Hi Tony,
can you please add a custom method beside the “Original Pixel Type”, “Square Pixel”, “Letterbox/Pillarbox” or “Crop to Fill”?
Here is the problem:
Some source video is non-square pixel aspect, like PAL 16:9, which comes in 720x576y resolution but needs to be stretched to a 16:9 format for a square pixel result. In some cases the original pixel aspect ratio might also not be set correctly, resulting in either cropping away important pixel parts or having a black pillar box left/right from the deformed image.
PAL 720x576y is 0.9375 : 1 pixel aspect ratio in 4:3 format
(unstretched 768x576y, so 720/768 = 0.9375)
PALplus 720x576y is 0.703125 : 1 pixel aspect ration in 16:9 format
(unstretched 1024x576y, so 720/1024 = 0.703125)
I am currently unable to process these videos directly, its simply impossible. I get either cropped top/bottom or pillarbox results.
It would be helpful to have you implement a simple “Stretch to fit” method, overriding pixel aspect ratio and simply scale source width to target width and source height to target height. This would solve the problem.
If that is not possible in the AI models, I might be forced to scale beyond UHD resolution (3840x3072y from 720x576y) and scale y down afterwards from 3072 to 2160 - which seems like a big waste of time and disk space, as I would need more than double the space for processing.
I know we can do correct the scale to true square pixel aspect and e.g. 1024x576y all prior to importing it into VideoAI, but each step could cause an extra iteration if not done uncompressed/lossless plus it would create additional artefacts in the process.
First bug:
Beside that there seem to be a bug anyway, as it crops away pixels on left and right without a need for it, resulting in a stretched pixel aspect again (which is wrong too):
In all pictures below look at the lower right corner and compare the results. Have the settings in right tab in mind. That does not make sense IMHO.
Target 3840x3072y original pixel aspect
Source 720x576y
Target 3840x3072y square pixel, letterbox/pillarbox
Target 3840x3072y square pixel, crop to fill
As long as I switch between “letterbox/pillarbox” and “crop to fill”, I get this preview, which seems correct. As soon as I render, the image is cut off as seen in all above examples (except for the source)
Second bug:
The size of the cropping handles does not match the size of the image. When you look on the left side, there are obviously pixels LEFT from the handle, but the handle is already set to 0 pixels. The scaling of the two is apparently off in terms of “not in sync”.
Third bug:
What honestly annoys me the most is the fact that the two images source/target (left/right side of the split bar) are not in sync. Often the right image moves while moving the split bar. That should simply completey match and stay stuck in place, of if you move one, the other should move accordingly.
Best option would be to stretch in case the source image to exactly match the target image. You may also use a nearest neighbor scaling on the source image to reflect on the poor source resolution (optionally).
Regards,
Axel
