static int alsa_run_out (HWVoiceOut *hw) { ALSAVoiceOut *alsa = (ALSAVoiceOut *) hw; int rpos, live, decr; int samples; uint8_t *dst; st_sample_t *src; snd_pcm_sframes_t avail; live = audio_pcm_hw_get_live_out (hw); if (!live) { return 0; } avail = alsa_get_avail (alsa->handle); if (avail < 0) { dolog ("Could not get number of available playback frames\n"); return 0; } decr = audio_MIN (live, avail); samples = decr; rpos = hw->rpos; while (samples) { int left_till_end_samples = hw->samples - rpos; int len = audio_MIN (samples, left_till_end_samples); snd_pcm_sframes_t written; src = hw->mix_buf + rpos; dst = advance (alsa->pcm_buf, rpos << hw->info.shift); hw->clip (dst, src, len); while (len) { written = snd_pcm_writei (alsa->handle, dst, len); if (written <= 0) { switch (written) { case 0: if (conf.verbose) { dolog ("Failed to write %d frames (wrote zero)\n", len); } goto exit; case -EPIPE: if (alsa_recover (alsa->handle)) { alsa_logerr (written, "Failed to write %d frames\n", len); goto exit; } if (conf.verbose) { dolog ("Recovering from playback xrun\n"); } continue; case -EAGAIN: goto exit; default: alsa_logerr (written, "Failed to write %d frames to %p\n", len, dst); goto exit; } } rpos = (rpos + written) % hw->samples; samples -= written; len -= written; dst = advance (dst, written << hw->info.shift); src += written; } } exit: hw->rpos = rpos; return decr; }