Correct Aspect Ratio for MPG files and Widescreen TV's (1 Viewer)

[dman_lfc]

Hi,

This is going to be a bit long-winded so please bear with me...

I have a widescreen TV and subsequently I use Media Portal in a 16x9 resolution. 832 x 468 to be exact. This allows me to overscan nicely.
Anyway the good thing with MediaPortal is that with AVI files in this resolution, 16x9 movies play full screen without any black borders etc like they should do.
Unfortunately with MPG files because the video is typically encoded at 480x576 (PAL) including borders if content is widescreen and because MP utilizes WMP then the aspect ratio does not display correctly. The various aspect ratio modes never display the content correctly and the video is squashed vertically as a result.

Is there a way to crop the black borders top and bottom for MPG files that have a 16x9 or other aspect ratio's as the video content? And then zoom / stretch it to the chosen screen resolution?

Here is my math on the subject....

SVCD PAL is encoded at a 480x576 resolution. All decent DVD software players know that the MPEG header should display the video at a 720x576 resolution. i.e. Stretching it horizontally by 1.5 which is how it should be displayed in any format / resolutuion.
Now with my resolution (832x468) the 'normal' aspect ratio mode in MP would therefore (I assume) scale this to 585x468.
Then if I changed the aspect ration to 'stretched' I would get a result of 832x468. (Squashed vertically)
But if I then changed to 'zoom' I should get 832x666. MP would then crop 99pixels top and bottom from the video hopefully displaying the video as it should look on a widescreen TV. Alternatively position it as 0,-99 in this mode.

Make sense or am I just babbling....

DMAN.

 

[dman_lfc]

More info after playing with WinDVD 6...

In WinDVD if you choose Widescreen as one of the video options it just stretches the video vertically by 1.42.
The height difference between a 4:3 & 16:9 display.
Hence when the normal resolution squashes the video this compensates for it.

I know I know... crazy DMAN

 

[dman_lfc]

768 768 768!!!

I'm enjoying having a conversation with myself....

Anyway, can someone look into this and verify?

DMAN.

 

[MrMario64]

tried pressing S ?

Also, as a sidenote, did you calibrate pixelratio ?
go to home, settings, calibration,screen calibration

 

[dman_lfc]

Yes and yes

AVI's play fine as they are cropped.
MPG's are not cropped and if widescreen content is in 4:3 resolution (i.e SVCD / VCD) and then displayed on a 16:9 screen they get squished even further.


DMAN.

 

[dman_lfc]

Here is my new math on the subject since i got DVD of 720 & 768 of SVCD mixed up...

SVCD PAL is encoded at a 480x576 resolution. All decent DVD software players know that the MPEG header should display the video at a 768x576 resolution. i.e. Stretching it horizontally by 1.6 which is how it should be displayed in any format / resolutuion.
Now with my resolution (832x468) the 'normal' aspect ratio mode in MP would therefore (I assume) scale this to 624x468 leaving a black border left and right.
Then if I changed the aspect ration to 'stretched' I would get a result of 832x468. Leaving no black border however a squashed aspect ratio.
But if I then changed to 'zoom' I should get 832x624. MP should then crop 78 pixels top and bottom from the video hopefully displaying the video as it should look on a widescreen TV. Alternatively position it as 0,-78 in this mode.

And also since I got my math wrong... WinDVD 6 compensates for this by stretching content by 1.3333333333333.

DMAN

 

[Anonymous]

I can confirm this indeed with other players the AR is correct. But with MP the 'normal' mode is not correct, you can get it right with zooming however.

So hopefully a dev can confirm this or I can make a sample mpg which does this.

 

[MrMario64]

When you can, always supply us with a sample movie

 

[dman_lfc]

Mr Mario,

I'll make a short MPG movie for you tonight and email you an FTP site to grab it from.
Also I'll include the source AVI file.

If you play this AVI on a widescreen TV in a 16:9 resolution you will see how it displays. (Which should take up the whole screen)
Then if you take the MPG file you will see the video contents is squashed to 3/4 of the original height and black borders appear top and bottom.
With my Nvidia card the MP 'Zoom' and 'Stretched' modes do not help to make this any better.

Cheers!

DMAN.

 

[dman_lfc]

MrMario,

Email sent with FTP details...

Cheers!

DMAN