Problems playing videos on quicktime

i am trying to play videos saved on a wireless external hard drive, but the video and sound plays slow and choppy. My QuickTime app is fully updated and the movies used to play great. Any ideas?

What is the normal playback data rate of the video and what is the bandwidth of your wireless connection. If the playback data rate exceeds the bandwidth of your wireless connect, then the QT player will normally drop frames in an effort to "catch up" during playback. Depending on the video codec used to create your file, the dimensions of your display and the the specific settings used, playback data rates can easily vary from less than 100 Kbps to more than 500 Mbps using the standard codecs that are included in the basic system codec configuration.

Oops! In my effort to simplify my explanation, I reversed the actual mechanism I wanted to describe. As more experienced users are aware, the dropping of frames is what occurs when the the player in not capable of processing enough data fast enough. (E.g., when playing very large display files having complicated video codecs using very high data rates on a wireles network having insufficient bandwidth.) In the case to which I was referring, the playback by the player overruns the ability of the wireless device to provide source data. If this difference is great, playback may actually freeze to allow addition data to be cached by the player. In instances where this difference is very small, the player may only stop for a fraction of a second which is long enough for your eyes to interpret the stop as a playback "jitter." While this is not the only possible problem here, it can be a common one for files having unspecified compression formats, display dimension, file data rates, and/or wireless bandwidth.