xiph / xiph/opus

DTX noise with 60ms framesize

Open
#442 7 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Dominant language
C
Stars
3.3k
Forks
808
PR merge metrics
No merged PRs in 30d

Description

Very similar to this issue:

When decoding audio generated with 60ms packet time, there is a distinct clicking noise. This is most certainly related to the 400ms DTX interval, maybe it could be attenuated more? On iOS devices playing out the speaker, the clicking sound is very noticeable. I don't here the sound with the default 20ms packet time, but it could be there.

A very short example file (uncompress it first):
example.raw.zip

Encode with our settings (CBR, DTX, 60ms framesize):

$ ./opus_demo -e voip 48000 1 32000 -cbr -dtx -inbandfec -framesize 60 -complexity 9 example.raw example.enc

Decode it:

$ ./opus_demo -d 48000 1 example.enc example.dec

The resulting audio will contain the noise. The volume of it is very low, but it is there amongst the background noise.

Thanks!

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by extracting example.raw.zip and reproducing the click with the provided opus_demo encode and decode commands using 60ms frames and DTX. Read issue #351 for related context; done means the audible artifact is eliminated or reduced for the supplied example without breaking the reported 60ms DTX behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
c
Domain
audio-video-rtc
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
38/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.