Audio Watermarking Source Code: Embedding Pseudo-Random Sequences into Audio Signals

The following source code demonstrates how to embed audio watermarks using pseudo-random sequences into audio signals. The implementation begins by defining a pseudo-random sequence generator function, typically employing Linear Feedback Shift Register (LFSR) algorithms or cryptographic hash functions to generate sequences with specific random properties while maintaining reproducibility. The audio signal is then read into the program using audio file processing libraries (such as scipy.io.wavfile in Python) and converted into digital signal format, ensuring proper sampling rate handling and amplitude normalization. A pseudo-random sequence matching the audio signal's length is generated using the predefined generator function. This sequence is then XORed with the audio signal sample-by-sample - a bit-level operation where each audio sample's binary representation is combined with corresponding pseudo-random sequence bits. This embedding process maintains audio quality while making the watermark resistant to common signal processing operations. Key implementation considerations include maintaining signal-to-noise ratio thresholds and ensuring the watermark's detectability through correlation-based detection algorithms. The watermarked audio signal is finally saved to a new file using appropriate audio encoding formats, preserving the original sampling rate and bit depth. This completes the successful embedding of pseudo-random sequence-based audio watermarks.