We need harddisk space for storage

When thinking about video storage there is a fundamental distinction we have to do between compressed and uncompressed video: the first is video encoded in a form ready to be streamed and wich shouln't be edited anymore because of loss of quality at every reencoding [1] ; the second is often occupying 5 to 10 times more space and usually employed for video cutting.

The harddisk is a crucial device when we have to acquire video from video sources like composite video or firewire. The harddisk is not involved in the operation only in case we are doing live stream and we don't want to store anything we broadcast; while often there is the necessity to acquire and store the uncompressed video to later cut it, which requires a sufficiently fast and large harddisk. In case we don't need to cut the video we acquire and we have a fast CPU, then we can compress on the fly the acquired video signal making CPU intensive compression operations on volatile memory before storing it, saving a lot of overhead to the harddisk which then doesn't needs to be especially fast or big.

Anyway in case your harddisk or your CPU is too slow or you don't have firewire equipment, you shouldn't get desperate: you can still use a middle-layer lossless codec for video acquisition before compression. It is about a different codec to store the video data before the process of encoding it in compressed form: a state in between the raw video and the fully encoded video. When such a codec is lossless it can then be a suitable source for video editing, it will require a lighter computation than MPEG2 and MPEG4 while occupying more space on your harddisk. Such an effective solution is implemented by a free software codec named NuppleVideo developed in Vienna by Roman Hochleitner and supported as an input format by most of the software encoders available on GNU/Linux.

Thanks to this software, a 800Mhz CPU with a fairly modest harddisk (as of models sold on the consumer market in 2001) can function as a MPEG2 or MPEG4 encoding station, acquiring video from composite or s-video using a cheap WinTV/Hauppage card. [2]