GNOME Bugzilla – Bug 501016
Limit DVD reading speed to reasonable levels
Last modified: 2018-05-04 09:12:31 UTC
Most computer DVD readers sound like lawn mowers when driven at full speed. This is unfortunately the linux kernel default (data-copy oriented). Therefore any attempt to read a shiny disk will be a noise disaster unless the video app requests limiting the drive to reasonable speeds such as 2× Totem does not do it right now but it should, the code needed is very small, as evidenced on http://safari.iki.fi/speedcontrol.c
This would probably be better off in the backends (GStreamer and xine), or even in the DVD video libraries they use. Bastien?
Definitely. Reassigning to GStreamer for now, if you're using xine-lib, please file a bug with them.
I'd like to do something like this in the new resindvd component. Gotta be careful with the detection code to make sure it's only used on supported platforms, and try and expand it to others at some point.
Maybe this is a stupid question, but don't modern kernels take care of automatically adjusting optical drive speed based on speed at which data is being read from the device ? Making this bug obsolete ? Jan ?
There's nothing new in the kernel afaik, and I haven't seen any change in behaviour. Generally when you hit play, the drive spins up to full speed (lawnmower mode) for a bit, until the pipeline is filled, and then automatically slows to match reading speed. It does that every time you un-pause or seek.
Ok, so we do agree that except for the initial read burst, it does go back down to regular speed. Is this really an issue ?
I'm not sure - I'm just stating my experience. It may vary with the drive and whether it's any good at automatically picking a speed, or if it just spins at highest speed unless told otherwise.
It can be a real problem in my experience, esp. with drives in laptops. You don't want to constantly have the drive go at max speed with high-pitch whine, just to then slow down to nothing, then shortly after spin up to max again, just to switch off. It happens.
Seems unlikely we'll ever get to this, and it's never been a problem for me with any of my drives.
5 years later, I don't think that many people still have laptops with DVD drives, and the importance of DVDs has declined. I think this should be done differently anyway, by implementing a device monitor for disc drives and exposing API for things like eject and setting playback speed anyway. No one seems to have cared enough to just make a patch for dvdnav, so let's just close this :)