asyncread errors: error -50 creating new movie from file

Mar 15, 2010 at 2:11am

asyncread errors: error -50 creating new movie from file

upon trying to perform a asyncread command, this happens randomly on different files, even with the included /media folder, either with javascript or a poly~ (andrew benson’s vps-4 patch).

anyone ever figure out why? this issue has persisted for awhile.

Jul 31, 2010 at 12:05am

Is anyone figured how to solve error -50?


Luis Marques

Jul 31, 2010 at 12:07am

there was a post on the boards somewhere that said deleting any generated text/subtitle tracks using quicktime pro seemed to alleviate some of these issues.

Jul 31, 2010 at 2:04am

I went to movie properties and my video doesn’t have that text track…

Luis Marques

Jul 31, 2010 at 5:24pm

Since asyncread works in another thread, I assume you are trying to load a file whose codec is not threadsafe.

A list of threadsafe and non-threadsafe components is listed here:

Jul 31, 2010 at 5:37pm

i’ve experienced this with photojpeg in the past, so im unsure of that being the sole cause.

Jul 31, 2010 at 6:14pm

Okay, we can investigate further, but we’ll need a patch and a link to a sample file, please.


Jul 31, 2010 at 7:09pm

hi, the patch is simply a message box whit “asyncread” connected to
I post the video link and the patch here.

– Pasted Max Patch, click to expand. –

Thanks a lot

Luis Marques

Aug 1, 2010 at 11:25pm

Thank you. I was able to reproduce on my machine. This example file is Sorenson Video 3. It would appear that this codec is not threadsafe. Here’s one thing I found when googling [quicktime sorenson thread safe component]

I am not familiar with how Sorenson Video 3 relates to “Apple Sorenson” which is allegedly threadsafe according to the chart in the earlier link I sent, however this codec doesn’t seem to work.

After I exported the movie to Photo-JPEG (video), AAC (audio), it loaded fine with asyncread.

So, AFAICT, my analysis remains appropriate to the reported problem. However, if someone can provide an example movie file which in theory should work (or definitive documentation or evidence that Sorenson Video 3 is in fact threadsafe), there may be some other problems. Keep in mind that the audio component, and perhaps additional tracks (like text/subtitle tracks mentioned in some of the asyncread threads) also need to be considered regarding whether or not the movie may be loaded in a background thread.


Aug 2, 2010 at 1:23am

Thanks, that was very helpful

Luis Marques


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