disc:0 versus disc:1 depends which drives contain discs

[BitJam2]

I have a dvd drive at /dev/sr0 and a bluray/dvd drive at dev/sr1. I figured that if I'm always streaming blurays then I would always use "disc:1" with makemkvcon. But that only works when there is a disc in the /dev/sr0 device. If there is no disc in /dev/sr0 but there is a bluray disc in /dev/sr1 and I try to "makemkvcon stream disc:1" then I get a segfault. Here is the debug log:

Code: Select all

Debug log started at Tue Sep 14 18:36:20 2010 , written by MakeMKV v1.5.8 linux(x64-release)
Using 524544KB for read cache.
001005:0000 MakeMKV v1.5.8 linux(x64-release) started
001004:0000 Debug logging enabled, log will be saved as /home/jbowlin/MakeMKV_log.txt
001003:0020 DEBUG: Code 0 at ={DN#c^S5134#z2N;qsM:213130122
001003:0020 DEBUG: Code 0 at ={DN#c^S5134#z2N;qsM:213130122
005010:0000 Failed to open disc

So if there is no disc in /dev/sr0 then I have to use "disc:0" to read the disc from /dev/sr1. But if there is a disc in /dev/sr0 then I have to use "disc:1" to read the disc from /dev/sr1.

I think it would be easier for GNU/Linux users if there was a fixed relationship between makemkvcon's disc:$N and the /dev/sr$N devices. I've seen in another thread that it is unlikely this will happen anytime soon. It's certainly more of an annoyance than a show-stopper but it is an annoyance.

[mike admin]

Please post /proc/sys/dev/cdrom/info for both cases.

[BitJam2]

The contents of /proc/sys/dev/cdrom/info do not change when I insert discs into the drives. So in all cases it gives:

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With only Bluray disc in sr1, need to use "disc:0"

CD-ROM information, Id: cdrom.c 3.20 2003/12/17

drive name:		sr1	sr0
drive speed:		102	12
drive # of slots:	1	1
Can close tray:		1	1
Can open tray:		1	1
Can lock tray:		1	1
Can change speed:	1	1
Can select disk:	0	0
Can read multisession:	1	1
Can read MCN:		1	1
Reports media changed:	1	1
Can play audio:		1	1
Can write CD-R:		0	1
Can write CD-RW:	0	1
Can read DVD:		1	1
Can write DVD-R:	0	1
Can write DVD-RAM:	0	1
Can read MRW:		1	1
Can write MRW:		1	1
Can write RAM:		1	1

I tried to replicate the problem this morning to be sure the contents of /proc/sys/dev/cdrom/info corresponded to the failure modes I reported. Of course, the failure modes changed. Today disc:0 corresponds to sr1 and disc:1 corresponds to sr0. This does not change when I insert or remove media. I get a segfault when I try to read from an empty drive and I also got a couple of "random" segfaults when trying to read from a drive that contained a disc.

I will try to replicate the original problem I reported after I reboot and if I can replicate it I will post the contents of /proc/sys/dev/cdrom/info.

[BitJam2]

After rebooting the "drive speed" line /proc/sys/dev/cdrom/info has changed. All the other lines are the same as before:

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CD-ROM information, Id: cdrom.c 3.20 2003/12/17

drive name:		sr1	sr0
drive speed:		32	94
drive # of slots:	1	1
Can close tray:		1	1
Can open tray:		1	1
Can lock tray:		1	1
Can change speed:	1	1
Can select disk:	0	0
Can read multisession:	1	1
Can read MCN:		1	1
Reports media changed:	1	1
Can play audio:		1	1
Can write CD-R:		0	1
Can write CD-RW:	0	1
Can read DVD:		1	1
Can write DVD-R:	0	1
Can write DVD-RAM:	0	1
Can read MRW:		1	1
Can write MRW:		1	1
Can write RAM:		1	1

And now disc:0 corresponds to sr0 and disc:1 corresponds to sr1. The correspondence does not seem to depend on which drives has discs inserted. I still get random segfaults.