I am trying to create a streaming video DVR like functionality in an app I am developing. I have an HTTP Live Stream that I have successfully gotten to play on the iPad. I w
DVR on the device is somewhat not encouraged, due to the limited space available and other factors like battery life, processing power, cleanup procedures after the user stops the dvr, etc.
If you want to achieve DVR playback on iOS devices (or other devices using HLS), I suggest you keep the video server side. The live stream is already captured and segmented server side, all you would have to do is keep the segments a bit longer, instead of deleting them. By using the EXT-X-PLAYLIST-TYPE and EXT-X-MEDIA-SEQUENCE tags, you can suggest to the player that he's opening a live stream which has DVR (earlier) video available.
Alternatively, you can use a server that does that out of the box, for example Wowza. Here's an article on how to achieve this with Wowza