Xpra: Ticket #1164: av-sync finer tuning
Follow up from #835.
Things that we want to quantify because they may need to be taken into account when calculating the video sync delay:
- operating system / driver output buffering: how long it takes from the moment we send bytes to the soundcard until they actually come out of the speakers
- gstreamer internal buffering its sink element, different on each OS
- application specific internal processing delay (which we should probably ignore - the application should submit sound and video in sync to the server OS)
- picture decoding time: this is small, but should have been substracted from the total already
- opengl double-buffering vs single-buffering and framerate (we do have a value for vsync we export) - also needs to be substracted from the total
- any other display specific delay: 4k vs 1080p should not make any difference, at least I can't think of how it would - maybe related to #981
From what I've heard, the audio is a bit late, especially on non-Linux platforms.
If that's the case, we can quite easily add per-OS tweaks.
Fri, 15 Apr 2016 14:51:22 GMT - Antoine Martin: milestone changed
- milestone
changed from 0.17 to 0.18
too late for 0.17
Sun, 19 Jun 2016 08:06:54 GMT - Antoine Martin:
Edit: ignore comment, reverted in r12870.
See also #1261 for multiple b-frames support, r12868 takes delayed frames into account when calculating the delay.
Tue, 12 Jul 2016 16:52:22 GMT - Antoine Martin: milestone changed
- milestone
changed from 0.18 to 1.0
Milestone renamed
Wed, 10 Aug 2016 02:31:19 GMT - Antoine Martin:
There may also be differences between codecs, see ticket:1075#comment:10 : Mp3, on the other hand, seemed to be about 6-8 frames audio late.
Fri, 23 Sep 2016 10:50:57 GMT - Antoine Martin: milestone changed
- milestone
changed from 1.0 to 3.0
Not going to happen for this release. Re-scheduling.
Mon, 06 Nov 2017 08:50:59 GMT - Antoine Martin: owner, status changed
- owner
changed from alas to Antoine Martin
- status
changed from new to assigned
As of r17223, users can tune the av-sync from the system tray.
Wed, 28 Mar 2018 05:17:53 GMT - Antoine Martin: milestone changed
- milestone
changed from 3.0 to 3.1
Wed, 20 Mar 2019 05:06:15 GMT - Antoine Martin: milestone changed
- milestone
changed from 3.1 to 4.0
Milestone renamed
Wed, 12 Feb 2020 05:29:45 GMT - Antoine Martin: milestone changed
- milestone
changed from 4.0 to future
See also #2517.
Sat, 23 Jan 2021 05:16:43 GMT - migration script:
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/1164