Consider moving codec parsers to separate crate

[knopp]

Hi,

it would be very useful to have access to codec parsers separately from the main crate.

I'm wondering if splitting the crate in two would be worth considering?

[dwlsalmeida]

I wonder if a feature to just build the parsers wouldn't suffice?

[knopp]

I forked the crate for the time being as I'm not sure my idea for codec parsers crate and cros-codecs are aligned, i.e. I'd want to add mpeg2 and mpeg4 parsers in future which I feel has very little value for cros-codecs. So I'm going to close the issue for now.

[Gnurou]

Hi - before forking and making things maybe difficult to merge back, I'd like to make sure we have discussed all options.

First, I have nothing against merging mpeg2 and mpeg4 parsers to cros-codecs - as long as they are built behind a feature (like all codecs should be), this should not cause any issue.

As for disabling the non-parsers parts of this case, as @dwlsalmeida said, we could put this behind a feature. Actually, if we put every backend behind a feature, we should be able to achieve that exact result.

There is also the fact that IIUC the Rust compiler will just link the code from cros-codecs that your own crate is using, and thus won't include any decoder or encoder stuff unless your code explicitly references it.

Can you elaborate on your use-case for these parsers?