[Bug Report] Previews for vertical videos are unnecessarily large

[JadedMagician]

Describe the bug
When video previews for scenes are generated, Stash appears to shrink the input video's width down to 640px for the preview, without taking into account the aspect ratio. So a preview for a 16:9 video is 640x360, while a 4:3 video with the same vertical resolution as the 16:9 video will get a 640x480 preview, resulting in a higher vertical resolution. For vertical 9:16 videos, the preview is 640x1138, practically HD, and with a significantly higher file size on average than the 16:9 previews! Looking through my stash/generated/screenshots folder, most of the 16:9 previews are under 1MB, whereas most of the 9:16 previews are near or over 2MB, with some even going over 3MB. The same is true of the scrubber sprite images; sprites for 16:9 videos are 1440x810 and an average filesize of 500kb, while 9:16 video sprites are 1440x2556 with an average file size of 1.3MB.

If a user has scenes primarily from professional studios in their stash, this isn't much of an issue; but I have a large amount of content from OnlyFans and PornHub, where vertical videos are common, and these larger previews really balloon the size of my generated folder. Also, when actually viewing stash in a browser, with the scene cards zoomed to the largest level, the previews appear to cap out at 360px vertically, so the 640x1138 preview resolution is completely impractical.

As a solution, would it be possible to instead set the generator to give all previews a vertical resolution of 360px instead of a horizontal resolution of 640px, or perhaps make it so that stash checks the aspect ratio during generation so that it knows to give portrait videos reasonably sized previews and scrubber sprites?

Screenshots
Example screenshots from generated preview videos showing the disparity in size:

Stash Version
v0.25.1
Build hash:
bf7cb78
Build time:
2024-03-13 03:30:08

Desktop

• OS: Linux
• Browser: Chrome