Patent ID: 7974840
Filing Date: 2011-07-05
Classification: G10H,G10L

Abstract:
1. A method of encoding an MPEG-4 BSAC audio bitstream having ancillary information and encoded quantized audio data, the method comprising: converting a time domain audio signal to a frequency domain audio signal and quantizing the audio signal into quantized audio data using a psychoacoustic model; counting a number of bits of bitrate controlled audio data; obtaining a number of available bits per layer of the encoded quantized audio data using a number of the counted bits and a number of layers in the audio bitstream; modifying the number of available bits of the encoded quantized audio data per layer by obtaining a size of the ancillary information and by reducing the obtained number of available bits per layer as many as the size of the ancillary information; encoding the quantized audio data in units of layers according to the modified number of available bits from a base layer to a top layer, wherein each layer has a different bit rate and the bit rate increases from base layer to top layer; and embedding the ancillary information in the audio bitstream, wherein ancillary information is embedded in the last portion adjacent to an N-th enhancement layer in the MPEG-4 BSAC audio bitstream comprising the base layer and N number of enhancement layers, where N is equal to or greater than 1.