Input Buffering

Audio Plugins
1

Hello,

i just used the soundtouch library for pitch shifting. 

For postprocessing it works fine now, but in realtime it just creates a lot of clicks and crackling.

 

I think it would solve the problem when i buffer the input. Is it possible to change the buffersize in the processblock?

Thank you!

2

You'll need to use a circular buffer. Obviously it's not possible to just randomly change buffer sizes, they're provided by the audio driver or plugin host.

3

Thank you!
Well i wonder were i should implement the buffer, because in the processBlock i get only the bufferdata from one call and this seems to be too less for quality pitch shifting.

Is there a way to store the input for the processBlock buffer call somewhere outside?


 

4

Dave from dRowAudio wrote an audiosource that wraps the SoundTouch library. (Using an interim buffer).  Should be helpful even if you want to implement your own.

 

https://github.com/drowaudio/drowaudio/blob/master/dRowAudio/audio/dRowAudio_SoundTouchAudioSource.h

5

Merci! 

I will have a look on this :)

 

Otherwise i have another kind of stupid question maybe....

I tested a plugin in audacity and it sounds like the processed data is "added" to the original one.

I used a float pointer to get the buffer data and afterwards get each sample in the process:

float in0 = 0;
        int numSamples = buffer.getNumSamples();
        float* data = buffer.getSampleData(channel,0);
        

        for (int i = 0; i < buffer.getNumSamples(); i++)
        {
            in0 = *data;
            *data = pro0.tick(in0);
            data++;
        }
        pro0.clear();

 

is there something missing?

thank you for your help!