Export fails-Linux Mint 18.3

I have had intermittant fails on exporting an edited project for a several months but thought it was processor heat shutting the render down. Cooling things down seemed to fix the problem and second attempt always worked…until last night.

Last night I made 4 attempts to render a project and all failed at the same point. Below is the contents of the log.

Perhaps related, I have never been able to get SC to render to anything but mp4, including to h.264 which IS mp4.

System is ASUS Sabretooth 990FX v1.0, AMD 6100, 16GB DDR3, and an NVIDIA GeForce 620 card.

Apologies if the solution is apparent and simple from the log below, but that is gibberish to me…I am NOT techie oriented.

EDIT: Message will not hold log. The message is limited to 32K characters and log is over 100K.

SECOND EDIT: The project is a combination of mp4, mov, WMA, and mp3 files…the ones that were suggested were converted. This SHOULDN’T make any difference as previously successful renders contained the same assortment of file types.

Workaround found, but not a fix. Still needs addressing…bug issue?

The render fail happened at the exact same frame every time. I cannot decipher the error log (NOT a techie type) so I went to that point on the timeline to see what “odd” was happening there.

I typically do clip transitions with filters…video fade out on one clip and video fade in on the next. Renders work this way.

On this project, however, I did a cross-fade by overlapping clips for about a second. The first frame in that transition is where the failure happened every time.

The workaround was to break the first clip one frame before the transition began and one frame after the transition ended and remove the transition itself, then go back and use the fade out.fade in filters. The project rendered, BUT…

I shouldn’t have to do that. Cross-fading transitions via overlapping clips is SUPPOSED to work with Shotcut. Is this a bug or am I doing something wrong?

You did not specify your version or where you got Shotcut. The latest version 18.08.14 reports a timecode when export fails. That timecode is a clue about where to look in the timeline for something causing a problem. We cannot read your computer to see what it is.

I am running 18.08.14 and downloaded it from the shotcut.org website. I saw the fail point in the fail message in the “jobs” panel which is how I found the exact frame where the failure occurred and did the workaround I described in my second post. That workaround should not be necessary though, I wouldn’t think…?

The workaround should not be necessary, but I do not know how to reproduce the bug. I must be able to reproduce it to fix it. I regularly do cross fade without a problem.

The project has been altered to use the workaround, so I cannot reproduce it either unless it happens again. Could this be the problem…My video clip is video only, no audio. I added the audio as a separate track, recorded with my digital voice recorder, and did the cross-fade AFTER adding the audio, cross-fading it as well. Then, after I had the editing done I added another audio track with the background music which played straight thru, only edited for length by clipping off the end to make the length match the rest of the project timeline.

Could cross-fading the audio from the voice recorder have caused the issue? Incidentally, if you want it I still have the fail log, but it won’t fit here as it exceeds the character limits on the forum…It runs about 135K characters.

I am fairly certain it will not have information about what exactly failed, but you can zip it and attach it here.

failed.txt (130.8 KB)

From the log

Assertion fctx->async_lock failed at libavcodec/pthread_frame.c:155

This is a crash inside a FFmpeg library, which means it had some trouble reading a file, but I cannot see which file from this log.

OK…I’ll just assume this was a one-off “ooops” and ignore it unless it happens again, at which point I’ll save the unaltered project file (no workaround) and send you the project and error log.

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