Patent Issued for Method and Device for Efficient Quantization of Transform Information in an Embedded Speech and Audio Codec

摘要

The assignee for this patent, patent number 8396707, is VoiceAge Corporation (Quebec, CA).nnReporters obtained the following quote from the background information supplied by the inventors: "In embedded coding, also known as layered coding, the sound signal is encoded in a first layer to produce a first bit stream, and then the error between the original sound signal and the encoded signal (synthesis sound signal) from the first layer is further encoded to produce a second bit stream. This can be repeated for more layers by encoding the error between the original sound signal and the synthesis sound signal from all preceding layers. The bit streams of all layers are concatenated for transmission. The advantage of layered coding is that parts of the bit stream (corresponding to upper layers) can be dropped in the network (e.g. in case of congestion) while still being able to decode the encoded sound signal at the receiver depending on the number of received layers. Layered coding is also useful in multicast applications where the encoder produces the bit stream of all layers and the network decides to send different bit rates to different end points depending on the available bit rate within each link.