Digitizing analog video

Step-by-Step descriptions of how to do things.
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^rooker
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Digitizing analog video

Post by ^rooker »

Finally I've decided to write down most of the knowledge I've gathered during my quest of digitizing my old VHS tapes.
Basically the procedure would be straightforward, but due to my never stopping perfectionalism I just had to find out the dark caveats of analogue video ripping.

I will not explain every step in detail, but if possible I'll list good sources of information which have helped me understanding the problem, too. (It's not just that I'm lazy, but I'm also a very bad writer)

Note: I am really sorry, but I haven't really tried all this in Linux, so this HowTo's gonna be 100% Windows... :(

[Overview]
  • - Capture
    - Make sure that audio/video are in sync (check framerate!)
    - Cut unwanted scenes out
    - Deinterlace (if necessary)
    - Crop borders (you will want an even resolution!)
    - Remove chroma artefacts (chroma smoother)
    - Leveling (to make sure that black IS black)
    - Denoising
    - Logo Removal
    - Resize (Bicubic!)
    - Process audio (Resample, mono?)
    - Choose final video codec (XviD)
    - Choose final audio codec (Lame)
    - Lean back and enjoy watching your PC doing the work...

[Prerequisites]

Hardware:
- Video capture card (e.g. Graphics card with Video-In (ViVo))
- Sound card
- Fast harddisk


Software:
- AMCap
- Virtual VCR
- VirtualDub
- AviSynth (only if you're going for high quality 50fps video)

VirtualDub PlugIns
- Smart Deinterlacer (Donald Graft)
- Smooth Deinterlacer (Gunnar Thalin)
- MSU Denoiser (Vatolin Dm.,Putilin S.)
- Smart Smoother (Donald Graft)
- Region Remove(Shaun Faulds)

Codecs
(Video)
- HuffYUV
- Koepi's XviD Binaries
- Some MJPEG codec

(Audio)
- LAME ACM Codec
Last edited by ^rooker on Wed May 18, 2005 9:58 pm, edited 5 times in total.
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^rooker
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Pre-Capture

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I've used a nVidia WDM compatible graphics card (FX5600XT).

Install the necessary WDM driver.
In the list of required software I've listed AMCap. This is due to strange problems I'm having with VirtualVCR initializing my card. After each reboot of your machine, run AMCap at least once BEFORE starting VirtualVCR, if you're experiencing problems.

If you need more detailed information than I'm giving you here, check Doom9 Capture Guide.

----------------------
Configuring VirtualVCR:
[Video]
- Choose full framesize and full framerate (e.g. PAL=720x576, 25fps)
- For compression use lossless compression if possible (HuffYUV), or an MJPEG codec. When using an MJPEG codec make sure that it's set to almost best quality, so that you will not have too many artefacts later on.

[Audio]
Basically you can always leave the audio at CD-resolution (44.1kHz, 16bit, stereo) and downsample it later on, if necessary.
Do NOT compress the audio during capture - this will only cause problems...

VirtualVCR's got a very nice feature, called "AV Sync" - I've had more problems when using than without, so try recording without it.
Don't be surprised if your recorded audio/video is not in sync - I'll explain later on how to fix this! (if it's linear)

[Devices]
This should be quite obvious if you don't have multiple audio/video cards in your system. simply choose your video-capture driver for video and your soundcard for audio.
If you have a tuner-card, I think you can choose your tuner-card as audio source, but I'm not sure.

- As videosource choose whatever you've connected (SVideo, Composite or Tuner).

With my setup I'm having some very, very strange distortions when using a Scart->SVideo adapter and then choosing the SVideo input on my card... Haven't found the reason, yet, so I'm still recording using Composite.
Last edited by ^rooker on Wed May 18, 2005 9:39 pm, edited 4 times in total.
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^rooker
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Capturing itself...

Post by ^rooker »

With VirtualVCR properly configured and every cable properly plugged in, you should be able to record the video, BUT beware of some nasty caveats:

- Make sure you mobile phone is faaaar away from your audio cables. You'll have ugly noise if you're getting a call while capturing.

- Turn off every program you don't need during capturing: ICQ, Browser, Mail-Client, ...

- If you're capturing for the first time or if you're using a codec you haven't tried before, check your CPU-load while capturing. If it's up too high most of the time you can be pretty sure that you'll have dropped frames.

- Avoid touching ANYTHING during the capturing process.
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^rooker
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Post-Capture

Post by ^rooker »

If everything went fine, you should end up with a huge .avi file.

Now it's time for VirtualDub! So, open the file using VirtualDub and start cutting out what you don't need (e.g. commercials,...).

It's quite a good thing to save your edits every now and then (especially when using the current unstable version 1.6.5 of VirtualDub):
Don't forget to check "Include selection and edit list" when saving!

If you see strange "combing-effects" your first step must be to deinterlace the video. There are several ways of doing this (see the probably most comprehensive source of information regarding deinterlacing: 100fps.com)

Personally I've settled with 2 ways of getting rid of interlacing artefacts:
1) Creating a final video at 50fps with "smooth deinterlace" (best!!)
2) Staying at 25fps, using "smart deinterlace"
(I'm only using this one if I'm afraid of problems replaying video at 50fps)

Using the second method, you will not get the best quality out of your video, because you are definitely losing a lot of information - This often leads to staircase-effects or strange moire-patterns in some scenes.

I'd suggest that if you're planning to create an XviD encoded file only, go for the 50fps - it looks incredibly better, is extremely fluid AND it doesn't need a lot more diskspace.
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Cropping, Leveling, Deinterlacing, ...

Post by ^rooker »

As you might have noticed so far, there are black borders around the actual video content. Where they come from is explained here.
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