'음성코덱'에 해당되는 글 1

  1. 2006/10/15 MLT를 사용하는 G.722.1 코덱 (0) _ beckgom

MLT를 사용하는 G.722.1 코덱

Coding fabula | 2006/10/15 20:12 | beckgom
    논문을 찾다보니 대역폭 확장을 위해 MLT (Modulated Lapped Transform)를 사용한 방법들이 몇개 나와서 이를 이용한 G.722.1를 정리하여보면...다음과 같다.

Developed to deliver wideband speech and music atlower bit rates than G.722, the G.722.1 standard is limited in scope tohandsfree operation and low packet loss conditions.

The VoiceAge G.722.1 implementation is fully compliant with the ITU-T G.722.1 recommendation, operating at 24 or 32 kbps.

Technology

 Encoded bandwidth

~ 50-7000 Hz

 Standardized

ITU-T 1999

 Coding type

Transform coding

 Bit rate

24/32 kbps

 Delay (ms):
     Frame size
     Lookahead

 
20
20

 Quality

Good music performance. Scope of standard limited to hands-free and lowpacket loss rates. Transform coding yields poor speech quality in someoperating conditions.

 Complexity:
     MIPS
     RAM (words)


< 15
2 K

Applications

  • Wideband telephony – Wi-Fi, VoIP
  • Audio and videoconferencing
  • Streaming audio over the Internet
  • Audio storage and playback
  • Voicemail
  • Store and forward messaging


출처 : http://www.voiceage.com/