| 摘要 |
<p>Auxialiary data subband samples representing an auxiliary data signal (315) are transported in a subband-coded compressed digital audio signal without decompressing the data. A pre-existing packetized data stream (305) is provided to an input of an encoder (310). Subband audio samples (406) are extracted from the packet stream and normalized (408). The data to be transported modulates data carrier subbands (SPD0, ---SPD-1, including a pseudo-noise (PN) spread spectrum signal, each subband of which has a bandwidth corresponding to those of the digital audio signal, The modulated data carrier sequence is combined with the audio subband samples (SS1, SS2---SSN-1) to form a combined signal (452), then muLtiplexed (460) into pre-existing packet stream (407). In the decoder (368), the combined signal is demodulated to recover the auxiliary data signal (672). The recovered auxiliary data signal is carried substantially inaudibly in the audio signal and is spectrally shaped according to the audio signal to enhance concealment. <IMAGE></p> |
