Error "Failed to open disc" from within dmg (disc image)

[LeTerrible]

Hello,

New to MakeMKV, I am trying to convert our Wedding DVD which I have saved as a Mac Disc Image (dmg). The dmg mounts ok (as /Volumes/DVD), and I've tried selecting the ISO file under:

/Volumes/DVD/VIDEO_TS/VIDEO_TS.IFO

using both "File --> Open files" and "File --> Open DVD files manually"

with both I get "Failed to open disc".

The DVD is perfectly viewable - if I run VLC from the command line using the above IFO file as the 1st arg, it opens fine, and I can view the DVD.

I switched on debugging. Debug lines when doing Open DVD files manually:

Debug log started at Mon Sep 12 18:59:48 2016 , written by MakeMKV v1.10.2 darwin(x86-release)
Using 524544KB for read cache.
001005:0000 MakeMKV v1.10.2 darwin(x86-release) started
001004:0000 Debug logging enabled, log will be saved as /Users/xxxx/MakeMKV_log.txt
005042:0000 The program can't find any usable optical drives.
003006:0000 Opening files on harddrive at /Volumes/DVD/VIDEO_TS
001012:0000 Manual String parse error : string is empty
001003:0020 DEBUG: Code 233 at REHKWC6msLrjPKRF724zFmrn:0
005010:0000 Failed to open disc


and debug lines from File --> Open files :

003006:0000 Opening files on harddrive at /Volumes/DVD/VIDEO_TS
001003:0020 DEBUG: Code 1073741829 at 79!>?x~/X>%lkSh":29393953
001003:0020 DEBUG: Code 1073741829 at 79!>?x~/X>%lkSh":29393953
001003:0020 DEBUG: Code 1073741829 at 79!>?x~/X>%lkSh":29393953
Title skip vts=1 pgcn=1 hash=973FAC11A0685C7C
005010:0000 Failed to open disc

Any ideas? (before you say try the original disc, I would if I knew where it was).

thanks in advance.

[Woodstock]

Try this: Do NOT mount the image. Open it directly with File->Open.

MakeMKV can mount ISO files without them being mounted, and sometimes the operating system gets in the way if you do mount it.

[LeTerrible]

Thanks for the reply woodstock, but MakeMkv doesn't understand mounting Mac dmg (disc images).

My dmg file is thus:

discImages> l Wedd*1.dmg
-rwx------ 1 xxxx yyyyyy 4612753498 Oct 19 2010 WeddingDVD1.dmg

This dmg file is not selectable with the File --> Open option (the dmg files are faint/unselectable).

If I mount the dmg (which mounts as volume "DVD"), then I see:

discImages> l -R /Volumes/DVD
total 4
dr-xr-xr-x 2 xxxx yyyyyy 560 Sep 4 2008 VIDEO_TS

/Volumes/DVD/VIDEO_TS:
total 9029864
-r-xr-xr-x 1 xxxx yyyyyy 12288 Sep 4 2008 VIDEO_TS.BUP
-r-xr-xr-x 1 xxxx yyyyyy 12288 Sep 4 2008 VIDEO_TS.IFO
-r-xr-xr-x 1 xxxx yyyyyy 55296 Sep 4 2008 VIDEO_TS.VOB
-r-xr-xr-x 1 xxxx yyyyyy 59392 Sep 4 2008 VTS_01_0.BUP
-r-xr-xr-x 1 xxxx yyyyyy 59392 Sep 4 2008 VTS_01_0.IFO
-r-xr-xr-x 1 xxxx yyyyyy 1073739776 Sep 4 2008 VTS_01_1.VOB
-r-xr-xr-x 1 xxxx yyyyyy 1073739776 Sep 4 2008 VTS_01_2.VOB
-r-xr-xr-x 1 xxxx yyyyyy 1073739776 Sep 4 2008 VTS_01_3.VOB
-r-xr-xr-x 1 xxxx yyyyyy 1073739776 Sep 4 2008 VTS_01_4.VOB
-r-xr-xr-x 1 xxxx yyyyyy 328132608 Sep 4 2008 VTS_01_5.VOB

I have several other dmg images, copied from different DVDs. I tried 2 others, I get the same error.

[LeTerrible]

oh, this is weird... it is working now.

I mounted the dmg manually (command line: hdutil attach Wedd*1.dmg -noverify), then used File --> Open files, started at the Computer level, and opened volume DVD, dir Video_TS, then the Video_TS.IFO file. And it works:

Opening files on harddrive at /Volumes/DVD/VIDEO_TS
Title #1 was added (1 cell(s), 1:29:02)
Operation successfully completed

I'm not doing anything differently to last night; and haven't knowingly changed any profile/option/preference, nor have I rebooted. Can't actually reproduce the problem now.

Oh well.... I've encountered many inexplicable glitches in 30 years of I.T., another one for the list.

Case closed