Post processing of VHS. Decrease file size before deinterlace and qtgmc?

[barbywasadream]

Hi guys. I have a bunch of VHS which I have digitalized using the capture chain: S-VHS JVC --> TBC-1000 --> AIW capture card. I have used virtual dub.

I end up with very large files which I know is normal. Around 24 gigs per hour. My end goal is to have encoded x264 videos that I can serve for streaming to friends and family. However before I do so I would like to "improve" the quality by 1) Deinterlacing and 2) trying my hands on QTGMC.

Now my system (Win 10) is not bad but it is older hardware. Would it help me in the overall time it would take to achieve this if I did a simple encode of the AVI first so as to decrease the file size? Or should I serve the raw avi to e.g. Hybrid, AVISynth or whatever. Or would it not make a difference in overall time?

Am I also correct in assuming that CPU usage is the way to go and that one should stay away from GPU encoding?


Thx,

[lordsmurf]

Good capture gear, hopefully good captures, from using correct settings. (Too many people are disabling VirtualDub settings lately, and it allows unreported dropped frames.)

I'm not sure I understand your question here.

For starters, how old is "older" to you? Exact specs of CPU, RAM? Since Win10, I'm assuming not at all old.

In general, all processing should be lossless, and only the final final step is the delivery/compressed encode.

Don't use Hybrid defaults. A 4:2:2 custom profile is suggested, to retain full color and detail of the source video.

[barbywasadream]

Hi Lordsmurf, thanks for the answer. I list my gear at the bottom.

My question is if I am to do deinterlace plus some kind of filter processing on the large AVI file or compress it beforehand through e.g. handbrake or whatever ffmpeg h264/x264 settings I choose. My initial testing on an smaller AVI file show processing time of many many hours. I actually found an older answer of yours where you said that you could do 10 files batch overnight.



OS Name Microsoft Windows 10 Pro
Version 10.0.19045 Build 19045
Other OS Description Not Available
OS Manufacturer Microsoft Corporation
System Name DESKTOP-xx
System Manufacturer System manufacturer
System Model System Product Name
System Type x64-based PC
System SKU SKU
Processor Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz, 3501 Mhz, 4 Core(s), 8 Logical Processor(s)
BIOS Version/Date American Megatrends Inc. 2104, 13/08/2013
SMBIOS Version 2.7
Embedded Controller Version 255.255
BIOS Mode UEFI
BaseBoard Manufacturer ASUSTeK COMPUTER INC.
BaseBoard Product P8Z77-V
BaseBoard Version Rev 1.xx
Installed Physical Memory (RAM) 16,0 GB
Total Physical Memory 15,9 GB
Available Physical Memory 11,4 GB
Total Virtual Memory 18,3 GB
Available Virtual Memory 12,0 GB


GPU: NVIDIA GeForce GTX 760

[Alwyn]

With your system, I think you're snookered. Philosophically, it is far better to process your AVIs first, because you are using a lossless copy of your captures (actually THE master). If you were to first "reduce" them down in size by encoding them into a lossy codec such as H264, you will be then processing an already-encoded video. The other disadvantage is that it will take you time to do that first reduction encode. Then you'll have to add on the final encode time.

Remember that AVISynth will serve your deinterlaced AVI to VDub. It doesn't do anything of itself. You can then encode it directly from there. But it will be slow. If you use the "Prefetch ()" code in AVISynth, you'll maximise your CPU usage., but, it's going to be slow.

Ultimately, you'll need to do an experiment and assess the times taken for each workflow:

1/Lossless deinterlace+other processing>final H264
2/ lossless>H264>deinterlace+other processing>final H264

Am I also correct in assuming that CPU usage is the way to go and that one should stay away from GPU encoding?

A good question, for which I don't have the answer. I'm just glad I have a nice speedy GPU.

[jagabo]

Would it help me in the overall time it would take to achieve this if I did a simple encode of the AVI first so as to decrease the file size?

AviSynth works only with uncompressed video frames. So compressing a large source to make it smaller will not make AviSynth work significantly faster.

[themaster1]

You could do H264 (x264) interlaced (gain of time and quality) Staxrip can do that