Hello, I’m new here and I could use some help getting a better handle on the export settings. My problem is that there’s too many variables, to many points that I’m not quite clear on, to improve my export results.
Maybe I only need to be pointed to the right tutorial or documentation, where I could find concise information on what each setting means, and what effect it has on image quality, file size, processing time and such. So I know what I’m working with when I try to find better settings. What I’ve been looking into so far has either been too basic or too detail specific.
Without that I have so many open questions that I don’t really know where to start, so, for those of you patient enough, I’ll give you an idea of what I’m trying to do and some of my questions, bullet point style. I’m not asking for scientific essays on all of these. Some short clarifications, maybe just a yes or no, on some of these points might help me a lot.
I’m using Shotcut, very amateurishly, to edit some videos to upload to a forum like this one. Meaning that it does seem to run on the same software, it looks almost identical. Only the subject matter is completely different. Unfortunately, due to that subject matter, I can’t really post any links or samples, my videos would be most inappropriate here. Also, don’t google my user name.
Anyway, there’s an upload file size limit of a little under 100 MB, which is one of the big restrictions I’m struggling with, at least for longer videos, say over 15 min. The footage I’m using is mostly screen captures of fixedly mounted, wide angle 1080p webcams. Due to compression and bad lighting the image quality is often not very good. In my edits, for aesthetic reasons, I mostly “zoom in” on the image using the “Size, Position & Rotate” filter, so my “virtual resolution” may vary between 900p and 400p from shot to shot. So pixelation becomes an issue. I usually export in 720 or 540p.
For my export files I often don’t know which ist the real bottleneck for the image quality I can achive, the file size limit or the low quality of my footage. Are some ot the “high quality” settings that I use to get the best possible image, just a complete waste of processing time, given the quality of the source material? When I’ve put hours and hours of editing into a 20min video, I don’t mind if it takes hours to compile. On the other hand, for a 5min video, that is just two or three clips with a few filters, I don’t necessarily want to wait 40min to post it.
With that, finally, here’s some of my open questions / unclear points. Yeah, brevity isn’t my strong suit:
- I use Codec libx264, should I be using H264_videotoolbox instead, and what’s the difference?
- I’m not using hardware acceleration, I heard that, while it’s probably faster, software encoding might calculate more thoroughly to get better image quality. True or waste of processing time, given low quality footage?
- I’ve been using progressive scan mode, only just learned what interlaced actually is. Is interlaced worth exploring, given my file size limitations, or is it a thing of the past, best forgotten?
- When neither my footage nor my export is interlaced, does the Deinterlacer setting have any effect at all on my image quality and processing time? Should I use the fastest one be default?
- Interpolation. I assume that, with all the rescaling and pixelation of my footage, this is an important one for me, so I’m using Lanczos be default. Right?
- Rate control: Constant Bitrate seems wasteful, I’m using Average Bitrate to aim for a file size. Depending on video length usually between 1 and 2 Mbps for 720p30fps. Would Quality-based or Constrained VBR deliver better quality at the same file size?
- How much of a difference in quality does “Dual pass” actually make, it sure takes much longer.
- No idea what GOP, B frames or Codec threads do. Should I bother?
And that is all I can think of, right off the top of my head. They say there are no stupid questions, only stupid answers. I hope I didn’t just prove the first part wrong. Thank you for your patience.
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