[LAU] Voice-to-drums in general and the Trigger LADSPA in particular

Lorenzo Sutton lsutton at libero.it
Fri Sep 23 07:39:56 UTC 2011

Hi Fons,

On 22/09/2011 23:38, Fons Adriaensen wrote:
> On Thu, Sep 22, 2011 at 11:42:05PM +0400, Artem Vakhitov wrote:
>> On 22.09.2011 23:16, Fons Adriaensen wrote:
>>> If you need not only the timing but also to control volume
>>> then it's unlikely this can be done without delay. The part
>>> of the input that would contain usable information to control
>>> volume would very probably come after the trigger, but to
>>> play the sample you need both. The only solution then is to
>>> delay the trigger. That means that simple solutions such as
>>> the ladspa plugin can't do what you want.
>> The thing is, I do not need to do that in any kind of real time. It
>> would be sufficient to feed a "beat box" .wav file at the input and get
>> the corresponding .wav or .mid file at the output. All digital
>> processing can be done fully off-line, so all timing and amplitude info
>> is there in advance.
> Even if it hasn't to work in real time Pd is probably the
> ideal tool to prototype such a system. The alternative
> would be to write some ad-hoc C/C++ code, possibly using
> existing 'feature extraction' libraries or plugin code.
> As a first guess, what you need would be:
> - (optional) some pre-filtering to make the trigger
>    more reliable,
> - the trigger itself,
> - a delay on the trigger,

I don't quite get what the delay is needed for. To sync with the 
envelope follower?

> and in parallel
> - (optional) some pre-filtering for the envelope
>    follower,
> - an envelope follower,
> - when the delayed trigger arrives, read the envelope
>    follower and start the sample playback.
> Ciao,


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