Difference between revisions of "Analog Capture"

Revision as of 21:02, 13 January 2007

Acquiring Equipment

First of all, if you don't have access to a computer running Windows, and are instead using a Mac, check out the Mac Capture page.

Otherwise, I recommend the ATI All-In-Wonder 9600. If you decide to record your run on VHS and let me capture, that is the card I will use. The American version supports every video standard I've ever heard of and captures in brilliant color, with full brightness transfer and virtually no dropped frames. It also captures full framerate ready video. Coming from inferior capture devices, I literally can not say enough good things about this card, so you will have to trust me that it is the best on the market.

Be sure to download and install the most recent drivers for the card (once you have it installed) from the ATI site, since you never know what might happen to your video (in terms of quality) if you use old drivers.

Acquiring Software

The software I recommend for capture and editing is called VirtualDub. It is freeware, which means you are not expected to pay for it. If you like VirtualDub, though, you should donate a few bucks to the man who wrote it, like I did.

VirtualDub comes as a .zip file. This means you will need a program to unzip it into its own directory. I recommend WinRAR, because it allows you to simply right click on the VirtualDub .zip file and select "Extract to VirtualDub-(version number)". This is the most efficient way I've seen to unzip things in Windows, because you don't have to open a program or make your own directory for VirtualDub. No further installation is required.

In addition, in order for you to capture full framerate video you will need to download two additional pieces of software. The first, avisynth, will allow you to split the fields of the captured video so that the full framerate is restored in progressive scan (since you will be capturing interlaced video). You will probably want to associate .avs files with Notepad (as you're asked to during the installation of avisynth) to make things easier on yourself later.

Acquiring Codecs

Once you have VirtualDub and the associated software ready to go, go ahead and download the codecs you will need. You will be using Huffyuv (pronounced "Huff Why You Vee," in case you're interested) as your codec when you capture. Huffyuv is also freeware. I also mirror version 2.1.1 of Huffyuv here at SDA..

Huffyuv also comes as a .zip. Do the same thing you did for VirtualDub, only this time you will need to open the Huffyuv folder, right click on the huffyuv.inf file and click "Install" in the menu that appears. This will install Huffyuv for you.

Your output codec will be the latest version of DivX, available from http://www.divx.com/divx/download/. Open the .exe file you download from there and follow the instructions to install DivX. You will probably have to reboot your computer to install it. It doesn't cost anything to install, either, though.

You don't need an input audio codec; you will just capture raw audio data without compression.

For an output audio codec, I use version 0.8.0 of the LAME ACM. This codec is a freeware MP3 encoder, maybe the best in the world. Be sure to only use the version I host here (0.8.0) - other versions have been proven to cause serious sound desynching issues. Once you've downloaded and unzipped the file, right click on the LameACM.inf file and click "Install" to install the codec, similarly to how you installed Huffyuv. You can visit LAME's homepage to learn more about the codec, but the LAME ACM is not available there. I've decided to host it myself because it's a bit hard to find on the Internet, and because you could easily get an older version of the codec on accident.

Capturing Video

Once all three codecs are installed, it's time to open VirtualDub for the first time. Double-click on the VirtualDub.exe application to open it. You are presented with VirtualDub's Dub Mode, where you apply filters to video and audio and export data to a new file. You're not ready to use this mode yet, since you still need to capture your run.

Getting Started (Capturing)

Start by hooking your VCR up to your capture card. You will probably need to use the red or black (right channel) and white (left channel) audio cables, as well as the yellow (composite video) cable. If your VCR has an S-Video output, by all means hook up your VCR using S-Video (instead of by the yellow Composite cable), though inexpensive VCRs seldom have such outputs. Press Play on the VCR or on the VCR's remote to start playing your run. You will want to have some video playing to make adjustments to the capture software before you rewind the tape and start to capture it for real.

Select "Capture AVI..." from the File menu. If all goes well, you should be blasted with a large amount of audio static and a window full of snow. If you see your run already, fine; you can skip the next step.

Setting Settings

If you see snow, you need to tell your capture card to select the Composite or S-Video source, whichever you hooked your VCR up with. Select Source from the Video menu, select Video Composite or S-Video from the "Select a Video Source:" dropdown menu, and then hit OK. If you have a card other than the ATI All-In-Wonder 9600, this process may be different for you. Consult your card's documentation.

Once you see your run playing on your computer, it's time to set up your capture settings. Start with the three buttons in the lower right hand corner of the VirtualDub Capture Mode window. You need to click on the first button (starting at the left) and set it to 22.05 KHz, 16-bit stereo. (If you only plugged in a white cable since your VCR doesn't have stereo sound, select "mono" instead of "stereo".)

For the second button, choose 29.97 fps (if you're capturing NTSC video) or 25.00 fps (if you're capturing a PAL or SECAM video). If you are in the US or in Japan, you are most likely using NTSC. If you are in Europe, Australia or elsewhere, you are most likely using either PAL or SECAM (remember to select 30.00 fps instead of 25.00 fps if you used 60 Hz equipment to play and record your run; just don't worry about this if you don't know what that means). The third button is a display of how much bandwidth you need to write the data to the drive. There's no need to do anything with it.

Next, choose Format from the Video menu. This shows the resolution you will be capturing at. If you are capturing NTSC, select 640 x 480. If you are capturing PAL or SECAM, select 704 x 576. This resolution will help you keep the image dimensions correct on the computer, so that the game isn't distorted (compared to watching it on a TV screen). Your capture will also be ready to be transformed into a full framerate video. Hit OK to close out of the Format window.

After setting your resolution, select Compression from the Video menu. You should see the Huffyuv codec in the left part of the window. Select it and hit OK. Huffyuv will compress the video you are capturing by a factor of 2 or more without changing what you see at all. It is said to be the only non-lossy video compression codec in the world because of this. There's no need to set the audio compression now; you will do that later, after you've captured.

Finally, set where you will capture by going to the File menu and selecting "Set capture file...". You should use your largest available hard drive, or else just save as "capture.avi" or something on your Desktop for easy access. This is the file VirtualDub will capture to. Make sure that the file doesn't already exist, or it will be overwritten when you start to capture.

Now go to the Capture menu and select "Preferences...". Select all of the boxes before the word "Save"; there should be four of them. Then hit OK. This will save all of your settings (EXCEPT for the very first setting, the source setting on your capture card) so that you don't have to reset them the next time you capture something.

Capturing

With all of your settings set, you're ready to capture. Press F6 to start VirtualDub capturing, then press Play on your VCR (assuming you're already in the right place on the tape). You should see your run start on the monitor. Keep an eye on the "Frames dropped" indicator on the right side of the VirtualDub Capture Mode window. You should stop dropping frames almost entirely once the picture clears up (after a couple seconds). If not, then there may be a problem with your CPU speed, with your hard drive speed, with your capture settings, or with your capture card. Try to use the other readouts on the right side of the window to diagnose the problem.

Beware of digital autotracking indicators. On many newer VCRs, annoying displays of the autotracking (or the time position) may cover your run. If this happens, press Rewind without stopping the tape (even though I say not to in the VHS section) and back up to just before your segment starts. If you press Play at the right time, the tape will start without trying to set the tracking again and the audio read head will sync before your segment starts. If head resynching happens too late and the video is distorted or audio is cut out, try pressing Rewind again to move further back. If you can't avoid losing some of your run due to VHS, try to remember to start recording longer before you start playing next time. Also keep in mind that every time you press Rewind or Fast Forward while your tape is playing, you risk damage to the tape.

When you are done capturing, press Escape to tell VirtualDub to stop. Then select "Exit capture mode" from the File menu. You are now ready to start editing your newly captured run!

Return to the front page.