What exactly is wrong about screenshots from hd-video?

[Zborik]

Hello,
I'm new to spriting and ripping. I want to make a decent Scott Pilgrim spritesheet. The game's for PS3, so no ripping possibility I assume. However there are some youtube videos in 720p(e.g. this one: http://www.youtube.com/watch?v=hwujcAzrjUM) and I wondered why you can't make some screenshots and cut the sprites you need out? Is the resolution not good enough? Are the colors changed?

I'd probably even make screenshots and re-color the pics with an original palette if necessary, but of course I'd appreciate saving the time.

[Dazz]

The sprites are stretched, and indeed, colours altered. Even if they are at perfect size, and the colours weren't altered, they would still be compressed due to the way in which videos work.
It's the same as saving a sprite sheet from this site as a jpeg.



This is saved with 0 image compression, just like the sheets on this site.
This is taken from that video, and blown up a bit, but keeping the aspect ratio.

See how it's completely messed up?



Dare to compare, the left, the sprite ripped directly, the right, ripped from the video.

We don't not accept the sheets because we're stingey assholes who don't want more content on the site, we do it because it lacks quality standards. And if we accepted sheets like this, the site would be infested with useless sheets.

[TomGuycott]

Another problem (which admittedly might happen LESS in HD video than in lower quality) is that sometimes you miss out on frames or certain effects, for whatever reason, don't appear in the video. This is an example I'm aware of:





In this video, the villain transforms into the boss form, and the video cuts out 80-90% of what was a much smoother transitional animation because of it being a higher speed flickering effect. So in addition to the aforementioned plummeting in quality and sizing, you also call into question whether or not you're even getting complete animations.

[Raccoon Sam]

Yeah, but if you manage to find an absolutely raw, uncompressed 60fps video, then maybe.