How a Little Bug Gets Created and Killed

It used to be that if you imported a sound file into Media Composer via drag and drop from the desktop, you got a clip with the same name as the file — but the name was truncated to 27 characters. Most of the time that didn’t matter. But with sound effects it could cause problems because sound effects libraries often have long, descriptive filenames.

Unlike a filename, there isn’t any intrinsic reason for a clipname to be shortened, so the MC was recently changed to take those filenames and turn them into clipnames intact.

And therein lies a tale.

Early last Friday I imported such a clip, and then blithely worked all day in the same bin without problems.

Monday morning I booted up to discover that the bin wouldn’t open. The error message included this text:

Exception: STRM_BUF_SMALL, buflen: 256

The attic only took me backwards a few hours — none of those bins would open either. I had a backup from Thursday which worked — but that meant losing a whole day’s work. Unacceptable.

Some internet research and a few frantic calls to friends turned up the idea that the bin might open in a PC system — and, indeed, our rental house was able to open it in a Nitris. We then began the laborious process of trying to figure out which sequence within the bin was the problem. Many hours of trial and error, passing bins back and forth over the net, produced an unambiguous result — it was that sound effects clip.

Avid tech support thought the problem might be with the clipname and suggested that I keep all clipnames to 27 characters. I was skeptical since I’ve had dozens and dozens of clips with names longer than that on every show I’ve ever done. Nevertheless, I did another hour or so of experimentation and learned the following:

Now that the MC doesn’t truncate your clipnames on import, you can indeed screw yourself up pretty badly using names the MC doesn’t like. There are three conditions:

  1. Files that won’t import. In this case the MC produces a generic error message telling you that the file couldn’t be imported. Just renaming the file that you’re trying to import, using a short name with pure alphanumeric characters (no punctuation), will cure this one, but you have to know the secret.
  2. Files that cause the MC to hang on import. These have clipnames with characters that don’t produce an error message — they just hang the machine.
  3. Files with clipnames that are too long. Here’s the gotcha that we faced this week. If your source file’s name is longer than 216 characters then the MC will import it just fine. And you will be able to use it without problems. But once you close any bin that contains that file, you won’t be able to open it again — on a Mac.

The good news is that I’ve reported all this to Tewksbury and a fix is in the works. The bad news is that it represents the kind of problem Avid faces when improving the MC. The system has grown so complex that even a simple change like this can produce unexpected side effects — and in this case, pretty disastrous ones.

Meanwhile, if you import files via drag and drop, double check the filenames before you bring them in. No punctuation except a single period between the name and file type, and make sure the filename is less than 216 characters long.

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8 Comments on “How a Little Bug Gets Created and Killed”

  1. Norman Says:

    Someday you’ll get paid by Avid’s QA department.

    Until then — thanks.

  2. steve Says:

    I just had the same problem today and all of my bins in the attic are corrupt as well.
    I would love to know how you opened the bin up in Nitris because its my bin where my sequences are located and I am in a lot of trouble if I can’t open these corrupt bins.

  3. Steve Says:

    Steve — did you get it worked out? There was no special technique to opening the bin in a Nitris. I think we could have done it on a PC Adrenaline, too.

  4. Jon Emmet Says:

    I have a SN system that I am currently working on. I can open up all bins except bins that have sequences in them. What’s a boy to do?

  5. Steve Says:

    Probably not the same thing. Did you import sound effects recently from clips with long filenames or names with non-alphabetic characters?

  6. Nina Says:

    We just had this problem with two reel bins on our Mac Adreneline 2.7.7 system. We threw out the bin logs which didn’t help and quickly ran out of other options. We had the same error on all four of our Avids so that seemed to rule out an individual system problem.

    There isn’t much out there on the Avid message boards about this error but nothing that has been written about this problem seems to relate to why we got the error message: We hadn’t imported the bins from somewhere else, we have mixed resolutions in other bins which have no problems, the length of the names are mac-friendly and changing the names on the Unity project drive didn’t help, the bins are smaller than other bins that open just fine…

    I was lucky enough that there were no changes to these bins since the last time I backed up so replacing them from my back-up drive solved the problem. Good luck to anyone else with this error.

  7. Zach Fine Says:

    If “a fix is in the works” means “importing a sound clip with a long filename will result in a bus error and media composer crashing”, then consider the bug fixed :)

    I’d think such issues are reasons to use OS frameworks for dealing with strings and files, since they tend to be battle-tested and support unicode and lengths that aren’t based on filesystem limitations from 15 years ago, but then again I don’t envy NLE developers the complexity of their work.

  8. Steve Says:

    For what it’s worth, I have not seen this problem in v5 and Avid says it’s fixed. But I’ve also been very careful about limiting punctuation and length of names, so I’m not really sure!

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