Add support for Opus codec for improve voice-chat quality

[bkdwt]

Suggestion

Could you guys add support for the Opus codec? Opus codec support was added to TF2 a few years ago, and since then, the voice-chat quality has become much clearer, sharper and overall better. The audio quality in L4D2 is poor compared to TF2. This addition would be very much appreciated!

Thanks in advance!

https://opus-codec.org/
https://wiki.xiph.org/Opus_Recommended_Settings

[Tsuey]

Requires code changes (which Valve is more averse to for L4D2) but yeah, we'll make sure it's on our list. Appreciate the issue and links!