Proxy Build Failing

I haven’t had any problem building proxies before but I’ve this one mp4 file that fails every time after about 4% or 5%. I’m using v24.04.28 on Windows 10. It’s not disk space that I can see. From the log, it looks like a problem with the file and ffmpeg but I don’t know how to resolve it.

failed proxy create.txt (15.3 KB)

Corrupt source

Is there any way of troubleshooting this a bit further? The reason I ask is I’ve just recently switched from filming with a GoPro to an Insta360 AcePro camera.

I never had any issues creating proxies with the GoPro but pretty much every other AcePro file fails with this error when I try to create a proxy.

The files play perfectly on the AcePro, with Insta360’s player and my video player of choice on my PC.

I recently took one of the 'corrupt files, trimmed a few seconds from it, exported it and then brought it back into Shotcut and it created a Proxy file without issue.

I appreciate this is probably an issue i need to take back to Insta360 but i probably need more info to feed them than ‘corrupt source’. Thanks.

You already have the details in the log provided. Any more detail requires correlating the error messages in the log with the source code of FFmpeg, the tool used to create the proxy, and the source file used. Insta360 can do that since it is open source.


I’ve raised this issue with Insta360. They have a copy of the file and are investigating. They have suggested they may be able to repair it? I’ve asked for further details.

Whilst I wait for their reply, I took the offending file and loaded it into Shotcut. I stopped the usual proxy file creation (it always fails at about 5% or 6%).

Then I did nothing to the file, no edits and then used my normal export preset to create an exported video. I expected that process to fail also at around 5% or 6%.

It didn’t. It carried on and created a usable mp4 file.

I don’t understand. How can an export be created from a Corrupt Source?

You could now use this file as your new source, and probably create a proxy over it.

Proxy and export work a little different. Export (by default) picks one video and one audio track, ignoring all other tracks. This might skip over corrupt tracks, and can also avoid some timestamp mismatches between tracks. Meanwhile, proxy is expected to transcode all tracks because it doesn’t know in advance which tracks the user will select for the timeline. Therefore, if there is corruption anywhere, proxy will run into it and likely fail.

Bear in mind, the corrupt Insta360 file showed something like 19 tracks, which is clearly inaccurate. Export will only pick two. Proxy will try to find all 19 and fail to find them.

Thank you - I can indeed. I tried that successfully before your response.

Thank you for the proxy v export explanation. That’s much appreciated.

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