sound synthesis with foo once again text & parenthesis but less - - PowerPoint PPT Presentation

sound synthesis with foo

“once again text & parenthesis – but less silly”

• non-realtime sound synthesis
• written in objective-c and scheme
• text interface (scheme)
• priority to high quality audio rendering over performance

lad meeting #2 zkm karlsruhe, april 30th 2004, martin rumori: foo sound synthesis – p. 1

foo history

• free software project
• *1993 zkm: gerhard eckel, ramón gonzález-arroyo
• NeXT platform, NeXT foundation library
• 1994: presentation at ICMC
• 1996 zkm: last version for a long time (2.1)
• only user: ramón gonzález-arroyo
• 2003 fraunhofer institute: first port to linux (martin rumori)

lad meeting #2 zkm karlsruhe, april 30th 2004, martin rumori: foo sound synthesis – p. 2

“foo”: the name

• from RFC 3092 (etymology of foo and bar):

"Used very generally as a sample name for absolutely anything, esp. programs and files (esp. scratch files)."

• in the beginning the admin was not willing to setup a cvs

repository

• now: sourceforge project (takeover of the “foo” sample

project) do they know what they did?

lad meeting #2 zkm karlsruhe, april 30th 2004, martin rumori: foo sound synthesis – p. 3

parts of foo

• foo kernel (objective-c)
• foo interface (c/objective-c)
• foo control library (scheme)
• abstraction
• envelope
• interface-lib
• node
• processes
• tools
• utilities

lad meeting #2 zkm karlsruhe, april 30th 2004, martin rumori: foo sound synthesis – p. 4

the first sine wave

(syn 1 3 (output~ 1 (sine~ (~ 440))))

• syn convenience macro: channels, synth duration
• ~ indicates signal-processing module
• output~ to specific channel
• “everything is a signal”

lad meeting #2 zkm karlsruhe, april 30th 2004, martin rumori: foo sound synthesis – p. 5

key features of foo

• simple
• clean semantics of context, task, time
• scalable sinc interpolator for resampling

(expensive!)

• bandlimited noise
• incremental mixing

lad meeting #2 zkm karlsruhe, april 30th 2004, martin rumori: foo sound synthesis – p. 6

context – task

context

(output~ 1 (gate~ (noise~) 2)) (output~ 2 (...))

task

reference, offset, samplerate..

context

(output~ 1 (gate~ (noise~) 2)) (output~ 2 (...))

task

reference, offset, samplerate..

soundfile

lad meeting #2 zkm karlsruhe, april 30th 2004, martin rumori: foo sound synthesis – p. 7

future plans

• port from old-stype NeXTStep to OpenStep
• LADSPA plugins as modules
• port to mac os x
• dynamically loadable modules (unit generators)
• typed signals
• rudimentary realtime support (→ jack support)
• cleanup context/task semantics

lad meeting #2 zkm karlsruhe, april 30th 2004, martin rumori: foo sound synthesis – p. 8