flutter_soloud provides various audio effects and filters that can be applied globally to all sounds or individually to specific sound sources.
Note: individual filters are not supported on the web platform.
echo- Echo/delay effect SoLoud documentationfreeverbFilter- High quality reverb effect SoLoud documentationbiquadResonant- Multi-mode filter (lowpass, highpass, bandpass) SoLoud documentationbassboost- Low frequency enhancement SoLoud documentationflanger- Classic modulation effect SoLoud documentationwaveShaper- Audio distortion/wave shaping SoLoud documentationlofi- Bit depth and sample rate reduction SoLoud documentationrobotize- Voice modulation effect SoLoud documentationequalizer- Multi-band equalizer flutter_soloud sourcepitchShifter- Change pitch without affecting speed flutter_soloud sourcecompressor- Dynamic range compression flutter_soloud sourcelimiter- Peak volume control flutter_soloud source
Information
- Individual filters for sounds are not supported on Web platform.
- freeverb supports only 2 channels. So using freeverb as global filter, the engine should be initializeded using the default 2 channels and when using it as sound filter it must be with 2 channels.
Apply filters to all audio output:
dart
// Initialize SoLoud with filters
await SoLoud.instance.init();
// Access filters through the filters property
final filters = SoLoud.instance.filters;
// Activate an effect
filters.echoFilter.activate();
// Configure parameters
filters.echoFilter.delay.value = 0.2;
filters.echoFilter.decay.value = 0.7;dart
// Fade parameter over time
filters.echoFilter.delay.fadeFilterParameter(
to: 0.5,
time: Duration(milliseconds: 1000),
);
// Oscillate parameter
filters.echoFilter.decay.oscillateFilterParameter(
from: 0.2,
to: 0.8,
time: Duration(milliseconds: 2000),
);dart
// Set up echo
filters.echoFilter.activate();
filters.echoFilter
..delay.value = 0.2 // 200ms delay
..decay.value = 0.7 // 70% decay
..filter.value = 1.0; // No filteringdart
// Enhance low frequencies
filters.parametricEqFilter
..stftWindowSize.value = 2048 //STFT window size parameter (32-4096, power of 2, default 1024)
..numBands.value = 64 // number of bands parameter (1-64, default 3)
..bandGain(0).value = 1 // gain parameter for a specific band
..bandGain(1).value = 0.5
..bandGain(2).value = 1.3;dart
// Enhance low frequencies
filters.bassboostFilter.activate();
filters.bassboostFilter
..boost.value = 2.0; // Double bassdart
// Add retro sound quality
filters.lofiFilter.activate();
filters.lofiFilter
..sampleRate.value = 8000 // 8kHz sampling
..bitDepth.value = 4; // 4-bit depthdart
// Add space/room effect
filters.freeverbFilter.activate();
filters.freeverbFilter
..roomSize.value = 0.8 // Large room
..damping.value = 0.5 // Medium damping
..width.value = 1.0; // Full stereo widthCreate evolving soundscapes:
dart
// Start with normal reverb
filters.freeverbFilter.activate();
filters.freeverbFilter.roomSize.value = 0.5;
// Gradually increase room size
filters.freeverbFilter.roomSize.fadeFilterParameter(
to: 0.9,
time: Duration(seconds: 3),
);
// Oscillate damping
filters.freeverbFilter.damping.oscillateFilterParameter(
from: 0.2,
to: 0.8,
time: Duration(milliseconds: 2000),
);- Use filters sparingly to avoid CPU overhead
- Be careful with feedback parameters in echo/reverb
- Consider mobile device performance
- Deactivate unused filters
- Use parameter fading for smooth transitions
- Test on various devices and platforms
- Monitor CPU usage when using multiple filters