HOA Tutorial Exercise 13

Extension

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The code below is a non-real-time NRT script to convert your b-format file between standard channel orders and normalization conventions.

First things first: let's start the sound server, which we configure first to get more audio buses and to have 36 output channels.s.quit; // quit the server first if it is still running with another configuration. ( ServerOptions.devices; s = Server.local; Server.local = Server.default; o = Server.local.options; // Get the local server's options o.numInputBusChannels = 2; // Set Input to number of Inputs o.numOutputBusChannels = 36; // lets start after chan 36 so as not to see the mic input o.numAudioBusChannels = 2048; o.blockSize = 512; o.numWireBufs = 1024 * 16; o.memSize = 2.pow(18); o.sampleRate = 48000; s.makeWindow; s.boot; )

We will first load a sound sample from a HOA scene.

First, load a soundfile:( ~order = 3; // al material is 3rd order ~hoaNumChannels = (~order+1).pow(2); ) ~hoaSoundScene = Buffer.read(s, HOA.soundsDir++"/eigen_ACN_N3D_Montreal_Metro_cello.wav"); ~hoaSoundScene = Buffer.read(s, HOA.soundsDir++"/eigen_ACN_N3D_Montreal_Metro.wav"); ~hoaSoundScene = Buffer.read(s, HOA.soundsDir++"/eigen_ACN_N3D_CIRMMT_Foyer_short.wav");

Then we make a Score and we add to the Score OSC messages invoking the SynthDef we have made earlier.( var seconds; // length of sound file 2 convert var informat; // input Format var outformat; // output Format informat =\ACN_N3D; // examples from above are ACN_N3D outformat =\FuMa; // \ACN_N3D; \ACN_SN3D; seconds = ~hoaSoundScene.numFrames / s.options.sampleRate; // length of the soundfile 2 convert ~myScore = Score.new(); Routine.run{ // we need to load the soundfile to get the buffer number for the NRT server ~sndbufBundle = s.makeBundle(false, { ~sndbuf = Buffer.read(s, ~hoaSoundScene.path); }); ~sndbufBundle = ~sndbufBundle.addFirst(0.0); ~myScore.add(~sndbufBundle); ~sndbuf.updateInfo; s.sync; // we need to make the SynthDef that will do the conversion for us SynthDef(\hoaConverter,{ arg buffer; var playFile; playFile = PlayBuf.ar(~hoaNumChannels.asInteger, buffer, startPos:0, loop:0, doneAction:2); OffsetOut.ar(0, HOAConvert.ar(~order.asInteger, playFile, inFormat: informat, outFormat: outformat);) }).load(s); s.sync; // we need to load the SynthDef with the sound buffer that we want to convert ~noteBundle = s.makeBundle(false, {Synth(\hoaConverter, [\buffer, ~sndbuf])}); ~noteBundle = ~noteBundle.addFirst(0.0); ~myScore.add(~noteBundle); // at the end we need to set the command to stop NRT ~myScore.add([seconds, [\c_set, 0, 0]]); // finish s.sync; ~myScore.score.do({|item,i| item.postln; }); // Now we can start the NRT synthesis. We will configure the ServerOptions for the NRT server first. // We render the file as float and normalize it once it is written to disk. ~nrtOptions = ServerOptions.new; ~nrtOptions.verbosity_(0); // 0 to see the events as OSCPacket ~nrtOptions.numOutputBusChannels_(16); // we need 16 channels because it is B-format 3rd order ~nrtOptions.memSize_(8192 * 6400); ~nrtOptions.maxNodes_(1024 * 48); ~nrtOptions.maxSynthDefs_(1024 * 48); Score.recordNRT(~myScore.score, thisProcess.platform.userHomeDir++"/convertHOA-oscFile.txt", thisProcess.platform.userHomeDir++"/convertHOA.wav", sampleRate: 44100, headerFormat: "WAV", sampleFormat: "float", options: ~nrtOptions, action: {"DONE".postln; SoundFile.normalize(thisProcess.platform.userHomeDir++"/convertHOA.wav", thisProcess.platform.userHomeDir++"/convertHOA_norm.wav", newHeaderFormat: "WAV", newSampleFormat: "int16"); } ); } )

Finally, we can delete the files:File.delete( thisProcess.platform.userHomeDir++"/convertHOA-oscFile.txt"); File.delete( thisProcess.platform.userHomeDir++"/convertHOA.wav"); File.delete( thisProcess.platform.userHomeDir++"/convertHOA_norm.wav");

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Next: HOA Tutorial Exercise 14