2.0.1-Win7 | Distorted sound Digital Clipping
Posted: 05 Apr 2012 16:55
by singul4r1ty
I just did a standard upgrade a week ago to 2.0.1;
and now the sound in mpeg4/mp4a videos I play is distorted in the lower frequencies (basses)
like its constantly peaking causing rumbling noise.
Opening the same video in Windows media player gives no audio troubles.
Re: 2.0.1-Win7 | Distorted low freq sound
Posted: 05 Apr 2012 18:31
by VLC_help
Does Tools -> Messages (set Verbosity to 2) complain something during playback?
Re: 2.0.1-Win7 | Distorted low freq sound
Posted: 05 Apr 2012 19:00
by singul4r1ty
Code: Select all
..
main warning: PTS is out of range (-31315), dropping buffer
main warning: audio output out of sync, adjusting dates (95081 us)
main warning: not synchronized (95081 us), resampling
main warning: buffer too late (94664), up-sampling
..
Full log:
http://pastebin.com/4rGgvdMR
Following warnings generated by an mp3 (mpga encoded) which has same distortion:
Code: Select all
main warning: PTS is out of range (-9990), dropping buffer
main warning: PTS is out of range (-36091), dropping buffer
mpgatofixed32 debug: libmad error: bad main_data_begin pointer
mpgatofixed32 debug: libmad error: bad main_data_begin pointer
main warning: audio output out of sync, adjusting dates (105975 us)
main warning: not synchronized (105976 us), resampling
main warning: buffer too late (105522), up-sampling
main warning: resampling stopped after 15724197 usec (drift: 827)
Re: 2.0.1-Win7 | Distorted sound Digital Clipping
Posted: 05 Apr 2012 21:31
by singul4r1ty
Ok so I did some google-fu with the log warnings started with upsampling into nyquist sampling
into Anti-Aliasing filter
http://en.wikipedia.org/wiki/Anti-aliasing_filter
into digital clipping
http://ubuntuforums.org/showthread.php?t=820766
So if you keep the volume level below 145'ish in VLC you will get no digital clipping/distortion, apparently the volume range in VLC is from 0-200% which I hadn't noticed.
I do miss an options to change the maximum volume scale in the VLC options, because of possible distortion I want to cap it to 140%.