/* TestCompressor2.ino Bob Larkin 23 January 2021
*
* Test of AudioEffectCompressor2_F32
* See AudioEffectCompressor2_F32.h for much detail and explanation.
* Choice of test signals is a single sine wave, a random sequence
* of sine waves of varying frequency and amplitude, a power
* sweep or a pulse of sine wave to see transient behavior.
*
* This version is for the Chip Audette OpenAudio_F32 Library. and
* thus has that interface structure.
*
* NOTE: As of 23 January 2021, the compressor AudioEffectWDRC2_F32.h
* was not finalized and could change in detail. Use here with
* this in mind.
*/
#include "Audio.h"
#include "OpenAudio_ArduinoLibrary.h"
#define RANDOM 1
#define POWER_SWEEP 2
#define PULSE 3
#define ALTERNATE 4
// Edit in one of the last four, here:
#define SIGNAL_SOURCE RANDOM
AudioSynthWaveformSine_F32 sine1; // Test signal
AudioEffectCompressor2_F32 compressor1; // Audio Compressor
AudioEffectGain_F32 gain0; // Sets volume sent to output
AudioEffectGain_F32 gain1; // Sets the same
AudioOutputI2S_F32 i2sOut;
AudioConnection_F32 patchCord1(sine1, 0, compressor1, 0);
AudioConnection_F32 patchCord2(compressor1, 0, gain0, 0);
AudioConnection_F32 patchCord3(compressor1, 0, gain1, 0);
AudioConnection_F32 patchCord4(gain0, 0, i2sOut, 0);
AudioConnection_F32 patchCord5(gain1, 0, i2sOut, 1);
AudioControlSGTL5000 sgtl5000_1;
uint16_t count17, count27;
float level = 0.05f;
void setup(void) {
AudioMemory(50);
AudioMemory_F32(100);
Serial.begin(300); delay(1000);
Serial.println("*** Test Compressor2 Gain Compressor **");
count17 = 0;
count27 = 0;
sine1.frequency(1000.0f);
sine1.amplitude(0.05f);
// CAUTION - If using ears on the output, adjust the following two carefully
gain0.setGain_dB(-25.0f); // Consider (-50.0f);
gain1.setGain_dB(-25.0f); // Consider (-50.0f);
sgtl5000_1.enable();
int16_t delaySize = 256; // Any power of 2, i.e., 256, 128, 64, etc.
compressor1.setDelayBufferSize(delaySize);
// *** Here are four sample compressor curves. ***
// Select by number here, and re-compile.
#define COMPRESSOR_CURVE 1
#if COMPRESSOR_CURVE == 1
// Specify arbitrary 5-segment compression curve. An example of specifying
// compressionCurve. See AudioEffectCompressor2_F32.h for more details.
struct compressionCurve crv = { -2.0f, 0.0f, // margin, offset
{0.0f, -10.0f, -20.0f, -30.0f, -1000.0f}, // kneeDB[]
{ 100.0f, 2.5f, 1.5f, 1.0f, 1.0f} }; // compressionRatio
compressor1.setCompressionCurve(&crv);
compressor1.begin();
#endif
AudioEffectCompressor2_F32 *pc1 = &compressor1; // Needed for any *macro* defined curve.
// Defines pointer to compressor1, called pc1
#if COMPRESSOR_CURVE == 2
// Sample of a limiter at -3 dB out for highest 15 dB, limiter macro
limiterBegin(pc1, -3.0f, -15.0f); // pc1 is a pointer to compressor1 object
#elif COMPRESSOR_CURVE == 3
// Another one, a basic compressor curve:
// (pobject, linearInDB, compressionRatioDB) <- macro parameters
basicCompressorBegin(pc1, -25.0f, 2.0);
#elif COMPRESSOR_CURVE == 4
// And one using a high gain region as a squelch (but no clicks or pops)
// (squelchIndB, linearInDB, compressionIndB, compressionRatioDB) <- macro parameters
squelchCompressorBegin(pc1, -40.0f, -25.0f, -10.0f, 1.5f);
#endif
}
void loop(void)
{
static uint16_t kk;
#if SIGNAL_SOURCE == RANDOM
/* To give an audio signal with interest, we alter the frequency
* every 17 blocks (49 msec) and alter the level every 27 b;ocks
* (78.4 msec) The pattern keeps changing to be more interesting
* Janet thinks it is aliens. */
delay(3);
// Serial.print(" CurInDB= "); Serial.print( compressor1.getCurrentInputDB(), 3);
// Serial.print(" CurrentGainDB= "); Serial.println( compressor1.getCurrentGainDB(), 3);
// Serial.print("Maximum Input = "); Serial.println(compressor1.getvInMaxDB());
if(count17++ == 17)
{
// Put a delay in, like between words
if(randUniform() < 0.03)
delay( (int)(1500.0*randUniform()) );
count17 = 0;
float ff = 350.0f + 700.0f*sqrtf( randUniform() );
sine1.frequency(ff); //Serial.println(ff);
}
if(count27++ == 27)
{
count27 = 0;
level = 1.0f*powf( randUniform(), 2 ); // 0 to 1, emphasizing 0 end
sine1.amplitude(level);
}
#elif SIGNAL_SOURCE == POWER_SWEEP
if(count17++ == 17)
{
count17 = 0;
level *= 1.0592537f; // 0.5 dB
delay(200);
if(level > 1.0f)
{
level=0.001f;
delay(500);
}
Serial.print( compressor1.getCurrentInputDB(), 3);
Serial.print(","); Serial.println( compressor1.getCurrentGainDB(), 3);
sine1.amplitude(level);
}
#elif SIGNAL_SOURCE == PULSE
// A pulse, repeats every 3 minutes or so
delay(3);
if(count17 == 5) sine1.amplitude(0.0f); // Settling
else if(count17 == 498) compressor1.printOn(true); //record it
else if(count17 == 500) sine1.amplitude(0.03f);
else if(count17 == 510) sine1.amplitude(0.0f);
else if(count17 == 700) compressor1.printOn(false);
// or build your own transient test pulse here
count17++;
#endif
}
/* randUniform() - Returns random number, uniform on (0, 1)
* The "Even Quicker" uniform random sample generator from D. E. Knuth and
* H. W. Lewis and described in Chapter 7 of "Numerical Receipes in C",
* 2nd ed, with the comment "this is about as good as any 32-bit linear
* congruential generator, entirely adequate for many uses."
*/
#define FL_ONE 0X3F800000
#define FL_MASK 0X007FFFFF
float randUniform(void)
{
static uint32_t idum = 12345;
union {
uint32_t i32;
float f32;
} uinf;
idum = (uint32_t)1664525 * idum + (uint32_t)1013904223;
// return (*(float *)&it); // Cute convert to float but gets compiler warning
uinf.i32 = FL_ONE | (FL_MASK & idum); // So do the same thing with a union
return uinf.f32 - 1.0f;
}