A Minimal MP3 to WAV Slicing/Converting tool based on minimp3

This project provides a utility to slice an MP3 file into multiple WAV segments. It uses the minimp3 library, a minimalistic MP3 decoder library, to decode MP3 files and supports SIMD optimizations for improved performance.

Features

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• Single dependency of minimp3 which is already included in this directory.
• Slices the decoded audio based on specified time ranges.
• Supports SIMD optimizations (AVX) for faster processing.
• Flexible slicing functionality to support multiple segments.
• Outputs each slice as a separate WAV file.
• To switch between 16-bit PCM and floating-point output, simply comment out or uncomment the #define MINIMP3_FLOAT_OUTPUT directive. When uncommented, the output will be in floating-point format; when commented out, the output will be in 16-bit PCM format.

Dependency

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• minimp3: A minimalistic MP3 decoder library. (Included in the directory)

Installation

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1. Clone the repository:

   git clone https://github.com/your-username/slice_mp3_to_wav.git
   cd slice_mp3_to_wav

2. Compile source file (mp3_wav.c)

   gcc -mavx -o mp3_to_wav mp3_wav.c -O3 -march=native -ffast-math -funroll-loops -lm 

Usage

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To use the program, simply run the compiled executable with the following arguments:

• input.mp3: The input MP3 file to be sliced.
• output_folder: The file name .
• starts: A comma-separated list of start times for each slice.
• ends: A comma-separated list of end times for each slice.

Example:

1. Download a test mp3 file

wget -O "test.mp3" "https://onlinetestcase.com/wp-content/uploads/2023/06/10-MB-MP3.mp3"

2. Convert

./mp3_to_wav "test.mp3" "a,b" "1,2" "2,3" 

Expected output

a_slice_1.wav Float 32 bit WAV file written successfully.
a_slice_2.wav Float 32 bit WAV file written successfully.

Functions I/O

1. slice_mp3_to_wav

Inputs:

• char *input_filename: Path to the MP3 file to convert.
• char *output_fn: Prefix for output WAV filenames.
• float lengths[][2]: Array of time ranges (start and end times) for slicing the audio.
• unsigned short length: The number of slices to create.

Outputs:

• info: A structure containing the sample rate, bit rate, and number of channels of the MP3 file.

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2. get_lengths

Inputs:

• char *starts: Comma-separated string of start times.
• char *ends: Comma-separated string of end times.
• float lengths[][2]: Array to store the parsed start and end times.

Outputs:

• lengths: A populated array of start and end times.
• Returns: The number of valid time slices parsed.

License

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This project is licensed under the MIT License.

Acknowledgments

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This project uses the minimp3 library, a minimalistic MP3 decoder library developed and maintained by Lieff.

Original minimp3 repository