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Buffer-related audio problem

Posted: 25 Feb 2020 15:01
by Petioneer
I'm digitizing VHS tapes to .mpg using Cyberlink Powerdirector 10. Previously that has produced OK results, but the recent collection of movies has had some problems when played in VLC. For all such files, after literally 1 second, the sound cuts with a pop/crack, without the actual volume control being altered, and remains mute if left undisturbed or simply paused/unpaused. The log spams "main warning: buffer too late (-1443477 us): dropped" (with slightly different us values) during this. If a timestamp after 0:01 is chosen trough the seeker, the audio will play as normal, but if I go back to 0:00 the problem will resume. This problem persists in VLC troughout different computers and OS:s, while QuickTime on a Mac and Windows Media Player on W10 plays as normal. Other mpg files (and other media files in general) don't have this problem with VLC. Any ideas on what can be causing this?
  • CPU remains around 20% while playing, so probably not a performance issue
  • I've tried all available output modules for audio (restarting each time)
  • In case VLC was intentionaly modifying the output audio, I've tried disabling all of the following: normalization, peak protection and dynamic range compression for both A/52 & DCA.

Re: Buffer-related audio problem

Posted: 26 Feb 2020 12:22
by Lotesdelere
Please open Tools -> Messages (set Verbosity to 2) before you start the playback, and then paste the full resulting log here or on Pastebin.com if it's too long.

Also upload a short sample of an original problematic file to Zippyshare.com (200 MB max) or to WeTransfer.com and then post the link to the file here.
http://www.zippyshare.com
https://wetransfer.com

If needed cut it with DGsplit and read here about how to do it:
http://forum.videolan.org/viewtopic.php?f=14&t=57724&p=193335#p193335
100 MB max should be enough.

Re: Buffer-related audio problem

Posted: 27 Feb 2020 09:48
by Petioneer
Thank you for the attention.

Log without seeker intervention
https://pastebin.com/pa9Nuxew

Log with seeker intervention
https://pastebin.com/sSPhJPPc

Sample link below (30 second run time). I digitized it myself rather than cutting an existing video for privacy/copyright reasons, but the principal bug still holds since the music at 0:25-0:30 isn't played. Interestingly enough, some, but not all, signal noise can be heard after the 0:01 mark.

https://wetransfer.com/downloads/7dadd920521ad4942e3ecf7422065aa020200227083308/c21d79

Re: Buffer-related audio problem

Posted: 28 Feb 2020 10:43
by Lotesdelere
Yes, there is something strange with this file and not only about the audio, VLC just doesn't play the end of the file.

You should create a new ticket on the VLC Trac with the links to your file and to this thread.
https://trac.videolan.org/vlc/

Re: Buffer-related audio problem

Posted: 02 Mar 2020 09:45
by Petioneer
Thank you for the confirmation. For reference, the ticket is here:
https://trac.videolan.org/vlc/ticket/24279

However, I'm a bit confused about your comment about VLC not playing the end of the file? The playbar seems able to fill fully with blue for me. Note that the file is really 28s long when I incorrectly said it was 30s.