13 Replies Latest reply: May 20, 2009 9:36 PM by ultraviolet7
Tony Starks Level 1 Level 1 (0 points)
I have a file I downloaded that is in the .nrg format (Nero for PC) and I need it in the .iso format so I can use Disk Utility to burn it to a DVD. How do I do that? I tried searching online and only found very confusing articles about using Terminal to do it that I don't understand. Thanks!

IMac G5 w/ iSight, Mac OS X (10.5.6)
  • Limnos Level 8 Level 8 (45,385 points)
    Some options:

    1) Use Toast. Apparently it can handle .nrg

    2) Try changing hte .nrg to .iso and see if the image will mount with Disk Utility. Some have found this to work, others not.

    3) From [http://forums.macrumors.com/showpost.php?p=2270274&postcount=9]:

    dd if=image.nrg of=image.iso bs=512 skip=600

    Basically you are just typing that line after the prompt in Terminal, using your .nrg file name where it says "image.nrg" in the above line, and your desired output name where it says "image.iso" It is important to make sure you have space where spaces exist in the above command, and don't have any where none are present.

    First, make a copy of the file so you have a copy in case something doesn't work well with the original. Second, read all of the instructions below before doing them so you don't do something prematurely.

    Now start Terminal application.

    On the line enter:

    dd if=

    Drag the file you wish to convert to the Terminal window (this saves a lot of typing). This should result in a line of text following the stuff already on the line, the text being the path to, and the name of, the file you wish to convert.

    Continue the line with:


    Note there is a space before the "of" but not at the end

    After the "=" enter the name of the file as your output file, ending with a ".iso" (see how this is structured in the original command line at the very start of the instructions).

    Finally enter:

    bs=512 skip=600

    making sure there is a space before "bs".

    As I said, all this should be on one long line. Finally, press the enter key to start the process.

    Note: I have not run this but have seen it referenced in several places. I just broke down the instructions so you could hopefully understand it.
  • Tony Starks Level 1 Level 1 (0 points)
    Thanks for the great answer Limnos! I don't want to buy Toast though, so I tried the Terminal method. It worked (perfect instructions) but the resulting iso didn't work with disk utility, nor would simply changing the extension to iso.

    What about the program nrg4iso (http://code.google.com/p/nrg4iso/)? I don't understand how to use it (it uses Terminal) but it looks promising. Any chance for some step by step instructions again? Thanks so much!
  • Limnos Level 8 Level 8 (45,385 points)
    There's a slightly abbreviated version of instructions at: http://macosx.com/forums/329612-post6.html

    If you use that utility there are two stages (I am interpreting this from reading, and haven't done it). One to actually build the application (binary). The second is to run the application (in Terminal) with the two file names (input file as dictated by the mname of the file you have, and output file (your choice but I suggest it end in .iso). The hardest part is when you need to enter the name of a specific file, but as you have already learned, the shortcut is to drag the desired file to the Terminal window and its path and name are automatically entered.
  • Tony Starks Level 1 Level 1 (0 points)
    Thanks! Most of it makes sense, but could you elaborate on this part?

    "You can then just type ./nrg2iso in that directory, add the source file and a destination name."
  • Limnos Level 8 Level 8 (45,385 points)
    Once you have the program compiled, type


    Type a space.

    Drag your .nrg file to Terminal window.

    Type a space.

    Type a file name for your new file. Make it just a single word (you can change it later).

    Press return/enter.
  • Tony Starks Level 1 Level 1 (0 points)
    Sorry to keep asking questions, but I follwed the steps to compile and when I type make, this is what I get:

    -bash: make: command not found
  • Limnos Level 8 Level 8 (45,385 points)
    You probably have to install developer tools from your osx DVD
  • Tony Starks Level 1 Level 1 (0 points)
    I did that, but now I'm getting different errors, so I guess I won't waste anymore of your time and just give up.

    Thanks a lot for your help though, at least I learned a little something about using Terminal along the way.
  • Limnos Level 8 Level 8 (45,385 points)
    Sorry it didn't work out fully. Unfortunately, for more obscure requirements there are not user-friendly tools available since there isn't the demand. If you have a friend with a PC you may be able to get them to convert the file to iso format and then you can work with it on your Mac.
  • KJK555 Level 4 Level 4 (2,895 points)
    Hi Limnos:
    I downloaded nrg2iso.

    It compiled easily, no errors. I haven't tried it yet, but I'm sure It will come in handy.

  • Tony Starks Level 1 Level 1 (0 points)
    Just an update, I got it to work with nrg4iso. Its a much easier program, all you need to type in terminal is "./nrg4iso foo.nrg foo.iso" and presto! Thanks again.
  • Ryan Vetter1 Level 2 Level 2 (460 points)
    Ok, can you expand on this? I downloaded nrg4iso, launched it, Terminal came up, and all that happens is it ends automatically on "process completed". I don't see where my .nrg file is converted anywhere, an I also input your commands that you state and nothing.

    I don't know if what I am doing is right, but I have used Toast Titanium 6... opened the .nrg file under the Disc Copy pane as a disc image, then clicked File>Save As Disc Image.

    Toast then saves it as .nrg.toast.

    I can then drag that .nrg.toast file into Disk Utility under Leopard, and mount it. Once mounted, I can burn it, which is what is underway right now.

    This is a Windows Vista disc, so hopefully it will boot... Why the person who knows I have a Mac, who uses Mac himself, would make an iso for me using Nero I don't know, but I have been working on this for 5 hours tonight and am not too happy...
  • ultraviolet7 Level 1 Level 1 (0 points)
    I've got an .nrg file (it's a DVD-Video VIDEO_TS folder). I can mount it with Toast Titanium. When mounted I can watch the DVD, use the menus, etc. with VLC. The problem is that when I burn the disc and pop it into a standalone DVD player, the DVD loads OK, gets to the main menu and when you click on any of the chapters the disc goes into play mode but there's no image and no audio (I see the display showing the chapters and time counter, but the image remains frozen on the menu). If I pop the same disc into the computer it works perfectly well. When I go into the navigation inner menu on my standalone (a Pioneer DV578A) it displays the titles it "sees" but the ones corresponding to the main movie are empty. The extras however play OK. Since this DVD player reads both PAL and NTSC, this is not the problem. I've never had any issue with discs burnt from regular .iso files, but since this is the first time I burn a disc from a .nrg file, which is not a Mac compatible format, I thought this might be the problem.

    I'm using Toast Titanium 7. I have no access to a Windows based computer. I tried mounting with nrg4iso, thinking that maybe there was some issue with the way Toast mounts the .nrg image, but the resulting iso is unreadable by disk utility and says something about the nrg files and iso files not being the same size (the iso being much smaller). However when I mount the Toast generated image the file size is identical to the nrg.

    I also tried nrg2iso which with an older version (0.4) does not mount the disc and gives me a "permission denied" line and on a newer version (1.2) a statement saying that the file is already an ISO 9660 (which isn't) and thus aborts the operation.

    Lastly I naturally burnt the disc twice to check for faulty media, though I'm using Verbatim DVD-Rs with which I've never had any trouble. The second disc had the same problem.

    Any ideas? Thanks in advance for any help.