> Most video formats are designed to handle > errors--they'll drop a frame > or two, but they'll resync quickly. So, depending on > the size of the > error, there may be a visible glitch, but it'll keep > working.
Actually, Let's take MPEG as an example. There are two basic frame types, anchor frames and predictive frames. Of the predictive frames, there are one-way predictive and multi-way predictive. The predictive frames offer significantly more compression than anchor frames, and thus are favored in higher compressed streams. However, if an error occurs on a frame, that error will propagate until it either moves off the frame, or an anchor frame is reached. In broadcast, they typically space the anchor frames every half second, to bound the time it takes to start a new stream when changing channels. However, this also means that an error may take up to a half second to recover. Depending upon the type of error, this could be confined to a single block, a stripe, or even a whole frame. On more constraint bandwidth systems, like teleconferencing, I've seen anchor frames spaced as much as 30 seconds apart. These usually included some minimal error concealment techniques, but aren't really robust. So I guess it depends upon what you mean by "recover fast". It could be as short as a fraction of a second, but could be several seconds. This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
