Hi. Nvenc producing modest quality, and if I try to use libx264 or 265 I get bad corruption on my projects that use ANY of the time control filters, which is pretty much all of my projects ever. I tried them all, and they all have a chance to fail badly. Also wanted to mention that using the quick load feature on the front page would then load up these corrupted versions, and it took me a minute to realize that clicking open file and then selecting the exact same file that way got passed this corruption and pulled the actual file which I saved before I hit export. But yeah anyways I figured I’d give VP9 a shot for a quality product. Constrained VBR doesnt seem to work at all. Does Quality-based VBR allow for average bitrates over 80MB/s? Why is Shotcut limited to 80? These options dont seem to line up with the options that VP9 has when I Google VP9 settings. Any education here would be awesome. So the first time I tried this export, I got a melt.exe error about 80% through. The CPU hit 90 degrees and I dropped .01 volts. Ok, no more of those now. Max temp now 88. Ive been focusing my efforts on Dual Pass options, because I really dont mind long cook times, and Im not terribly concerned about file size. My videos have never been more than 15 minutes in length and Im usually looking for high quality results. But the first product that failed I was able to watch some of, and the overlaid effects do look noticeably better than Nvenc, so it’d be cool to get this working. But it’s failed a few times now, probably wasted 15 hours rendering lol. Not sure what the deal is. I just realized that Ive got a single audio source at 22050 sample rate, it could be as simple as that. There’s a billion messages about 16s —> f32le but idk what that means bro lol. I’ve been using the Webm preset with libvpx-vp9 and tried quality = best and flac for the audio, flac seemed to actually indicate that it wasnt compatible after failing, gave up on the “experimental” best setting, have had speed = 0 the whole time, and have tried Qmin = 1-4 and Qmax = 13. No luck so far, keeps failing at 80% on the second pass. Could just be that 22050 audio but Im seeing messages about deprecated pixel formats. Help and edumacate me plz
vpfail1.txt (2.4 MB)
vp9fail2.txt (11.1 KB)
vpfail3.txt (2.7 MB)
There are several things going wrong. The main one is this:
[filter swscale] Initializing swscale failed with -12 (Cannot allocate memory)
Basically, the computer is running out of RAM. This is the most fundamental problem that is affecting all encodes. Any of the codecs you tried should work if RAM isn’t a problem.
Also, FLAC doesn’t work with WebM. WebM only supports Opus and Vorbis.
vp1fail.txt says
[libopus @ 00000266f99bd6c0] Specified sample rate 44100 is not supported by the libopus encoder
[libopus @ 00000266f99bd6c0] Supported sample rates:
[libopus @ 00000266f99bd6c0] 48000
[libopus @ 00000266f99bd6c0] 24000
[libopus @ 00000266f99bd6c0] 16000
[libopus @ 00000266f99bd6c0] 12000
[libopus @ 00000266f99bd6c0] 8000
D:/a/_temp/msys64/home/runneradmin/build/src/mlt/src/modules/avformat/consumer_avformat.c: Unable to encode audio - disabling audio output.
You are messing around in Export > Advance. This does not just mean “extra options.” It means for advanced users who know what to do.
It is not. Those are just some preset values. You can type in anything you want including values with invalid suffix or no numbers at all. This is part of what makes this area “Advanced.” There are very little guard rails in there by design.
if I try to use libx264 or 265 I get bad corruption on my projects that use ANY of the time control filters
I have never seen that, and it does not make sense that it could. The encoders do not see the time changes. All it receives are configuration parameters (including a constant frame rate) and a sequence of images. I suspect that your problem was that you were applying time filters to some files that struggle to support that, and then you used x264 or x265 to export that. As the saying goes: correlation is not causation.
Your best bet is to not change anything in export and simply click Export File. If already did change something, click Reset to get back. If you still feel the need to use VP9, choose the WebM VP9 preset and don’t change much of anything in Advanced except maybe Codec > Bitrate or switch to Quality-based VBR and increase the Quality %.
I ended up lowering the quality settings and got a decent export. So, thank you for pointing out the glaring oversight of running out of RAM. I’d been keeping a close eye on all my temps, but foolishly forgot about the RAM usage itself. I think I went with ~5 for Qmin and ~20 for Qmax in the end. I just didnt immediately reply because some of the failed ones looked slightly better and I have yet to get around to trying to export that portion of my project again; it still looked good, but for anyone trying out VP9 settings, Id suggest focusing on getting Qmax as low as possible. It seems to be more impactful than Qmin.