Aspect ratio wrong

[dolph]

Hello,

I have a vob file with dimensions 720:480, when I drag in in VLC latest version, it is played at 720:540.

The media info menu tells the correct size, but I am not able to play it at that size.

The screenshot is wrong too.

The file is played well in Media Player Classic and Gom Player. Their screenshots are correct too.

I have tried several options, but nothing works. I right click the play area and set video, zoom 1:1 original and video, aspect ratio default, why it is not enough?

What should I set else?

Thanks.

[dolph]

No one?

What does this mean? There is no solution, no one cares, or?

I am afraid if this topic goes in older pages it will be forgotten.

I have installed latest version because the previous had this problem, but it is the same.

I find quite curious this basic problem is not considered while a lot of strange and microscopic problems (command line, encoding...) are discussed for days.

[Lotesdelere]

We need a SHORT sample of a non working file.

[dolph]

Hello thanks for your answer.

Here it is

http://rapidshare.com/files/407571443/VTS_01_1.VOB.html

I hope you can be able to get it, I did not found any recommendations about passing files here in the rules above.

[Lotesdelere]

I'm sorry but there is nothing wrong with this file.
It has a Display Aspect Ratio (DAR) of 4:3 so playing it at 720*540 is correct because it is a 4:3 aspect ratio resolution.

And 720*480 is the standard D1 anamorphic storage resolution for an NTSC DVD so everything looks absolutely normal to me.

Code: Select all

Width : 720 pixels Height : 480 pixels Display aspect ratio : 4:3 Frame rate : 29.970 fps Standard : NTSC

[dolph]

Hello, thanks again for your answer.

I think you are speaking a bit complicated for me

I have tried to read Wikipedia about that and it seems you are right in what you are saying. So, VLC invents some interpolated horizontal lines to reach the 4:3 aspect ratio?

These informations are embedded somewhere in the VOB file? I do not see them in the VLC Codec Details menu.

How do I check what is the correct aspect ratio to display and what is the standard (NTSC or other)?

[tjkong]

Hello,

I have a vob file with dimensions 720:480, when I drag in in VLC latest version, it is played at 720:540.

The media info menu tells the correct size, but I am not able to play it at that size.

The screenshot is wrong too.

The file is played well in Media Player Classic and Gom Player. Their screenshots are correct too. [...]

There is your problem. Media Player Classic and Gom Player do not display DVD resolutions correctly, or any anamorphic video for that matter.

VLC Player does.

[...] So, VLC invents some interpolated horizontal lines to reach the 4:3 aspect ratio?[...]

No, VLC does not 'invent some interpolated horizontal lines'.


Your VOB is from a 4:3 (1.33:1) AR DVD. The video is stored in an NTSC 720x480, but DVD players (just like VLC Player) will correctly use the DAR (display aspect ratio) to resize it to the proper AR during playback instead of the NTSC or PAL SAR (storage aspect ratio). 720x540 is the proper display AR for that VOB. (720/540=1.33). Some other players will resize a 4:3 NTSC DVD to 640x480 to accomplish the same thing (640/480=1.33). Either is correct, but playing it at 720x480 is not (720/480=1.50).

Here's a relevant quote found via google in an application support section that explains the difference between a DVD's stored video resolution and the DAR during playback in a proper player...

The dimensions as defined by the Picture Standards for DVD videos are as follows:

Picture Standard | DVD Video Dimension
NTSC | 720 x 480 pixels
PAL | 720 x 576 pixels

DVD Video and Display Aspect Ratio
Both NTSC and PAL videos have aspect ratios that do not match aspect ratio for Television, HDTV or Cinemascope movies. Then how can you play back a DVD and see the video in the correct aspect ratio? Each DVD video has a Display Aspect Ratio, which instructs the player (DVD player or software program) what aspect ratio to use when playing back the video.

If DVD video is intended to be played on standard television, it has a Display Aspect Ratio of 4:3. Even though the dimensions of the DVD video are either 720 x 480 pixels or 720 x 576 pixels, it is displayed with an aspect ratio of 4:3. This lets DVDs be played with the correct aspect ratio, even though all their video is stored with standard dimensions.

^ That's exactly what VLC Player does, and fwiw so will PowerDVD or KMPlayer, but MPC and GOM Player will not.

How do I check what is the correct aspect ratio to display and what is the standard (NTSC or other)?

Dropping the VOB into GSpot will tell you the DAR:

GSpot Codec Information Appliance
http://www.headbands.com/gspot/

[fishstyc]

tjkong, I have a question that you might be able to answer

You say that VLC player correctly resizes the video on screen to honour the aspect ratio saved in the video-file. I am using LibVLC, and I would like to know how I can get this value, so that I can decode my video to a 'corrected' pixel plane. I know how I can get the pixel size of a video, but if I decode to this width and height the aspect ratio is wrong so when I set my callback functions and I call set_format, I would like to give other values that take the aspect ratio into account.

Do you know how I can do that, because the function libvlc_video_get_aspect_ratio doesn't return any value, and I can't find information in the structs describing the stream either...

Thanks