Default window size for video file changes after conversion.

[dodo23]

Hello,

I have a strange problem where sometimes when I convert a video file from one format to another (eg. MKV x264->regular XviD, or XviD ISO MPEG-4->DivX 6) the resulting video file will display an improper aspect ratio when played, even though the AR was not changed during conversion.

Example (sorry for black screens. print screen+photoshop=black screen for some reason.):

original video file (shows the proper 2.35:1 aspect ratio)


converted file (as you can see the window is a bit higher)


So when I converted the file I simply wanted to "switch the codec" (to enable hardware player support), so aspect ratio, frame rate, etc was not changed in the program. And the aspect ratio was not changed for the resulting file either, so if I use a software player I can easily fix this problem by changing the AR in the player. Problem happens when I use a hardware player though...

It's really strange, since the AR is technically correct, but when the file is played it by default shows a vertically "stretched-out" window

I use River Past Video Cleaner Pro 7.5 and ffdshow (XviD) or DivX 6.8.5.

If anyone can help, thanks a lot

[jagabo]

Set the PAR or DAR flags in your output codec. Since you're not changing the frame size set Format Out to the same value as the current source:

[dodo23]

Thanks for your reply, just as an experiment (since I still don't quite know how PAR works in relation to the regular AR) I set 'Format in' and 'Format out' to PAL 16:9 and did a test conversion. But the result was the same stretched window. What should I set the PAR to, for a 2.35:1 AR video file?

[dodo23]

I just noticed that River Past Video Cleaner has what seems like a similar option, so I messed around with different options there but always got the same stretched window...

[Case]

What should I set the PAR to, for a 2.35:1 AR video file?

It depends. You might say the PAR is the stretch factor to use, to get the desired AR (DAR).

Suppose your source file is 720x364, and should be displayed as 2.35:1. This requires a PAR of 1.188:1 ((h*ar)/w).

Some movie formats do not support a PAR other than 1:1. Most notably "regular XviD" AVI. Some apps allow you to set such a parameter even in AVI, but most player software just ignores it.
Better stick to formats as MKV or MP4 for such trickery. Note sure about DivX 6 support.

[dodo23]

What should I set the PAR to, for a 2.35:1 AR video file?

It depends. You might say the PAR is the stretch factor to use, to get the desired AR (DAR).

Suppose your source file is 720x364, and should be displayed as 2.35:1. This requires a PAR of 1.188:1 ((h*ar)/w).

Some movie formats do not support a PAR other than 1:1. Most notably "regular XviD" AVI. Some apps allow you to set such a parameter even in AVI, but most player software just ignores it.
Better stick to formats as MKV or MP4 for such trickery. Note sure about DivX 6 support.

Alright, thanks for the help. I guess there's not much to do in this case then.

[Case]

Alright, thanks for the help. I guess there's not much to do in this case then.

In this case, let go of the source dimensions and encode to a new width and/or height for accommodating square pixels.

[jagabo]

You have two choices:

1) Resize the frame so that the relative frame dimensions are equal to the Display Aspect Ratio (DAR, the final shape of the picture) and encode with square pixels (Pixel Aspect Ratio = PAR = 1:1). For a 2:35:1 video that would be about 400x176.

2) Use any frame size you want and encode with PAR/DAR flags to tell the player what the final shape should be.

DAR = PAR * SAR

DAR = Display aspect ratio, the final shape of the displayed picture
PAR = Pixel Aspect Ratio, the shape of individual pixels
SAR = Storage Aspect Ratio, the frame dimensions.

Some players don't respect PAR/DAR flags. Most current players will respect PAR/DAR flags of Divx AVI files. You may need to enable it in the player.

It's impossible to tell you the exact settings to use with your current video without knowing exactly what you have. Post what MediaInfo tells you about the file. Your earlier attempt probably didn't work because you set Divx's input AR and output AR to the same settings. The input AR needs to be set to the input file's PAR. Since you told it the input AR and output AR were the same it didn't do anything to the video.