Significant distortion and noise for highly tonal signals
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- Dominant language
- C
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Description
Hello,
With OPUS 1.3.1, significant noise is present when encoding/decoding highly tonal signals.
Attached is an image of a 1 kHz sine tone encoded and decoded via "./opus_demo audio 48000 1 76800 -framesize 5 -max_payload 48 input.raw output.raw"
It looks like the comb postfilter amplifies the noise at multiples of the fundamental frequency.
The noise is audible in this configuration. Are there some parameters to tune to reduce the noise?
Thanks in advance!
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Research direction
Reproduce the report with the provided ./opus_demo command, a 1 kHz sine tone, and the stated 48 kHz, mono, 76800 bitrate, 5 ms frame-size, and 48-byte payload settings. Investigate the suspected comb postfilter behavior and determine whether a parameter or code change can reduce the audible noise; done means the cause and a reproducible mitigation are established.
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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
- 35/100