Presents 2006 IMTC Forum ITU-T T Workshop

Transcription

1 Presents 2006 IMTC Forum ITU-T T Workshop

2 G.729EV: An 8-32 kbit/s scalable wideband speech and audio coder bitstream interoperable with G.729 Presented by Christophe Beaugeant On behalf of ETRI, France Telecom, Matsushita, Mindspeed, Siemens

3 G.729EV Standardization history Standardization work conducted in SG 16, WP 3, Question 10 (Rapporteur: Claude Lamblin) T0 (approval of Term of References) declared in November 2004 Qualification test results in July 2005 ETRI, France Telecom, Matsushita, Mindspeed, Siemens and VoiceAge qualified These companies collaborated together to provide a single candidate Optimization phase 08/05-01/06 Quality assessment tests (02-03/06): G.729EV passed all the requirements. Current status: under AAP procedure at the ITU-T

4 High level overview 8-32 kbit/s scalable wideband ( Hz) extension of G.729 Wideband: More natural voice, better intelligibility, enhance communication comfort Scalability : flexibility; dynamic, simple and low cost bit rate adaptation Robustness : packet loss protection and concealment integrated Build upon a three-stage structure, with 12 embedded layers: layers 1-2 : CELP, Hz, 8-12 kbit/s Layer 3 : TDBWE, Hz, 14 kbit/s Layers 4-12: TDAC, Hz, 14 to 32 kbit/s G.729a+ EXT. TDBWE TDAC TDAC

5 8 G.729EV bitrate flexibility 12 G.729a+ EXT. Original spectrum Narrow band Encoded spectrum Wide band Embedded CELP stage generates layers 1 and 2 : narrowband synthesis ( Hz) at 8 and 12 kbit/s. Layer 1 compliant with G.729 bitstream

6 G.729EV bitrate flexibility G.729a+ EXT. TDBWE Original spectrum Narrow band Encoded spectrum Wide band Layer 3: Wideband Extension (TDBWE) Wideband output ( Hz) at 14 kbit/s

7 G.729a+ G.729EV bitrate flexibility EXT. 12 TDBWE 14 TDAC 24 TDAC 32 Original spectrum Narrow band Encoded spectrum Wide band Layers 4 to 12: Predictive transform coding referred as TDAC Quality improvement from 14 to 32 kbit/s. Encoding of the weighted CELP coding error in Hz band Encoding input signal in Hz band.

8 Encoder: High level overview FEC encoder H 1 (z) 2 H h1 (z) S LB (n) embedded CELP encoder (8-12 kbit/s) S enh (n) S WB (n) W LB (z) A ˆ( z ) M U MDCT X TDAC encoder (16-32 kbit/s) MDCT H 2 (z) 2 (-1) n H h2 (z) S HB (n) TDBWE encoder (14 kbit/s)

9 Decoder: High level overview embedded CELP decoder (8-12 kbit/s) ˆ d echo LB adaptive postfiltering ( n) HPF ˆ S echo HB ( n) 2 G 1 (z) D E M U X TDAC decoder (14-32 kbit/s) MDCT -1 MDCT -1 pre/post-echo reduction W LB (z) -1 ˆ S HB ( n) ˆ S WB ( n) MDCT TDBWE decoder (14 kbit/s) pre/post-echo reduction ˆ S echo LB ( n) (-1) n 2 G 2 (z)

10 Quality of G.729EV Listening tests (02-03/06): G.729EV passed all the requirements. Advanced embedment of three technologies: CELP : Good performance for Speech Bandwidth Extension: reduced bit rate to switch to wideband Transform Coding: high wideband quality with music and non speech signals Quality equivalent or better than other speech coding standard Optimum "state of the art" wideband quality for all types of signals (including music) at 32 kbps High wideband quality of speech maintained at 14 kbps Narrow band "PSTN quality" at 12 kbps (equivalent to G711)

11 Subjective tests Clean speech in Narrowband in French 5 4,5 4 3,5 3 2,5 Direct G.729A CuT-8 k G.729E CuT-12 k

12 Subjective tests 5 Wideband clean speech in French 4,5 4 3,5 3 Direct G ,85k G k CuT-14 k G k CuT-24 k CuT-32 k

13 Objective Measurement PESQ SCORES FOR CUT (MOS-LQO) All Languages English French German Japanese Korean k 16k 18k 20k 22k 24k 26k 28k 30k 32k Bitrates

14 Subjective tests Wideband music at 32 kbit/s 5 4,5 4 3,5 3 Direct 56 k CuT-32 k

15 Complexity of G.729EV Complexity measured using ITU-T Software Tool Library STL2005 v2.1. Complexity figures of the G.729EV coder (encoder/decoder). Computational complexity Static RAM Scratch RAM Data ROM Program ROM Delay Low delay mode (narrow-band) WMOPS 5 kwords 3.7 kwords 8.5 kwords 32 kwords ms 25 ms

16 Foreseen application Designed for packetized wideband voice (VoIP, VoATM, IP phone, private networks) Applications requiring scalable wideband on top of G.729, Easy integration with existing VoIP infrastructure and services, fast deployment Extension to Multimedia services (Videoconference, VOD ) High quality with graceful degradation from WB (face-to-face) quality to NB (telephone) quality Advantage of Scalability: Simple and low cost bit rate adaptation (very limited CPU) Design for devices (gateways) that multiplex data/audio streams Handling heterogeneous accesses/terminals Optimization of bitrate to network capabilities (Network congestion) Easy modification of bitrate by intelligent router (adjustment to network capabilities) Voice messaging: capacity vs quality trade-off, access adaptation

17 WB VoIP & Conversational e-learning service Excellent voice quality to fixed users Fittest quality and service connectivity to mobile users Trial service will be deployed by KT in Q3/2006 Service & QoS Manager Wireline(xDSL (xdsl,, FTTH, Cable) G.729EV 32kbits/s Fixed User Conversational e-learning Contents G.729EV 32kbits/s IP Backbone Public Wireless LAN WiBro (Portable Internet) G.729EV 8~32kbits/s For fittest quality Mobile Users

18 Enterprise Wideband VoIP Excellent voice quality among G.729EV terminals Seamless interoperability of legacy G.729 VoIP users and facilities Anticipated companies: Dacom, Netcodec, Essetel,Onnet,, Enterprise Headquarter (Seoul) G.729EV WiFi Phone or G.729EV WiFI + Mobile G.729EV IP phone IEEE b/g/e AP IEEE802.1 p/q AAA, Call Agent QoS Manager Flow-based QoS IP Network Existing VoIP Facilities G.729-G.711 Gateways Enterprise Branch A (LA) AP IEEE802.1 p/q IEEE b/g/e G.729 WiFi Phone G.729EV Soft-phone T1/E1 PSTN Analog phones (Seoul) PSTN T1/E1 Analog phones (LA)

19 G.729 EV Wifi phone G729 EV Wifi + Mobile G.729 EV IP phone AP Intelligent service Conference call with heterogeneous terminals Adaptability to terminal capabilities Adaptability to Up-link / Downlink voice Quality requirement 14 kbit/s 14 kbit/s 24 kbit/s 32 kbit/s 12 kbit/s Service Manager 12 kbit/s 14 kbit/s 32 kbit/s G.729-G.711 Gateways Fixed User PSTN Analog Phone

20 Conclusion G729 EV : 8-32 kbit/s scalable codec for narrowband speech (8-12 kbit/s), wideband speech (12-32 kbit/s) and audio (32 kbit/s) Good quality compared to existing codecs Applications foreseen used the advantage of scalability Codecs obtained through collaboration of ETRI, France Telecom, Matsushita, Mindspeed, Siemens and VoiceAge. Quick development to fit to operators needs in the field applications over IP Extension: Stereo coding, Super Wideband (32 khz)

21 Back-up

22 Subjective tests Interfering Talker Background noise at 15 db in NB in German 5 4,5 4 3,5 3 Direct G.729A CuT-8 k CuT-12 k

23 Subjective tests Interfering talker background noise at 15 db in WB in English 5 4,5 4 3,5 3 G k G k CuT-24 k CuT-32 k Direct