Bug Report: VTM unexpectedly handles (vertical) videos with rotation metadata (versions 18 and 19)

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oremavo
Posts: 2
Joined: 13 Aug 2022, 10:09

13 Aug 2022, 11:52

I'm having a few issues dealing with vertical video thumbnail generation with VTM 18 and 19

When VTM is generating thumbnails for a video that has the following feature:
-Vertical video that is actually stored in a horizontal format (video width is greater than height e.g. 1280x720 px) but the rotation metadata field is set ( to 90 or -90 degrees) to fix the orientation and display the video vertically

Example horizontal video with dimensions 1280x720 rotated via metadata to display vertically: https://bayfiles.com/S4P8Dd3aya/horizon ... tadata_mp4
Sample actual vertical video with dimensions 720x1280: https://bayfiles.com/h7Q6De3fyd/vertica ... 0x1280_mp4

In VTM 18:
While VTM successfully detects the video rotation and generates the thumbnails in a vertical format, it still makes an error in the following way:
In cases where a tile width is set to a value e.g. 200, VTM applies this value to the video width *before* the rotation (i.e. applies it to the height), when in fact it should apply it to the video's new width after the rotation to get the expected behavior (because the width and height values are switched after the rotation)

Example with tile width set to 200 and auto-height checked:
Result from VTM18 using horizontal video rotated via metadata (1280x720): https://files.catbox.moe/tphm3u.jpg (notice how the tile width is smaller than expected since the set width is actually being applied to the height, resulting in an overall smaller image. Also note the information fields above the thumbnails, the "resolution" field says 1280x720, while this is a technically correct since this is a horizontal video with rotation being done using metadata, I think the expected behavior is for VTM to show 720x1280)
Expected result from using an actual vertical video (720x1280): https://files.catbox.moe/4qvel7.jpg


In VTM 19:
The behavior here is different in that VTM completely ignores the video rotation in image thumbnail generation. However in case there is an animated tile present, then VTM will rotate only the animated tile but will keep the original width and height values (width greater than height) resulting in the animated thumbnail being stretched horizontally. VTM should switch the width and height value during rotation.

Example with an animated tile and tile width set to 200 and auto-height checked:
Result from VTM19 using horizontal video rotated via metadata(1280x720): https://files.catbox.moe/vsrzkd.webp (notice how the tile width is also smaller than expected similar to VTM18, and the animated tile is stretched)
Expected result from using an actual vertical video (720x1280): https://files.catbox.moe/ehj4yk.webp


I hope I explained this issue clearly enough.

Best regards
-Luke
Last edited by oremavo on 13 Aug 2022, 23:27, edited 4 times in total.
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admin
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Posts: 1373
Joined: 03 Jun 2014, 22:14

13 Aug 2022, 14:34

Hello,

Thank you for your findings, need to debug, but first 2 links are broken. Please check.
oremavo
Posts: 2
Joined: 13 Aug 2022, 10:09

13 Aug 2022, 23:05

admin wrote:
13 Aug 2022, 14:34
Hello,

Thank you for your findings, need to debug, but first 2 links are broken. Please check.
Sorry about that, I fixed the links they should be working now. Thank you for checking out this problem.
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admin
Site Admin
Posts: 1373
Joined: 03 Jun 2014, 22:14

18 Aug 2022, 21:34

Will try to fix in the next version of the app.

Meanwhile could you please provide more examples with different rotations?
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admin
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Posts: 1373
Joined: 03 Jun 2014, 22:14

25 Aug 2022, 09:48

Fixed in VTM 20.0.0.0.
Please check.
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