Decoding in real-time becomes gaped

[OnkelTem]

My question may look a little unrelated to the usage of this particular library.

Basically, I receive an Opus stream from the internet, decode it with prism.opus.Decoder, get PCM packets and stream them forward to the speakers:

    events.onAudioData(async ({ event, opusInfo, getStream }) => {
        // A stream with Opus packets
        const stream = getStream(undefined, false);

        const frameSize = (opusInfo.inputSampleRate * opusInfo.frameSize) / 1000;
        const opusOpt = {
          rate: opusInfo.inputSampleRate,
          channels: opusInfo.channels,
          frameSize,
        };
        const opusDecoder = new prism.opus.Decoder(opusOpt);

        const normalizer = new NormalizeRateStream({
          bufferLengthMs: 2 * 1000,
          packetLengthMs: event.packet_duration,
        });

        const speaker = new Speaker({
          channels: opusInfo.channels,
          bitDepth: 16,
          sampleRate: opusInfo.inputSampleRate,
        });

        stream.pipe(getOpusStatsStream(pinoLogger)).pipe(opusDecoder).pipe(normalizer).pipe(speaker);
    });

There is also a duplex normalizing stream which ensures requested rate of packets per time.

The problem is that sound becomes gaped and I cannot find a way to glue pieces in one steady stream.

I recorded a helping video which demonstrates the problem:

https://www.youtube.com/watch?v=O7Fv3GTMjKQ

Do you have any idea why it's happening?

[amishshah]

Hi @OnkelTem, I'm afraid I'm not too sure what is happening either :(

Is onAudioData only fired once after connecting to the radio? The only thing I can think of is that it is being called repeatedly and giving the weird gap.

The issue is unrelated to the library, however I think I'll keep it open until I run out of ideas :sweat_smile: