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For example I have a simple play() function that plays arbitrary tone just fine. The problem is that as soon as I decide to stop playing tone ALSA produces click/pop sound. I've already tried using snd_pcm_drain(), stopping tone when it finishes period and in case of finite loop even tried to gradually silence tone. Is there a way to avoid this popping?

void play()
{
    int err;

    while (1) {
        for (unsigned i = 0; i < buffer_size; i++)
        {
            buffer[i] = (AMP - 1) * gen_sine(time) + AMP;
            time += time_step;
        }

        err = snd_pcm_writei(handle, buffer, buffer_size);
        if (err == -EPIPE) {
            fprintf(stderr, "underrun occurred\n");
            snd_pcm_prepare(handle);
        }
        else if (err == -EBADFD) {
            fprintf(stderr, "PCM is not in the right state\n");
        }
        else if (err < 0) {
            fprintf(stderr, "error from writei: %s\n", snd_strerror(err));
        }
    }
}
vmf91
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another_random
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  • I don't if that is possible, but try to mute sound before stop. – Paul Ogilvie Mar 10 '19 at 15:02
  • This might help... On some Linux installations I have had pops/clicks from alsa. The usually remedy was to install a `pulseaudio` package. You don't need to run `pulseaudio`, but having the package installed did seem to remedy this problem. I can't speak to the specific C library though. – Deanie Mar 10 '19 at 15:56

0 Answers0