THE REAL-TIME IMPLEMENTATION OF G.723.1 SPEECH CODER AND THE RESEARCH OF PACKET RECOVERY ALGORITHM
| Autor: | Jian-Jia Wang, 王建傑 |
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| Rok vydání: | 1999 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 87 G.723.1 is the newest standard of ITU. Because of the good quality of G.723.1, it is widely used in the video-phone and the internet phone system. Furthermore, the coding standard will also be applied to the digital telephone network system. The coding standard takes too much computational effort since its complicated algorithm. In this paper, we propose some methods including the reduction and improvement of coding algorithm and using MMX technology to modify the algorithm, so that the real-time requirement can be achieved. Predictive type speech coders, however, incorporate filters with memories which present an extra source of degradation. Frame reconstruction strategies which cut down on the propagation of the corrupted filter memories have to be adopted. In this paper, we introduce three methods to cut down on the propagation of frame lost effects to future frames and it is applicable to G.723.1 speech coder. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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