September 20, 2020, 07:37:52 am



190527 Crashes before completing large file encoding

Started by Cormy1, May 29, 2019, 02:47:40 pm

Previous topic - Next topic


So I've been trying to re-encode an 18.5GB file of game footage. There is nothing special about this footage besides the filesize. I recently re-encoded the same file after having cut out many parts of it, reducing it to 4.5GB before I started re-encoding it.
I'm not sure how to get the logs for this but with my most recent attempt to encode it, my PC itself ended up crashing.
I've tried running this encoding maybe 5 times now and everytime it needs to run for over 8 hours. I came close to finishing it once, but it just keeps ending up with Avidemux not responding.
I think I'll be able to complete this if I once again split it at keyframes and encode the files separately, I just don't feel like this is an ideal solution to whatever my issue is =\


QuoteI'm not sure how to get the logs for this

As always, after the crash and before restarting Avidemux, open the location the environment variable %localappdata% points to, go into the avidemux subfolder, compress admlog.txt with 7zip to reduce its size as much as possible and attach it to your reply. You may edit out your username and the filename of the video before doing so.

It would be helpful if you could observe the memory consumption of Avidemux after many hours of encoding. Maybe there is a memleak and the system simply runs out of available memory.


Do I need to be monitoring memory usage before it crashes?
I see no memory issues while it hangs.
How much compression do you want on the logs?
This one isn't the file in question but a much smaller one but it still crashed.
I included admlog_old aswell


Quote from: Cormy1 on May 31, 2019, 03:44:06 am
Do I need to be monitoring memory usage before it crashes?


QuoteThis one isn't the file in question but a much smaller one but it still crashed.
I included admlog_old aswell

Thanks, but the logs don't originate from an Avidemux session which ended in a crash. Was it from loading a video you mentioned above which triggered the crash when re-encoded (it seems to be MJPEG)?


I opened a video file, which was an MKV encoded using NVidia's NVENC H.264 from OBS, wanted to re-encode to x265 after downscaling to 720p and cropping 170pixels from the left and right.
That process was supposed to take maybe 2 hours for this significantly smaller file, but it ends up hanging... All day.
So I guess Avidemux doesn't register that as a crash...?


QuoteSo I guess Avidemux doesn't register that as a crash...?

Ideally, you would have attached the log file from that session. Did you notice at what position (at when percentage) the encoding stalled? If you save a portion of the source video around that position in copy mode and try to re-encode this fragment only, are you able to reproduce the hang?

The file size may be a factor, or it can be a particular location in the source video, which was cut away as you re-encoded a shortened version of the file.


It may not even be the size, but the length. You said the encode is taking 8 hours... which makes me wonder about the length of the video. What is the run length?


It doesn't matter, been at this for a while now.
Had 1 18.5GB recording, 7 hours long.
Cut it up at keyframes into ~3GB chunks roughly 1.5hrs long, been encoding them but it's the same thing, for every single one.
This particular attempt started hanging at 60%, there's no pattern to when it does it, besides maybe my PC activity, which is why I usually do this when I'm away from the PC but even then it just seems to fail randomly.
I could give more log files, don't see why that would change anything since it's so consistent. The first log should have everything, nothing's changed.
The estimate time to finish these is always around the duration of the video itself so for the smaller chunks, 1.5 hours or so.
I may have attached my last log from the wrong location. There are logs in Roaming but they aren't generated when it hangs and I have to end the process.
There is 1 generated in Local aswell.


Thank you, it seems to crash in libx265 (so likely not directly fixable on Avidemux part, unless the crash is triggered by a hardware issue specific to your system). Could please test whether this crash happens when using the latest MinGW-compiled nightly as well? -->


Which nightly is the latest MinGW-compiled one?
I put my version in the subject title of the topic, 190527, which is the latest on that link so far as I can tell.


Oops, other way round (your MinGW nightly was perfectly up-to-date). Could you please check whether the crash happens with the latest VC++ nightly (190527 at the moment) as well?


VC++ nightly same issue, but it's probably a Windows error...?


Thank you for testing. Due to specifics of the VC++ build which flushes the buffer to disk only when opening the log from the menu or upon regular application exit, the crash info is missing. Additionally, the crash happens here almost instantly.

I'll try to reproduce the issue when I get to booting Windows.