2014-05-28, 18:08
Although I have no time atm for any testing or debug logs, I'd like to add my findings here for reference. I hope this is useful to anyone.
A/V desync appears to be different from file to file, with more similarities between files of the same container.
Independent of the file type, the A/V offset changes (it usually gets "better", ie. more similar between different files) when rewinding or fast forwarding by a few seconds after playback starts.
Examples:
I don't see any temporal a/v sync fluctuations, though.
As for environment and settings, here are mine:
A/V desync appears to be different from file to file, with more similarities between files of the same container.
Independent of the file type, the A/V offset changes (it usually gets "better", ie. more similar between different files) when rewinding or fast forwarding by a few seconds after playback starts.
Examples:
- MKV files usually need a different audio delay than MPEG-TS (live TV) or AVI of the same frame rate, while the difference between most MKV files of the same frame rate is usually negligible (after rewinding/fast-forwarding at least, see above)
- On the other hand, 24p YouTube streams need about 200ms longer audio delay than non-YouTube 24p MP4 files.
I don't see any temporal a/v sync fluctuations, though.
As for environment and settings, here are mine:
- My TV doesn't report A/V delay via EDID. Its frame rate specific delays are set to the best of my knowledge via advancedsettings.xml <latency>.
- I'm using WASAPI "best match" for audio output.
- I'm using true full screen with "sync playback to display" set to "video clock (resample audio)" as all other settings are causing stuttering for me.
- "Change display rate to match video" is set to "always" with overrides specified via advancedsettings.xml <adjustrefreshrate>