>> 720p does make it sound like your distro is doing something terrible like
>> specifying a --dpi argument to X.
>>
>>
>> Mike
>>
>
> I'm using Gentoo, and I'm pretty sure it doesn't do that (From what I've
> seen, Gentoo doesn't generally presume to know what's best for their
> users). Something changed in a version of X maybe ~8 months ago that broke
> it. PreferredMode is completely ignored. I'm using the built-in Intel
> graphics (i3 Sandy Bridge), not nVidia. But I will investigate the
> DisplaySize first in xorg.conf and if that doesn't work, then as an
> argument to my xrandr command.
>
> Karl
>

Okay, not terribly surprised given my history with X and this motherboard,
but this didn't work at all. DisplaySize is accepted, but Myth apparently
doesn't use it. I used the actual measured display size. Maybe it can't use
non-square pixels (1280x720 pixels is 16:9 but 559x419 mm is 4:3)? I
couldn't find the "Monitor Aspect Ratio" setting per se, but I did see
something like that if I enable separate modes for GUI and video playback.
I don't use that feature, so maybe that's why it's not working for me.
Anyway, I went back to using the Aspect Override to fake that I have a 16:9
screen so that recordings will fill the screen and not be horizontally
squashed. So, from my perspective there is still a need for that setting.

Karl
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