AN AFTERNOON ON LOUDNESS Las Vegas Convention Center, room S204 1 PM - PowerPoint PPT Presentation

Tuesday 17 April AN AFTERNOON ON LOUDNESS Las Vegas Convention Center, room S204 1 PM Thomas Lund, Dev. Manager HD, TC Electronic: Program Delivery in Accordance with ITU-R BS.1770-2 2 PM Jay Yeary, Director of Audio & Studio Eng., Turner Studios: Loudness at Turner Studios and Broadcast Engineering 3 PM Florian Camerer, Chairman of EBU P/LOUD: EBU R128 Explained and Implemented 4 PM Roundtable and Refreshments, All Presenters, Q&A: The Welcome Revolution

Program Delivery In Accordance With BS.1770-2 T h o m a s L u n d T C E l e c t ro n i c A / S D e n m a r k NAB After noon on Loudness • Las Vegas • April 17, 2012

Agenda The Standards From BS.1770 to BS.1770-2 Loudness, True-peak, Gating Production Guidelines, EBU R128 Tools Loudness Meter Harmonization Transmission Distribution, Cross-platform, Commercials, Metadata Worldview ATSC A/85, TR-B32, OP-59, EBU R128 BS.1770-1 and BS.1770-2

Loudness

Leq Weighting “K”

BS.1770 Loudness Power Gain Sum Mean Left Pre Filter RLB Filter 0.0 dB Square Mean Right Pre Filter RLB Filter 0.0 dB Square � Mean Center Pre Filter RLB Filter 0.0 dB Square Mean L Srnd Pre Filter RLB Filter +1.5 dB Square Mean R Srnd Pre Filter RLB Filter +1.5 dB Square LFE Currently not used in Loudness Calculations Works for mono, stereo and 5.1. Digital input preferable

Words: LUFS, LKFS and LU Unit for absolute loudness level LUFS = LKFS Compare with [dBFS] for peak level -23.0 LUFS is the same as -23.0 LKFS Only the spelling is different LU Unit for relative loudness level Compare with [dB] for peak level Loudness at Target Level = 0 LU

LUFS and LU 0 LU denotes Target Level. In this example, Target Level is -23 LUFS. Remember: LUFS is the same as LKFS.

Meter Examples : LUFS and LU

0 LUFS Program Loudness -4 -8 -12 Use to normalize -16 programs -20 A static gain of +5 dB -24 brings Program Loudness on Target -30 -36 -42 -48 -54 -60 Ingest Corrected

Speech and all that Jazz - Dialog normalization is easily fooled, and creates level- jumps between programs and commercials. - Mixing esthetics are different from genre to genre. - Measuring speech is ambiguous and patent protected. - There are better alternatives...

Speech normalized example Four Programs: 1. Movie 2. Commercial 3. Drama 4. Pop LUFS = Too simplistic Broadcast is not Film (speech) Broadcast is not Music (peak)

News Speaker (NLR) Green: Ungated Red: Gated LUFS

Episode of Friends (MLR) Green: Ungated Red: Gated LUFS

The Matrix Movie (WLR) Red: Gated Green: Ungated LUFS

Measurement Gate EBU A relative gate between -10 and -6 LU gave significantly better normalization results than no gate, or other gating schemes. Independent verification by NAB/ARIB NHK & ARIB and by NHK support relative gating method and a threshold of -8 LU. Independent verification: -8 LU relative CRC gate shows best MSD performance.

CRC

Leq(K) “Loudness” Un-gated Gated @ -10 LU ATSC A/85 BS.1770-2, R128, TR-B32 Includes silence Focus on foreground Application critical Application friendly Cross-genre critical Cross-genre friendly S i m i l a r n u m b e r s w i t h N L R m a t e r i a l D i f f e r e n t n u m b e r s w i t h W L R m a t e r i a l

True-peak Level AES 23 Nielsen & Lund, 2003 Even in a linear audio system, analog and digital level is not the same. 1 Analog Level: Black Line Digital Level: Red Dots 2

True-peak Level AES 23 Nielsen & Lund, 2003 Even in a linear audio system, analog and digital level is not the same. 1 Analog Level: Black Line Digital Level: Red Dots True-peak Level: 2 Grey Lines

CD True-peak Level Original CD level Bit cloned No gain change No sample rate conversion Note: Meter must be digital & synchronous in order to display true-peak level correctly

0 dBFS+ Listening example: Don’t Stop, Anastacia Original CD, normal stereo Remember how loud this track is in order to compare against distortion level in the next examples.

0 dBFS+ Same song, NAD512 CD player, listening here

Data Reduction AES 23, 2003

Data Bandwidth 50% growth p.a. = double in 20 months 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 9 9 9 9 9 0 0 0 0 0 0 0 0 0 0 1 1 9 9 9 9 9 0 0 0 0 0 0 0 0 0 0 0 0 1 2 2 2 1 1 1 1 2 2 2 2 2 2 2 2 2

Agenda The Standards From BS.1770 to BS.1770-2 Loudness, True-peak, Gating Production Guidelines, EBU R128 Tools Loudness Meter Harmonization Transmission Distribution, Cross-platform, Commercials, Metadata Worldview ATSC A/85, TR-B32, OP-59, EBU R128 BS.1770-1 and BS.1770-2

production logging ingest transmission

THE BS.1770 R UTION LOVE

Loudness on three time-scales Momentary Loudness Short-term Loudness Program Loudness

Harmonized Metering M Momentary 400 ms measure of loudness. Loudness Un-gated rectangular window. S Short-term 3 sec measure of loudness. Un-gated sliding window. Loudness I Program The loudness of a full program . Loudness Gated measure. Same as BS.1770-2. Loudness LRA The loudness variations of a program . Range Independent of absolute level.

Loudness Range Example: LRA = 10 LU To keep a constant loudness during the program, a +- 5 dB fader gain ride would be required.

Loudness Range Example: LRA = 10 LU To keep a constant loudness during the Fader ride program, a +- 5 dB fader gain ride would be required.

Loudness Range Example: LRA = 10 LU To keep a constant loudness during the Fader ride program, a +- 5 dB fader gain ride would be required.

Loudness Range in Production Delivery Specs Guideline: Settle expectations. Not car radio, not cinema.

EBU Mode Features A set of requirements for loudness meters How loudness is measured, BS.1770 What numbers are displayed Not the design of meters => different meters, same numbers

Target Level EBU Meter Example Momentary Loudness 400 ms, “M” Short-term Loudness U L 6 3 sec, “S” Target Level At 12 o’clock and at bold circle Loudness Range Variation of program, “LRA” Program Loudness Loudness of program, “I”

Live Metering Loudness meters easier to use than peak or VU Look at a Sliding measure and Program Loudness Start 1 LU below the Target Tolerance allowed Peak meters are used only to avoid overload Move up to the Target at the end

Live Sports Sliding Window and Program Loudness

Production Guidelines Speech Regular speech: -27 to -23 LUFS Music Foreground: -24 to -21 LUFS Loudness Range Get expectations cleared early Note: Also useful for speech only programs True-peak Level No higher than -1 dBTP May need further lowering downstream, depending on platform and codec

Monty Croc Olympics coming up: -22.3 LUFS => gain -1.7 dB Mixing example using Rock’n Roll Train, AC/DC BS.1770-2 normalization -5.7 LUFS => gain -18.3 dB (!) Ruby Baby, Donald Fagen -20.7 LUFS => gain -3.3 dB BBC Jingle -16.5 LUFS => gain -7.5 dB Monty Croc Olympics (same) BBC Jingle (same)

Production Summary • Peak Level is not important, unless -1 dBTP is exceeded • Use Program Loudness to target -23/-24 LUFS • Use Loudness Range (LRA) as production guideline • Observe Momentary (M) and Short-term (S) Loudness Consider mixing at a calibrated listening level

Agenda The Standards From BS.1770 to BS.1770-2 Loudness, True-peak, Gating Production Guidelines, EBU R128 Tools Loudness Meter Harmonization Transmission Distribution, Cross-platform, Commercials, Metadata Worldview ATSC A/85, TR-B32, OP-59, EBU R128 BS.1770-1 and BS.1770-2

Loudness Jumps How much can be tolerated between programs? 2003 “Comfort Zone” paper - Blind to anything but speech - Study not based on BS.1770 when measuring segments AES 2009 paper: New study based on BS.1770 - Commercials, drama, news, pop music, movie - Measures all sources

Loudness Jump Tolerance Tests with mostly speech Tests with mostly music and effects

Loudness Jump Tolerance Results 50% would adjust volume for a loudness increase of 3 LU for a loudness decrease of 6 LU 95% would adjust volume for a loudness increase of 5 LU for a loudness decrease of 8 LU Conclusion Any type of sound could trigger a level-adjustment.

Where to Normalize At the station or using metadata? EBU recommends normalization at the station: - one thing less to go wrong - a benefit to all platforms - more predictable - lower workload - cheaper (fewer Dolby boxes) Normalization => Less transmission processing iTunes example

Loudness Range in Transmission Delivery Specs Guideline: Settle expectations. Not FM radio, not cinema. Compatibility Loudness Range predicts if a program fits consumer requirements, or if platform processing is needed. Quality Control To check downstream signal-path incl. satellite, cable and STB.

Target Loudness Range Loudness Range U L U 0 U 2 L < L U 2 1 8 L The ideal loudness < < 6 < range depends on the listener. A high background noise calls for a low loudness range.