5 Replies Latest reply: Sep 28, 2011 1:22 AM by Silviu Vergoti RSS

    MP4 Buffering Problem

    jfharper

      I've run my mp4 through mp4box which is supposed to put the moov atom at the beginning of the file, and so when I test in the webpage, after pressing play, the video will start downloading and start to play, then playback is paused at 1 second until the rest of the video completely downloads...then playback resumes.  I can't figure out if this is a player problem, server problem, or mp4 problem...if the mp4 starts to buffer then stops, I'm thinking it is not the mp4 or the server since it started to buffer, but does not buffer properly...can someone offer any advice?  Thanks.  BTW, I'm using strobe media playback as the player.

        • 1. Re: MP4 Buffering Problem
          Silviu Vergoti Adobe Employee

          Hi,

           

          I could be either:

          - an asset problem (moov atom not correctly moved)

          - an asset length problem. If it's a short asset, the dynamic buffer change from the starting shorter value to the longer playback value (10s) will start rendering the movie when the whole movie has been downloaded

          - a buffering problem (our optimizations applied to your specific video could have affected this)

           

          Can you try it with optimizeBuffering=false?

          • 2. Re: MP4 Buffering Problem
            jfharper Community Member

            I tried optimizeBuffering=false and this had no effect.

             

            I also tried initialBufferTime: "3.0" with no effect...the video continues to act the same as before, start buffering immediately (like 0.1 seconds) then buffer to 1 second and pause playback until the entire video is downloaded (14 seconds in total).  The scrubber never catches up to download...meaning, the download always stays ahead of the playback during the first second...so I can't figure why it pauses at 1.0 second.

             

            I'm going to try a different moov atom tool, the old one qtindexswapper...can you offer any other ideas I can try?

            • 3. Re: MP4 Buffering Problem
              jfharper Community Member

              OK, here are the results I got with qtindexswapper:

              Version: v2.3.1

              Atom Metadata: [code: ftyp,size: 20,offset: 0]

              Atom Metadata: [code: moov,size: 8271,offset: 20]

              Atom Metadata: [code: mdat,size: 893584,offset: 8291]

              Atom Metadata: [code: free,size: 69,offset: 901875]

              ERROR: MOOV is in proper place, processing not needed.

              Completed Time: 0.031s

              • 4. Re: MP4 Buffering Problem
                jfharper Community Member

                OK...I fixed it...I had mispelled optimize to optimze, then I corrected it to optmize...then saw it again misspelled and corrected it to optimized...now the video does not pause at 1 second and continues to stream properly...thanks.

                • 5. Re: MP4 Buffering Problem
                  Silviu Vergoti Adobe Employee

                  Good job!

                   

                  btw, the setup.html page helps you adding the parameters with correct names if you want to do some quick and dirty tests.

                   

                  S.