What is Loudness?

• Analog world of yesterday– Limited dynamic range, no meta-data volume adjustments– Setting peak effectively leveled programs

• Digital world of today– +40db more effective dynamic range, volume metadata

• Tragedy of the commons- Ads are too loud– Too much flexibility - allows “Tragedy of the commons” with ads

Who cares about Loudness?

SpecificationWhat is LKFS?

Recommended PracticesHow to use Loudness

RegulationHow will it be enforced?

BS.1770-1/2 LKFS gated

R128Tech 3341/2/3 A/85 RP TR-B32

What is Loudness?

• ITU Recommendation on Loudness Measurement

– BS.1770-1 (09/2007) & BS.1770-2 (03/2011)

• For entire audio track Mono, Stereo or 5.1

– Rear surrounds are weighted at +1.5dB

– .1 track is not incorporated

• Models human perception of loudness

– K- Weighting

What is Loudness?

• For the entire length of the content

Short form -< 2 minutes ad or promo

Long form - > 2 minutes program or promo

Overall channel - time (e.g. 6h, 1d, ..)

• Not counting quiet periods

Gating (-10dB)

Don’t silence/quiet to lower measurement

• Into one LKFS measurement (dB scale)

Logarithmic K-weighted Full Scale -x.yz LKFS

Ungatedaverage

HigherGatedaverage

-10dB gate

What is Dialnorm?

AC-3 metadata that allows programs originated with different levels to be decoded with the same perceived loudness.ATSC only

Everything sounds the same!

What really happens with Dialnorm?

It is always set to -24 (-7dB of gain)

Assets should be gain adjusted to have a -24 LKFS level

before being transmitted.

Observer Loudness Monitoring

• Loudness measurements -LKFS and LUFS -with gating

• Short (S), Medium (M) and Interval (I) measurements

• Up to 7 Short-form Interval (SI) - e.g 10s, 15s, 20s, 30s

• Up to 7 Long-form Interval (LI) - e.g. 6h, 1d, 5d

• Loudness Range (LRA) to measure audio companding

• Detailed 10Hz measurements - with Audio & Video

Loudness Monitoring Features

• Graphing of S, M and I measurements over time Multiple channel, multiple meas. Graph <=> video time navigation

• Export : Logged measurements as csv Affidavit - A/V with burned in measurements

• Short form Asset measurements • Alarming (SNMP, email, visual)

Customizable alarming profiles based on SI and LI measurements

A/V affidavitWith meas Burn-in

export

CSV values report