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Having trouble with aspect ratio

Started by claine1964, October 02, 2022, 06:04:32 PM

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claine1964

Hi everyone! I just started using the program to clean up some avi files. A couple of questions: As you can see in the image the aspect ratio is not the same as the input file which is 4:3 from an old VHS copy. How can I correct this? Also - the input file is an avi file from the DVD but in order to edit it, I had to change the video output to an mp4. Help would be much appreciated!

Thanks!



claine1964


eumagga0x2a

Quote from: claine1964 on October 02, 2022, 06:04:32 PMAs you can see in the image the aspect ratio is not the same as the input file which is 4:3 from an old VHS copy. How can I correct this?

Please post (or send by personal message if CleanTalk prevents you from posting it) the output of MediaInfo tool for the original source video. The file loaded in Avidemux on the screenshot is a MPEG program stream (MPEG-PS) according to filename extension ".VOB". In doubt, please load the file, close Avidemux and provide admlog.txt from %localappdata%\avidemux\ directory.

It is difficult to recommend anything without knowing what kind of input you are dealing with.

Blues

#3
I think this is one of those D formats, I had some analogue satellite records like this. It had lower resolution horizontally to reduce bandwidth, the picture was stretched during playback. You can easily do the same, just specify the correct format 4:3 in container and leave the video aspect as it is.
Basically, the DVD recorder was set to this format when recording from VHS to create smaller VOB. You cannot undo it, you need to re-record it from VHS and use different format.

alexstorm

This copy is the wrong Aspect Ratio.  To fix it, use Video out to Mpeg4 AVC (x.253).  Filters Crop out the bottom black bar. Then Filters swsResizer.  Unclick upper left checkbox for Lock Aspect Ratio and do a resize to 640 x 480.  I like using Resize Method Lanczos-3.  I think it's nicer and less blury compared to the default setting Bilinear.  Video Config - usually on this size video something like 800 kbit/s Single pass would be enough.

Ideally, when you first copy video fron VHS several steps can be done to get the best quality.

1) If the original media is made for film, then you can check that it probably has 3:2 pull down.  This can be removed with Filters / Interlacing / Decomb Telecide, check blend. 

2) Then Filters / Transform / Resample FPS to 23.976 and check the blend box again.

2) If the original is TV broadcast, you can skip steps 1 and 2 and try Libawler Deinterlacers check autolevel.  See which option looks best to remove interlace lines.

3) Then go to Filters / Transform / Crop to remove any black bars.

4) 4:3 TV shows then need Filters / Transform / swsResizer - uncheck Lock Aspect ratio and change Width to 640 and height to 480.

5) If the original is a movie and there were top and bottom black bars, that you removed with crop, you have to leave width at 640 and change height to match the original movie Aspect ratio.  640 / 1.85 = 346 height (nearest even number),   or  640 / 2.45 = 272 height,   or 640 / 2.39 = 268.  you might have an odd one 640 / 1.67 = 384.

The filters need to be in this order.  The improved quality will not work if you mix up the order.  Most people never bother doing all this for VHS tapes and just go, instead to find a higher quality copy.

Hope that helps.