Hi,
I've the following configuration in my asound.conf:
|-----| - - > |-----| - - > |-----| - - > |-----| - - > |-----| - - > |----------|
|plug | | | - - > | | - - > | | - - > | | - - > | (output) |
|-----| - - > | | - - > | | - - > | | - - > | | - - > | hw |
| | - - > | | - - > | | - - > | | - - > | |
| | | | |route| - - > |dmix | - - > | |
| | | | | | - - > | | - - > | |
| | | | | | - - > | | - - > | |
| | | | |-----| - - > |-----| - - > |----------|
|route| |multi|
| | - - > | |
| | - - > | | - - > |----| - - > |----| - - > |----------|
| | - - > | | - - > | | - - > | | - - > |(loopback)|
|-----| - - > | | - - > |plug| - - > |dmix| - - > | hw |
|-----| - - > |----| - - > |----| - - > |----------|
As you can see I'm using a loopback interface.
I open the pcm plug in the block mode to write.
writtenFrames = snd_pcm_writei(handle, bufferToWrite, bufferToWriteSize);
Using the configuration above I have several "writes" with 0 written frames.
It seems like the snd_pcm_writei does not hold until data will be written.
In general, 0 written frames sounds weird to me, because snd_pcm_writei should block itself if no space is available in the circular buffer right?
So, my questions are two:
1. Writing 0 frames is an expected behaviour (regardless of my configuration in the asound.conf)? In what scenarios can I have that?
2. How my configuration could trigger this behaviour?
Best Regards
Giuliano Zannetti
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