Audio For PBS BROADCAST

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Lip Sync

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Errors Can Hide Below Threshold Scenario #1

Show: -1 frame, looks OKStation: -1 frame, looks OKBroadcast Show: -2 frames, looks bad

Solution: All sync must be correct (not just look it)

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Errors Can Cancel Scenario #2

Show: -3 framesStation: +3 framesBroadcast Show: 0 frames, looks good But two wrongs don’t make a right!Good shows will look bad on this station!

Solution: All sync must be correct

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Errors Can Drift Scenario #3

Broadcast Now: GoodBroadcast Later: Bad

Solution: Be Careful! Change Channels! Millions of commercial and consumer MPEG

decoders drift!

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Error Perception Can Drift Scenario #4

Sync Now: looks goodSame Sync Later: looks bad

Solution: PatienceNeed tight shots of people talking Some people talk out of sync!Stare at sync long enough, you will start seeing things!

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Production Tips Delay audio with every video delay

FramesyncsSwitcher effectsLCD & Plasma Displays!Don’t trust your earsTEST!

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Station Tips Align sync at every point

Framesyncs & processorsMPEG & ATSC encoder settingsSurprisesDon’t trust your earsTEST!

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Test Tools Edit Suites and QC Stations

syncheck.com

TV StationsID with 1 frame dot and beep, then non-linear editorNormal programming with Miranda or Evertz solutions

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Consumer Tips LCD & Plasma TV's

Internal decoder should be OKSeparate decoder & audio systems require offset!

MPEG decoders Try changing channels

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TV Loudness

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Industry Progress Early Confusion Subsequent Conflict & Loudness Wars Recent Consensus: ATSC A85!

www.atsc.org/cms/standards/a_85-2009.pdf

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Production Tips Buy an LKFS meter (BS.1770)

Your mix engineers will like it!

No money?Dialog peaks at -10 dBFS works pretty well

Produce content to -24 LKFSAverage over entire show, ± 2 dBDramatic moments can still be ±10 dB!

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Station Tips Set plant for unity gain Set encoder dialnorm to -24 Get an LKFS meter (BS.1770) Measure day-long compliance with -24 LKFS Apply processing if needed Compare local stations and share

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Tolerance

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5.1 Surround

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5.1 Surround PBS Submission Requirement

Effective March 2011!Up-mix OR actual 5.1 productionRequires Dolby E

CautionCalibrate your LFE monitoring per ATSC A85Insure downmix is compatibleMost stations cannot afford to broadcast 5.1

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