Gerhard Spikofski GmbH Research and Development Institute of ARD, ZDF, Dradio, ORF and SRG/SSR Target Loudness Level and Dynamic Range 3rd International VDT Symposium An Eye on Hearing Schloss Hohenkammer Bavaria Oct. 30th - Nov.1st
Overview Programme Level Normalisation Loudness Level Normalisation Definitions Target Loudness Longtime/Shorttime Loudness Loudness Range Loudness Range and Listening Level Conclusions
Programme Level Normalisation
Programme meter specifications stereo IEC-268-10 Type IIa IEC-268-10 Type I BBC IEC-II IEC-268-17
Programme meter specifications MCA IEC-268-10 Type I
Programme meter specifications Quasi Peak Programme Meter QPPM (IEC-268-10, ARD-Pflichtenheft 3/6) Modulation Range Headroom programme level 9% 35% 100% 180% 10 ms 90% indication -51 relative level -21-9 0 +5 +9 db 10 ms 90% indication R -60 digital Level -18-9 0 dbfs -45 analogue Level ITU-R 0 +9 +14 +18 dbu -45 analogue Level ARD -3 +6 +11 +15 dbu L EBU- Alignment Level Technical guidelines of TV-productions, HFBL-K
Recommendations Meter: IEC-268-10, ARD-Pflichtenheft 3/6 QPPM t i = 10 ms (level control) PPM t i = 0 ms (peak control) Level: R68 (EBU), Headroom in digital audio (ARD), Technical guidelines of TV-productions (ARD/ZDF/ORF) QPPMmax = 100% = -9 dbfs!!! PPMmax = -3-6 dbfs
Loudness Level Normalisation
Algorithm Recommendation ITU-R BS.1770 LKFS RMS Prefilter + RLB-Filter = K-Filter Seite 9
LM100 Broadcast Loudness Meter, Dolby Seite 10
DP 600 Programme Optimizer, Dolby Seite 11
Surround Monitor 11900, RTW Seite 12
Surround Loudness Meter with Datalogger (Ldn Server/Viewer), Pinguin
Ldn Normalizer, Pinguin
LM5 Loudness Radar Meter, TC electronic Seite 15
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Does loudness normalisation constrain sound engineer s creative work, his scope for design?
Measurements on P/LOUD test item pool 27 Wide loudness range (WLR) 20 Narrow loudness range (NLR) 12 Speech based (SP) 5 Mixed content (MXD) 13 Music based (MUS) 77 Total Seite 20
Target Loudness Longtime/Shortime Gated/Ungated Gating Treshhold Loudness Range
LKFS Loudness parameters Longtime: LKFS average from start to stop (e. g. whole file) Shorttime/Monotoring: LKFS average over 3 s and 10 s Ungated: reading the entire signal Gated: excluding low loudness passages (e. g. 6 LKFS below target level) Loudness range: ratio between maximum and minimum LKFS level (3 s) (e. g. 95th and 5th percentile) Seite 22
Measurements on the P/LOUD test item pool Seite 23
Measurements on the P/LOUD test item pool Seite 24
Target Loudness = -23 LKFS
Measurements on P/LOUD test item pool All items normalized to the (still) valid reccomendation QPPMmax (10 ms) = -9 dbfs Can each item - especially WLR - be adapted to the target loudness -23 LKFS? Seite 26
Measurements on P/LOUD test item pool Seite 27
Measurements on P/LOUD test item pool Seite 28
Loudness Range
Measurements on P/LOUD test item pool Seite 30
Measurements on P/LOUD test item pool Seite 31
Loudness range and Listening level
SMPTE RP 200 Relative and Absolute Sound Pressure Levels for Motion-Picture Multichannel Sound Systems (fixed) Measuring signal Pink noise SPL/speaker Left Center Right Left Surround Right Surround Total SPL -20 db RMS 85 dbc 85 dbc 85 dbc 82 dbc 82 dbc 91 dbc
SMPTE RP 200 (Draft) Home cinema (fixed) Measuring signal Pink noise SPL/speaker Left Center Right Left Surround Right Surround Total SPL -20 db RMS 77 dbc 77 dbc 77 dbc 74 dbc 74 dbc 83 dbc
EBU Tech. 3276 Reference listening level broadcast (variable!) Measuring signal Pink noise SPL/speaker Left Center Right Left Surround Right Surround Total SPL -18 db RMS 78 dba 78 dba 78 dba 78 dba 78 dba 85 dba
Differences between EBU Tech. 3276 and SMPTE RP 200 dba/channel dba/all dbc/channel dbc/all EBU Tech. 3276 78 85 86 93 SMPTE RP200 77dBC 69 76 77 84 SMPTE PR200 85dBC 77 84 85 92
Dynamic range of original sources Ratio between maximum and minimum SPL Respectively programme level fff = 100 dba / -9 db QPPM ppp = 40 dba / -69 db QPPM Dynamic range = 60 db
Loudness range of original sources Ratio between maximum and minimum SPL respectively Loudness level LKFS fff = 100 dba / -6 LKFS ppp = 40 dba / -66 LKFS Loudness range = 60 LKFS
Control room/listening level 0 db Dynamic range of reproduction environment (DRR) > 50 db -23 LKFS
Car environment/listening level 0 db DRR > 25 db 120 110 fff ppp 100 90 80 70 60 50 40 30 20 10 0 Noise floor -23 LKFS
ipod/listening level -10 db DRR < 20 db Noise floor -23 LKFS
City appartment/listening level -20 db DRR > 30 db Noise floor -23 LKFS
Loudness range needs to be adapted to DRR!
Solution: Variable dynamic range by means of a transmitted dynamic control signal G. Plenge, G. Spikofski, G. Theile "Variable dynamic range: a method for improving the sound broadcasting and television service". EBU - Review - Techn. No. 218, 1986, S. 230-240
Solution: DRC in the receiver X
Solution: DRC in the receiver X
Conclusions Loudness normalisation at target level -23 LKFS introduces negligible constrains with respect to loudness range Loudness normalisation cannot solve adaptation of programme loudness range to dynamic range of reproduction environment A programme loudness range compromise could be 20 LKFS Sound engineers should not be biased in their aesthetic producing Certainly special audio productions need higher loudness range Adaption to reproduction environment can be achieved by transmission of metadata and/or DRC in the receiver
Vielen Dank für Ihre Aufmerksamkeit Gerhard Spikofski Audiosystemtechnik Floriansmühlstraße 60 80939 München Tel. +49-(0)89-32399-258 Fax +49-(0)89-32399-415 E-Mail: spikofski@irt.de Die Folien/Dokumente sind durch das Urheberrecht geschützt. Eine Vervielfältigung ist nur mit Genehmigung des Verfassers gestattet. Dieser Urheberrechtshinweis darf nicht entfernt werden.