Mike,
Over the past year or so, I've periodically had problems processing discs (both DVD and blu-ray) with MakeMKV. The periodic problems were random "corrupt or invalid" errors and more recently random "hash check failed" errors. I say "random", because if I re-preocess the same disc, the errors occur at different offsets, or not at all. The discs themselves always visually appear to be "pristine" with no scratches, etc., so I just keep re-trying until I get a clean run (which has never been a problem). I've been OK with this until two days ago were this "re-processing" just doesn't work for me anymore.
Two days ago, I had a particular blu-ray disc (new and "pristine" looking) that has taken me TWO DAYS to process. Somewhere along the way on the second day, the disc read rate seemed to lock in at 2X and the disc processed with absolutely no re-tries and NO ERRORS. I have seen on the forum past posts about some drives having a "rip lock". It seems that on that particular processing run, that may have happened to my drive. I have tried to re-create this, but so far have not been able to. I'm just glad that it happened or I'd still be trying to process the same perfectly good disc.
I believe that this particular problem occurred when the drive was driven near its maximum speed (6X) and the drive just could not reliably maintain that speed. Additionally, at that speed, this particular disc caused significant vibrations, which contributed to the random errors.
My purpose for this post is to plead with you to finally put in a user option to specify the maximum drive speed for MakeMKV to use! I know from past posts that people have asked for this option before. I think it is time to help us out by adding this option. If I could have forced MakeMKV to slow down the drive speed, I could have processed the disc in an hour or so and be assured that no errors occurred. Instead, it took me TWO DAYS, and I constantly had to do random quality checks of the resulting files to look for anomolies in the video. Not very pleasant watching the same video over and over.
Please, add a maximum drive speed option. There is no way that anyone can code to cover every possible disc, drive or disc/drive combination. Sometimes a simple option can cover a large range of potential problems.
I am a big fan, so I hope this is taken as positive feedback. Thanks.