CONVERTING ANALOG VHS CAMCORDER FOOTAGE TO DIGITAL

FILES AND EXTRACTING STILLSHOTS FROM THE DIGITAL FILES

THE BASICS: I have been using a VHS-C camcorder to videotape soccer games. The VHS format is analog and must be converted into a digital format before any stillshots can be extracted. The conversion can be performed by inputting the camcorder video footage into a computer with a hardware input device and using software to both assist and complete the conversion process. My initial attempt at converting my VHS footage used a hardware capture device that connected to the USB 1.1 port on my computer. This first choice enabled me to capture footage in digital format with reasonable playback clarity, but I soon discovered through further research that a video capture card inserted into a PCI slot in my computer would provide much better capture results and maximize the potentiality of my camcorder. Why? My VHS camcorder records at a frame-size of 640x480 pixels at a frame-speed of 29.97 fps (frames per second). If your input device cannot capture this footage onto your hard drive at the same frame-size and frame-speed, then you are degrading your footage while converting to a digital format. The problem with the USB 1.1 input device was that its maximum permissible frame-size was 352x240 and recording at a frame-speed of more than 15 fps produced a number of dropped frames because it couldn't maintain a higher frame-speed. By comparison, most PCI video capture cards produced within the past 3 years can capture at 640x480 and 29.97 fps with few or no dropped frames. So I bought an ATI TV Wonder VE and inserted it into a PCI slot in my computer, attached the video and audio cords from my VHS camcorder to the video composite inputs on the TV Wonder card, and began to capture footage using the bundled ATI video capture software. Whoa-problem #2!! The ATI software did not allow me to capture more than 240 lines of vertical resolution although the Brooktree 878 chipset in the TV Wonder card is rated to permit capture of 480 lines. After intensive internet research and experimentation with various software, I discovered other software that would permit me to use the TV Wonder card to capture at a full 640x480 frame-size and 29.97 frame-speed. There proved to be several candidates, but the easiest to use were also freeware: ATV2000, VirtualVCR and VirtualDub.

CAPTURE FORMAT: I prefer to capture camcorder footage using minimal on-the-fly compression and then use other software to convert the original captured footage into MPG-2 format. Once the footage is in the MPG-2 format, I can burn it onto a CDR disk using the SVCD option available in Nero's cd-burning software and play it on a standalone DVD player that is SVCD-capable or on the CDROM drive on my computers. If your computer is powerful enough, you can capture directly into MPG-2 format with minimal dropped frames, but then you lose the flexibility to crop the video or apply various filters that can enhance the original footage. Specifically, I capture VHS camcorder footage into AVI format using Huffyuv lossless compression to reduce the file size by approximately 50%. Then I use TMPGEnc with its deinterlace filter to convert the AVI into an SVCD MPG-2. Lastly I delete the source AVI file which is usually 20-25 times the size of the output MPG-2 file. E.g., 7 minutes of VHS footage of a soccer match consumes four gigabytes of hard-drive space in AVI format and only 150 megabytes in MPG-2 format. Converting from AVI to MPG-2 also somewhat improves the color and focus of the footage.

EXTRACTING STILLSHOTS: There is software, such as PowerDVD orWinDVD, which plays back the SVCD MPG-2 file and allows the capture of stillshots while the video is being played or when the video is paused. I prefer to use the freeware version of VirtualDub, modified to play MPG-2 files, because it permits me the option of advancing the video frame by frame and capturing a specific frame to the Windows clipboard. However, frame by frame advance can be very time-consuming. Consider that 7 minutes of soccer footage contains over 13,000 frames. Advancing frame by frame while searching for ones with suitable focus can take well over an hour for a 7 minute segment. VirtualDub also permits me to fast-forward the video, so to save time, I fast-forward while looking for "action" frames where a player is engaged with the soccer ball in a manner which proves helpful to her team. I further winnow the frames if a player's back is showing (unless the action is particularly compelling), or the players appear too small (considered by me as filling less than 30 percent or so of the vertical resolution of the frame), or the player's focus is too blurry. Occasionally I'll capture a frame if I spot a well-focused closeup of player(s) running or reacting to other action such as a corner kick or throw-in. And almost any save by a goalie will be captured. After capturing a frame to the Windows clipboard, I then paste the frame into a new photo in my photo-editing software. Because the SVCD MPG-2 has a frame-size of 480x480 (shrunk from the source AVI frame-size of 640x480), I then must resize the pasted frame back to 640x480 to restore the original dimensions of the players. (Aside: The SVCD standards call for a frame-size of 480x480, but when played back on a standalone DVD player or on the computer, the screen dimensions are 640x480.)

BY: Arthur McGlauflin: 2/8/03