1129140 - Report supported codecs in about:support

Status: NEW

(Toolkit :: General, defect, P5)

Description

[Ralph Giles (:rillian)]

Since the codecs and containers supported by the HTML media elements vary from platform to platform, it would be helpful for troubleshooting to have a summary on the about:support page.

We can just use canPlayType() with a list of specific media types to determine this.

Comment 1

[Ralph Giles (:rillian)]

quoth :cpearce on irc:

We can detect whether a windows machine has the 
codecs installed, by testing 
HTMLMediaElement.canPlayType("video/mp4; codecs=\"avc1.42001E, 
mp4a.40.2\"") != "". The codecs strings have to be there for 
that to work.  So we should report that in about:support.

Comment 2

[Justin Dolske [:Dolske]]

Seems reasonable. What specific types do you want to test for (beyond mp4)?

Also, how do we want to report the result? The API returns "maybe" and "probably", which is fine for web developers but showing those strings to users is not confidence-inspiring. :) Should we map "probably" to "yes", and perhaps "maybe" too?

Alternatively... Benjamin, is this something that would be a good fit for the self-support API? Reporting it on about:support may still be useful, but more proactively helping the user fix a potential problem (bug 1127111) would be ideal.

Comment 3

[Chris Pearce [:cpearce (Not reading bugmail)]]

(In reply to Justin Dolske [:Dolske] from comment #2)
> Seems reasonable. What specific types do you want to test for (beyond mp4)?

I think MP4 is the main one, since we rely on using the decoders installed on the system, and they're not always installed there. Whereas other media types (Ogg, WebM) we know they'll work unless the user prefs them off, so it seems lower value in reporting them.

Basically, we want users on Windows Vista and on Enterprise versions of Windows to have a way to determine that they can't play MP4 because they don't have the requisite service packs installed. We can determine whether the decoders are available by looking in the registry, and this implies the service pack is not installed.

> Also, how do we want to report the result? The API returns "maybe" and
> "probably", which is fine for web developers but showing those strings to
> users is not confidence-inspiring. :) Should we map "probably" to "yes", and
> perhaps "maybe" too?

Converting non-empty string results to "yes" is adequate.

Comment 4

[Benjamin Smedberg]

There are two questions here: one is whether we can show this in about:support, and the answer to that is pretty much always "yes".

The other is whether we should expose this via the support API which goes to SUMO/input. I don't see why we shouldn't, but we don't need to (since the site can use .canPlayType directly). So unless they specifically ask for it I'd like to avoid it, just to minimize risk.