1263836 - [META] Introduce struct that encapsulates media format MIMEtype, codecs, and DecoderDoctorDiagnostics

Status: NEW

(Core :: Audio/Video: Playback, task, P3)

Description

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Spawned from bug 1248507 comment 29 by :jya, in the context of DecoderDoctorDiagnostics being passed as parameters through many methods:
"""
This is starting to look very messy and exacerbate and existing problem when it comes to passing arguments to either the DecoderTraits utility or creating a MediaDataDecoder.

We have two cases:
1- Passing the mimetype as used with canPlayType which is an extended mimetype for the container along side optional codecs.
2- Passing the mimetype to create the decoder. This mimetype is different to the one above in that it refers to the codec itself.

Now depending on the method, sometimes it take a char*, sometimes a nsACString&, something a nsCString&, sometimes an optional string.

And now we're adding one extra parameter.

It would be much better to create a new parameter type that could be extended in the future.
This parameter would allow to pass either type of mimetype, a pointer to the diagnostic structure etc.

It would be complete enough to handle all the current uses and could be universally shared between the media client (either the HTMLMediaElement or the MediaFormatReader) and the end MediaDataDecoder.
"""

Comment 1

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

To the eventual implementer: There's a lot of information about MIME types&subtypes in bug 1230353 (thank you Jean-Yves).

Comment 2

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Bug 1281632 may make this one a bit easier to implement?

Comment 3

[Anthony Jones (:ajones, :kentuckyfriedtakahe, :k17e)]

Mass change P2 -> P3

Comment 4

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Making this bug a META bug, the implementation will be covered by several linked bugs