The Use of Entropy Coding in Speech and Television Differential PCM systems
Abstract
Much of the redundancy in a speech or television signal is eliminated when that signal is encoded into digital form by a differential PCM encoder. Further coding of the differential PCM output using entropy coding techniques (Huffman or Shannon-Fano coding) can result in a further increase in the signal to quantizing noise ratio of 5.6 dB without increasing the transmission rate. This conclusion is reached by comparing the performance of a DPCM system without entropy coding with one using entropy coding. The DPCM without entropy coding uses a minimum mean square error quantizer (Max quantizer) while the system with entropy coding uses an equilevel density function. This is consistent with previous experiments with speech and television signals. Gaussian quantizer inputs result in only a 2.8 dB improvement for entropy coding.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 04, 1972
- Accession Number
- AD0740670
Entities
People
- J. B. O'neal Jr.
Organizations
- North Carolina State University