4 Replies Latest reply on Aug 2, 2008 12:08 AM by Mylenium

    Audio problems after rendering

      I think it is best if I explain what I did first...I placed a quicktime file in my comp with a few solids. I designated my in and out times, pretty simple stuff. I choose Composition>Make Movie, and click on Output module in the render details so I can select audio.

      The problem is that my audio is in the finished quicktime movie, but there are catches and crackles in it that are not in the original movie and sometimes the audio does not line up with the video. Any ideas on why this is happening? I would be happy to provide more info if needed.

        • 1. Re: Audio problems after rendering
          David Wigforss-Hv1BNN Level 2
          Make sure the sample rate is the same in the footage, project settings and render queue.
          • 2. Re: Audio problems after rendering
            Level 1
            I can locate the sample rate in the AE comp, but cannot locate it in the footage or render queue. Where do I find the sample rate?
            • 3. Re: Audio problems after rendering
              David Wigforss-Hv1BNN Level 2
              Load footage with audio into project window. It should list what the sample rate of that footage is, typically 48khz. Take a look at File/Project Settings. Audio Settings/Sample Rate should match the footage. Lastly, in Render Queue, in Output Module, you can specify the sample rate under Audio Output. I think that defaults to 44.1khz and that might be your problem. Try changing to 48khz.
              • 4. Re: Audio problems after rendering
                Mylenium Most Valuable Participant
                You can get info about the sample rates by simply selecting the footage in the project panel. just like the video specific stuff like resolution and color depth, sample rate will be displayed in the info pane at the top. if it isn't, then you are using a source file with variable bitrate and/or a multiplexing pattern AE does not understand, such as some MP3 variations or embedded audio in some MPEG-4 files. This would quite nicely explain any issues on the rendered output and in such cases the only resolution to the problem is to convert the files into a WAV/ AIFF before using it in AE. For the output, simply follow David's guidelines. Be aware, though, that clean audio playback is also affected by your system settings, so double-check your audio hardware settings and make sure the sample rates are not set to exotic and unnecessarily high values or you are not using any "enhgancement" functions. In theory today's computers have enough performance to do thjis all in realtime on the fly, but you never know...