Le 11/05/14 16:40, Roy Smith a écrit :
In article <536f869c$0$2178$426a7...@news.free.fr>,
lgabiot <lgab...@hotmail.com> wrote:
Hello,
Le 11/05/14 16:40, Roy Smith a écrit :
If you are going to use threads, the architecture you describe seems
perfectly reasonable. It's a classic producer-consumer pattern.
But, I wonder if you even need anything this complicated. Using a queue
to buffer work between threads makes sense if the workload presented is
uneven. Sometimes you'll get a burst of work all at once and don't have
the capacity to process it in real-time, so you want to buffer it up.
I would think sampling audio would be a steady stream. Every x ms, you
get another chunk of samples, like clockwork. Is this not the case?
Thanks for your answer,
yes, I guess I can consider audio as a steady stream. PyAudio gives me
the audio samples by small chunks (2048 samples at a time for instance,
while the sound card gives 48 000 samples/seconds). I accumulate the
samples into a numpy array, and once the numpy array has reached the
needed size (for instance 5 seconds of audio), I put this numpy array in
the queue. So I think you are right in thinking that every 5 seconds I
get a new chunk of audio to work on. Then I perform a calculation on
this 5 seconds of audio (which needs to be done in less than 5 seconds,
so that it will be ready to process the next 5 second chunk), but
meanwhile, I need to still constantly get from Pyaudio a new 5 second
chunk of audio. Hence my system.
I guess if my calculation had to be performed on a small number of
samples (i.e. under the value of the Pyaudio buffer size (2048 samples
for instance), and that the calculation would last less than the time it
takes to get the next 2048 samples from Pyaudio, I wouldn't need the
Queue and Thread system.
But in my case where I need a large buffer, it might not work?
Unless I ask pyaudio to feed me directly with 5 seconds chunks (instead
of the usual buffer sizes: 1024, 2048, etc...), which I didn't try,
because I hadn't though of it.
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