Sound Processor

Final C++ project: a CLI WAV sound processor with a filter pipeline.

Supported WAV format

The project intentionally supports the assignment format only:

• PCM
• mono
• 44100 Hz
• signed 16-bit samples

Build

cmake -S . -B build
cmake --build build

CLI usage

./build/sound_processor/sound_processor [-i input.wav] [-o output.wav] [-f filter [params...]]...

Examples:

./build/sound_processor/sound_processor -i input_example.wav -f lowpass 101 -f ampl 10 -o output_example.wav
./build/sound_processor/sound_processor -o sine.wav -f generator sin 440 2000 -f fade in 250
./build/sound_processor/sound_processor -i input_example.wav -o output_example.wav -f lowpass 5 -f normalize 0.9

JSON usage

./build/sound_processor/sound_processor -c pipeline.json

Example JSON:

{
  "output": "sine.wav",
  "filters": [
    { "name": "generator", "params": ["sin", 440, 2000] },
    { "name": "fade", "params": ["in", 250] },
    { "name": "ampl", "params": [0.8] }
  ]
}

Filters

Required transform filters:

• ampl factor
• normalize [peak]
• silence unit start end, where unit is sec or ms
• timestretch factor
• lowpass window_size

Required generators:

• generator sin frequency_hz duration_ms
• generator am amplitude carrier_hz modulation_hz depth duration_ms
• generator fm amplitude carrier_hz modulation_hz deviation_hz duration_ms

Extra custom filters:

• fade in duration_ms
• fade out duration_ms
• reverse

Architecture

The code is split by responsibility:

• app: application orchestration, result codes and logging
• cli: command-line parsing and filter descriptors
• wav: WAV reader/writer and waveform model
• filtering: IFilter, Pipeline, registry and factory
• filters: concrete filters and generators
• json: JSON pipeline loader
• tests: unit-style tests for core components

Filters are created through FilterRegistry, so adding a new filter does not require changing parser or pipeline logic.

Tests

cmake --build build
./build/sound_processor/sound_processor_tests
cd build && ctest --output-on-failure