I've been copying DVDs to the hard drive using a Linux program called dvdbackup. I then run a script which calls makemkvcon to create mkv files from the copied dvd directory. It executes makemkvcon for each title which I want to copy. The makemkvcon command randomly fails to copy a title and gives the error
MSG:1002,32,1,"LIBMKV_TRACE: Exception: Error while reading input","LIBMKV_TRACE: %1","Exception: Error while reading input"
The thing is that if I run the script again against the same copied DVD directory it will either work for all titles or give that error on a different title. The failure rate seems to be about 1 time out of 4, so extracting 4 titles from a disc will usually work 1 time out of 2.
Here's an example of the command the script is running:
/usr/bin/makemkvcon -r --cache=1024 mkv file:"/data/television/Babylon5/S1D6/Babylon5 Season 1/VIDEO_TS" 0 "/data2/encode_work/Extract_Babylon5Season1Disc6" --minlength=0 --profile="/homedata/homedirs/properties/makemkv_profile.xml"
If the command failed on the same title every time, that would indicate the DVD copy is bad, but it doesn't.