What is HART?

HART is a testing framework for audio DSP. It's a header-only library, and compatible with C++11.

Create a simple test signal: auto mySignal = SineWave (440_Hz);
Create automation for any DSP: auto myEnvelopeCurve = SegmentedEnvelope (-10_dB).hold (5_ms).rampTo (0_dB, 25_ms)
Create an effect for a signal with sample-accurate automation: auto myGain = GainDb ().withEnvelope (GainDb::gainDb, myEnvelopeCurve);
Add DSP chain to a signal: auto envelope = SineWave (440_Hz) >> HardClip (-6_dB) >> MyCustomDSP() >> GainDb().withEnvelope (GainDb::gainDb, myEnvelopeCurve) >> LPF (1.2_kHz);

Test case example

HART_TEST_WITH_TAGS ("My Test Name", "[my][test][tags]")
{
    // Create effect automation
    const auto myEnvelopeCurve = SegmentedEnvelope (-10_dB)
        .hold (5_ms)
        .rampTo (0_dB, 25_ms, SegmentedEnvelope::Shape::sCurve)
        .hold (5_ms)
        .rampTo (-10_dB, 35_ms, SegmentedEnvelope::Shape::linear);
 
    // Play wav file through your effect and test the output
    processAudioWith (MyEffect().withEnvelope (GainLinear::someAutomatedParam, myEnvelopeCurve))
        .withLabel ("Pre-recorded wav test")
        .withInputSignal (WavFile ("my_test_input.wav"))
        .withSampleRate (48000_Hz)
        .withBlockSize (2048)
        .withValue (MyEffect::someOtherParam, -oo_dB)
        .withValue (MyEffect::andAnotherParam, 3.5_kHz)
        .withDuration (75_ms)
        .assertTrue (PeaksBelow (-1_dB))
        .expectTrue (EqualsTo (WavFile ("my_test_reference_output.wav")))
        .process();
 
    // Create test signal instead of using pre-rendered wav
    const auto myTestSignal = SineWave (2.2_kHz) >> GainDb().withEnvelope (GainDb::gainDb, SegmentedEnvelope) >> HardClip (-3_dB) >> HPF (100_Hz);
 
    // Play generated signal through your effect, save input and output audio if fails
    processAudioWith (MyEffect())
        .withLabel ("Generated signal test")
        .withValue (MyEffect::someParam, 67_percent)
        .inStereo()
        .withInputSignal (myTestSignal)
        .saveInputTo ("my_failed_test_input.wav")
        .saveOutputTo ("my_failed_test_output.wav")
        .expectTrue (PeaksAt (-3_dB))
        .expectFalse (equalsTo (SineWave (2.2_kHz) >> HardClip (-3_dB) >> GainDb (+1_dB)))
        .process();
 
    // Traditional unit test assertions are also supported
    HART_ASSERT_TRUE (MyEffect().isAwesome());
    HART_EXPECT_TRUE (someValue == someOtherValue);
}

Output example

On pass:

88                                         
88                                    ,d   
88                                    88   
88,dPPYba,   ,adPPYYba,  8b,dPPYba, MM88MMM
88P'    "8a  ""     `Y8  88P'   "Y8   88   
88       88  ,adPPPPP88  88           88   
88       88  88,    ,88  88           88,  
88       88  `"8bbdP"Y8  88           "Y888
 
[   <3   ] GainDb - GainDb Values - passed
[   <3   ] GainDb - Channel Layouts - passed
[   <3   ] HardClip - Threshold Values - passed
[   <3   ] DSP Chains - Basic Gain - passed
[   <3   ] DSP Chains - Order Matters - passed
[   <3   ] DSP Chains - Long Chains - passed
[   <3   ] Envelope - Gain Envelope Regression - passed
[   <3   ] Host - DSP Move, Copy and Transfer - passed
 
[ PASSED ] 8/8

On fail:

88                                         
88                                    ,d   
88                                    88   
88,dPPYba,   ,adPPYYba,  8b,dPPYba, MM88MMM
88P'    "8a  ""     `Y8  88P'   "Y8   88   
88       88  ,adPPPPP88  88           88   
88       88  88,    ,88  88           88,  
88       88  `"8bbdP"Y8  88           "Y888
 
[  </3   ] GainDb - GainDb Values - failed
-------------------------------------------
expectTrue() failed at "Attenuation"
Condition: PeaksAt (-2.5_dB, 0.001000)
Channel: 0
Frame: 11
Timestamp: 0.100 seconds
Sample value: 0.707941 (-3.0 dB)
Observed audio peaks at -3.0 dB
-------------------------------------------
[   <3   ] GainDb - Channel Layouts - passed
[   <3   ] HardClip - Threshold Values - passed
[   <3   ] DSP Chains - Basic Gain - passed
[   <3   ] DSP Chains - Order Matters - passed
[   <3   ] DSP Chains - Long Chains - passed
[  </3   ] Envelope - Gain Envelope Regression - failed
-------------------------------------------
expectTrue() failed at "Envelope B"
Condition: EqualsTo (WavFile ("Gain Envelope B.wav", Loop::no), 0.000010)
Channel: 0
Frame: 1
Timestamp: 0.000 seconds
Sample value: 0.107372 (-19.4 dB)
Expected sample value: 0.104125 (-19.6 dB), difference: 0.003246 (-49.8 dB)
-------------------------------------------
expectTrue() failed at "Envelope C"
Condition: EqualsTo (WavFile ("Gain Envelope C.wav", Loop::no), 0.000010)
Channel: 0
Frame: 1
Timestamp: 0.000 seconds
Sample value: 0.311974 (-10.1 dB)
Expected sample value: 0.310784 (-10.2 dB), difference: 0.001190 (-58.5 dB)
-------------------------------------------
[   <3   ] Host - DSP Move, Copy and Transfer - passed
 
[ PASSED ] 6/8
[ FAILED ] 2/8

What's next?

See Testing Your DSP in HART to learn how to use it.

Note that HART is still in its infancy! It still needs some time to land on somewhat final API, and become a complete and bug-free solution we all want it to be. Speaking of complete and bug-free, contributions are very welcome!

Github repo: https://github.com/daleonov/HART