Copyright Michael Karbo, Denmark, Europe.
Chapter 22. Grabber cards
Analog video is probably still best transmitted with the use of a grabber card.
We are talking about a plug-in card, which is installed on a PCI socket directly on the motherboard. Which means that there is also access to the transmission of large amounts of data, which is necessary when working with video. I am going to describe the card and how to use it here plus an actual sequence, where I re-record an old VHS tape into a computer.
We can find the necessary plugs for video signals on the back of the grabber card. The card is, however, in some models connected to a desktop box, which simplifies the connection between video cables, which is clearly an advantage.
There are, in fact, lots of different models of video grabber cards. A lot of the models are multifunction cards, where the grabber function is combined with an audio card, a television/radio tuner or a screen card.
Here are some examples of the card:
Figure 141. Examples of grabber cards with different extra functions.
The problem with video grabbing is, that the function isn’t standardized. There isn’t a definite industrial standard that can tell you how it should be done. Which means that every single card has its own video system and most often the software to be used has been tailor-made exactly for a particular card. You cannot just use any video program to capture a video signal.
I have personally tried four different grabber cards over the years (from Terratec, Pinnacle, Matrox and Winnov). My experience (which isn’t a lot) is, that each of them has their good and their bad sides. I really can’t say which one of them is the best.
These grabber cards can, incidentally, also be used for gathering video signals from a lot of digital cameras. If the camera has a port called TV-Out, then it can be connected to a grabber card’s video port (the yellow RCA plug). So you can, in fact, use your digital camera as a webcam!
Another thing is, that it requires a good deal of computer power to digitise analog video. I have worked with a 2,5 GHz Pentium 4 machine with 512 MB RAM and masses of available space on the hard disk. With this equipment, there aren’t any problems at all with the quality. But if your computer is much slower than this, then you should expect that some images will be lost and that the result will be hacked. See also the more general description in the sections ”Hardware” and ”Windows” in the booklet’s appendix.
A cheap card with TV tuner
Let me start by introducing one of the really cheap cards on the market. Terratec is a German company, which develops and produces both sound and video cards. You get value for your money with Terratec’s products; and they generally receive good reviews from the various magazines that test them.
I have tried the deluxe model called Cinergy 600. This is a grabber card with a built-in tuner for both television and radio.
If the card is connected to two aerials, then I can see television on the computer, and I can listen to normal FM radio. There is some special software for this, but this isn’t the subject here.
Figure 142. Remote control and lots of software with the Cinergy card.
I can also record television programs directly from the aerial signal to a hard disk, which is really smart. I can, in fact, pre-program the Cinergy card to record at pre-determined times.
Figure 143. A grabber card for analog video with built-in radio and television tuners (Terratec Cinergy 600).
The card itself isn’t particularly big, and all the plugs are on the back. We feel the need of a desktop box, so that the cable connections could take place on the desk. It is troublesome having to rummage down at the back of the computer every time a plug has to be put in.
Figure 144. The little ”audio loop-through cable”, which leads the audio signal to the audio card
Audio is processed outside the grabber card
The Cinergy card has (just like most grabber cards) no built-in audio function. Which is why there is a plug called Audio Out. This means that the audio has to be digitised by the sound card. Which is why the audio signal is connected to the sound card.
You can connect the audio signal to the Cinergy card and then send the signal to the sound card via the Audio OUT port on the card (see Figure 144). You can also connect the audio signal directly to the sound card, which will probably give the same result.
I have now introduced a little grabber card. Let us see how it works, how do we use it? Even though you don’t have exactly the same products, as I describe here, I am sure than you will get something out of reading the explanation. Because regardless of what sort of equipment you make recordings with, the course of events will be very much like the one I am going to describe.
The grabber card is fitted onto the computer and all of the accompanying software is installed. As I will mention later, it’s always a good idea to fetch all the newest versions of the programs from the manufacturer’s website. Which I have done – I went to www.terratec.com and picked up all the newest software I could get hold of.
Then all the devices have to be connected. I am going to digitize an old VHS tape. But my video player doesn’t have an S-Video port. I use a SCART plug instead, which can always be found on a video player. I use a small SCART to video / audio converter. This is a little box that converts the SCART plug’s signals to three RAC plugs (Video OUT and 2 x Audio OUT).
Figure 145. The SCART plug is converted to three RCA connections.
I connect the video signal (the yellow one) to the Cinergy card’s Video IN. The two audio cables (as the sound is stereo) can be connected to the sound card, and here I select an AUX 2 port. Here is a little diagram:
Figure 146. Two signals have to be lead into the computer. The grabber card looks after the video image while the sound card manages the audio signal.
As I have already indicated, there are many variations in the set up demonstrated in Figure 146. It could be, that you use an S-Video connection to the image; most video cameras have such a port. The audio can be captured via a headphone port and be connected to an analog port on a sound card. It is not important whether it is called MIC, AUX or LINE.
Figure 147.Windows’ audio control is used to check whether the right audio port has been activated.
Check the audio and ready for recording
The right audio port has to be activated if the system is to function. Windows can, in fact, control, which of the sound card’s ports are active. I check this with Windows’ little audio control. In my case, I use the port AUX 2, which, therefore, mustn’t be switched off Figure 147).
When all the cables are connected and all the software is ready, then I am also ready, in principle, to ”record”. So I open the capture program, which came with the grabber card. In my case, the company Terratec have supplied the program WinDVR, which conforms to the Cinergy card:
Figure 148. Capture software, which comes with the Cinergy card.
The first thing I do is to control the set up for this program. I can select sources for video and audio. The video source is in my case ”made-up”, as I don’t use S-Video. The source ”TV”, which can be selected in Figure 149, is attached to the TV tuner, which is also found on the Cinergy card. This means that, in practice, I can record television programs directly onto a hard disk. But not just at the moment. I capture the audio from the sound card and I give the AUX 2 port as the source:
Figure 149. Set up for recording.
The next step is to determine which format the recording should be stored in. There are various possibilities here.
Figure 150. Specifications for re-recording on a Super Video CD.
I want to store my recordings on a CD in the format SVCD (Super Video Compact Disk), because it gives good quality and the film can be played back on a normal DVD player. So this is the format I choose:
Figure 151. The video program has to know, which format the recording is to be stored in.
Finally I select, the size of the screen image. This is a normal television recording, so I select the size ratio of 4:3:
Figure 152. You have to choose the height and width of the screen image.
The WinDVR is ready for recording. The screen is black with a strange floating control panel:
Figure 153. The screen is black because the video isn’t switched on.
Recording of analog video takes place in real time. This means that the transmission takes just as long a time as the video playback does. You have to control the playback yourself to be sure that the right film sequences are re-recorded.
I press the play button on the video player. A second later the image comes onto the screen in the big window.
Figure 154. We have acces to the video player.
The video player is recording now just as it does when recording from the television. The only difference is that the computer receives the video signals. The grabber card converts the analog signals to data and the video image is displayed on the screen.
When I am ready to start recording I click on the red Record button. The software behind the whole of it starts to re-encode the recording (rendering) to the selected video format. This could be AVI, MPEG or WMF; in my case the format is MPEG, because that is what is used for SVCD.
The video plays and I watch it on the screen. At some point I ask the program to stop the recording and then I can stop the video player. All I have to do now is to give the recording a name.
Figure 155. The recording is stopped and the video film is stored.
You have to be aware of the fact that a computer works hard when it converts your analog video recordings into files. The analog signals have to be converted to data. This takes place partly in the grabber card but computer power is also exploited. At the same time as this conversion, every single image is rendered, compressed and stored. A powerful CPU and lots of RAM is really necessary!
Burn a video disk
I have just outlined a recording sequence. I had a six-year-old VHS tape with in all eight recordings of the DK4 programs ”About personal computers”. I want to save them for the future because VHS tapes have a limited life span.
I selected a SVCD format (see Figure 151). Which means that my video file was stored as an MPEG file. Each of the programs lasted about 30 minutes, which fits very well in with a videodisk of the best quality (SVCD). These MPEG files are stored in my video folder and are easy to access:
Figure 156. Two VHS recordings that have been converted to MPEG files.
The final task is to burn the video onto a normal CD. A lot of video programs do this by themselves but I still use my loyal Nero software burner.
Figure 157. Nero can burn a video CD on the basis of an MPEG file.
I open Nero and ask it to make a Super Video CD. All I have to do now is to drag the right MPEG file into the left window and click on Burn. Then the SVDC is burnt!
Figure 158. The MPEG is automatically prepared for the SVCD.
Video CD is a brilliant format, as the disks can be played on almost all DVD players. It is a really smart way of distributing homemade videotapes. I managed to transmit all of 240 minutes of video onto 8 big MPEG files. And after that it was very easy to burn a corresponding number of CDs. It took only an afternoon.
During the operation, I can see the screen image and hear the audio while the recordings are running. My only job is to stop and start the recordings every 30 minutes. With a couple of wireless headphones it is easy to follow the progress so that you don’t have to sit glued to the screen all of the time. Or else you can use a stopwatch. Alternatively, you can just let the recording run, and the program will by itself split the MPEG files up, when the limitation of a CDs’ contents is reached. An MPEG file mustn’t come over 600 MB, if it is to be burnt on a CD.
Considering that the VHS tape was six years old and that I couldn’t use the S-Video signal, I was rather surprised at what a good quality the video-CD had. And the recording itself was made, as described, without any trouble. Just don’t use your computer for any other jobs while the recording is taking place; this can give crackles and hacking. Which is why it would be optimal to have two computers to work with.