QG
Lip Sync
QG
Errors Can Hide Below Threshold

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)
QG
WGBH Public Television Quality Workshop
Errors Can Cancel

Scenario #2
 Show: -3 frames
 Station: +3 frames
 Broadcast 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
QG
WGBH Public Television Quality Workshop
Errors Can Drift

Scenario #3
 Broadcast Now: Good
 Broadcast Later: Bad
Solution: Be Careful! Change Channels!
 Millions of commercial and consumer MPEG
decoders drift!

QG
WGBH Public Television Quality Workshop
Error Perception Can Drift

Scenario #4
 Sync Now: looks good
 Same Sync Later: looks bad

Solution: Patience
 Need tight shots of people talking
 Some people talk out of sync!
 Stare at sync long enough, you will start seeing things!
QG
WGBH Public Television Quality Workshop
Production Tips

Delay audio with every video delay
 Framesyncs
 Switcher effects
 LCD & Plasma Displays!
 Don’t trust your ears
 TEST!
QG
WGBH Public Television Quality Workshop
Station Tips

Align sync at every point
 Framesyncs & processors
 MPEG & ATSC encoder settings
 Surprises
 Don’t trust your ears
 TEST!
QG
WGBH Public Television Quality Workshop
Test Tools

Edit Suites and QC Stations
 syncheck.com

TV Stations
 ID with 1 frame dot and beep, then non-linear editor
 Normal programming with Miranda or Evertz solutions
QG
WGBH Public Television Quality Workshop
Consumer Tips

LCD & Plasma TV's
 Internal decoder should be OK
 Separate decoder & audio systems require offset!

MPEG decoders
 Try changing channels
QG
WGBH Public Television Quality Workshop
TV Loudness
QG
Industry Progress
Early Confusion
 Subsequent Conflict & Loudness Wars
 Recent Consensus: ATSC A85!

 www.atsc.org/cms/standards/a_85-2009.pdf
QG
WGBH Public Television Quality Workshop
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 LKFS
 Average over entire show, ± 2 dB
 Dramatic moments can still be ±10 dB!
QG
WGBH Public Television Quality Workshop
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

QG
WGBH Public Television Quality Workshop
Tolerance
QG
5.1 Surround
QG
5.1 Surround

PBS Submission Requirement
 Effective March 2011!
 Up-mix OR actual 5.1 production
 Requires Dolby E

Caution
 Calibrate your LFE monitoring per ATSC A85
 Insure downmix is compatible
 Most stations cannot afford to broadcast 5.1
QG
WGBH Public Television Quality Workshop