notube: loudness normalisation

WP 4 Loudness Normalisation

Peter Altendorf, IRT

Technical Achievements

• Provision of a Loudness Normalisation web service compliant with ITU and EBU for UC7a

• Provision of Loudness Analysis results to support ads insertion in UC7b

• Evaluation of Loudness Normalisation on the web

2 26-27 March 2012 NoTube 3rd review

Loudness Normalisation Process Chain as Web Service

3 26-27 March 2012 NoTube 3rd review

Analysis Synthesis

1 Decompr. Synthesis

2 Remux * Demux Recompr. Synthesis 1 Extract

PrestoSpace

TVA

TVA

WP2

WP2

Web service for implementation of loudness normalisation

Metadata conversion Webservice

CRUD Service

Normalisation Web Service – Demo Video –

4 26-27 March 2012 NoTube 3rd review

Normalisation Web Service – Demo –

5 26-27 March 2012 NoTube 3rd review

Loudness Web Evaluation

6 26-27 March 2012 NoTube 3rd review

Web Evaluation - Feedback

• Feedback in the community:

– Almost 100 participants from >20 countries

– >240 views on notube.tv on Dec 1st 2011 (posting of the preliminary results in the blog)

7 26-27 March 2012 NoTube 3rd review

• Paper “User Evaluation on Loudness Harmonisation on the Web“ accepted for presentation at the AES 132nd Convention in Budapest, Hungary, 2012 April 26-29.

Web Evaluation – Loudness adaptation (descriptive)

8 26-27 March 2012 NoTube 3rd review

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% (N

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Preferences of Loudness Adaptations

-7 LU (-30 LUFS) 0 LU (-23 LUFS) +4 LU (-19 LUFS)

Web Evaluation – Loudness adaptation (analysis)

9 26-27 March 2012 NoTube 3rd review

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-7 LU (-30 LUFS) 0 LU (-23 LUFS) +4 LU (-19 LUFS)

Web Evaluation – Loudness range adaptation (descriptive)

10 26-27 March 2012 NoTube 3rd review

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Knight and Day Offenbach Beethoven_Lang Lang Shostakovich BMW M5

% (N

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Preferences of Loudness Range Adaptations

0 dB compression +15 dB compression +25 dB compression

Web Evaluation – Loudness range adaptation (analysis)

11 26-27 March 2012 NoTube 3rd review

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0 dB compression +15 dB compression +25 dB compression

Evaluation Summary

• Loudness adaptation: – Homogeneous results for all listening parameters under test – Independence from the listening parameters (“age”, “speaker

type” and “listening level”) – A strong background noise seems to increase the need for

higher loudness levels

Verification of the sufficiently accurate approximation of the human loudness perception for broadcast audio signals by the algorithm defined in EBU R128 and ITU-R BS.1770-2.

• Loudness range adaptation: – Results not as homogeneously – Tendency: Participants seem to prefer rather medium or even

strong loudness range compression to uncompressed audio with high loudness range.

12 26-27 March 2012 NoTube 3rd review

Conclusion

• Proof of concept for loudness normalisation using dedicated metadata

• Generic approach for loudness normalisation on the web is challenging and could not be achieved in the project

• Evaluation shows applicability of ITU-R BS.1770 and EBU R-128 for web applications

• Loudness Range for internet should not exceed 20LU (subject to further research)

13 26-27 March 2012 NoTube 3rd review