Really bad voice quality after latest upgrade of opus-rs

[Object905]

In webrtc call it's unbearable. Worked fine on previous version.

[Object905]

Remedied by fixing patch version to "=0.3.30" for now.

[shenjinti]

Sorry for that. :(

[Object905]

No worries, thanks for your work! Glad to be an early tester)

[shenjinti]

Thanks, Could you share a flow we can run locally.

[Object905]

I'll try to make a repro. It's a bit harder because of multiple services involved.

[Object905]

Just round-tripping wav seems to be enough. I don't know it it's exact repro of what happens in call, but audio artifacts are similar.

repro.wav.gz
repro_48k.wav.gz
Both repro.wav (8kHZ) and repro_48.wav are scrambled.

use audio_codec::{
    create_opus_decoder, create_opus_encoder,
    opus::OpusApplication,
};
use hound::{WavReader, WavWriter, WavSpec, SampleFormat};

fn main() {
    let home = std::env::var("HOME").unwrap();
    let mut reader = WavReader::open(format!("{home}/repro.wav")).unwrap();
    let spec = reader.spec();
    println!("Input: {} Hz, {} ch, {:?}", spec.sample_rate, spec.channels, spec.sample_format);

    let samples: Vec<i16> = reader.samples::<i16>().map(|s| s.unwrap()).collect();

    let sample_rate = spec.sample_rate;
    let channels = spec.channels as usize;

    // 20ms frame: sample_rate / 50 samples per channel, interleaved
    let frame_samples = (sample_rate as usize / 50) * channels;

    let mut encoder = create_opus_encoder(sample_rate, channels as u16, OpusApplication::Voip);
    let mut decoder = create_opus_decoder(sample_rate, channels as u16);

    let mut decoded_all: Vec<i16> = Vec::with_capacity(samples.len());
    let mut total_encoded_bytes = 0usize;

    for chunk in samples.chunks(frame_samples) {
        let frame: Vec<i16> = if chunk.len() == frame_samples {
            chunk.to_vec()
        } else {
            let mut padded = chunk.to_vec();
            padded.resize(frame_samples, 0);
            padded
        };

        let encoded = encoder.encode(&frame);
        total_encoded_bytes += encoded.len();
        let decoded = decoder.decode(&encoded);
        decoded_all.extend_from_slice(&decoded[..frame_samples.min(decoded.len())]);
    }

    decoded_all.truncate(samples.len());

    let out_spec = WavSpec {
        channels: spec.channels,
        sample_rate: spec.sample_rate,
        bits_per_sample: 16,
        sample_format: SampleFormat::Int,
    };

    let out_path = format!("{home}/repro_opus_rt.wav");
    let mut writer = WavWriter::create(&out_path, out_spec).unwrap();
    for s in &decoded_all {
        writer.write_sample(*s).unwrap();
    }
    writer.finalize().unwrap();

    println!("Encoded {} frames → {} bytes total", samples.len() / frame_samples, total_encoded_bytes);
    println!("Decoded {} samples → {}", decoded_all.len(), out_path);
}

[Object905]

@shenjinti with latest git version it's fixed. Thanks!

But there seems to be typo in crates.io release version. Should It be 0.3.32?

[Object905]

With 0.3.32 in active call I get AsrProcessor: empty PCM samples debug logs with jumpy audio. Perhaps it should be fixed there, but maybe there is a new bug.

[shenjinti]

With 0.3.32 in active call I get AsrProcessor: empty PCM samples debug logs with jumpy audio. Perhaps it should be fixed there, but maybe there is a new bug.

Thanks, please try 0.3.33 again and show me the client useragent if there are any issues.

[Object905]

Its better after upgrade, at least It's audible, but still bad because of cracking sounds 😢

[shenjinti]

Its better after upgrade, at least It's audible, but still bad because of cracking sounds 😢

Which client is tested?

[Object905]

I'm using webrtc from browser in firefox. What info might be helpful from that? SDP? active-call logs?
I'll be able to provide needed info tomorrow.

[shenjinti]

Is firefox <--> active-call via Opus codec?

[Object905]

Yes. I've tested with chrome too now, just in case - same issue.
And I've tested with MicroSIP with opus - same audio artifacts.

With g722/g711 it's working fine, no cracking.

[Object905]

FYI Tested again with latest version. Problem remains, lots of loud high pitched crackling sounds.