Opus to CAF Converter

This repository provides a Go package for converting Opus audio files to Core Audio Format (CAF) files. The Opus codec is known for high-quality, low-latency audio compression, while the Core Audio Format is a container format developed by Apple for use with their Core Audio framework.

Significance

This converter is particularly important because Apple does not natively support the Opus codec in its ecosystem. This limitation necessitates the conversion of Opus files to a format that Apple's platforms can readily use, such as CAF.

Advantages of Opus

Opus is a highly efficient audio codec that can significantly reduce file sizes compared to other formats:

• Opus files are typically about half the size of MP3 files at equivalent quality
• This size reduction is achieved without compromising audio fidelity

Efficient Conversion

A key feature of this converter is its ability to perform the Opus to CAF conversion:

• Without relying on external tools like FFmpeg
• While maintaining the original audio quality (lossless conversion)
• Directly in Go, making it easy to integrate into existing Go projects

Installation

To install the package, use the following command:

go get github.com/nabil6391/opus_caf_converter

Usage

As a Package

Import the package in your Go code:

import "github.com/nabil6391/opus_caf_converter/caf"

Use the ConvertOpusToCaf function:

func main() {
    inputOpus := "path/to/input.opus"
    outputCaf := "path/to/output.caf"
    err := caf.ConvertOpusToCaf(inputOpus, outputCaf)
    if err != nil {
        log.Fatalf("Conversion failed: %v", err)
    }
    fmt.Println("Conversion successful!")
}

As a CLI Tool

You can also use this converter as a command-line tool:

1. Install the CLI tool:

go install github.com/nabil6391/opus_caf_converter@latest

2. Run the converter:

opus_caf_converter input.opus output.caf

Features

• Supports conversion of Opus files to CAF format
• Handles both mono and stereo audio channels
• Preserves audio quality during conversion (lossless conversion)
• Efficient processing of large files
• No dependency on external tools like FFmpeg

Implementation Details

The conversion process involves several steps:

1. Parsing the Opus file structure
2. Extracting audio data and metadata
3. Constructing the CAF file with appropriate headers and chunks
4. Writing the converted data to the output file

Testing

The package includes a comprehensive test suite. Run the tests using:

go test ./...

Limitations

• Currently supports only mono and stereo audio channels
• Does not support all possible Opus configurations

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• The Opus codec developers
• Apple's Core Audio Format documentation

For more detailed information about the implementation, please refer to the source code and comments within the package.