There's something wrong when trying to crop a 16:9 frame from anamoprhic 4:3 PAL DVD

Trying to crop a 16:9 frame from a 4:3 PAL DVD (720x576 DAR 4:3) fails, because there seems to be something wrong with the underlying math.

That’s the source:


Here comes the crop settings:


With square pixels and a given width of 768 pixels (suggested by the GUI), I would expect to see a width of 432 pixels to match 16:9, but it shows 406, which gives an aspect ratio of 1,892 (instead of 1.778).


If you know a way how to upscale this properly to 1280x720 or 1920x1080 to match the desired frame without stretching or further cropping, let me know, please.

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I would suggest you open a ticket with the support team so that they can investigate and try to replicate the issue?

Thank you.

Was thinking tickets can only by opened by staff members and that everybody who has access to a PAL DVD can replicate the issue based on my screenshots.

Are you a staff member?

How can I open a ticket?

You can open a ticket via the chat function on the website or by emailing, and it will go to the support team.

Thank you.

I wonder how to decide in the future when to post a bug report and when to contact support directly?

You are more than welcome to do both as some users have helped solve issues before when the support team is not in the office. The support team is generally available 9am-630pm Central Standard Time in the US Monday-Friday.

Thank you.

After posting my request, I received already an answer from Tony Martinez. He was able to see where the issue is happening and has sent it to the dev team for a fix hoping that it can be resolved in a patch soon, which is very good, because there is no reasonable workaround except of re-encoding for frame dimensions after export.

I really appreciate the fast reaction from both of you.

Thanks again.


This issue obviously has been flagged as resolved, but it is not resolved with 4.1.2.

I see exactly the same problem as before, unfortunately.

The only obvious change to the GUI related to aspect ration is that the know acronym SAR (Sample Aspect Ratio, according to MPEG-2 spec: SO/IEC 13818-2) has been replace with PAR, which is unknown in the context of ffpmeg/ffprobe, or does anybody know an ffmpeg command line where you can specify “PAR”?

What additional information do you need to see the problem?

Yes, it appears that the crop (or maybe just the calculation) is occuring before the conversion to square pixels, so the widescreen crop is being stretched horizontal by the conversion, making it a bit wider than it should be relative to the vertical (768x406).

If the crop (calculation) was done after the conversion to square pixels you would have the proper 16:9 ratio (768x432).

Thank you for confirming. Your explanation sounds very plausible to me. The frame is displayed on-screen with proper transformation to 4:3, but the crop ( read: the yellow rectangle and the displayed values for X,Y, W, H) seems to refer to anamorphic pixels. Beside of creating undesired aspect ratio, this has also some other negative side effects, one of those:

This is a 16:9 image centered in a 4:3 frame with 1440x1080 pixels, with crop set to 16:9. It looks as expected:

That’s exactly the same frame converted to PAL DVD. The crop says 16:9, but in fact it isn’t:

Another side effect is that the function Fit truncates the frame:

This is the crop (720,432,0,72):

That’s what Fit shows, which isn’t what you will get when exporting:

100% preview looks as epected:

Because I cannot share the original media I’m working on, I created a set of test clips and attached them below. Perhaps, it can help reproducing what my screenshots show.

Topaz Anamorphic Crop (47.9 MB)

Hello everyone,

We’ve made some changes to the crop function for non-square PAR videos in the latest Video AI Beta release. Here’s a link to download:

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Thank you Tony,

I will have a look. Is there a chance to install two different versions side by side?

Beta builds can be installed alongside any other main release. You’ll see a new app icon and start menu item labelled “Topaz Video AI BETA”

Thanks. Installing the beta worked even while the release was rendering. Lovely.

Feedback follows, but might take a while.

I’m back on this, earlier than expected, because I don’t see improvements in the context of cropping anamorphic media, unfortunately.

What exactly is supposed to be fixed?

Widescreen videos (1.21 PAR for NTSC) should now display the full size of the video frame in the in-app player.

In the current version, crop dimension values are set based on the SAR, but we are working on having the Crop function match the “Original Pixel Type/Square Pixel” selection in the Video Input Options panel.

I see. I stopped testing after I saw that the aspect ratio of the crop rectangle is still wrong. I’m on PAL DVD. Without pixel peeping, I can confirm that the cropped frame adjusted with the crop rectangle is displayed as expected in the in-app player, and, when visually cropping to 16:9 centered, the resulting frame dimensions in square pixels are correct. Those changes make the function usable for my purposes.

Correctly displayed crop presets and the crop button not vanishing all existing settings would be nice to have.

Off topic: The GUI of the beta sticks in full screen mode, cannot be moved and the usual controls to shrink and close the window up right are missing. I couldn’t find a function to revert to normal. Is there any?

Re: window size, we previously had an issue where maximizing the window would not account for the height of the Windows-native title bar. Beta fixes part of the issue but caused some users to have a window size that goes beyond the size of the display.

This will be fixed in 4.2.1 main release on Tuesday. I’ve also added you to the beta testers group for access to that forum section.

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