Help me open a file.

September 29, 2008 1:18 PM

Was sent an "untyped binary data" file with no extension. It's audio. Using a Mac, I've tried adding the .mp3, .aac, .wav extensions, and it won't open. What now?

- What extensions have I failed to try? This is recorded audio of some sort.

- Am I changing the extensions correctly? I just select+click on the file and manually add the extension.

- Is there a program that will figure it out for me?

posted by acidic to Technology (14 answers total)

- Is there a program that will figure it out for me?

From the command prompt, try file filename, where filename is the full path to the file. The file command exists exactly for problems like these. (The output may or may not be helpful: it can be fairly terse at times.)

I'm not a Mac user, but this is pretty much a "standard" UNIX utility, so I'm assuming it's available on Macs.
posted by fogster at 1:26 PM on September 29, 2008 [2 favorites]

Try opening it in a text file viewer and see if anything looks familiar near the start. A lot of file formats have a header that has readable bits in it somewhere.
posted by smackfu at 1:27 PM on September 29, 2008

Audacity can guess audio file types, and load them properly. Otherwise, what fogster said.
posted by scruss at 1:46 PM on September 29, 2008

Do you have access to a windows machine or VM? The last time this happened to me, I had a lot of luck with an app named, ahem, gspot.
posted by damn dirty ape at 1:47 PM on September 29, 2008

in the game of guess the file type, you have left off both .ogg and .flac
posted by phil at 1:49 PM on September 29, 2008

You can try all these too. At the very least mid, midi, aac, ac3, wma, aif, mpa, ogg, pcm, ra, ram, band, and aup.
posted by damn dirty ape at 1:54 PM on September 29, 2008

Another thought that occurs to me is, could the file be compressed? You could try renaming it .zip and other compression archive extensions and see if it can be uncompressed.
posted by XMLicious at 2:03 PM on September 29, 2008

if the 'file' command doesn't work, from the terminal, type 'strings filename'. It will return a list of text strings in the binary file which may give hints
posted by chrisamiller at 2:22 PM on September 29, 2008

MediaInfo Mac
posted by phrayzee at 2:33 PM on September 29, 2008

Definitely try aiff.
posted by O9scar at 3:58 PM on September 29, 2008

Ask the person who sent it to you what it is.
posted by Class Goat at 4:34 PM on September 29, 2008 [2 favorites]

If the person who sent it can't tell you the format, and the content isn't sensitive material, post it somewhere we can all have a crack at it.
posted by flabdablet at 5:43 PM on September 29, 2008

Good ole VLC will guess at and play nearly anything.
posted by ostranenie at 6:36 PM on September 29, 2008

sound forge, pre-Sony versions of which I'm most familiar, would let you open raw data files as audio- letting you choose sample rate and bit depth. I would use that and try a bunch of combinations.
posted by tremspeed at 12:40 AM on September 30, 2008