ImageSynth190402.scala

// version 02-Apr-2019 - Mellite 2.33.0
// written by Hanns Holger Rutz
// license: CC BY-SA 4.0

val in0         = ImageFileIn("in")
val w           = in0.width
val h           = in0.height
val hm          = h - 1
val in1         = in0.out(0)
val dur         = "dur"       .attr(10)
val numVoices   = "maxVoices" .attr(128).min(h)

val gainType    = "gain-type" .attr(0)
val gainDb      = "gain-db"   .attr(0.0)
val gainAmt     = gainDb.dbAmp
val fileType    = "out-type"  .attr(0)
val smpFmt      = "out-format".attr(1)
val sampleRate  = "sampleRate".attr(44100.0)

val minFreq     = "minFreq"   .attr(100)
val maxFreq     = "maxFreq"   .attr(18000)
val fadeTime    = "fadeTime"  .attr(0.1)
val numFrames   = (dur * sampleRate).floor.max(2)
val fadeFrames  = (fadeTime * sampleRate).floor.max(1)
val inverted    = "inverted".attr(0) > 0
val in = in1 * (1 - inverted) + (-in1 + (1: GE)) * inverted
val minAmp      = "minLevel".attr(-60.0).dbAmp
val maxAmp      = "maxLevel".attr(  0.0).dbAmp

val framesXY    = numFrames * numVoices
val x0          = LFSaw(1.0/numFrames).linLin(-1, 1, 0, numFrames)
val frame       = x0.take(framesXY)
val xs          = w / numFrames
val x           = frame * xs
val voiceIdx    = (Frames(x) / numFrames).floor
val ys          = h / numVoices
val y0          = voiceIdx * ys
val y           = y0 + WhiteNoise(0.5)
val freq        = y .linExp(0, hm, maxFreq, minFreq)

val amp0        = ScanImage(in, width = w, height = h, x = x, y = y,
  wrap = 0, zeroCrossings = 0)
val amp1        = amp0.linExp(0, 1, minAmp, maxAmp)
val fdIn        = frame.clip(0, fadeFrames) / fadeFrames
// N.B.: this is still a problem in FScape 2.16: BinaryOp is
// not commutative with respect to signal lengths!
val fdOut       = (-frame + numFrames).clip(0, fadeFrames) / fadeFrames
val fade        = fdIn * fdOut
val amp         = amp1 * fade
val osc         = (SinOsc(freq/sampleRate) * amp).take(framesXY)

val synthesized = Frames(osc)

def mkProgress(frames: GE, n: GE, label: String): Unit =
  Progress(frames / n, Metro(sampleRate) | Metro(n - 1),
    label)

mkProgress(synthesized, framesXY, "synthesized")

// XXX TODO --- this is a limitation of using overlap-add,
// we have to shift at least one frame per window...
val mix         = OverlapAdd(osc, size = numFrames, step = 1)
val framesOut   = numFrames + (numVoices - 1)
val sig0        = mix

val sig = If (gainType sig_== 0) Then {
  val rsmpBuf   = BufferDisk(sig0)
  val rMax      = RunningMax(Reduce.max(sig0.abs))
  val read      = Frames(rMax)
  mkProgress(read, framesOut, "analyze")
  val maxAmp    = rMax.last
  val div       = maxAmp + (maxAmp sig_== 0.0)
  val gainAmtN  = gainAmt / div
  rsmpBuf * gainAmtN

} Else {
  sig0 * gainAmt
}

val written     = AudioFileOut("out", sig, fileType = fileType,
  sampleFormat = smpFmt, sampleRate = sampleRate)
mkProgress(written, framesOut, "written")