[HELP] Random FFmpeg crashes when using Hybrid / Avisynth

[Selur]

Okay, since it's amDCT, have you tried a lower ncpu value?

Cu Selur

[The_Tinkerer]

Yes, I tried it with ncpu set to 1, 2, 3, and 4. It doesn't seem to affect performance, and it crashes on any of them. Some videos will get past the crash by just trying again, but others will not complete without crashing. On those, I've tried recoding them first... with crf set to different settings, different average rates, different max rates, such videos crash every time.

The only thing I haven't tried is a Win8 or Win10 computer... maybe it's only crashing on Win7's kernelbase.dll.

According to the Doom9 thread the author has been trying to make a x64 version but he has problems getting it to load in x64 Avisynth.

Great filter for what it does when it works, but frustrating as hell when it crashes randomly.

[Selur]

Try if it helps to use the amDCT_v1.1_Testing version from https://sites.google.com/site/amdctfilter/
Simply extract the amDCT.dll from the archive into your Hybrid\32bit\avisynthPlugins-folder.

Cu Selur

Ps.: I'll also create a dev version for testing which will use the testing build and add an additional parameter,...

[The_Tinkerer]

I seem to have gotten amDCT to run stable now. While I had tried the version 1.1, what I hadn't tried, was running version 1.1 with nCPU set to numbers other than 4. When I set nCPU to 1 in version 1.1, it no longer crashes. The CPU speed appears to be slower, but it runs at about the same speed, and doesn't crash.

[Selur]

Happy that worked out.

Cu Selur

[The_Tinkerer]

Well... it didn't really work out, because as soon as I changed the filter stack, I got the crashing again, including removing all filters except for amDCT as the only single filter.

I seem to get the most stable behavior with LWLibavVideoSource, aus2yuv.exe, 2 x264 threads, and 4 Avisynth threads. But it still sometimes crashes randomly.

Despite that, this filter sometimes produces HORRIBLE anomalies. I've included below a 15 second clip that produces these anomalies with the author's settings from the Doom9 Thread:

LoadPlugin("C:\PROGRA~1\Hybrid\32bit\AVISYN~1\LSMASHSource.dll")
LoadPlugin("C:\PROGRA~1\Hybrid\32bit\AVISYN~1\amDCT.dll")
SetFilterMTMode("DEFAULT_MT_MODE", MT_MULTI_INSTANCE)
# loading source: E:\USER\temp_dvd\Video\Test\cut_orig.mp4
#  input color sampling YV12
#  input luminance scale tv
LWLibavVideoSource("E:\USER\temp_dvd\Video\Test\cut_orig.mp4",cache=false,stacked=true,format="YUV420P8",repeat=true)
# current resolution: 1920x1080
# deblocking
# deblocking using amDCT
# padding to mod16 for speed
# Current resilution: 1936x1088
AddBorders(8,4,8,4)
amDCT(adapt=31,shift=5,quality=4,quant=9,matrix=8,expand=16,sharpWpos=6,sharpTpos=7,sharpWAmt=24,sharpTAmt=31,brightStart=205,brightAmt=30)
# removing mod16 padding
Crop(8,4,-8,-4)
PreFetch(4)
return last

https://i.imgur.com/HxxTs1S.mp4

I tried both amDCT_v1.0 and amDCT_v1.1_Testing... same behavior in both of them.

I don't trust this filter.

Here's the original (unprocessed) clip: https://bit.ly/2ZXH4Gp

I reported this on the Doom9 thread as well.

[Selur]

Sadly it doesn't really seem like anything I can do atm.
I will try to reproduce the issue here tomorrow and report back.

Cu Selur