Flash video playback, how to determine seconds loaded?

I'm trying to accurately determine how many seconds of a video (NetStream) have been loaded so I can scrub/seek correctly. First I tried doing duration*(ns.bytesLoaded/ns.bytesTotal) but this is inaccurate by maybe 15%, ie if that calculation says 20 seconds is loaded and I scrub to 20 seconds ns.time will tell me it can't go past 17 seconds.

I think this is because the size of the file loaded doesn't map perfectly to the number of seconds loaded (obviously), ie as the video loads, some of th开发者_JAVA百科e bytes loaded aren't the actual video but are overhead of the container/file the video is in. So to load 1% of video you have to actually load 1.15% of the file's size.

Anybody know a work around to determine seconds loaded?

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bufferLength indicates the number of seconds currently in the buffer. You can use this with time to determine how much in total has been loaded.