Stream underflow detection failed on Ubuntu 16.04 LTS

[napent]

Hi, I found that there is no way, to detect stream underflow under Ubuntu 16.04 using librtaudio4v5 from apt repositories and ALSA. Use following 'use case':

diff --git a/tests/playsaw.cpp b/tests/playsaw.cpp
index d1953b6..f9193fe 100644
--- a/tests/playsaw.cpp
+++ b/tests/playsaw.cpp
@@ -102,6 +102,7 @@ int saw( void *outputBuffer, void *inputBuffer, unsigned int nBufferFrames,
       *buffer++ = (MY_TYPE) (lastValues[j] * SCALE * 0.5);
       lastValues[j] += BASE_RATE * (j+1+(j*0.1));
       if ( lastValues[j] >= 1.0 ) lastValues[j] -= 2.0;
+      usleep(1);
     }
   }

Unfortunately no errors about underflow gets printed.

[garyscavone]

I don’t think 1 microsecond is enough … try 10 or 100. Also, make sure you are doing this inside the version of the saw() function that is being called (interleaved or non-interleaved).

…

On Feb 6, 2017, at 1:38 PM, Adam ***@***.***> wrote: Hi, I found that there is no way, to detect stream underflow under Ubuntu 16.04 using librtaudio4v5 from apt repositories and ALSA. Use following 'use case': diff --git a/tests/playsaw.cpp b/tests/playsaw.cpp index d1953b6..f9193fe 100644 --- a/tests/playsaw.cpp +++ b/tests/playsaw.cpp @@ -102,6 +102,7 @@ int saw( void *outputBuffer, void *inputBuffer, unsigned int nBufferFrames, *buffer++ = (MY_TYPE) (lastValues[j] * SCALE * 0.5); lastValues[j] += BASE_RATE * (j+1+(j*0.1)); if ( lastValues[j] >= 1.0 ) lastValues[j] -= 2.0; + usleep(1); } } Unfortunately no errors about underflow gets printed. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#84>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AFOBpeH6Ug0ZARKkeBjlMVhrIx9WR4fzks5rZ2izgaJpZM4L4j8n>. {"api_version":"1.0","publisher":{"api_key":"05dde50f1d1a384dd78767c55493e4bb","name":"GitHub"},"entity":{"external_key":"github/thestk/rtaudio","title":"thestk/rtaudio","subtitle":"GitHub repository","main_image_url":"https://cloud.githubusercontent.com/assets/143418/17495839/a5054eac-5d88-11e6-95fc-7290892c7bb5.png","avatar_image_url":"https://cloud.githubusercontent.com/assets/143418/15842166/7c72db34-2c0b-11e6-9aed-b52498112777.png","action":{"name":"Open in GitHub","url":"https://github.com/thestk/rtaudio"}},"updates":{"snippets":[{"icon":"DESCRIPTION","message":"Stream underflow detection failed on Ubuntu 16.04 LTS (#84)"}],"action":{"name":"View Issue","url":"#84"}}}

[napent]

Thanks for fast response!
In my case even 1 microsecond is causing audible glitch. In a minute I will check behavior with jack as back-end.

Same thing with jack,

RtAudioStreamStatus status

is always 0

[garyscavone]

It works for me on OS-X. I don’t have easy access to a linux box to check.

…

On Feb 6, 2017, at 3:28 PM, Adam ***@***.***> wrote: Same thing with jack.. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#84 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AFOBpaRJBIqLAFjRKQhyUlnzWKQE6Y0Jks5rZ4JYgaJpZM4L4j8n>. {"api_version":"1.0","publisher":{"api_key":"05dde50f1d1a384dd78767c55493e4bb","name":"GitHub"},"entity":{"external_key":"github/thestk/rtaudio","title":"thestk/rtaudio","subtitle":"GitHub repository","main_image_url":"https://cloud.githubusercontent.com/assets/143418/17495839/a5054eac-5d88-11e6-95fc-7290892c7bb5.png","avatar_image_url":"https://cloud.githubusercontent.com/assets/143418/15842166/7c72db34-2c0b-11e6-9aed-b52498112777.png","action":{"name":"Open in ***@***.*** in #84: Same thing with jack.."}],"action":{"name":"View Issue","url":"#84 (comment)"}}}

[radarsat1]

I can confirm that no underflow message is printed (ubuntu 16.10, macbook pro), even though usleep(1) is enough to cause glitches.

I looked into it a bit and snd_pcm_writei always returns 512 and if I force a call to snd_pcm_state it always returns SND_PCM_STATE_RUNNING. In otherwords, ALSA is not returning an error. I don't have more ideas at the moment.