wav_io 3.0.2

RIFF-WAV audio file format handling and manipulation written in pure dart.

example/README.md

wav_io Examples

This directory contains example scripts showing how to use the wav_io library for reading, writing, streaming, and manipulating WAV audio files.

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1. Sine Generator (sine.dart)

Generates a sinusoidal test wave and saves it as a WAV file using the requested format.

Usage

dart example/lib/sine.dart \
  --samplerate <sample_rate> \
  --duration <duration_in_seconds> \
  --freq <frequency_in_hz> \
  --format <u8|i16|i24|i32|f32|f64> \
  -o <output.wav>

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2. Wave Concatenator (concat.dart)

Concatenates multiple WAV audio files into a single, merged output WAV file. Converts mono tracks to stereo and converts audio to Float32 format dynamically during the mixing process.

Usage

dart example/lib/concat.dart <in1.wav> <in2.wav> <in3.wav> ... -o <output.wav>

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3. Streaming Swept-Sine Generator (stream_write.dart)

Demonstrates how to use WavWriter to stream and write audio chunks to disk on the fly, which keeps memory usage low even for large files. Generates an exponential frequency sweep in stereo.

Usage

dart example/lib/stream_write.dart \
  --samplerate <sample_rate> \
  --duration <duration_in_seconds> \
  --freq-start <start_freq_in_hz> \
  --freq-end <end_freq_in_hz> \
  -o <output.wav>

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4. Metadata and Format Inspector (info.dart)

Reads a WAV file and prints comprehensive format specifications along with RIFF LIST INFO metadata.

Usage

dart example/lib/info.dart <input.wav>

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5. Audio Reverser (reverse.dart)

Demonstrates how to reverse a WAV audio file from end to start. It reads input blocks backwards using WavReader, reverses the samples for each channel, and writes the reversed blocks sequentially using WavWriter. This is a memory-efficient way to reverse long audio files.

Usage

dart example/lib/reverse.dart -i <input.wav> -o <output.wav>

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6. Multi-Channel to Mono Merger (merge_mono.dart)

Demonstrates how to merge all audio channels from a WAV file into a single mono track. It reads input chunks using WavReader, sums the sample values across all channels, and writes the resulting mono chunks sequentially using WavWriter. This is a memory-efficient way to process and mix multi-channel WAV files.

Usage

dart example/lib/merge_mono.dart -i <input.wav> -o <output.wav>