[Feature Request] Allow black/white frame detection to look for frames before the offset

[eliottmusk]

I use Icaros to make the thumbnails for .mov prores 4444 format, prores format is used a lot in video edition because this format has transparency or alpha, and black/white frame detection don't detect frames that is fully transparent, we need a "black/white/transparent frame detection" please implement it if possible. And I use the latest version of Icaros and of Win 10 x64, and File Explorer show huge thumbnail margins look:

If you scroll up and down several times the margins decrease the size:

How I can make this small margin of the last image the "default" one or is it a bug?

Thanks!

[clsid2]

Margins and layout are controlled by Explorer. Icaros is used for nothing more than generating a thumbnail image at request of Explorer. The issue is likely related to the wide AR and Explorer reserving space for images with different AR that may follow during the generation process. Once all files have been processed, it can re-align the images.

Transparency is not something that occurs in "normal" videos that 99% of users have, so I would advice Xanashi against wasting performance detecting such frames in a default configuration. A fully transparent frame is a rare oddity.

[eliottmusk]

For who work with video edition, a fully transparent frame is common as much as black or white, maybe even more common, prores 4444 with alpha is a industry standard, so is very, very common, anyone in this industry work with this format often and I use Icaros mainly for this format, I think many Icaros users work with video edition and need thumbnails to preview the materials easily.

[eliottmusk]

If margin is not related with Icaros, has some workaround? Something can be implemented to fix it?

[Xanashi]

Controlling how the margins work in File Explorer is entirely up to Microsoft. Nothing I can do on my end.

About the transparent frame detection, wouldn't the transparent pixels usually be all black or white as well?
(e.g. rgba: 0,0,0,0 is a fully transparent black pixel). And as such be detected by Icaros?
Could you send me a sample file where this issue occurs?

@clsid2 I'll make sure to keep performance in mind, and if a feature such as this would impact speed, I'll make sure to make it optional. Thanks for quick answer on the Explorer margins!

[eliottmusk]

Sad about the margins, but I understand, thanks,

Sample, Thumbnail offset 25%, threshold 8%:

MF - Neon VFX 14.zip

[Xanashi]

In this particular sample, the reason why Icaros doesn't find a better frame is because the only "good" frames are at the very beginning of the file, and Icaros only searches for better frames forward from the current offset.

If you for example set the the offset to 0 or 3%, this file will produce a better frame. (just remember to refresh the thumbnail by dropping the file onto the "Thumbnailing" page, so it doesn't use the a cached version of the thumbnail).

[eliottmusk]

Thanks the attention of both friends. I get, the problem of set 0-3% is that this make bad thumbnails for a lot of other videos, overall 25% is the ideal value really, I tried a lot, you know. And if implement a little change that if Icaros find a empty frame forward from the current offset, then search backward from the current offset? This would be a optional checkbox.