From: Josh Coalson
- Blocked data is passed to the predictor stage one subblock (channel) at a time. Each subblock is independently coded into a subframe, and the subframes are concatenated into a frame. Because each channel is coded independently, it means that one channel of a stereo frame may be encoded as a constant subframe, and the other an LPC subframe. The FLAC format has reserved space for supporting mid-side coding of stereo data, but it is currently not defined or implemented in the reference codec. + Blocked data is passed to the predictor stage one subblock (channel) at a time. Each subblock is independently coded into a subframe, and the subframes are concatenated into a frame. Because each channel is coded separately, it means that one channel of a stereo frame may be encoded as a constant subframe, and the other an LPC subframe.
Interchannel Decorrelation @@ -193,7 +193,7 @@ FLAC currently defines two similar methods for the coding of the error signal from the prediction stage. The error signal is coded using Rice codes in one of two ways: 1) the encoder estimates a single rice parameter based on the variance of the residual, and Rice codes the entire residual using this parameter; 2) the residual is partitioned into several equal-length regions of contiguous samples, and each region is coded with its own Rice parameter based on the region's mean. (Note that the first method is a special case of the second method with one partition, except the Rice parameter is based on the residual variance instead of the mean.)
- The FLAC format has reserved space for other coding methods. Some possiblities for volunteers would be to explore better context-modeling of the Rice parameter, generic Golomb coding (Rice codes are a subset of Golomb codes where the Rice parameter k is the Golomb parameter m = 2^k), and Huffman coding. See LOCO-I and pucrunch for descriptions of several universal codes. + The FLAC format has reserved space for other coding methods. Some possiblities for volunteers would be to explore better context-modeling of the Rice parameter, or Huffman coding. See LOCO-I and pucrunch for descriptions of several universal codes.
Format