Audio buffer views

[messmerd]

Adds two non-owning views for audio buffers: InterleavedBufferView and PlanarBufferView.

The channel count can be specified at either compile-time or runtime. Specifying at compile-time provides both performance and space optimizations. The way this works is the same as std::span except this uses the new DynamicChannelCount constant rather than std::dynamic_extent.

These are not used for anything yet, but will be used in #7459 and #7858.

[sakertooth]

Overall nice job, the transition to use this PR in #7858 was almost seamless.

[sakertooth]

The PR is fine with me, you can merge on your own terms.

[sakertooth]

Oh yeah, I also thought about something: Do we care for sample rate support?

[messmerd]

Oh yeah, I also thought about something: Do we care for sample rate support?

Maybe that could be handled separately, at least for now

[sakertooth]

Maybe that could be handled separately, at least for now

I am thinking of a situation where we have an audio source (e.g., Sample) writing to a buffer at a certain sample rate, and that knowledge is needed in a class that has to resample that audio to another rate. This differs from the current approach to resampling, where the resampler happens internally, so inside Sample::play, Sf2Instrument::renderFrames, etc.

If I need this for some reason though I can add it, I am just going through a couple more designs for the PR.

[messmerd]

I think I'd prefer if the buffer views didn't store that information, since most places where I use them the sample rate isn't needed, so it would just waste space.

[sakertooth]

I think I'd prefer if the buffer views didn't store that information, since most places where I use them the sample rate isn't needed, so it would just waste space.

Yeah I was thinking about this. Most of the time it won't be needed so it should be handled separately on a case by case basis.