Sample audio files are given there as well. Since the code
operates on raw 2-byte data, the link also gives simple matlab
conversion code to read and write .wav and .raw data.
Internally, audio data is treated as float, in the range [-1..1].
So if we are operating on 8-bit samples, the conversion
from external, byte, data to internal, float, data can be carried
out by the operation
This converts from the range [0..255] to the range [-1..1].
For 2-byte, 16-bit data, the conversion is
For audio, the court of final appeal is the ITU standards body itself: it is standards promoted by such groups that in fact allow our modems to talk to each other, mobile communications to be developed, and so on. The ITU sells standards: it is linked to from the URL
More information on speech coding may be found in the speech FAQ files, linked from
LPC and CELP code may be found at
The following links are for sample C source code for a LPC-10 coder and a CELP coder