|5. Recording, Playback and TimeShift
File Size and Basic Information about File Systems
Video recordings require a large amount of hard disk space, although it is hard to tell exact numbers. It is dependant on the bitrate and the resolution of the broadcast. As there are different formats, usually 480 * 576 (2/3 D1) and 704/720 * 576 (cropped/full D1) pixels, the necessary space will differ between about 300 to 900 kbytes per second which results in approximately 28.5 MB per minute. It is safe to say that you will need about 3-4 gbytes for a two-hour recording.
While this seems to be quite large, you must keep in mind that it is a 1:1 reproduction of the original broadcast. With DVB you won't have any audio or video distortions you know from analogue-recordings. Furthermore you will be able to use the recorded file for creating a video DVD without time-wasting re-encoding.
While modern harddisk drives provide more than enough space for DVB recording, you must keep in mind the limitations of the file-system. The ancient file-system of DOS and Windows 95 is the so called FAT or FAT16 (file allocation table), which is limited to a file-size of 2 gbytes. Windows 98 and ME feature the FAT32 system. This one allows you to record up to 4 gbytes, but another limitation is often caused by certain software, which is still limited to 2 GB.
Windows NT, 2000, 2003 and XP work with the modern NTFS (new technology file system). This one is more reliable and designed to work with large file-sizes. You may also use the FAT32 file-system with Windows NT, 2000 and XP although it is not advisable. With NTFS there is virtually no limit to the file-size, but here, too, you have to remember the limitations of certain software used for further editing of your recordings. There are no known problems with VirtualDub MPEG2, Vidomi, NeroVision Express and Ulead Movie Factory 2 for example.
To avoid unwanted surprises you should do the following:
Check the type of your file-system: You can do that by right-clicking your drive in the Windows explorer and selecting properties.
When using Windows 2000 or XP you should convert the partition(s) to NTFS as soon as possible to avoid problems. This can be done without formatting. Just use the windows help system (search word NTFS) for a step-by-step description. You can also use programs like Partition Magic from Powerquest. If you are not that experienced you should consider asking a friend for help.
At last you ought to check the free space available. As already mentioned you will need about 3-4 GB for a two-hour recording plus overlap. You should also know that your harddisk performance deteriorates the less free space there is.