optimize webm cpu usage and memory consumption

[yocontra]

for discussion.

to start, i think switching to blobs will decrease cpu usage. also when messages are off-screen we can deallocate the blob via revokeObjectURL

cc @tec27 @ednapiranha

[operatorjen]

yeah as long as this will work for native ios and android and whatever else (that they can render w/ the same format) then i don't see why not.

[operatorjen]

contra, i talked to @tec27 about this - the best course of action is for you to have static html pages with 20 blobs on one page replaying in a loop and 20 data uris on another page replaying in a loop. check the perf and take a screenshot in both chrome canary and firefox nightly. we can determine what to do after if the difference is significant.

and then we can use these files to file bugs on both browsers.

[yocontra]

@tec27 Can you explain how you came to that idea?

[MylesBorins]

I have not done the perf test yet, but here are the fixtures you need

https://github.com/thealphanerd/webm-test

[operatorjen]

I filed a bugzilla bug for the webm base64 test case #32

[operatorjen]

We just did a test in the bug listed in #32 with changing it to blobs for 20 videos - the cpu change was not that much different. We checked the performance tools and nothing was happening with the main thread - so the suspicion is that it's a decoding issue on the browser core.