872dbb7264
- Implement radix-2 Cooley-Tukey FFT algorithm - Add windowing functions: Hann, Hamming, Blackman, Rectangular - Support configurable frequency bin count - Add peak detection with configurable decay rate - Include temporal smoothing for visualization - Add spectrum analysis example program - Proper memory management with init/close lifecycle Bug-fix: Add buffer bounds checking to prevent overflow when sample count is not power of 2 Signed-off-by: Srikanth Patchava <spatchava@meta.com>
95 lines
4.1 KiB
C
95 lines
4.1 KiB
C
/**********************************************************************************************
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*
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* raudio_analyzer - Audio spectrum analysis module for raylib
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*
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* DESCRIPTION:
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* FFT-based audio spectrum analysis with windowing functions, peak detection,
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* and smoothing for real-time audio visualization.
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*
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* FEATURES:
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* - Radix-2 Cooley-Tukey FFT algorithm
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* - Multiple windowing functions (Hann, Hamming, Blackman, Rectangular)
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* - Configurable frequency bin count
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* - Peak detection with configurable decay rate
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* - Temporal smoothing for stable visualization
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*
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* LICENSE: zlib/libpng
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*
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* Copyright (c) 2024 raylib contributors
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*
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* This software is provided "as-is", without any express or implied warranty. In no event
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* will the authors be held liable for any damages arising from the use of this software.
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*
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* Permission is granted to anyone to use this software for any purpose, including commercial
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* applications, and to alter it and redistribute it freely, subject to the following restrictions:
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*
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* 1. The origin of this software must not be misrepresented; you must not claim that you
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* wrote the original software. If you use this software in a product, an acknowledgment
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* in the product documentation would be appreciated but is not required.
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*
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* 2. Altered source versions must be plainly marked as such, and must not be misrepresented
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* as being the original software.
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*
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* 3. This notice may not be removed or altered from any source distribution.
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*
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**********************************************************************************************/
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#ifndef RAUDIO_ANALYZER_H
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#define RAUDIO_ANALYZER_H
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#include <stdbool.h>
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//----------------------------------------------------------------------------------
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// Defines and Macros
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//----------------------------------------------------------------------------------
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#ifndef MAX_SPECTRUM_BINS
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#define MAX_SPECTRUM_BINS 1024
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#endif
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#ifndef DEFAULT_SMOOTHING_FACTOR
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#define DEFAULT_SMOOTHING_FACTOR 0.8f
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#endif
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#ifndef DEFAULT_PEAK_DECAY_RATE
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#define DEFAULT_PEAK_DECAY_RATE 0.95f
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#endif
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//----------------------------------------------------------------------------------
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// Types and Structures Definition
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//----------------------------------------------------------------------------------
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// Window function types for FFT preprocessing
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typedef enum {
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WINDOW_RECTANGULAR = 0, // No windowing (rectangular/boxcar)
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WINDOW_HANN, // Hann (raised cosine) window
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WINDOW_HAMMING, // Hamming window
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WINDOW_BLACKMAN // Blackman window
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} WindowFunction;
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// Spectrum analyzer configuration
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typedef struct {
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int binCount; // Number of frequency bins (must be power of 2)
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WindowFunction windowFunc; // Window function to apply before FFT
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float smoothingFactor; // Temporal smoothing factor [0.0 - 1.0]
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float peakDecayRate; // Peak value decay rate per frame [0.0 - 1.0]
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int sampleRate; // Audio sample rate in Hz
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} SpectrumConfig;
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//----------------------------------------------------------------------------------
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// Module Functions Declaration
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//----------------------------------------------------------------------------------
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// Lifecycle management
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void InitSpectrumAnalyzer(SpectrumConfig config); // Initialize spectrum analyzer with config
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void CloseSpectrumAnalyzer(void); // Free all allocated resources
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// Spectrum processing
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void UpdateSpectrum(float *samples, int sampleCount); // Process audio samples through FFT
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void ApplySmoothing(void); // Apply temporal smoothing to spectrum data
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// Data retrieval
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float *GetSpectrumData(void); // Get array of frequency bin magnitudes
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float GetPeakFrequency(void); // Get the dominant frequency in Hz
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float GetPeakMagnitude(void); // Get the magnitude of the peak frequency bin
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int GetSpectrumBinCount(void); // Get the current number of frequency bins
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bool IsSpectrumReady(void); // Check if analyzer is initialized and ready
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#endif // RAUDIO_ANALYZER_H
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