Lib.rs

# Rustic Audio Tool

`RusticAudio` is a Rust library for recording, processing, and playing back audio with support for DSP effects and Opus compression. It provides a simple API for handling audio files, including recording, playback, and encoding.

## Features

- Record audio to WAV files.
- Apply DSP effects to audio files.
  - RMS normalization
  - Spectral noise gate
  - Amplitude gate
  - High-pass and low-pass filters
  - Gain boost
  - Lookahead limiter
- Encode audio to Opus format.
- Playback original, processed, and Opus-encoded audio.
- Thread-safe operations with atomic flags for state management.

## Installation

Add the following to your `Cargo.toml`:

```toml
[dependencies]
rustic_audio_tool = "0.0.1"

Linux Debian/Ubuntu-based Dependencies Installation

sudo apt-get install libasound2-dev pkg-config
sudo apt-get install libopus-dev

Usage

Creating an Instance

use rustic_audio_tool::RusticAudio;

let mut audio_tool = RusticAudio::new();

Recording Audio

if let Err(e) = audio_tool.start_recording("output.wav") {
    eprintln!("Failed to start recording: {}", e);
}

// Stop recording
if let Err(e) = audio_tool.stop_recording() {
    eprintln!("Failed to stop recording: {}", e);
}

Playing Audio

• Play Original WAV:

  if let Err(e) = audio_tool.play_original_wav("output_original.wav") {
      eprintln!("Failed to play original WAV: {}", e);
  }
  

• Play Processed WAV:

  if let Err(e) = audio_tool.play_processed_wav("output_processed.wav") {
      eprintln!("Failed to play processed WAV: {}", e);
  }
  

• Play Unprocessed Opus:

  if let Err(e) = audio_tool.play_unprocessed_opus("output_unprocessed.opus") {
      eprintln!("Failed to play unprocessed Opus: {}", e);
  }
  

• Play Processed Opus:

  if let Err(e) = audio_tool.play_processed_opus("output_processed.opus") {
      eprintln!("Failed to play processed Opus: {}", e);
  }
  

• Stop Playback:

  if let Err(e) = audio_tool.stop_playback() {
      eprintln!("Failed to stop playback: {}", e);
  }
  

Processing Audio

• Apply DSP Effects:

  if let Err(e) = audio_tool.process_file("input.wav", "output_processed.wav") {
      eprintln!("Failed to process file: {}", e);
  }
  

• Encode to Opus:

  if let Err(e) = audio_tool.encode_to_opus("input.wav", "output.opus") {
      eprintln!("Failed to encode to Opus: {}", e);
  }
  

Managing Opus Settings

• Set Opus Bitrate:

  audio_tool.set_opus_bitrate(64000); // Set bitrate to 64 kbps
  

• Get Opus Bitrate:

  let bitrate = audio_tool.get_opus_bitrate();
  println!("Current Opus bitrate: {} kbps", bitrate);
  

Querying Audio Information

let info = audio_tool.get_audio_info();
println!("File size: {} bytes", info.file_size);
println!("Duration: {} seconds", info.duration);
println!("Last message: {}", info.last_message);

Checking States

• Check if Recording:

  if audio_tool.is_recording() {
      println!("Currently recording...");
  }
  

• Check if Playing:

  if audio_tool.is_playing() {
      println!("Currently playing...");
  }
  

Flags

The library uses the following flags to manage state:

• is_recording: Indicates if recording is in progress.
• is_playing: Indicates if processed audio playback is in progress.
• is_playing_original: Indicates if original WAV playback is in progress.
• is_playing_unprocessed_opus: Indicates if unprocessed Opus playback is in progress.

DSP Settings

The AudioProcessor provides several configurable DSP settings to control audio processing. These settings can be adjusted to enable or disable specific effects or fine-tune their behavior.

Available DSP Settings

Example: Configuring DSP Settings

You can customize the DSP settings by modifying the AudioProcessor instance:

use rustic_audio_tool::AudioProcessor;

let mut processor = AudioProcessor::new(48000.0); // Set sample rate to 48 kHz

// Enable or disable specific effects
processor.rms_enabled = true;
processor.filters_enabled = true;
processor.spectral_gate_enabled = true;

// Adjust parameters
processor.gain_db = 10.0; // Increase gain boost to 10 dB
processor.lowpass_freq = 20000.0; // Set low-pass filter cutoff to 20 kHz
processor.highpass_freq = 75.0; // Set high-pass filter cutoff to 75 Hz
processor.limiter_threshold_db = -3.0; // Set limiter threshold to -3 dB

Processing an Audio File

Once the DSP settings are configured, you can process an audio file:

if let Err(e) = processor.process_file("input.wav", "output_processed.wav") {
    eprintln!("Failed to process file: {}", e);
}

Opus Encoding Settings

The OpusEncoder provides configurable settings for encoding audio to the Opus format. These settings allow you to control the bitrate and other encoding parameters.

Available Settings

Example: Configuring Opus Encoder

You can customize the Opus encoder settings by modifying the OpusEncoder instance:

use rustic_audio_tool::OpusEncoder;

let mut encoder = OpusEncoder::new();

// Set the bitrate to 12 kbps
encoder.set_bitrate(12000);

// Get the current bitrate
let bitrate = encoder.get_bitrate();
println!("Current Opus bitrate: {} bps", bitrate);

Encoding a WAV File to Opus

To encode a WAV file to Opus format, use the encode_wav_to_opus method:

if let Err(e) = encoder.encode_wav_to_opus("input.wav", "output.opus") {
    eprintln!("Failed to encode WAV to Opus: {}", e);
}

How the Encoding Works

1. Resampling: If the input WAV file is not 48 kHz, it will be resampled to 48 kHz.
2. Mono Conversion: If the input WAV file is stereo, it will be converted to mono by isolating the left channel.
3. Encoding: The audio is encoded to Opus format using the specified bitrate and channel configuration.
4. Output: The encoded Opus file is saved to the specified output path.

Opus Header and Metadata

The encoder automatically adds the following metadata to the Opus file:

• OpusHead: Contains information about the Opus stream (e.g., version, channel count, sample rate).
• OpusTags: Contains vendor information.

License

This project is licensed under the GPLv3 License. See the LICENSE file for details.