Audio

1. Audio

2. Audio Sync

3. Audio Sync • Theory • Perceptual Threshold • Errors That Cancel • Errors That Drift • Errors That Confound • Practice • Production • Distribution • Consumer San Francisco Public Television Quality Workshop

4. Perceptual Threshold San Francisco Public Television Quality Workshop • Perplexing scenario • System A = Looks OK • System B = Looks OK • System A + System B = Looks Bad • Solution: All systems must beOK • The threshold is also asymmetrical! • Sync is not like noise or resolution

5. Errors That Cancel San Francisco Public Television Quality Workshop • Perplexing scenario • System A + System B = Good • System A = -3 frames • System B = +3 frame • System A + System C = Bad • Solution: All systems must beOK • Two wrongs don't make it right

6. Errors That Drift San Francisco Public Television Quality Workshop • Perplexing scenario • System A Now = Good • System A Later = Bad • Solution: Replace system A! (Good luck!) • Millions of commercial and consumer MPEG decoders drift!

7. Errors That Confound San Francisco Public Television Quality Workshop • Perplexing scenario • System A Now = Good • System A Later = Bad • Solution: Wait • Need tight shots of real people talking • Some people talk out of sync! • Stare at sync long enough, you will start seeing things!

8. Production San Francisco Public Television Quality Workshop • Delay audio with every video delay • Framesyncs • Switcher effects • Monitors (Syncheck.com)

9. Distribution San Francisco Public Television Quality Workshop • Align sync at every point • Framesyncs • MPEG encoder setting • Surprises • Monitors (Syncheck.com) • Beware of drifting MPEG decoders • Try changing channels.

10. Consumer San Francisco Public Television Quality Workshop • Be aware of consumer issues • LCD/Plasma TV's with external audio • Drifting MPEG decoders (Try changing channels)

11. Loudness

12. Loudness • dialnorm must = average loudness at encoder • -24 (for PBS and everybody else) • Set plant for unity gain • Get an LKFS meter (BS.1770) • Produce content to -24 LKFS • Peaks at -10 dBFS works amazingly well • Compare local stations and share San Francisco Public Television Quality Workshop

13. Loudness Tolerance San Francisco Public Television Quality Workshop • dialnorm must = average loudness at encoder • -24 (for PBS and everybody else) • Set plant for unity gain • Get an LKFS meter (BS.1770) • Produce content to -24 LKFS • Peaks at -10 dBFS works amazingly well • Compare local stations and share

14. How Close?

15. 5.1 Surround

16. 5.1 Surround Submission • Required of all PBS shows starting in 2011! • Upmix • Insure compatible downmix - demand from your vendor! • 5.1 Production • Insure compatible downmix - demand from your engineer! • Traditionally all dialog in C only • Calibrate your LFE San Francisco Public Television Quality Workshop

17. 5.1 Surround Broadcast San Francisco Public Television Quality Workshop • Increasing Demand • Consumers are building theaters • PBS will be supplying more content • For PCM, decoder needed for every IRD • NRT eliminates this expense • Compelling 5.1 shows have long lead and will come via NRT

18. PCM Plant - SAP on 7/8 San Francisco Public Television Quality Workshop

19. PCM Plant - SAP on 3/4 San Francisco Public Television Quality Workshop

20. PCM Plant - Future Stereo SAP San Francisco Public Television Quality Workshop