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Description:

waveform extractor

waveform_extractor #

A Lightweight dart library for extracting waveform data from audio streams using Amplituda.
Platforms Support: #

Android: ✅

Installation #

Add as dependency
in android/build.gradle:

buildscript {
repositories {
google()
mavenCentral()
maven { url 'https://jitpack.io' } // <-- add this
}
}
allprojects {
repositories {
google()
jcenter()
mavenCentral()
maven { url 'https://jitpack.io' } // <-- add this
}
}
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Usage #

Basic Usage:

final waveformExtractor = WaveformExtractor();
final audioSourceFile = audioPath; // source could be a path to local file
final audioSourceNetwork = audioUrl; // or a network url
final result = await waveformExtractor.extractWaveform(audioSourceFile);
print("Waveform: $result");

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Available Data:

final result = await waveformExtractor.extractWaveform(audioFile.path);
final List<int> waveformData = result.waveformData;
final List<int> amplitudesForFirstSecond = result.amplitudesForFirstSecond;
final Duration duration = result.duration;
print("Waveform Data: $waveform");
print("Waveform Data (first second): $amplitudesForFirstSecond");
print("Waveform Audio Duration: $duration");
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With Progress:

waveformExtractor.extractWaveform(
source,
onProgress: (progress) {
final percentage = progress.percentage; // current percentage (0-100)
final operation = progress.operation; // the type of operation (processing, decoding, downloading)
final source = progress.source; // the current source being extracted.
final type = progress.type; // the type of event (start, progress, stop, done)
print("Progress $progress");
},
);
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Caching:

// Caching is useful to avoid unnecessary re-extractions.
_waveformExtractor.extractWaveform(
source,
useCache: true, // caching is enabled by default.
cacheKey: 'my_unique_key', // optional cache key used for storing output data, defaulted to hashcode of source path.
);

// Clearing cache key:
_waveformExtractor.clearCache(
audioPath: audioPath, // audio source if you have't specied cacheKey before
cacheKey: cacheKey, // clears specific cache key
);

// Clearing all cache:
_waveformExtractor.clearAllWaveformCache();

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Compressing:

// Compressing is a good choice for long audios, as the resulted data would be huge; causing, possibly, memory overload or jank
final staticSamples = 4; // use default sample for all audios
final dynamicSamples = _waveformExtractor.getSampleRateFromDuration(audioDuration: audioDuration); // or dynamically change depending on audio duration
_waveformExtractor.extractWaveform(
source,
samplesPerSecond: dynamicSamples,
);
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Benchmarks #

waveform_extractor is extremely fast, thanks to the inlying ffmpeg implementations made by Amplituda
Estimated extraction time:

1 second for a 3min 20s audio.
20 seconds for a 1 hour audio.

For more details and real-time testing, check out the full example

Special thanks #
@lincollincol for providing Amplituda Library based on FFMPEG.