I am looking for 3 things, each of which helps me increasingly towards my goal.

I want to put webm related in the side of a video or a stream, preferably as a perfect loop, and preferably without sound. I also want to do that with this webm >>>/wsg/3213551

I have attempted to do so already using Vegas 15, however, it doesn't admit webm format, so I used a free online webm-to-mp4 converter, editing the perfect loop using vegas, then rendered it to a .wmv using the highest settings available. After doing so, I realised the quality was terrible. Athough admittedly, the drop in quality was more so the mp4 to wmv part rather than the webm to mp4

1. From what anime/source does this come from? Alternatively from where does >>>/wsg/3213551 come from?

2. Are there better render settings on Vegas 15 to turn an mp4 to some format with better quality?

3. Is there any video editing software (not necessarily free) that admits and edits webm, hence skipping the middle step?