[chuck-users] Urgent shot in the dark -- Audible clicks when spawning shreds when SndBuf reads from disk

[mike clemow]

Hi Szilveszter, Kassen,

Thanks for the quick response!  It's definitely the reads between
samples that's causing the issue, because I only kill the last shred
twice during the piece.  The dropouts occur only when spawning new
shreds.

I've already set the chunk-size to 1024...  I assume that this is
samples, although the documentation says "frames."

I'll try preloading the files in a big array and see if I run out of RAM.

Thanks so much!!!

Mike



2009/11/8 Szilveszter Tóth <silvestre.toth at gmail.com>:
> Mike,
>
> if you record the audio from ChucK using a WvOut like this:
>
> dac.chan(0) => Gain g => WvOut w => blackhole;
> "tmp.wav" =>  w.wavFilename;
>
> do you hear the click in the resulting tmp.wav? If not, then the problem is
> with reading a file between samples. If yes, then the abrupt sample change
> may play a role, too.
>
> Szilveszter (Hillaby)
>
> Szilveszter Tóth escribió:
>>
>> Mike,
>>
>> Just some thoughts.
>>
>> When you kill the "last shred" that was playing, the audio signal drops to
>> 0 (or to the first sample of the next WAV file), which may cause clicks.
>> Also, reading an entire file (or part of it) between two samples may not
>> be feasible, which will not only cause a click, but the realtime timing will
>> also be lost (ChucK will wait for the entire file to be read in.)
>>
>> I'd use an Envelope for the first problem and I'd try changing chunk size
>> for the second. (Or maybe pre-read the next file to be played, if it can be
>> determined beforehand.)
>>
>> I hope I could help a little
>> Szilveszter (Hillaby)
>>
>> mike clemow escribió:
>>>
>>> This is a shot-in-the-dark...
>>>
>>> At the last minute, the person who was responsible for doing the sound
>>> with a Kyma system, couldn't get it to trigger sounds with MIDI (for
>>> some reason or another) and I'm stepping up and doing the whole show
>>> with pre-recorded material in ChucK.  (I know, I know -- I'm crazy.)
>>>
>>> It's 9:25am here on the East Coast of the U.S.  We're onstage at 2pm
>>> and 8pm.  I have a script that receives OSC messages from a Java
>>> program.  The messages contain the string name of a file to play.
>>> It's a simple stereo file (I'm already working with a very kludgy way
>>> of playing stereo files--loading it twice into two buffers).  But
>>> every time I spawn a new thread, the file loads from disk and there's
>>> an audible click, or drop in audio.
>>>
>>> Now, I know that one way around this is to pre-load all the files into
>>> SndBuf objects and then trigger them to play using Events.  The only
>>> trouble is that there are 73 files for this piece and some of them are
>>> pretty large.  I'm afraid of eating all my RAM / bringing everything
>>> to a grinding halt.
>>>
>>> I'm posting my entire script at the end of the email.  If anyone has
>>> any thoughts, please send them along.  Otherwise, we'll just deal with
>>> the way things are.
>>>
>>> Best,
>>> Mike
>>>
>>>
>>
>>
>
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