[tbb-dev] Media Codecs and the canPlayType/Media Capabilities API

[Tom Ritter]

On Wed, 6 Feb 2019 at 11:33, Tom Ritter <tom at ritter.vg> wrote:
> I suppose step one is to make a fingerprinting test that identifies
> what codecs you can handle...

I started work on this; but got some tribal knowledge from jya and others:
https://mozilla.logbot.info/media/20190206#c15931239-c15932085

Summarizing:
 - Only AAC, h264, and vp9 may give different reports

- AAC Mac - always there
- AAC Windows - May not be present on Windows N or KN
- AAC Linux - Missing if ffmpeg is missing

- h264 Mac - always there. Almost always accelerated, except
"hackintosh with nvidia cards and the mac pro 2013 trashcan"
- h264 Windows - always there; but not hardware accelerated if your
GPU card is blocklisted
- h264 Linux - Missing if ffmpeg is missing or not compiled with h264
support. never hardware accelerated.

- vp9 Mac - Always present
- vp9 Windows - Always present, but may or may not be hardware
accelerated. If not hardware accelerated, you can roughly benchmark
the machine using different video size inputs and the resulting output
of the smooth value
- vp9 Linux - Always present

So by hardcoding a response for hardware acceleration and the smooth
value; the only data we would leak would be information about your
ffmpeg install (or lack thereof) on Linux; and on Windows whether
you're missing the Media Framework (which is a good indicator of being
a European user AIUI).

-tom