Wednesday, October 28, 2015

Codec Compression Method & Codec Complexity supported by PVDM3

Understanding Codecs: Complexity, Hardware Support, MOS, and Negotiation

Codec Compression Method
PCM = Pulse Code Modulation
ADPCM = Adaptive Differential Pulse Code Modulation
LDCELP = Low-Delay Code Excited Linear Prediction
CS-ACELP = Conjugate-Structure Algebraic-Code-Excited Linear-Prediction
MP-MLQ = Multi-Pulse, Multi-Level Quantization
ACELP = Algebraic Code Excited Linear Prediction

Medium Complexity (4 calls / dsp)High Complexity ( 2 calls / dsp)
G.711 (a-law and m -law)G.728
G.726 (all versions)G.723 (all versions)
G.729a, G.729ab (G.729a AnnexB)G.729, G.729b (G.729-AnnexB)

Compression MethodBit Rate (kbps)MOS ScoreCompression Delay (ms)
G.711 PCM644.10.75
G.726 ADPCM323.851
G.728 LD-CELP163.613 to 5
G.729 CS-ACELP83.9210
G.729 x 2 Encodings83.2710
G.729 x 3 Encodings82.6810
G.729a CS-ACELP83.710
G.723.1 MP-MLQ6.33.930
G.723.1 ACELP5.33.6530

Table 3. Supported Codecs
High-Complexity Codecs
Medium-Complexity Codecs
Low-Complexity Codecs
G.723.1 (PVDM2 only), G.728, G.729, G.729B, Internet Low Bit Rate Codec (iLBC), and Modem Relay
G.729A, G.729AB, G.726, G.722, and Fax Relay
G.711 and clear-channel codec