4K Video Not Worth The Trouble?


#1

I use my cell phone (LG V20 Android) to take videos I intend to edit together and upload to Youtube.

Highest recording resolution for my phone is 4K (3840 x 2160) at 30 fps. So that is what I use.

It’s also helpful to have the detail of 4K video because I intend my videos to delve into technical stuff, such as soldering circuit boards, so the more detail (pixels) the better.

But like all cell phones, the videos I record are variable framerate. This is not good for video editing software. In Shotcut things get weird (ex. clips missing from timeline even though I know they’re there, crashing, slow, etc.).

So I tried using HandBrake to encode my videos to a constant framerate but for a 5 minute clip it would take 4 hours on my Windows PC! I have several videos I want to edit together so the conversion time makes this impossible.

Tried letting ShotCut encode to a constant framerate and it turned my 4 GB video file into a 37 GB video file! Don’t have enough HD space for that.

BUT if I use HandBrake to lower the resolution to 1080p and make the framerate a constant 30 fps, it only takes about 15 mins and the file size is almost the same.

So should I give up and dumb these videos down to 1080p at 30 fps and edit from there?

Going forward, should I shoot on 1080p in 60 fps (the next lower video setting on my phone) and convert them into constant framerate?


#2

try this converter
https://www.xmedia-recode.de/en/download.html


#3

Thanks for the suggestion.

Not much info on the web about that one and only 3 posts on these forums that reference it.

Is that a better encoder than Handbrake for variable to constant frame rate?


#4

I never used Handbrake and that one has tones of settings.


#5

Personally I use tencoder it’s foss https://www.fosshub.com/TEncoder-Video-Converter.html that said I generally find 4k worth the trouble in situations where you want to crop down, you get effectivly 4 separate 1080p cameras worth of screen to work with so you have room to pan/zoom with no loss of detail.

You may also find a different camera application on your phone a better solution, I know my HTC10 didn’t shoot VFR at 4k(although it was limited to 5 minutes) things like Camera FV-5 and opencamera might be a better solution to avoid VFR from the start. Regarding conversion times and performance we don’t know what PC you’re working with 4k might be too much for it in general.


#6

Thank you. I will check out Tencoder.

Will also look into a different camera app that can record with a constant frame rate. Didn’t even think that existed! Just assumed it was a function of the phone camera but it makes sense that it would be app specific. Great suggestion!

My PC is a Sager NP9280 (Built on Clevo D900F)
Intel Core i7-920 (2.66GHz) 12GB RAM
nVidia GeForce GTX 280M 1024MB DDR3
Win7 Home Premium

Do you think I should upgrade to a more powerful PC to edit 4K video with Shotcut?


#7

Short answer yes.
Long answer… it depends on how much you edit and what you can do to upgrade your current system.
Being a mobile system a new cpu is out of the question although an SSD(or two since your laptop supports 3 drives simultaneously) would improve your edit times. You’re still bound to your cpu however and although I haven’t tested the i7-920 you can probably guess where it would fall on this chart(or even run the benchmark yourself) https://nwgat.ninja/thefireescape/

A little digging on geekbench puts the i7-920 somewhere in the same ballpark as the i5-7200u these days an ultra mobile chip https://browser.geekbench.com/v4/cpu/compare/6452057?baseline=2150968 if you’re only editing 4k every so often that’s not a terrible place to be(although you’re dragging a lot of laptop around to get there) you can pick up a refurbished P50 or P51 for under 1k on lenovo’s outlet these days(granted you might want to throw a stick of ram in it depending) but that is easily twice as fast especially with x265 benefiting from new instructions


#8

Tried TEncoder. It is very fast.

But the the maximum bitrate it can do is 12 Mbit/s.

This is 1/3 the YouTube recommendations for 4K video which are:
35-45 Mbit/s [24FPS, 25FPS, 30FPS]
53-68 Mbit/s [48FPS, 50FPS, 60FPS]

So need to find something else.


#9

Is that 4GB for a 5 minute clip? I highly doubt that that is how big youtube wants 4K files to be. I have seen many clips that are 4K on youtube and they are never that big. This Ed Sheeran music video is close to 5 minutes and the 4K upload is only slightly over 400 MB with a bitrate of 11.7 Mb/s. Its FPS is 23.976.

When Shotcut asks about converting a video with variable framerate, that process exports the video as lossless which is why the files are so big. Have you tried though skipping that part and exporting the video? Shotcut is designed to always export in constant framerates. So maybe you can try importing your 4K video, skip the lossless constant conversion option it asks you, hit Export on the menu, pick the youtube preset from the left side of the Export menu, keep the rate control at “Quality Based VBR”, leave the quality at “60%” and finally hit “Export File”. If you haven’t tried that before let us know how it works out.


#10

You just have to type the higher bitrates in. So I took this(mp4)


Set TEncoder up like this

Which stayed inside the summary
image
I’ll follow up with the export result later

And just like that a file with the target bitrate


#11

You are looking at the clip transcoded by YouTube to prepare it for streaming. If you are uploading, the greater the size, the better to preserve quality as much as possible. You are not seeing what was uploaded. They do not make that available. I don’t even think they make the source videos you uploaded available for you to download. I know some people upload ProRes, which is very heavy.


#12

Ah, okay. I wonder if they have a set percentage that they reduce the uploaded files to for streaming or is it an algorithm of sorts that determine how much a particular file will be reduced to.


#13

They convert to multiple resolutions and bitrates that provide what is known in the streaming industry as a ladder.

This facilitates something called adaptive bitrate streaming, particularly for streaming over HTTP. This means the stream changes resolution and/or bitrate on the fly to adapt to changing network conditions.
https://bitmovin.com/adaptive-streaming/


#14

Thanks for the explanation and links. :slight_smile:


#15

Didn’t try typing in that box for TEncoder because I assumed the choices were hard coded since they were in a drop down menu.

But I did try Xmedia and it worked! Speed is decent and file size actually got slightly smaller (around 95% of the original file size).

I am currently using Xmedia to batch encode a constant frame rate of 30 with all my 4K videos. It looks like it will take 16 hours to convert 1.5 hours of 4K video contained in 40 files totaling 31.2 GB. Should be done in another 3 hours.

BTW, I ran the Fire Escape Benchmark and got these results with the 264 test:
475.19764614105225
484.3842520713806
495.19572615623474
495.6550712585449
486.2356550693512

Couldn’t find where you sourced your more extensive benchmark list but do you think I can get much improvement with a new PC?


#16

I have that list because I built it myself, every system on there is either mine or has been through my office at work one way or another.(I’m an IT department head) ~500s is about where I would have guessed and yes a new PC be it desktop or laptop could be faster, the P50 is what we issue to our video editors at work right now although one guy has a P52 that was a ~2500usd purchase so the value of that is up to how much 4k you’d edit like I said.


#17

Wow. Thanks for sharing the benchmarks.

IT head makes sense. Knew you were good when you actually looked up my obscure laptop brand and nailed the specs (3 hard drive bays)!

My laptop is 9 years old but it was a beast when I got it. Paid about $3,000 USD back then and made some upgrades since. Still runs fine except for the unexplained occasional slow down. But been looking for an excuse to upgrade and I think this is it.

Going to go back to a desktop and don’t want to spend more than $3,000 USD. Comfortable building my own machine just don’t know about the good specs and equipement these days.

I’ll start a new thread about it because I think my questions here been answered.

Thanks to everyone that has commented.

The answer is that 4K video IS worth the trouble if you:

  1. Convert to Constant Frame Rate with either TEncoder or Xmedia; OR
  2. Find a camera app that can shoot 4K video in CFR.

#18

I’d probably start with a setup similar to this, at 1600 you’re getting massive cpu power(more cores and ghz than the T7500 on my list with a newer arch) 196Gb of ram and you just need to add drives and a gpu.
Drive wise I’d probably get a few of these for your edit drives, they’re not the fastest but at that price they don’t need to be


and the GPU is dealers choice, personally I like nvidia cards and blower coolers, it looks like the RTX blower cooler cards aren’t out yet but it’s hard to go wrong with a 1080 ti still


#20

Thanks. I’ll make a separate thread because I’ve still got issues with 4K.

EDIT
Posted new thread for PC Build here - Best New Computer for Video Editing under $3,000 USD


#21

I worked all day yesterday and finished my edits last night! Added 0:20 video fade ins and outs for transitions between my clips. Encoded at 4K and … disaster.

My edit is 14 minutes long but the exported video is 28 minutes long. Same thing happens with encoding in 1080p. It contains long blackouts for the fade transitions and my clips contain video and audio that I’m sure I cut out of the timeline.

I saved different versions of the .mlt file as I went along so I’ll need to revert back to an old one that works, redo all my edits one-by-one and encode after each batch of edits to see where it messes up.

Love the program but so disappointed in the outcome. Really thought I was finished editing.