Continuously Variable Slope Delta modulation is a voice coding method. It is a delta modulation with variable step size (adaptive delta modulation), first proposed by Greefkes and Riemens in 1970, What is the CVSD format?
.ima A headerless file of IMA ADPCM audio data
A headerless file of IMA ADPCM audio data. IMA ADPCM claims 16-bit precision packed into only 4 bits, but in fact sounds no better than .vox., What is the IMA format?