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Audio For PBS BROADCAST. Lip Sync. Errors Can Hide Below Threshold. WGBH Public Television Quality Workshop. Scenario #1 Show: -1 frame, looks OK Station: -1 frame, looks OK Broadcast Show: -2 frames, looks bad Solution: All sync must be correct (not just look it). Errors Can Cancel. - PowerPoint PPT Presentation
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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)
WGBH Public Television Quality Workshop
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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
WGBH Public Television Quality Workshop
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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!
WGBH Public Television Quality Workshop
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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!
WGBH Public Television Quality Workshop
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Production Tips Delay audio with every video delay
FramesyncsSwitcher effectsLCD & Plasma Displays!Don’t trust your earsTEST!
WGBH Public Television Quality Workshop
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Station Tips Align sync at every point
Framesyncs & processorsMPEG & ATSC encoder settingsSurprisesDon’t trust your earsTEST!
WGBH Public Television Quality Workshop
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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
WGBH Public Television Quality Workshop
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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
WGBH Public Television Quality Workshop
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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!
WGBH Public Television Quality Workshop
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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
WGBH Public Television Quality Workshop
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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
WGBH Public Television Quality Workshop
