Compressed Domain Automatic Level Control Based on ITU-T G.722.2
Abstract
To control speech level automatically in 3G mobile networks in which Transcoder Free Operation (TrFO) is adopted, a compressed domain automatic level control (ALC) method is proposed based on the ITU-T G.722.2 speech codec. The level of decoded speech is first measured using the ITU-T P.56 tool. Then, based on the difference between the measured level and the target level, the gain of ALC is calculated. Finally, the codebook gain parameters of the speech codec are modified according to the ALC gain and the level of decoded speech is adjusted to the target level. The results of a performance evaluation show that, in comparison with the traditional method, the proposed method has smaller speech level bias, lower computational complexity (65% to 75% less), and higher objective quality. The proposed ALC method can easily be applied to transmission networks in which the CELP-based speech codec is adopted, not only restricted to the G.722.2 codec.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2012
- Accession Number
- ADA592114
Entities
People
- Bing-yin Xia
- Chang-chun Bao
- Yu-wen He
Organizations
- Beijing University of Technology