2 Replies Latest reply on May 1, 2007 3:59 AM by Peter Lorent

    Playing FLV in reverse

    Peter Lorent Level 2
      Seems that you can't play an flv in reverse? I've searched a lot but couldn't find a solid answer or any hints to overcome this. Is this simply impossible (without embedding and reversing the timeline) or is there a solution out there?
        • 1. Re: Playing FLV in reverse
          Greg Dove Level 4
          I think the format of the flv does not make this easy... perhaps not even possible. The only way I could think of attempting it would be like this:

          1. Encode your video to have a keyframe every frame. (This has implications in terms of quality vs. bitrate). This allows seeking to each frame for a progressive video (assuming its completely downloaded).

          2. Use the freeware tool FLVMDI (easy to find with google) to inject metadata for the keyframes. This will give you the timecode (and byte address - which we don't need here) of every keyframe in a keyframes.times property of the metadata.

          3. use the playheadTime property of the FLVPlayback component to track the current frame (because all frames are keyframes) as the index in the array of timecodes in the metadata. When you want to go backwards, seek to previous keyframes (using the metadata timecodes) at the fps rate of the flv (also obtainable from the metadata). You would also have to maintain a paused state after each seek to prevent the playhead moving forward.

          This is a very much a workaround to get over the limitations (design?) which is that a flv format is not really designed to play backwards- I think it could work in principle, but I have no idea how well it would work in practice - I haven't tried it. It's all I can think of.
          • 2. Re: Playing FLV in reverse
            Peter Lorent Level 2
            Thanks for your reply. Nope, I've considered testing that but it is not an option in terms of performance. I'll have to generate the reverse sequence as a seperate .mov somehow so I can just play the flv normally. Is there any program that you know of - other than After Effects or Final Cut - than can save a reverse sequence as a movie?