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A new codec within ITU-T: new bandwidth

2nd Workshop on Wideband Speech Quality in Terminals and Networks: Assessment and Prediction 22nd and 23rd June 2005 - Mainz, Germany. A new codec within ITU-T: new bandwidth Catherine Quinquis - France Telecom R&D Vice-chair of 3GPP SA4 and co-rapporteur of ITU-T Q7/12

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A new codec within ITU-T: new bandwidth

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  1. 2nd Workshop on Wideband Speech Quality in Terminals and Networks: Assessment and Prediction22nd and 23rd June 2005 - Mainz, Germany A new codec within ITU-T: new bandwidth Catherine Quinquis - France Telecom R&DVice-chair of 3GPP SA4 and co-rapporteur of ITU-T Q7/12 catherine.quinquis@francetelecom.com 2nd Workshop on Wideband Speech Quality - June 2005

  2. A new codec within ITU-T: G722.1 Annex C • Extension toward higher frequency of existing transform codec G.722.1 • Input/output signal bandwidth : [50 Hz;14 kHz] • The foreseen applications for the extension codec are: • Video conferencing • Hands-free teleconferencing • And internet streaming audio • Qualification in November 2004 • Only one candidate (that passes the requirements) Characterisation phase • Approval date : April 2005 2nd Workshop on Wideband Speech Quality - June 2005

  3. A new codec within ITU-T: G722.1 Annex CCharacterisation methodology • Phase 1 dealing with the main foreseen application: audio conferencing • Clean speech (ACR method) • Case of high quality sound recording with minimised room effect • Reverberant speech with background noise (DCR method) • Case of typical audio conferencing systems (different room sizes, distances to microphone and types of background noise) • Phase 2 dealing with optional application :audio streaming • Mushra methodology • Selected Anchors: 7 kHz and 10 kHz band limited signals • Music • Classical, jazz, modern, singer, orchestral • Mixed content items • Advertisement, film trailer, news music announcement 2nd Workshop on Wideband Speech Quality - June 2005

  4. A new codec within ITU-T: G722.1 Annex CRequirements • Terms of reference • Bit rates : 24 kb/s, 32 kb/s and 48 kb/s • Quality requirements • Clean speech • Not worse than MPEG4 AAC-LD for the same bit rate at 99% confidence interval • Reverberant speech with background noise • Not worse than MPEG4 AAC-LD for the same bit rate at 99% confidence interval • Characterisation • Comparison at 95 % confidence interval to avoid problems with Type I and type II errors. • Type I error: reject a true null hypothesis (5% for 95% CI) • Type II error: fail to reject a false null hypothesis • The smallest Type I error is, the larger type II errors will be • Add comparison to existing 3GPP audio codecs operating at same bit rate • Audio codec for MMS, PSS and MBMS services • Extended AMRWB (3GPP TS 26.304) • Enhanced aacPlus (3GPP TS 26.410) • Comparison limited to 24 and 32 kbps, 3gpp audio codecs did operate above 36 kbps in mono. 2nd Workshop on Wideband Speech Quality - June 2005

  5. A new codec within ITU-T: G722.1 Annex CPhase 1 Characterisation results (1/4) • Clean Speech • All requirements are met; even better than MPEG4 AAC-LD at low bit rates (24 and 32 kbps) 2nd Workshop on Wideband Speech Quality - June 2005

  6. A new codec within ITU-T: G722.1 Annex CPhase 1 Characterisation results (2/4) • Reverberant speech with office noise • Reverberation: Small room (5 people) and microphone at 50 cm • All requirements are met; even better than MPEG4 AAC-LD at low bit rates(24 and 32 kbps) 2nd Workshop on Wideband Speech Quality - June 2005

  7. A new codec within ITU-T: G722.1 Annex CPhase 1 Characterisation results (3/4) • Reverberant speech with interfering talker • Reverberation: medium room (25 people) and microphone at 50 cm • All requirements are met; even better than MPEG4 AAC-LD at low bit rates(24 and 32 kbps) 2nd Workshop on Wideband Speech Quality - June 2005

  8. A new codec within ITU-T: G722.1 Annex CPhase 1 Characterisation results (4/4) • Reverberant speech with office noise and interfering talker • Reverberation: medium room (25 people) and microphone at 100 cm • All requirements are met; even better than MPEG4 AAC-LD at low bit rates(24 and 32 kbps) 2nd Workshop on Wideband Speech Quality - June 2005

  9. A new codec within ITU-T: G722.1 Annex CPhase 2 Characterisation results (1/3) • 24 kbps • better than MPEG4 AAC-LD and about the same as 3GPP codecs • G722.1 annex C and MPEG 4AAC-LD and Enhanced aacPlus are more sensitive to content type than extended AMRWB 2nd Workshop on Wideband Speech Quality - June 2005

  10. A new codec within ITU-T: G722.1 Annex CPhase 2 Characterisation results (2/3) • 32 kbps • better than MPEG4 AAC-LD and about the same as 3GPP codecs • G722.1 annex C and MPEG 4AAC-LD and Enhanced aacPlus are more sensitive to content type than extended AMRWB 2nd Workshop on Wideband Speech Quality - June 2005

  11. A new codec within ITU-T: G722.1 Annex CPhase 2 Characterisation results (3/3) • 48 kbps • better than MPEG4 AAC-LD • 3GPP codecs do not have 48 kbps with mono input signal. 2nd Workshop on Wideband Speech Quality - June 2005

  12. A new codec within ITU-T: G722.1 Annex CExtension of P.341 • P.341 • Need to extend the P.341 recommendation to the super wide band • filter simulating the terminal response has been made available in the STL with ITU-T SG16; this simulation was used for the characterization testing exercise. P341 Extension: upper and lower limits P341 and its Extension Frequency (Hz) Frequency (Hz) 2nd Workshop on Wideband Speech Quality - June 2005

  13. A new codec within ITU-T: G722.1 Annex CE model • E model • An extension to wide band (50 Hz- 7 kHz) is been discussed • A new bandwidth (50 Hz – 14 kHz) is going to be used in the network: it should also be taken into account. • Only one codec has been tested in this bandwidth with some adaptation on MNRU range 2nd Workshop on Wideband Speech Quality - June 2005

  14. A new codec within ITU-T: G722.1 Annex CMNRU curve • MNRU adaptation • to get more score outside the saturation region, in G722.1 C characterisation test, lowest MNRU is 18 dB 2nd Workshop on Wideband Speech Quality - June 2005

  15. A new codec within ITU-T: G722.1 Annex C Thank you 2nd Workshop on Wideband Speech Quality - June 2005

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