Stretch video horizontally but not vertically

[imilne]

Hi all,

Bit of a strange request this one, coming from a friend of mine who has decided to give gbpvr a try but has a weird way of wanting to watch stuff.

He watches a lot of old 4:3 content, but wants it stretched to fill the entire 16:9 screen (gbpvr's fill mode does that fine).

All his films though are DVD rips to xvid, which I'm guessing have had the black bars removed as part of the transcode, which means they usually stretch vertically so that a 2:35:1 film also fills the entire screen. In this case, that's not what is wanted. The original aspect ratio (with black bars) should be visible. Toggling to Auto usually fixes this.

Now for the killer... he controls all this via a bluetooth mouse and doesn't want to get up to press F7 to toggle modes. So he needs a mode that stretches 4:3 but leaves the 16:9 and 21:9 stuff alone.

So the questions are really:

a) is there a way to toggle using the mouse?
b) is there a way to set the aspect ratios in config.xml so that any video is always stretched horizontally but never vertically?

I'm not expecting a solution, but thought I'd ask anyway :-)

(Actually, in the case of a) - does anyone know of a program to allow a key press to be mapped to a mouse button?)

[johnsonx42]

oh, sure, it's always a 'friend' who wants some kinky aspect ratio.; the person asking is straight as an arrow...

a) no, not directly, but there are plenty of programs that can do that. I use EventGhost for such things, though it's probably overkill for your purpose.

b) it depends on exactly which modes give the desired results, vs which mode is being used when Auto is selected (understand that all Auto does is choose one of the other modes based on whether the source is 16:9 or 4:3). The aspect ratios are controlled in this bit of config.xml (assuming he has the TV Shape set to 16x9):

Code:

<AspectRatioModes shape="16x9">
    <AspectRatioMode name="Auto" ratio="0,0,0,0" />
    <AspectRatioMode name="Fill" ratio="0,0,1,1" />
    <AspectRatioMode name="Remove LetterBox" ratio="0,-0.125,1,1.125" />
    <AspectRatioMode name="PillarBox" ratio="0.08,0,0.92,1" />
  </AspectRatioModes>

So for 16:9 content, gb-pvr selects the Fill ratio, while for 4:3 content, GB-PVR selects PillarBox (I think; I have a 4:3 set, so I haven't played with 16x9 settings). So what your 'friend' needs to do is see which mode gives the desired result for each content type, vs which mode is selected with Auto (ie, see how the screen looks when Auto is selected, then toggle the modes to see which one looks the same as Auto). It may be possible then to mess with the modes so that Auto results in the desired appearance, even if the resulting mode no longer matches the name.

Example from my setup:

Code:

<AspectRatioModes shape="4x3">
    <AspectRatioMode name="Auto" ratio="0,0,0,0" />
    <AspectRatioMode name="Fill" ratio="0,0,1,1" />
    <AspectRatioMode name="LetterBox" ratio="-0.15,0,1.15,1" />
    <AspectRatioMode name="WideScreen" ratio="0,0.125,1,0.875" />
    <AspectRatioMode name="Zoom" ratio="-0.15,-0.15,1.15,1.15" />
  </AspectRatioModes>

For 16:9 source material when the TV Shape is set to 4x3, GB-PVR picks "LetterBox". By default, this mode letterboxes the 16:9 content... but that's not what I wanted. Much of the time, my HD channels are broadcasting 4:3 content pillarboxed into a 16:9 frame. So by default, the show becomes a 4:3 square in the middle of the TV. Also, even on many 16:9 shows, the left and right sides are just 'extra', because they know the frame is likely to be cropped to 4:3 later. So, I changed the numbers for "Letterbox" to fill the screen (pushing the left and right sides off the edges of the screen). Then for cases where I really do want to see the full widescreen display, I added the new "WideScreen" ratio (which has the numbers from the original "Letterbox" mode). Finally, because I have a couple of 'funny' channels that broadcast in a 4:3 format, but often re-broadcast a 16:9 feed from somewhere else which can in turn include a pillarboxed 4:3 show, I added the "Zoom" ratio which fixes that.

90% of the time then, Auto does what I want. 4:3 channels fill the screen, as do 16:9 channels. Then I use F7 (mapped to a button on my remote) for the odd cases.

[johnsonx42]

Further question though: does your 'friend' have his TV Shape setting in Config (i think it's on the first page) set to 16x9? I keep thinking that leaving the setting on 'Fill' all the time should give him the desired results, but you're saying Fill stretches the 4:3 content as desired, but he has to go back to Auto for 16:9 stuff... I'd have thought Auto would select "Fill" anyway, so it doesn't quite add up to me.

[imilne]

Further question though: does your 'friend' have his TV Shape setting in Config (i think it's on the first page) set to 16x9? I keep thinking that leaving the setting on 'Fill' all the time should give him the desired results, but you're saying Fill stretches the 4:3 content as desired, but he has to go back to Auto for 16:9 stuff... I'd have thought Auto would select "Fill" anyway, so it doesn't quite add up to me.

Sadly it is a real friend, not a "friend" friend. I'm quite happy with a harmony remote talking to an MCE receiver via HIP, etc and have no problems with aspect ratios. Plus I mainly watch real DVDs where Auto behaves as it should. In friend's case...his problems are a) he's too lazy to use F7 (and can't via a mouse) and b) he has too many crappy AVIs that are probably no longer in the correct aspect ratio anyway.

To answer your question though, yes the TV shape setting was set to 16:9.

Fill stretches the 2:35:1 content because I'm guessing the process of ripping/xviding has removed the black bars in an attempt to save space so Fill then stretches the edge of the actual video to the edge of the screen. With a proper DVD, the black bars are still part of the content (someone correct me if I'm wrong?) so Fill can only stretch the edge of the blackness to the edge of the screen, leaving the picture part in the correct ratio.

[imilne]

I keep thinking that leaving the setting on 'Fill' all the time should give him the desired results, but you're saying Fill stretches the 4:3 content as desired, but he has to go back to Auto for 16:9 stuff... I'd have thought Auto would select "Fill" anyway, so it doesn't quite add up to me.

Actually, thinking about it, if left on Auto, when a 2:35:1 AVI was played, the picture filled the entire screen (acting like Fill). But if you toggled through all the modes and back to Auto, then the aspect ratio was correct (with black bars).

[johnsonx42]

Actually, thinking about it, if left on Auto, when a 2:35:1 AVI was played, the picture filled the entire screen (acting like Fill). But if you toggled through all the modes and back to Auto, then the aspect ratio was correct (with black bars).

That's odd. Cycling through the aspect ratios shouldn't change anything when you get back to Auto. Aside from Auto, which other aspect ratio was correct?

[athomas]

Auto should display any video aspect ratio in its proper form if the codec is working properly. I once had a problem with different aspect ratios not properly displaying. It was the codec. Once I had the proper one selected and configured, it worked great.

[johnsonx42]

Auto should display any video aspect ratio in its proper form if the codec is working properly. I once had a problem with different aspect ratios not properly displaying. It was the codec. Once I had the proper one selected and configured, it worked great.

Yes, you're right, ffdshow won't work with auto until you change a setting somewhere in it's config, but I have no recollection which setting it was. I haven't seen a similar issue with other decoders, but I imagine there are others.

Also, you can't leave the decoder selection at 'System Default', even if whichever decoder you have as default happens to work. Likewise, the decoder you do have selected has to work; if that decoder fails to connect and the graph fails back to a different decoder, Auto won't work that way either.

[imilne]

Yes, you're right, ffdshow won't work with auto until you change a setting somewhere in it's config, but I have no recollection which setting it was. I haven't seen a similar issue with other decoders, but I imagine there are others.

Also, you can't leave the decoder selection at 'System Default', even if whichever decoder you have as default happens to work. Likewise, the decoder you do have selected has to work; if that decoder fails to connect and the graph fails back to a different decoder, Auto won't work that way either.

Hmm, that's maybe part of the problem then. I think nVidia PureVideo was selected in the decoder section but the AVIs are probably all xvid which I think was being handled by ffdshow.

I've emailed him about EventGhost but haven't heard back so who knows...