Investigate performance of video uploading

[mikolalysenko]

We should figure out what is the fastest way to upload videos in WebGL and then make regl always take this path whenever possible. There are basically two functions:

1. gl.texImage2D
2. gl.texSubImage2D

We should make a benchmark for videos and try out both of them to see which is the fastest. Also we should modify the texture API to check if there is a way to short circuit all the argument parsing logic and upload directly so that we can do this as efficiently as possible.

[usefulthink]

Florian Bösch (@pyalot) did a lot of investigation into this: http://codeflow.org/issues/slow_video_to_texture/

Complete with benchmarks and historical data (a lot more information about this can be found in the linked issues).

[pyalot]

There's also by now a bunch of other video upload performance tests written by other people. The one I published is a bit dated.

[jwerle]

@pyalot where can we see these newer performance tests ?

[pyalot]

I've found one there: http://krpano.com/ios/bugs/ios8-webgl-video-performance/

[jwerle]

ah, klaus's page ! we've seen this thanks :]

[jwerle]

Adding known and relevant tickets with their up-to-date status for this issue on various platforms.

NEW: Chromium#612542

TODO	RESOLVED	TOTAL
5	6	11

Chromium

• [ ] 612542
• [ ] 91208
• [ ] 349871
• [x] 443151
• ~436538~

Firefox

• [x] ~978828~
• [x] ~814524~
• [x] ~880114~
• [x] ~1060121~

Webkit

• [x] ~129626~

Internet Explorer

• [x] ~941984~