Design And Implementation Of A Digital Audio Watermarking Algorithm With Embedded Audio Tester

A new self-adapting audio watermarking algorithm aiming for digital audio broadcasting is put up in this paper. This algorithm is implemented in the frequency domain combined with compression domain and is well suited for the Digital Audio Broadcasting System. The watermark is embedded by changing both the amplitude of the coefficients of the Fourier Transformation of the audio signal and the Scale Factor of the MPEG audio stream. Test results show that this algorithm is robust to MP2 compression, noise and low-pass filtering. Incorporated this algorithm, DAB system would have better performance in digital authentication and have a more promising future in China.The implementation of embedded Linux based handy audio analyzer which aims at measuring the audio parameters of broadcasting transmitters is introduced in this paper. The design process of both hardware and software of the analyzer as well as methods of measuring signal to noise ratio, frequency response and harmonic distortion is described in detail. The technique of using qt-embedded to render frequency spectrum is also showed in his paper. To avoiding flickering and saving computational resource during the rendering phase, off-screen buffering is introduced. The design is proved feasible by the experimental results.