xiph / xiph/opus

Unexpected continuous noise when combining NoLACE with DTX

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Dominant language
C
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Description

Are NoLACE and DTX supposed to be usable together? I have observed that when turning on NoLACE, as soon as the stream switches to DTX mode, the decoded 0/1-byte packets start generating some noise which sounds like it could be the tail of the last word that was said.

Here's an example of this noise (normalized to make it obvious): opus dtx+nolace.zip

I suppose we could simply mute the output of the decoder if we know we're in DTX mode, but this smells like a bug to me.

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Research direction

Start by reproducing the report with the attached opus dtx+nolace.zip and inspect the decoder path used when NoLACE is combined with DTX. Determine why decoded 0/1-byte packets produce continuous noise; done means the combination no longer emits that noise and the behavior is covered by a regression test.

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Assessment

Tech stack
c
Domain
audio-video-rtc
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
30/100

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