Hi all, I am writing to ask how can I record audio from a live input, store it in a buffer, and return the length of it? Now I am only to record sound into a fixed length table, which has silence remaining in the buffer if the recorded time is smaller then the table length. I am hoping to using a button to toggle start and stop recording, with the buffer length changeable according to the recording time. Is that achievable?
Record Buffer and return it's length
Yes. All you need to do is store the number of samples you have recorded. If you post your code we can modify it to do this.
Hi Rory, thank you very much for the reply! I am using several UDO opcodes I found. I use BufCt1 for creating buffer, BufRecord1 for recording, and BufPlay1 for playing. It maybe not be a convenient way of doing record and play, Do you have better solution on that? Here is the code:
opcode BufCt1, i, io
ilen, inum xin
ift ftgen inum, 0, -(ilen*sr), 2, 0
xout ift
endop
opcode BufRec1, k, aikkkk
ain, ift, krec, kstart, kend, kwrap xin
setksmps 1
kendsmps = kend*sr ;end point in samples
kendsmps = (kendsmps == 0 || kendsmps > ftlen(ift) ? ftlen(ift) : kendsmps)
kfinished = 0
krec init 0
knew changed krec ;1 if record just started
if krec == 1 then
if knew == 1 then
kndx = kstart * sr - 1 ;first index to write minus one
endif
if kndx >= kendsmps-1 && kwrap == 1 then
kndx = -1
endif
if kndx < kendsmps-1 then
kndx = kndx + 1
andx = kndx
tabw ain, andx, ift
else
kfinished = 1
endif
endif
xout kfinished
endop
opcode BufPlay1, ak, ikkkkkk
ift, kplay, kspeed, kvol, kstart, kend, kwrap xin
;kstart = begin of playing the buffer in seconds
;kend = end of playing in seconds. 0 means the end of the table
;kwrap = 0: no wrapping. stops at kend (positive speed) or kstart (negative speed). this makes just sense if the direction does not change and you just want to play the table once
;kwrap = 1: wraps between kstart and kend
;kwrap = 2: wraps between 0 and kend
;kwrap = 3: wraps between kstart and end of table
;CALCULATE BASIC VALUES
kfin init 0
iftlen = ftlen(ift)/sr ;ftlength in seconds
kend = (kend == 0 ? iftlen : kend) ;kend=0 means end of table
kstart01 = kstart/iftlen ;start in 0-1 range
kend01 = kend/iftlen ;end in 0-1 range
kfqbas = (1/iftlen) * kspeed ;basic phasor frequency
;DIFFERENT BEHAVIOUR DEPENDING ON WRAP:
if kplay == 1 && kfin == 0 then
;1. STOP AT START- OR ENDPOINT IF NO WRAPPING REQUIRED (kwrap=0)
if kwrap == 0 then
kfqrel = kfqbas / (kend01-kstart01) ;phasor freq so that 0-1 values match distance start-end
andxrel phasor kfqrel ;index 0-1 for distance start-end
andx = andxrel * (kend01-kstart01) + (kstart01) ;final index for reading the table (0-1)
kfirst init 1 ;don't check condition below at the first k-cycle (always true)
kndx downsamp andx
kprevndx init 0
;end of table check:
;for positive speed, check if this index is lower than the previous one
if kfirst == 0 && kspeed > 0 && kndx < kprevndx then
kfin = 1
;for negative speed, check if this index is higher than the previous one
else
kprevndx = (kprevndx == kstart01 ? kend01 : kprevndx)
if kfirst == 0 && kspeed < 0 && kndx > kprevndx then
kfin = 1
endif
kfirst = 0 ;end of first cycle in wrap = 0
endif
;sound out if end of table has not yet reached
asig table3 andx, ift, 1
kprevndx = kndx ;next previous is this index
;2. WRAP BETWEEN START AND END (kwrap=1)
elseif kwrap == 1 then
kfqrel = kfqbas / (kend01-kstart01) ;same as for kwarp=0
andxrel phasor kfqrel
andx = andxrel * (kend01-kstart01) + (kstart01)
asig table3 andx, ift, 1 ;sound out
;3. START AT kstart BUT WRAP BETWEEN 0 AND END (kwrap=2)
elseif kwrap == 2 then
kw2first init 1
if kw2first == 1 then ;at first k-cycle:
reinit wrap3phs ;reinitialize for getting the correct start phase
kw2first = 0
endif
kfqrel = kfqbas / kend01 ;phasor freq so that 0-1 values match distance start-end
wrap3phs:
andxrel phasor kfqrel, i(kstart01) ;index 0-1 for distance start-end
rireturn ;end of reinitialization
andx = andxrel * kend01 ;final index for reading the table
asig table3 andx, ift, 1 ;sound out
;4. WRAP BETWEEN kstart AND END OF TABLE(kwrap=3)
elseif kwrap == 3 then
kfqrel = kfqbas / (1-kstart01) ;phasor freq so that 0-1 values match distance start-end
andxrel phasor kfqrel ;index 0-1 for distance start-end
andx = andxrel * (1-kstart01) + kstart01 ;final index for reading the table
asig table3 andx, ift, 1
endif
else ;if either not started or finished at wrap=0
asig = 0 ;don't produce any sound
endif
xout asig*kvol, kfin
endop
instr 1 ;creates the buffer and using button to create record and play event
iSwitchPin1 init 0
iLED_Pin1 init 1
kSwitch1 digiInBela iSwitchPin1
digiOutBela kSwitch1, iLED_Pin1
gibuf BufCt1 10 ; **Create buffer of 10 seconds**
; If Button Pressed, call Recording
gkRecord = kSwitch1
if changed(gkRecord) == 1 then
prints "PRESS THE button FOR RECORDING!\n"
event "i",2,0,-1
endif
;If button pressed, call Playing
iSwitchPin2 init 2
iLED_Pin2 init 3
kSwitch2 digiInBela iSwitchPin2
gkPlay = kSwitch2
gkOnOff init 0
kTrig trigger gkPlay, .5, 0
if kTrig == 1 then
gkOnOff += 1
endif
if changed(gkOnOff) == 1 then
if gkOnOff == 1 then
prints "PRESS THE button FOR PLAYING!\n"
event "i",3,0,-1
else
turnoff2 2, 1, 2
gkOnOff = 0
endif
endif
digiOutBela gkOnOff, iLED_Pin2
endin
instr 2 ;Using BufRec1 for recording
krec init 0 ;reset krec for multiple triggering
ain inch 1 ;audio input from channel 1
kplay BufRec1 ain*0.5, gibuf, krec, 0, 0, 0 ;record buffer without wrap
krec = 1
endin
instr 3; Using BufPlay1 for playing
aout,k0 BufPlay1 gibuf, gkOnOff, 1, 0.5, 0, 0, 1 ;play back buffer
out aout
endinIt looks like this might work (warning: untested!)
Add this to the start of instr 2:
gkend timeinsts
That should save the recording time to a global gk variable. Then pass that to instr 3:
instr 3; Using BufPlay1 for playing
aout,k0 BufPlay1 gibuf, gkOnOff, 1, 0.5, 0, gkend, 1 ;play back buffer
out aout
endin
It looks like the playback opcode is already set up to accept the end time variable in seconds.
I think… 
. I hope… 