Evolution of PVR

With compression allowing us to store about a month's worth of video on a 300Gb disk today, we're getting very close to the point where it will be feasible for a DVR to record every channel all the time, with a sliding window going back as far as you can afford to buy disk space for. Do this for every channel that you are allowed to receive, and you no longer need to schedule recordings ahead - you just look back to see when it was last shown and view it from the memory. No more hassles with sports shows running over time, forgetting to set the DVR, not knowing about a show until someone mentioned it at work the next day, etc.

With current technology you'd need several CPUs to handle the processing load (even with hardware support for the video compression) and a separate tuner for each channel you want to record, but with machines getting faster and having more cores, the first impediment ought to disappear on a predictable timescale, and the second may be solved by creating the TV equivalent of "soft radio" which is a technology that is almost upon us. My guess is we could prototype this today with a rack the size of a large fridge, and it could be in a consumer-sized box with within 5 years.

(although compression is getting better and with hardware support can be done in real time or less, with disk drives growing faster than compression is improving, it may be easier to throw a petabyte of disk at the problem in a few years rather than excessive hardware support for tight compression)

By the way the difficulty in building one of these today clearly comes from the large number of channels available for cable or satellite TV. However if you just record terrestrial broadcast TV - or limit yourself to a small number of preferred channels, such as 4 - we could implement this today with current technology in a single box.