2 Replies Latest reply on Dec 3, 2010 10:01 AM by frootjooce

    mp4/flv video playback

    frootjooce Level 1

      I am building a program that plays back full screen video.  So far I have tried flv and mp4 playing back at 720x576 (16:9) ratio encoded to 1500- 2000kbps but am getting consistent stuttering rather like playing at a low framerate.  Couple of things I have notices so far is that tempo channel framerate directly seems to control playback (which is didn't before) but even running at 25 fps (same as video) doesn't help.


      Has anyone experience or tips to help here.


      Thanks in advance

        • 1. Re: mp4/flv video playback

          There are a few gotchas (thank Sarah Palin for ruining that phrase for me) that will impede performance.


          1. Are you going direct to stage? If not, and you have stuff intersecting the video that updates (like a text field) you will have noticeable stuttering. Rather than putting your video behind a mask, put it on top.

          2. Are you running linearly through a set of frames or cycling on the same frame? A linear run over a series of frames will have better script performance than a single frame idle loop.

          3. Do you have other Flash (swf) assets on the stage at the same time or touching the video frame? This will also reduce the frame rate.

          4. Reduce the use of enter frame scripts and keep your exit frame scripts to a minimum. Be sure you don't have large loops, case, if-else or lots of behaviors that have exit/enter frame functions.

          5. Consider using Quicktime if you want static overlays in your videos. Quicktime tracks are handy that way.

          6. Run your tempo at the fastest rate available. Videos are controlled by their own clock.

          7. Be sure you haven't misidentified the media as a Flash movie and have lock-step set (how you might accomplish that, I don't know).


          I am currently running a 1080P (1920 X 1080) 24FPS Quicktime video compressed at 34MBits/sec, Apple Prores Proxy, Millions of colors, at full frame rate with complex logic, no problem. So it can be done.


          There are other issues that are dependent upon your application, but these are some of the big ones.

          1 person found this helpful
          • 2. Re: mp4/flv video playback
            frootjooce Level 1

            Some good points here natfast.


            1. Tried it both ways, there's nothing in the way of the video it just plays in a window over a bitmap background.


            2. Using a 'go the frame' loop, the videos are quite long and 32 of them.  This is a good point though because I noticed that unlike qt movies where a slower score framerate say 8fps used to be recommended because it wouldn't use so much processor time and the qt clip would play at its own framerate anyway.  With flv the slower the score framerate the slower the video played - like they were linked??  So I set the score framerate to 25fps to match the clip.??


            3. No nothing see (1)


            4. Again there's nothing else going on other than the loop 'go the frame'


            5. Well that's where I'm at, now using QT for the mac version and wmv for the PC these play fine no problem.


            6.  Hm well that what I though but not flv's it seems.


            7.  The clips were imported as flv which auto brought in the flv xtra, what's lock step ??  I also tried mp4 which it seems it treated the same way as flv and had the same problem.


            I agree on your last point I don't have any probs with quicktime playback.  The flash video feature in 11/11.5 looked like a real plus for cross platform work such as this getting round the reliance of installed software ie QT for the pc.  But if it won't play properly its as much good as a chocolate teapot.  I can appreciate that the overhead of the projector is always going to reduce the performance compared to playing the clip directly but you would think in these days of streaming and quad core processors we wouldn't still be having these issues. It takes me back to the nineties when I was trying to get quarter frames to play in Win98


            If it is a limitation I just wish Adobe would give some steer on what to expect.