Diese Seite auf deutsch

Stand 28.09.03

Digital video recorder solution for analog-TV


Using the new capabilities of digital video recording through the front panel of a living-room digital recorder or working laboriously through onscreen menus seems absurd to me. Video editing only becomes convenient on a computer, even if you just want to cut out the commercials. The following article shows that you don’t have to give up the convenience of standalone devices including time shift mode, by providing a digital video recorder solution for analog-TV.


What do we need?

The right choice!

Hardware preferred!

Record and playback at the same time?

Tips for this solution!


What do we need?

First an overview of the components needed for a video recording solution on a PC:


1.       TV-tuner

2.     MPEG-encoder card or a PC over 2.4 GHz with software MPEG-encoder

3.     MPEG-decoder card or a PC over 600 MHz with software MPEG-decoder

4.     TV-out on your computer

5.     Video radio link or a long video cable

6.     Remote control extension and an infrared-receiver on your computer


The first four devices are available in different combinations. Common examples include: graphics cards with TV-out; MPEG decoder cards also with TV-out; TV-tuner cards available with or without MPEG-encoder, and last but not least cards that combine all four devices into one. If do not want to use the TV-tuner card, you will need a television near your computer and a video-input. Video-in is usually found on MPEG-encoder cards, but rarely on graphics cards.


So that you do not have to put your computer into the living room next to your television (or vice versa), you will need a radio link for video signals or a long enough video cable. You’ll also need a remote control extension and an infrared receiver on your computer. If you choose the video radio link, the remote control extension (so called feedback-channel) is usually included. MPEG-decoder cards and TV-tuner cards usually include an infrared-receiver with remote control for your computer. So now, nothing should get in the way of comfortably handling the system right from your living room chair.


The right choice!

 Considering the different devices that you will need, the whole solution may appear to be somewhat complicated and you may be wondering about the costs. But it doesn’t have to cost more than a standalone solution. Of course you will have some additional expenses for purchasing and installation, but this is justified by the flexibility of the system and the capabilities you get. For example, you can easily replace (or upgrade) a hard disk, edit videos with professional effects, or archive and playback old footage that was digitized over the video input. In addition, with this solution you get a DVD player for the living room television.


The choice of components depends on your circum­stances, your personal taste, and the amount you are willing to invest. The most convenient choice is of course a card that combines TV-tuner, MPEG-encoder, MPEG-decoder, TV-out and perhaps an infrared receiver with remote control.


If you value devices that have successfully stood their ground in the market, the combination of TV-tuner with MPEG-encoder from Hauppauge, Dazzle, Pinnacle or Vidac, and MPEG-decoder card with TV-out from Sigma Designs is recommended. The benefit of these cards is that these products run smoothly on nearly every computer and the installation costs of the system stay in a reasonable frame.


The MPEG-encoder card is the most expensive component. If you have a fast enough PC, a software encoder may get more bang for your buck. The products mentioned above cost about $250, but do not expect professional quality, because these devices are mainstream products. High end MPEG-encoders, regardless of hardware or software, could cost over $1000. With the noise quality of some analog TV signals from cable or antenna, the products mentioned are a very good alternative.


The combination of TV-tuner card with software MPEG-encoder/decoder and graphics card with TV-out is not recommended. Even using computers with superior performance, the recording quality remains behind that of the other solutions.


Hardware preferred!

Next we will look at the combination of TV-tuner card with MPEG-encoder and MPEG-decoder card with TV-out, because it has some advantages. With their MPEG-decoder card Sigma Designs stands out as an established brand. They provide simultaneously two products, the Hollywood+ and the follow-up model, the XCard. For about $150 the quality is as good as the MPEG-encoders mentioned above and comparable to a high quality DVD player. This primarily concerns the TV output, since some graphics cards with TV-out  do not have the same level of quality. Another advantage of the two cards in comparison to a software solution is that the remote control together with infrared-receiver for the computer are included. Of course there are applications (e.g. WinLIRC, GIRder or IRAssistant), which allow you to control your software with a commercial remote control through an infrared-receiver connected to the PC, but that may require additional meticulous work.


The MPEG-encoder card from Hauppauge is called WinTV-PVR. It has an analog TV- and FM-tuner as well as integrated videotext, so it enables direct recording of telecasts on hard disk in DVD-quality.  In this case the recorded file may become up to 4 GByte per recorded hour. In order not to be bound to the maximum file size, the use of Windows 2000 or higher (for Windows 98/ME the limit is at 4 GByte) is recommended. There may be other comparable products with which I have no experience.


For the video radio link make sure a feedback-channel for the remote control is included. I recommend Isiropa Megalink from Telestar, which was rated the best in picture and sound quality tests. For about $150 you get a device that can also be used for transmission of any video signals. With the help of several receivers, you can also use the signal in different rooms at the same time.


There are primarily two signal formats for transmission of analog video- and TV-signals that represent different quality: composite or FBAS and the better S-video. While the Hollywood+ and the XCard as well as most graphics cards with TV-out support both formats, video radio links just provide the composite signal. If you categorically want to use the S-video signal format, forget about the video radio link and lay a cable that is the appropriate length instead. When using the Isiropa Megalink in combination with the XCard, you will hardly notice any quality difference with the naked eye. The XCard also supports additional signal formats, like component or HDTV.


Record and playback at the same time?

One of the new preferences of digital video recording is playback of a telecast in time shift, while recording. If you use products from different manufacturers, even with a software based solution, it may lead to the problem that the playback device cannot access the file, while it is being used by the recording device. If recording and playback is done by the same software, you don’t need to worry about it, but you should pay attention to the resolution in time shift mode. Not all software provides full DVD-resolution in time shift!


For the combination of WinTV-PVR and XCard there is a special configuration solution for the WinTV-PVR to split the recording periodically, for example into 10-minute blocks. With a maximum time offset of 10 minutes you can view the recording.  This way you can fast-forward and rewind or skip from one block to the next, as long as it already exists. The XCard is able to playback automatically all blocks consecutively. The only constraint is a small dropout of approximately half a second for the change from one block to another.


Tips for this solution!

The XCard and many software MPEG decoders for e.g. PowerDVD or WinDVD have a problem with subsequent blocks that WinTV-PVR generates after the 1st block (see time shift). You will need a small application that solves this problem. You can download this small application here.


If you hide the TV window of the WinTV application while recording, you can further reduce the number of possible frame drops, because CPU and bus capacity are not wasted needlessly on displaying the TV picture. The progress bar will still be visible. To hide it you can use a free application called AutoIt.  It does require you to write a small script. A little example is here for download.


It is practical to enhance the script, so that it hides the TV window at the beginning of a scheduled recording and shows it again at the end of the recording. You can download this extended script here. It is necessary to convert the script into an executable with the same name as the original WinTV application and to set the recording scheduler via the registry key entry TVAppPath” - „HKEY_LOCAL_MACHINE\SOFTWARE\Hauppauge\Radio” to the path to your executable file.


Because the remote control signal is transmitted with video radio links in a frequency range more sensitive than the video signal itself, you may have some trouble receiving the remote control signals. You may need to laterally adjust the receiver and/or sender in different directions.


Comments and suggestions to info@seconis.net.


© 2003, Hendrik Utsch