Why is InqScribe not recognizing the full length of my media file?

For instance, your file is 12:40 minutes long, but InqScribe only recognizes it as 2:16 minutes long. Why?

This issue usually arises on OSX with WAV files that are not being saved incorrectly.

First, some background. There are two different QuickTime playback engines in OSX. The older one that InqScribe uses is also used by “QuickTime Player 7” (QT7). So one of the first things we do in a case like this is open the file in QT7 to see if we see the same issue as seen in InqScribe.

(Note: QT7 is not installed by default in Mac OS 10.6 (Snow Leopard) or later. You might be able to get it via an optional install your OS X DVD, or follow one of the links in this article.)

QuickTime Player (QT), also known as QuickTime X, is the default playback app in OS 10.6 and later. It uses QTKit under the hood. This is a more recent playback engine.

If you open the WAV file in “QuickTime Player 7”, you’ll see that QT7, like InqScribe, thinks the WAV file is 2:16 long.

If you open the WAV file in “QuickTime Player”, you’ll see that QT thinks the file is 12:40 long. However — try playing the file in QT beyond the 2 minute point. Basically, you can’t. Something’s wrong.

The reason is that the WAV file is not as long as its internal data chunk (where the samples are stored) claims.

The header for the data chunk claims that the chunk should be 67,047,808 bytes long. This would indeed be 12:40, given the sampling rate and number of channels.

But the file itself is only 12,007,632 bytes long. Which happens to be about 2:16 given the sampling rate.

QT7 (and thus InqScribe, since it uses the same engine) handle this problem gracefully. They recognize that the file is much shorter than advertised and ignore the incorrect length value in the data header.

QT believes the length in the data header, and so presents the file as if it was 12:40. But once you try to play past the 2:16 mark, it gets confused.

So the fundamental problem here is that the app that generated the WAV is buggy. Please let us know what app you’re using to generate the WAV, and you might also try pushing back on the app developer to fix the underlying problem.

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