[Csnd] Real Time Filter Issues

Date	2014-08-23 02:24
From	Marshall West
Subject	[Csnd] Real Time Filter Issues
	Hello, I'm having trouble successfully implementing Csound's filter opcodes in the MIDI-controlled instrument I've pasted below. I'm wanting a low-pass resonant filter, and the few that I've tried work until I apply a sweep to the cut off frequency, at which point the audio drops out entirely. I've tried varying ksmps and my buffer values to no avail. I've written a version of this instrument to read from a score and am very pleased with the sound. Would love to get this to run via MIDI. Any advice would be greatly appreciated as I'm relatively new to csound. Thanks in advance, Marshall sr = 44100 ksmps = 256 nchnls = 2 gisquare ftgen 1, 0, 4097, 10, 1, 0, 1/3, 0, 1/5, 0, 1/7, 0, 1/9 ctrlinit 1,74,.30,71,0,73,0,72,.025,3,40,9,40,80,.1 opcode Smooth,k,k ;Applies portamento to incoming MIDI data kres xin ;Opcode input kportTime linseg 0,0.001,0.01 ; create a value that quickly ramps up to 0.01 kres portk kres,kportTime ; create a filtered version of kres xout kres endop opcode AD,k,ik ;Realtime Attack/decay envelope iatt,kdec xin ;Opcode inputs ktime init 0 ;Initialize variables kv init 0 kt init 0 ikontrolBlock = 1/kr ;Calculate seconds per control sample ktime = ktime+ikontrolBlock ;Clock if ktime < iatt then ;Attack interval kt = iatt kv = 1 else ;Decay interval kt = kdec kv = 0 endif kenv portk kv, kt ;Apply portamento to changes in volume xout kenv endop instr 1 iamp ampmidi 32768 ;Oscillators 1 and 2 kosc1Tune ctrl7 1,3,40,1500 kosc1Tune Smooth kosc1Tune kosc2Tune ctrl7 1,9,40,1500 kosc2Tune Smooth kosc2Tune aosc1 poscil iamp.5, kosc1Tune, 1 aosc2 poscil iamp.5, kosc2Tune, 1 ;Resonant lowpass filter kfco ctrl7 1,74,30,4000 ;Cut-off frequency kfco Smooth kfco krez ctrl7 1,71,0,1 ;Resonance krez Smooth krez ;Filter envelope iatt = .01 ksweep ctrl7 1,73,0,1 ;Filter sweep amount ksweep Smooth ksweep ksweepDec ctrl7 1,72,0.025,5 ;Filter envelope decay ksweepDec Smooth ksweepDec kfiltEnv AD iatt,ksweepDec kfiltEnv = kfiltEnviamp ;Envelope is velocity sensitive kfco = kfco+(kfiltEnvksweep(4000-30)) asig moogladder aosc1+aosc2,kfco,krez kampDec ctrl7 1,80,0.1,5 ;Amplitude envelope decay kampDec Smooth kampDec kampEnv AD iatt,kampDec out asigkampEnv endin -- View this message in context: http://csound.1045644.n5.nabble.com/Real-Time-Filter-Issues-tp5737082.html Sent from the Csound - General mailing list archive at Nabble.com.

Date	2014-08-23 06:22
From	Kevin Welsh
Subject	Re: [Csnd] Real Time Filter Issues
	I think I was having similar problems last night when working with an instrument that uses moogvcf2. I also tried moogvcf as a test, and had the same result. Strangely, I seemed to have more of a problem when panning the sound as compared to keeping it static. I didn't get to experiment with it much more past that tho. On Fri, Aug 22, 2014 at 9:24 PM, Marshall West wrote: > Hello, > > I'm having trouble successfully implementing Csound's filter opcodes in the > MIDI-controlled instrument I've pasted below. I'm wanting a low-pass > resonant filter, and the few that I've tried work until I apply a sweep to > the cut off frequency, at which point the audio drops out entirely. I've > tried varying ksmps and my buffer values to no avail. I've written a version > of this instrument to read from a score and am very pleased with the sound. > Would love to get this to run via MIDI. Any advice would be greatly > appreciated as I'm relatively new to csound. > > Thanks in advance, > > Marshall > > sr = 44100 > ksmps = 256 > nchnls = 2 > > gisquare ftgen 1, 0, 4097, 10, 1, 0, 1/3, 0, 1/5, 0, 1/7, 0, 1/9 > > ctrlinit 1,74,.30,71,0,73,0,72,.025,3,40,9,40,80,.1 > > opcode Smooth,k,k ;Applies portamento to > incoming MIDI data > kres xin ;Opcode input > kportTime linseg 0,0.001,0.01 ; create a value that quickly ramps up to > 0.01 > kres portk kres,kportTime ; create a filtered version of kres > xout kres > endop > > opcode AD,k,ik ;Realtime Attack/decay > envelope > iatt,kdec xin ;Opcode inputs > ktime init 0 ;Initialize variables > kv init 0 > kt init 0 > ikontrolBlock = 1/kr ;Calculate seconds per control sample > ktime = ktime+ikontrolBlock ;Clock > if ktime < iatt then ;Attack interval > kt = iatt > kv = 1 > else ;Decay interval > kt = kdec > kv = 0 > endif > kenv portk kv, kt ;Apply portamento to changes in volume > xout kenv > endop > > instr 1 > iamp ampmidi 32768 > ;Oscillators 1 and 2 > kosc1Tune ctrl7 1,3,40,1500 > kosc1Tune Smooth kosc1Tune > kosc2Tune ctrl7 1,9,40,1500 > kosc2Tune Smooth kosc2Tune > aosc1 poscil iamp.5, kosc1Tune, 1 > aosc2 poscil iamp.5, kosc2Tune, 1 > ;Resonant lowpass filter > kfco ctrl7 1,74,30,4000 ;Cut-off frequency > kfco Smooth kfco > krez ctrl7 1,71,0,1 ;Resonance > krez Smooth krez > ;Filter envelope > iatt = .01 > ksweep ctrl7 1,73,0,1 ;Filter sweep amount > ksweep Smooth ksweep > ksweepDec ctrl7 1,72,0.025,5 ;Filter envelope decay > ksweepDec Smooth ksweepDec > kfiltEnv AD iatt,ksweepDec > kfiltEnv = kfiltEnviamp ;Envelope is velocity sensitive > kfco = kfco+(kfiltEnvksweep(4000-30)) > asig moogladder aosc1+aosc2,kfco,krez > kampDec ctrl7 1,80,0.1,5 ;Amplitude envelope decay > kampDec Smooth kampDec > kampEnv AD iatt,kampDec > out asigkampEnv > endin > > > > -- > View this message in context: http://csound.1045644.n5.nabble.com/Real-Time-Filter-Issues-tp5737082.html > Sent from the Csound - General mailing list archive at Nabble.com. > > > Send bugs reports to > https://github.com/csound/csound/issues > Discussions of bugs and features can be posted here > To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe csound" > > >