Hardware options

A typical video capture card is a system of hardware and software which together allow a user to convert video into a computer-readable format by digitising video sequences to uncompressed or, more normally, compressed data files. Early devices employed a hardware Motion-JPEG codec, which used JPEG compression on each frame to achieve smaller file sizes, while retaining editing capabilities. The huge success of DV-based camcorders in the late 1990s led to the use of a DV codec instead. An all-in-one graphics card equipped with suitable video input connections is a more economic alternative to a dedicated capture card.

Some video capture cards keep their price down by omitting their own sound recording hardware, instead providing pass through connectors that allow audio input to be directed to the host PC's sound card. This isn't a problem for simple editing work, but without dedicated audio hardware problems can arise in synchronising the audio and video tracks on longer and more complex edits.

An increasingly popular solution is the use of an external converter box in which the codec is embedded in hardware. The video and audio output from your VCR will be connected to the appropriate connectors of the capture device, which streams the digitised format to the PC via either a USB2 or FireWire interface. As well as DV, such devices can typically encode to MPEG-1 and various qualities of the MPEG-2 format.

The amount of work your PC's processor has to perform during video capture will vary depending on the capture device being used. If it's an external converter box, the processing load on your CPU will be less than if it's an all-in-one graphics card. However, there are other phases of a conversion from video cassette tape to DVD - such as video editing and the transcoding of digitised video streams - that are CPU-intensive, and generally speaking a processor of at least 1.5GHz and a minimum of 256MB of memory is recommended.

During video capture the ability to write the digitised video to hard disk in real time is of critical importance. The total data stream for DV amounts to 3.6BMBps, so your system needs to support this sustained rate of transfer to hard disk to avoid dropped frames. This rate of transfer also dictates that external converter boxes need to have either a FireWire or USB2 interface. USB1.1 models - which have a bandwidth of only 12Mbit/sec compared with USB2's 480Mbit/sec - simply aren't up to coping with streamed DV.

DV also has implications with respect to file sizes. Firstly, you need to ensure you've enough disk space to accommodate the amount of digitised video you're going to be producing. In calculating this you need to take account of temporary files that will be produced during processing as well as the final digital video files themselves. Moreover, you need to be aware that the FAT32 files system, used by Windows 98 and ME and an option under Windows XP, has a file size limit of 4GB. The NTFS file system used by Windows 2000 and XP doesn't have this limit.

Finally, there is another option that wins hands down in terms of simplicity, and doesn't involve use of a PC at all. That is to use a standalone DVD Recorder/VCR combo unit. These devices provide a one-touch copy function that'll allow you to copy a tape to DVD in one of a number of different qualities, typically "XP" (1 hr/disc), "SP" (2 hrs/disc), "LP" (4 hrs/disc) and "EP" (6 hrs/disc). As well as VHS-based source, you can connect both external analogue and DV devices and while it may be somewhat limited, you have the ability to edit your captured footage, insert chapter points and create a playlist menu.

For the purposes of this tutorial, we're going to use an external analogue-to-digital converter box.