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Ç¥ÁعøÈ£ | TTAE.IT-G729.1 | ±¸Ç¥ÁعøÈ£ | |
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Á¦°³Á¤ÀÏ | 2006-12-27 | ÃÑÆäÀÌÁö | 112 |
ÇѱÛÇ¥Áظí | G.729¿Í ¿¬µ¿ °¡´ÉÇÑ 8 - 32 kbit/s ±¤´ë¿ª À½¼º ¿Àµð¿À ¸ÖƼ ÄÚµ¦ | ||
¿µ¹®Ç¥Áظí | G.729 based embedded variable bit-rate coder: An 8-32 kbit/s scalable wideband coder bitstream interoperable with G.729 | ||
Çѱ۳»¿ë¿ä¾à | º» Ç¥ÁØ ÄÚµ¦Àº G.729, G.729A ±×¸®°í G.729B¿Í ¿¬µ¿ °¡´ÉÇϸç, ±¤´ë¿ª À½¼º ¹× ¿Àµð¿À ½ÅÈ£¸¦ 8 - 32 kbit/sÀÇ ºñÆ®À²·Î ¾ÐÃàÇÒ ¼ö ÀÖ´Â ÄÚµ¦¿¡ ´ëÇØ ±â¼úÇÑ´Ù.
º» Ç¥ÁØ ÄÚµ¦Àº 8,12 kbit/s¿¡¼ Çù´ë¿ª (50 ~ 4000 Hz) À½ÁúÀ» Á¦°øÇÏ°í, 14 ~ 32 kbit/s ¿¡¼´Â ±¤´ë¿ª (50 ~ 7000 Hz) À½ÁúÀ» Á¦°øÇÑ´Ù. ƯÈ÷, 8 kbit/s¿¡¼´Â ITU-T Çù´ë¿ª ÄÚµ¦ÀÎ G.729, G.729A ±×¸®°í G.729B¿Í ºñÆ®½ºÆ®¸² ·¹º§¿¡¼ »óÈ£ ¿¬µ¿ÀÌ °¡´ÉÇÏ´Ù. ÀÌ ÄÚµ¦Àº 20 ms ´ÜÀ§·Î µ¿ÀÛÇÏ¸ç ¾Ë°í¸®Áò Áö¿¬Àº 48.9375 msÀÌ´Ù. ºÎȣȱâÀÇ ÀԷ°ú º¹È£È±âÀÇ Ãâ·ÂÀº ±âº»ÀûÀ¸·Î 16 kHz·Î Ç¥º»ÈµÈ 16 ºñÆ® ½ÅÈ£ÀÌ´Ù. ºÎȣȱâ´Â 8¿¡¼ 32 kbit/s±îÁö ÃÑ 12°³ÀÇ °èÃþÀ¸·Î ±¸¼ºµÈ ÀÓº£µðµå ºñÆ®½ºÆ®¸²À» Ãâ·ÂÇÑ´Ù. ÀÌ·¯ÇÑ ÀÓº£µðµå ºñÆ®½ºÆ®¸² ±¸Á¶¸¦ ÀÌ¿ëÇÏ¿© ÅëȵµÁß¿¡ º¹È£È±â ¶Ç´Â Åë½Å ½Ã½ºÅÛÀÇ ¾î¶² ºÎºÐ¿¡¼µµ ºñÆ®À²·Î ÀÚÀ¯·Ó°Ô º¯°æÇÒ ¼ö ÀÖ´Ù. ÀÌ Ç¥ÁØ ÄÚµ¦Àº Å©°Ô ¼¼ °¡Áö ÄÚµù ¾Ë°í¸®ÁòÀ¸·Î ±¸¼ºµÇ¾î ÀÖ´Ù: 1) ÀÓº£µðµå ÄÚµå ¿©±â ¼±Çü ¿¹Ãø(Code-Excited Linear-Prediction: CELP) ¾Ë°í¸®ÁòÀ» ÀÌ¿ëÇÑ Àú´ë¿ª (50 - 4000Hz) ½Åȣó¸®, 2) ½Ã°£¿µ¿ª ´ë¿ªÆø È®Àå(Time-Domain Bandwidth Extension: TDBWE) ±â¹ýÀ» ÀÌ¿ëÇÑ °í´ë¿ª (4000-7000Hz) ½Åȣó¸®, 3) ½Ã°£¿µ¿ª ¿¡Àϸ®¾î½Ì Á¦°Å(Time-Domain Aliasing Cancellation: TDAC)¿Í °°Àº ÁÖÆļö¿µ¿ª º¯È¯ ÄÚµù ¾Ë°í¸®ÁòÀ» ÀÌ¿ëÇÑ Àú´ë¿ª ¿ÀÂ÷ ½ÅÈ£ ¹× °í´ë¿ª ½Åȣó¸®ÀÌ´Ù. |
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¿µ¹®³»¿ë¿ä¾à | This Standard describes an 8-32 kbit/s scalable wideband speech and audio coding algorithm interoperable with G.729, G.729A and G.729B.
The output of this coder has a bandwidth of 50-4000 Hz at 8 and 12 kbit/s and 50-7000 Hz from 14 to 32 kbit/s. At 8 kbit/s, this standard is fully interoperable with G.729, G.729 Annex A and G.729 Annex B. Hence an efficient deployment in existing G.729 based VoIP infrastructures is foreseen. The coder operates on 20 ms frames and has an algorithmic delay of 48.9375 ms. By default, the encoder input and decoder output are sampled at 16 kHz. The encoder produces an embedded bitstream structured in 12 layers corresponding to 12 available bit rates from 8 to 32 kbit/s. The bitstream can be truncated at the decoder side or by any component of the communication systems to adjust ¡°on the fly¡± the bit rate to the desired value with no need for outband signaling. The underlying algorithm is based on a three-stage coding structure: embedded Code-Excited Linear Predictive (CELP) coding of the lower band (50-4000 Hz), parametric coding of the higher band (4000-7000 Hz) by Time-Domain Bandwidth Extension (TD-BWE), and enhancement of the full band (50-7000Hz) by a predictive transform coding technique referred to as Time-Domain Aliasing Cancellation (TDAC). |
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±¹Á¦Ç¥ÁØ | ITU-T G.729-1 | ||
°ü·ÃÆÄÀÏ | TTAE_IT-G729_1.zip |