Timeline for By how much can video and audio be out of sync?
Current License: CC BY-SA 4.0
8 events
| when toggle format | what | by | license | comment | |
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| Oct 23, 2020 at 2:29 | comment | added | Michael Liebman | @PeterBarton I edited the link, thanks for finding the archive. SMPTE recently went through a branding refresh, so I guess that swept away a bunch of older stuff. | |
| Oct 23, 2020 at 2:28 | history | edited | Michael Liebman | CC BY-SA 4.0 |
Fix dead link
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| Oct 22, 2020 at 22:54 | comment | added | Peter Barton | The SMPTE handout appears to have been removed from their site - archive.org has a copy at web.archive.org/web/20150328054944/https://www.smpte.org/sites/… | |
| Oct 24, 2018 at 3:00 | comment | added | Michael Liebman | Keep in mind, the ATSC is US-based organization and the recommended practice was developed for a system that is predominantly 30/60 fps. At those frame rates, one field/frame is roughly 16ms. It basically says that if the audio leads the video by even one frame, it is noticeable and that is consistent with what I've run into. The European (EBU) standard matches what you said about a 25 fps world. | |
| Oct 24, 2018 at 0:11 | comment | added | stib | given that at 25fps each picture is displayed for 40ms there's a +/- 20ms margin for sync even for sound recorded with the picture. Say the shutter opens at the start of the frame, while audio of course records continuously. At the beginning of the frame the picture will be in sync with audio, and at the end the picture is 40ms behind. So one wonders how you can possibly be 15ms out of sync. | |
| Oct 23, 2018 at 3:42 | vote | accept | user3643 | ||
| Oct 23, 2018 at 3:42 | comment | added | user3643 | Great, this helps a lot. I think I'll update my margin to -100 ms to 45 ms, per the ITU BT.1359. This conveniently also answers if positive is more noticeable than negative. I'm tentatively giving you the selection, but might change it if a better comes along. Not that your answer isn't good. You've earned the selection. It's just that I don't usually like to give it so early. | |
| Oct 23, 2018 at 2:11 | history | answered | Michael Liebman | CC BY-SA 4.0 |