[alsa-devel] [PATCH 5/6] compress: add the core file

Nallasellan, Singaravelan singaravelan.nallasellan at intel.com
Tue Dec 6 04:00:34 CET 2011

> The notion of a START threshold isn't self-explanatory for compressed data. The
> decoder may or may not have enough data available for specific values of the
> threshold, and the behavior would be decoder/implementation specific.
> Besides, this was never implemented in the proprietary Intel API we've been using for
> 2+ years and no one complained...

Even the thread which actually writes the data to ring buffer may not have the idea of frames
So the start threshold does not require to be on frame boundaries. It is just to avoid START 
when the buffer is written with the data. If the write gives more data than the ring buffer, 
write will not unblock and the user space application may not be able to call START. 
This will be an issue if you go for non-blocking implementation. Otherwise, START should
be called in another thread than the thread which writes the data.

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