Re: [alsa-devel] start_threshold and stream controls for PCM streams

At Fri, 9 Dec 2011 11:05:19 +0530, Nallasellan, Singaravelan wrote:

Hi,

Would like to know how start_threshold is expected to be used in single_threaded audio player?

I assume that in blocking implementation, the write call will block till the ring buffer becomes empty. Is it right?

Not really. It's not necessarily to be empty. The condition is that the empty space becomes avail_min or more.

But, this has nothing to do with start_threshold. The start_threshold is the value to start the stream automatically. When it's 1, the stream is started immediately when something is written. When it's buffer_size, the stream is started when all data is filled in the buffer.

And, the write-block behavior is irrelevant with start_threshold.

Takashi