Update isSupported for browsers without MPEG-LA licensed codecs

[zemlanin]

Is your feature request related to a problem? Please describe.

#5528 has added playback support for codecs other than H.264 and H.265, but isSupported still checks for H.264

If a site that streams VP9/AV1 checks isSupported's return value before using HLS.js, this check would return false on Linux distros without H.264 codecs installed even though 1.5.0 should be able to play VP9/AV1

Describe the solution you'd like

Either:

• extend the list of codecs in isSupported check to include VP9/AV1/etc.
• remove the codec check from isSupported altogether

Additional context

Related PRs:

• MP4 Sample Description CODEC Parsing #5528
• Feature/mpeg ts hevc #5847

[robwalch]

Thanks for creating this issue @zemlanin,

What do you run instead of Hls.isSupported() to check for MSE support? On which platforms?

One option is not to call isSupported, instead letting HLS.js load the MVP and perform checks based on the Variant CODECS attribute values. The downside is if MediaSource is not present or the types you deliver are unsupported all that effort results in exceptions or an incompatible codecs error.

Another option is to have a function similar to isSupported tailored to the types you deliver. This could run even before loading hls.js on the page.

For v1.5 see #6006. I don't want to add every possible codec, but will take changes given specific device or platform specifications. Ideally this will be kept to a very short list of the most widely supported codecs required for compatibility.

• Expand isSupported check to allow alternative codecs #6006

[zemlanin]

What do you run instead of Hls.isSupported() to check for MSE support? On which platforms?

We're still using it — AV1 encoding and streaming are WIP — on web (starting with Safari 14), Tizen (5.0+), and webOS (4.0+)

[robwalch]

I'll move the MediaSource/SourceBuffer half of the check out into an isMSESupported helper. Apps that need to can perform isTypeSupported checks after calling isMSESupported.

We're still using it — AV1 encoding and streaming are WIP — on web (starting with Safari 14), Tizen (5.0+), and webOS (4.0+)

A list of devices that do not support AVC, and what is used primarily on these platforms would be useful for #6006. I'd like to scale back the number of things we check, and add isMSESupported to address both sides of what we discussed.

done! #6006

[zemlanin]

AFAIK, most of our platforms support AVC, and only Firefox on Linux (and *BSD?) might not (depending on pre-installed packages)