The length in samples that the Slice will stay ON. Changes of states during that period will be ignored.
ARGUMENT:: highPassFreq
The frequency of the fourth-order Linkwitz–Riley high-pass filter (https://en.wikipedia.org/wiki/Linkwitz%E2%80%93Riley_filter). This is done first on the signal to minimise low frequency intermodulation with very fast ramp lengths. A frequency of 0 bypasses the filter.
The frequency of the fourth-order link::https://en.wikipedia.org/wiki/Linkwitz%E2%80%93Riley_filter##Linkwitz–Riley high-pass filter::. This is done first on the signal to minimise low frequency intermodulation with very fast ramp lengths. A frequency of 0 bypasses the filter.
RETURNS::
An audio stream with square envelopes around the slices. The latency between the input and the output is dependant on the relation between the two envelope followers.
@ -54,7 +54,8 @@ code::
// detrending explained
// Our source here is a sinewave that does not go to silence and has sharp-ish amplitude bumps as onsets we try to track
@ -17,79 +17,78 @@ By default, this UGen spawns a new thread to avoid blocking the server command q
CLASSMETHODS::
METHOD:: process
This is the method that calls for the slicing to be calculated on a given source buffer.
This is the method that calls for the slicing to be calculated on a given source buffer.
ARGUMENT:: server
The server on which the buffers to be processed are allocated.
The server on which the buffers to be processed are allocated.
ARGUMENT:: source
The index of the buffer to use as the source material to be sliced through novelty identification. The different channels of multichannel buffers will be summed.
The index of the buffer to use as the source material to be sliced through novelty identification. The different channels of multichannel buffers will be summed.
ARGUMENT:: startFrame
Where in the srcBuf should the slicing process start, in sample.
Where in the srcBuf should the slicing process start, in sample.
ARGUMENT:: numFrames
How many frames should be processed.
How many frames should be processed.
ARGUMENT:: startChan
For multichannel sources, which channel should be processed.
For multichannel sources, which channel should be processed.
ARGUMENT:: numChans
For multichannel sources, how many channel should be summed.
For multichannel sources, how many channel should be summed.
ARGUMENT:: indices
The index of the buffer where the indices (in sample) of the estimated starting points of slices will be written. The first and last points are always the boundary points of the analysis.
The index of the buffer where the indices (in sample) of the estimated starting points of slices will be written. The first and last points are always the boundary points of the analysis.
ARGUMENT:: rampUp
The number of samples the envelope follower will take to reach the next value when raising.
The number of samples the envelope follower will take to reach the next value when raising.
ARGUMENT:: rampDown
The number of samples the envelope follower will take to reach the next value when falling.
The number of samples the envelope follower will take to reach the next value when falling.
ARGUMENT:: onThreshold
The threshold in dB of the envelope follower to trigger an onset, aka to go ON when in OFF state.
The threshold in dB of the envelope follower to trigger an onset, aka to go ON when in OFF state.
ARGUMENT:: offThreshold
The threshold in dB of the envelope follower to trigger an offset, , aka to go ON when in OFF state.
The threshold in dB of the envelope follower to trigger an offset, , aka to go ON when in OFF state.
ARGUMENT:: minSliceLength
The length in samples that the Slice will stay ON. Changes of states during that period will be ignored.
The length in samples that the Slice will stay ON. Changes of states during that period will be ignored.
ARGUMENT:: minSilenceLength
The length in samples that the Slice will stay OFF. Changes of states during that period will be ignored.
The length in samples that the Slice will stay OFF. Changes of states during that period will be ignored.
ARGUMENT:: minLengthAbove
The length in samples that the envelope have to be above the threshold to consider it a valid transition to ON. The Slice will start at the first sample when the condition is met. Therefore, this affects the latency.
The length in samples that the envelope have to be above the threshold to consider it a valid transition to ON. The Slice will start at the first sample when the condition is met. Therefore, this affects the latency.
ARGUMENT:: minLengthBelow
The length in samples that the envelope have to be below the threshold to consider it a valid transition to OFF. The Slice will end at the first sample when the condition is met. Therefore, this affects the latency.
The length in samples that the envelope have to be below the threshold to consider it a valid transition to OFF. The Slice will end at the first sample when the condition is met. Therefore, this affects the latency.
ARGUMENT:: lookBack
The length of the buffer kept before an onset to allow the algorithm, once a new Slice is detected, to go back in time (up to that many samples) to find the minimum amplitude as the Slice onset point. This affects the latency of the algorithm.
The length of the buffer kept before an onset to allow the algorithm, once a new Slice is detected, to go back in time (up to that many samples) to find the minimum amplitude as the Slice onset point. This affects the latency of the algorithm.
ARGUMENT:: lookAhead
The length of the buffer kept after an offset to allow the algorithm, once the Slice is considered finished, to wait further in time (up to that many samples) to find a minimum amplitude as the Slice offset point. This affects the latency of the algorithm.
The length of the buffer kept after an offset to allow the algorithm, once the Slice is considered finished, to wait further in time (up to that many samples) to find a minimum amplitude as the Slice offset point. This affects the latency of the algorithm.
ARGUMENT:: highPassFreq
The frequency of the fourth-order Linkwitz–Riley high-pass filter (https://en.wikipedia.org/wiki/Linkwitz%E2%80%93Riley_filter). This is done first on the signal to minimise low frequency intermodulation with very fast ramp lengths. A frequency of 0 bypasses the filter.
The frequency of the fourth-order link::https://en.wikipedia.org/wiki/Linkwitz%E2%80%93Riley_filter##Linkwitz–Riley high-pass filter::. This is done first on the signal to minimise low frequency intermodulation with very fast ramp lengths. A frequency of 0 bypasses the filter.
ARGUMENT:: action
A Function to be evaluated once the offline process has finished and indices instance variables have been updated on the client side. The metric will be passed indices as an argument.
A Function to be evaluated once the offline process has finished and indices instance variables have been updated on the client side. The metric will be passed indices as an argument.
RETURNS::
Nothing, as the destination buffer is declared in the function call.
Nothing, as the destination buffer is declared in the function call.
EXAMPLES::
code::
// define a test signal and a destination buffer
(
b = Buffer.sendCollection(s, Array.fill(44100,{|i| sin(i*pi/ (44100/640)) * (sin(i*pi/ 22050)).abs}));
c = Buffer.new(s);
b = Buffer.sendCollection(s, Array.fill(44100,{|i| sin(i*pi/ (44100/640)) * (sin(i*pi/ 22050)).abs}));
var proc= FluidBufAmpGate.process(s, b, indices: c, rampUp:1, rampDown:10, onThreshold: -30);
proc.wait;
(Main.elapsedTime - t).postln;
}.play
}.play
)
// list the indicies of detected attacks - the two input channels have been summed. The two channels of the output, respectively onset and offset indices, are interleaved as this is the SuperCollider buffer data formatting
## 0 || Cepstrum: Returns a pitch estimate as the location of the second highest peak in the Cepstrum of the signal (after DC).
## 1 || Harmonic Product Spectrum: Implements the Harmonic Product Spectrum algorithm for pitch detection . See e.g. FOOTNOTE:: A. Lerch, "An Introduction to Audio Content Analysis: Applications in Signal Processing and Music Informatics." John Wiley & Sons, 2012.https://onlinelibrary.wiley.com/doi/book/10.1002/9781118393550 ::
## 2 || YinFFT: Implements the frequency domain version of the YIN algorithm, as described in FOOTNOTE::P. M. Brossier, "Automatic Annotation of Musical Audio for Interactive Applications.” QMUL, London, UK, 2007. :: See also https://essentia.upf.edu/documentation/reference/streaming_PitchYinFFT.html
## 2 || YinFFT: Implements the frequency domain version of the YIN algorithm, as described in FOOTNOTE::P. M. Brossier, "Automatic Annotation of Musical Audio for Interactive Applications." QMUL, London, UK, 2007. :: See also https://essentia.upf.edu/documentation/reference/streaming_PitchYinFFT.html
//looking at the result is not easy to grasp, since it is interleaved: first number is mean of L, second is mean of R, third is stddev of L, fourth is stddev or R
//this will make it tidier - the first value of each line is Left, the second is Right
@ -48,8 +48,6 @@ A function that will run when the query returns, whose argument is an array of d
EXAMPLES::
code::
// Make a DataSet of random 2D points
s.reboot;
(
@ -117,13 +115,40 @@ fork{
)
::
subsection:: Server Side Queries
subsection:: Queries in a Synth
Input and output is done via buffers, which will need to be preallocated to the correct sizes:
LIST::
##Your input buffer should be sized to the input data dimension (2, in this example)
##Your output buffer should be the number of neighbours * output dimensionality
::
We can't simply return labels (i.e. strings) from a UGen, so the query returns the actual data points from a DataSet instead. By default, this is the FluidDataSet against which the tree was fitted. However, by passing a different dataset to code::kr::'s code::lookupDataSet:: argument instead, you can return different points, so long as the labels in the two datasets match. In this way, the FluidKDTree can be used to perform nearest neighbour mappings in a synth.
For instance, whilst fitting the tree against some n-dimensional descriptor data, our lookup dataset could use the same labels to map descriptor entries back to buffers, or locations in buffers, so that queries can be used to trigger audio.
code::
//populate the lookupDataSet
(
Routine{
var inputBuffer = Buffer.alloc(s,2);
var outputBuffer = Buffer.alloc(s,10);//5 neighbours * 2D data points
s.sync;
{
var trig = Impulse.kr(4); //can go as fast as ControlRate.ir/2
//here we populate with numbers that are in effect the indicies, but it could be anything numerical that will be returned on the server-side and would be usable on that side
(
~dsL = FluidDataSet.new(s,\kdtree_help_indices);
~dsL = FluidDataSet.new(s);
fork{
d = Dictionary.with(
*[\cols -> 1,\data -> Dictionary.newFrom(
@ -132,31 +157,23 @@ fork{
~dsL.load(d, {~dsL.print});
}
)
// instantiate a tree with a lookup dataset. Note that this 'association' has to be done at instantiation.
Because FluidStandardize runs in its own link::Classes/Synth:: on the server, communication is done via control-rate link::Classes/Bus:: objects for triggering and link::Classes/Buffer:: objects for passing and retreiving data.
Owen Green
5 years ago