Aspect Ratio Looks Different After Encoding VHS Source

[jrodefeld]

Hi everyone,

I'm sure many of you know about the other threads I have started relating to an ongoing project to capture VHS to put on DVDs. Anyway, I have a very specific problem that I don't really understand and I am hoping someone can help me. I have captured video in Huffyuv AVI through the Panasonic AG-1970P source and Cypress TBC-100 Time Base Corrector with S-Video.

However, once I encode the video to Mpeg 2 the aspect ratio changes and the video appears vertically stretched a bit. I am setting it to encode with the aspect ratio of 4:3, which I assume is what VHS is, yet the video is distorted. I really prefer the original image and dimensions but I can't seem to preserve it once it is run through an encoder.

Is it possible that some VHS is not 4:3? Since I can only encode with 16:9 or 4:3 selected, what are my options to preserve the original dimensions of the footage? Should I encode with 16:9 but add borders on the left and right sides?

Here is what I am talking about:

http://imageshack.us/photo/my-images/829/vlcsnap2011070205h48m18.jpg/

This is from the original Huffyuv AVI of the captured footage

http://imageshack.us/photo/my-images/36/vlcsnap2011070205h48m40.jpg/

And this is the same frame from the encoded Mpeg 2 file



Can someone explain to me why the encoded video is stretched and has a different aspect ratio than the source? How do I fix this?

Thanks.

[poisondeathray]

You took screenshots with VLC.

Your Huffy AVI video has no aspect ratio flags, thus is usually displayed as 1:1 in media players.

When you encode to MPEG2 and set the AR, a media player will "stretch" the content to the proper Display Aspect Ratio converting to square pixels when playing it back on a PC monitor

Notice the dimensions are 720x540 in that screenshot. 4/3 = 720/540 x 1/1

Look at the inner radius of the circle. Which looks more like a circle, which looks more like an oval ? Go to a frame that has a clearer picture of something like a tire or that life preserver

Some media players will display 4:3 content as 640x480 (which is also 4:3 when using square pixels)