>>16335008anon........
>>16335072well researched it a bit and
>Today we added support for WebM files on 4chan’s image boards.While WebM is technically a video file format, it offers many advantages over animated GIFs—namely superior image quality, support for more than 256 colors, and reduced file size. Its main disadvantage is browser compatibility, however 86% of 4chan’s visits come from browsers that include full or partial support for WebM, and plug-ins are available for those that don’t (like Internet Explorer and Safari).
We decided to disallow WebM files with sound for a few reasons, but mainly because it’s our intention to provide the site with better animated images, and not true video support. To that end, we only accept WebM files with one video stream and no audio streams, that are shorter than 120 seconds long, no larger than 2048x2048 pixels, and less than 3 MB in size.
We’re eager to see how 4chan’s users will adopt WebM, and have posted this short guide on encoding them to ease adoption. Many thanks to desuwa for both championing and implementing this feature.
>—mootTLDR: basically this an image board, not video board and you don't want to hear the moans of sonic at 160 decibel