Flash audio losing sync.

Okay, just got another email about this issue of audio in Flash not syncing up after a certain amount of time. Most people report it takes a few minutes for the sync to get all screwy. And this is definitely a common problem, since this is probably the 30th email I’ve gotten on this. Fortunately here’s a solution that MOST people reply back and say works. It just takes two things…

  1. Make sure all your audio in Flash is set to Stream instead of Event. So if you’re scrubbing through the timeline, you should be able to hear little bits of audio at each frame. Versus Event where you only hear the audio if you trigger the first frame. You can choose between Stream or Event in the Properties window ( if you at least one frame selected of  the audio in the timeline)
  2. Okay the really important part, and this is weird but it works… In your HTML embed code, switch your Quality parameters to BEST. They are probably set to HIGH, and if so, just do a find and replace switching HIGH to BEST. This should make the playback of the swf favor keeping time with the audio instead of trying not to skip frames during playback. Usually the reason the audio gets out of sync in Flash is because the player is trying to show you as many frames as possible and disregarding the audio. Which might be a good thing if your audio is just some cheesy sound loop, where it doesn’t matter if it syncs. Skipping frames can also make the playback look way less smooth, but thats a good sacrifice if your speaking characters in an animation keep time.

Here’s what Adobe has to say about the Quality parameter (note they don’t mention anything about audio, but trust me, the above is true )…

Defines the quality of playback in Flash Player. Valid values of quality arelow, medium, high, autolow, autohigh, and best. The default value is typically best.
The low setting favors playback speed over appearance and never uses anti-aliasing.
The autolow setting emphasizes speed at first but improves appearance whenever possible. Playback begins with anti-aliasing turned off. If Flash Player detects that the processor can handle it, anti-aliasing is turned on.
The autohigh setting emphasizes playback speed and appearance equally at first, but sacrifices appearance for playback speed if necessary. Playback begins with anti-aliasing turned on. If the actual frame rate drops below the specified frame rate, anti-aliasing is turned off to improve playback speed. Use this setting to emulate the View > Antialias setting in Flash.
The medium setting applies some anti-aliasing and does not smooth bitmaps.
The high setting favors appearance over playback speed and always applies anti-aliasing.
The best setting provides the best display quality and does not consider playback speed. All output is anti-aliased and all bitmaps are smoothed.


12 thoughts on “Flash audio losing sync.

  1. I use flash primarily for character animation for series and commercials, so I dunno if this issue you describe is similar to the one I have when export my animation as a movie…but often times whether its quicktime, or swfs, or wmv…if I have several clips of audio in my main timeline..the audio will not export in sync….especially if there is no audio on the first key frame.

    For some reason, Flash either misinterprets any audio not on frame one and plays it faster…or automatically finds the first frame of audio which may be frame 50…and exports it as if it were on frame 1, which plays the audio clips 50 frames too early. ..

    Anyways…the fix we came up with on a show i worked on, and MIGHT be another fix for this issue, is by putting in a blank avi, or wav onto your main timeline.. what I mean by this is, open an empty comp in After effects, doesnt matter the specs, except for the length. I usually make a 3 minute one, but it doesnt matter really.

    Export that empty comp as a wav or aiff file and call it blank….which basically it is….it will just be a flat waveform……

    import into flash and set it at frame one and just let it live there. Add your audio as you normally would. Since the blank aiff or wav, IS a sound file…flash will recognize it at frame 1..and it exports everything else just fine…

    Anyways…not sure if this will be a fix for web stuff..but it might….

  2. Hey Justin, this audio sync thing is a great pain in the butt many have experienced. There’s other work arounds too. Weird things that work. One I use is to import a 5 second loop then place it on the first frame of my timeline on a new layer. In the Effect properties, I bring the volume down to zero, set it to stream, and make it loop for however long my timeline is. Thought it’s not audible, it keeps the rest of my sounds in sync, this has worked for me throughout the years, and is what I always do.

  3. Yeah, just another example of why Flash is not great for commercial animation. Its awesome for web animations, in .swf form, but when you want to do broadcast animation there’s issues in Flash that have persisted for many versions now. Another thing, exporting from Flash to Quicktime hasn’t been fixed since CS3. The export usually gets rendered with “trails” in it.

    Check out Toon Boom Animate sometime. Very good for broadcast.

  4. Just want to back up what Ramiro Olmos said. I do the same thing just with a silent audio clip. Solves the problem every time for me.

  5. I changed quality to best in my publish settings and the audio sync to “stream” rather than “event” and it seemed to do the trick, thanks.

  6. Asya says:

    This is a great tip – who knew that the difference between “high” and “best” was so great?

    I did however find that setting the audio to Stream degraded it significantly, but with the help of Clearly Trained (http://clearlytrained.com/blog/?p=52), I corrected this by setting the streaming export bit rate to 80 kbps Best in the Publish settings.

  7. Kevin says:

    I can’t thank you enough for this. This totally saved my project. You rule. If you had a paypal button, i’d give you money. Not enough to retire on, but you might be able to get a pack of gum.

  8. Aleko says:

    same here, thanks a lot, this also save my proyect, may the force be with you Justin

  9. Hi Folks,

    After several hours of R&D me and my buddy found that setting the document properties to 24.95 instead of 25 matches the animation to the track almost perfectly!!

  10. DJ says:

    Much respect to Ramiro Olmos for the looping silent wav technique. That also saved my project.

    I just recorded a silent wav for 5 seconds. Then I created a new layer and looped that wav for the entire length of my clip. This fixed all audio-syncing issues! I thought my problem was that I was using 24 fps but it wasn’t.

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