Patent ID: 7106943
Filing Date: 2006-09-12
Classification: G10L,H04N

Abstract:
1. A coding device, comprising: a decoder for decoding a first stream signal in which a first video stream including a first video stream information generated by coding a first video signal and a first audio stream including a first audio stream information generated by coding a first audio signal are multiplexed; and a re-encoder for generating, based on the decoded first stream signal, a second video stream including a second video stream information having a bit rate lower than the first video stream information and a second audio stream including a second audio stream information having a bit rate lower than the first audio stream information, and multiplexing the second video stream and the second audio stream to generate a second stream signal, wherein the first audio stream information is obtained by performing a time-frequency conversion on the first audio signal into a frequency domain signal to quantize the frequency domain signal; the re-encoder calculates psychoacoustic model information indicating frequency bands of the first audio signal masked by auditory characteristics; the re-encoder converts, based on the psychoacoustic model information, the first audio stream information into the second audio stream information having a bit rate lower than the first audio stream information to generate the second audio stream; and the re-encoder calculates the psychoacoustic model information based on the quantized information.