Newbee codec choice question - using MP4 from G85 4:2:0
Hello! 🙂 And good morining! It's freezing cold here in Canberra.
So - quick history - I'm doing multicam (3 cameras) editing of 4K video footage in Powerdirector (latest version). Super high spec Win10 system.
Doing this with 2K footage is easy. But... if more than one of the cameras is set to 4K, Powerdirector stutters and sound goes out of sync while in the multicam editing mode.
So - my specs and setup and question.
Purchased and installed MagicYUV ultimate. Yay!
Installed FFInputDriver_64.vdplugin into plugins folder of VirtualDub. So I can open MP4s (man, that info was hard to find).
Input source videos from Lumix G85's. 4K 30fps MP4s. 100Mbps. 4:2:0 8bit (as far as I know).
What MagicYUV CODEC should I use in VirtualDub as my output codec?
Should I use MagicYUV RGB or MagicYUV 4:2:0. Or are those two guesses wrong?
I want to retain max quality when converting my MP4s to AVIs, so that I can edit them with ease in Powerdirector, whilst retaining maximum quality.
My final output from Powerdirector will vary from 4K max quality to 2K 16 Mbps for youtube.
If you can help me, I'll buy you a beer, once Covid18 lockdown is eased.
Kind Regards and hello to all,
Installed VirtualDub 2. Well, it's about 150 times faster at processing video than VirtualDub 1.
I still don't know what codec is optimal. But at least now it converts them at lightspeed 🙂
Hi and welcome.
If your input footage is mp4 it's likely 4:2:0 8-bit. To be sure, you can check the File -> File Information in virtualdub (look for stuff like yuv420p or something similar). With that in mind it's pointless to use the MagicYUV RGB codec, using MagicYUV YUV 4:2:0 is sufficient, it'll also result in faster decoding and also much smaller files sizes (about half at least).
EDIT: Regarding the FFInpuDriver, I'm nut sure why that's required, as far as I know VirtualDub2 should open mp4s out of the box. Are you using the old VirtualDub or the new one ( http://virtualdub2.com/ )?
Thank you so much for replying Balázs.
If you are new to this whole re-encoding thing, and you search for VirtualDub, you might be like me and not even see that there's a VirtualDub 2. Hence me installing V1 (which can't convert anything but AVI files) and having to figure out how to get it to convert MP4 files. Only later on to discover VirtualDub 2 - which is just soooo much nicer all round.
Oddly, if I convert to the MagicYUV 4:2:0 codec, the quality of output is (to my eyes) noticeably worse than if I conver to MagicYUV RGB. And even odder, the file sizes are practically the same no matter which codec I choose.
Sadly, at the end of all this, it made no difference to the ability of Powerdirector to gracefully handle the 4K videos in the Multicam editor module.
It looks like it's an issue with the Mbps of the encoded footage, not necessarily the 2K/4K side of things. If I use anything above 20Mbps, it's like I'm using a computer from 1994. But if I stick with 20Mpbs, it does everything with ease. Meh. I'll have to edit each clip, crop/pan etc as 4K 100Mpbs, then convert it to 2K 20Mbps, prior to editing with the Multicam editor.
This is a beautiful codec though 🙂
There shouldn't be any difference whatsoever between MagicYUV YUV 4:2:0 and RGB if the input mp4 is YUV 4:2:0. If there is, then it indicates some possible conversion issue somewhere, either during encoding or decoding. If you use VirtualDub2 to transcode, you have to be careful what pixel format does VirtualDub2 send to the codec. Notably Rec.601 or Rec.709. It should be Rec.709, but I don't know what the default is, and it could be Rec.601. Check Video -> Decode Format -> "Interpret YCbCr properties".
Regarding the file size, it absolutely has to be noticably smaller for the YUV 4:2:0 case, if not then that definitely indicates some misconfiguration.
Essentially, using this codec you trade CPU time for disk space. Decoding mp4s directly can be slow if you seek, because of b/p-frames. MagicYUV seeks much faster in that case, but you need a fast SSD for that.