Ooops, this is much more compicated than I thought. I tested, and with a single-scene 30 sec raw clip I got the “same” export time, using 190228, 171107. 1k or 4k clips, exporting to MP4 or WEBM 1080p result. No “noticeable” differences between Ubuntu or Windows.
So I looked at one of the problems I had. An 12 min 4K timeline, consisiting of many small individual clips. On Ubuntu 190228 Shotcut says (after some thinking) that it will be ready in about 4 hours. Ok, started Shotcut 171107 (same, ubuntu, same hardware), now it looked like it would be ready in about 50 minutes. I did not bother to time it accurately, but it was finished (MP4) in about 50 (say 45-55) minutes. Much less than 4 hours.
Ok, started Windows 7 (same computer, same hardware, I7 something, 16 gb ram). Shotcut 190228 wanted about 4 hours. So I uninstalled 190228, and installed 190127 (Windows 7). Now it claims it will be ready in about 50 minutes! When I write this, 38% is done, 20 min elapsed, and shotcut claims 33 min remaining.
I did actually let one of the 5 hour conversions run overnight, and yes, it does take about 5 hours. The timer estimate is “correct”.
So what is the problem? Now same long time in Windows 7. Long timeline, 12-13 minutes of 4K footage? Many small clips (about 14 pieces)? Note that all Shotcut is downloaded from officual website, Fosshub or Github.
Same effect has been seen on Xeon E5-1620, and other Intel as well. I have no AMD really.
Sometimes all is well, sometimes not. No special configuration, just installing or tar Jxvf to get the start-app. No GPU enabling.
But “old” Shotcut uses similar time using Windows 7 and Ubuntu. Up until 190127 version used short Windows 7 time. MP4 or WEBM does not seem to be the magical thing.
It is replicable to me, on different hardware (all Intel though), i7 and Xeon. I have no Mac, but I have Windows 7 nad Ubuntu. I could (with a lot of effort) do Windows 10 and (say) Fedora, CentOS. But I believe results will be the same.
Any suggestions for further testing?
Best Regards from Jan