5 Replies Latest reply on Jan 22, 2013 8:13 AM by Jim_Simon

    H.264 .mp4 file playback issue ...

    joneisele Level 1

      I have a home movie made from predominantly 1080i, 29.97 footage off a consumer Sony camcorder that stores the video in .mts files; see MediaInfo screen shot below.   One of my targets is a single file for playback on a PC and PS3; after some discussions with the forum H.264 / .mp4 looked to be the best choice.   I noticed upon playback of the .mp4 shots with motion took on that interlaced look or whatever it is called where you see lots of lines and blur - see screen shot below.   The original clip does not have this issue.   I was just doing some trial and error hacking and noticed that MediaInfo was reporting level 4.0.   When I switched the export to 4.0 the .mp4 then looked ok.    

       

      When one is encoding to .mp4 do they need to pay close attention to the level along the lines of matching resolution, frame rate, etc.?  Or is what I'm observing just a PC playback issue and I need not worry other than PC playback?    What would you recommend in this case for export format?

       

      Other details:

       

      • H.264 Level 4.1 as well as DNxHD and Matrox I-Frame HD exhibit the issue
      • H.264 Level 4.0 is ok
      • H.264 Blu-ray multiplexed .m2t with either level 4.0 or 4.1 is ok - I was suprised here
      • MPEG2 doesn't have the issue, although I don't think it looks quite as good
      • Sony PS3 doesn't have any of these issues although I can't play the DNxHD .mov file
      • I did most of my testing in WMP here.  I also tried VLC - same results for the .mp4, but VLC has other issues with .m2t, etc.

       

      Capture.JPG

       

       

      Capture MediaInfo.JPG

        • 1. Re: H.264 .mp4 file playback issue ...
          Jim_Simon Level 8

          Levels and Profiles define what settings are possible more than the quality of the export.  So long as you have the correct settings available, you shouldn't need to worry about the Level.  The problem exports are more likely the result of incorrect settings.

          • 2. Re: H.264 .mp4 file playback issue ...
            joneisele Level 1

            Jim: what would I have messed up here on the settings?  Let's ignore the other cases and just focus on .mp4.  I double check just before this post: exported two .mp4 files.  The only change I made to the settings on the second export (different from the first) was the level and the file name.   If it was a settings issue I would have expected both files to have the same issue, or not.  

            • 3. Re: H.264 .mp4 file playback issue ...
              Jim_Simon Level 8

              What are your sequence settings?  Export settings?

              • 4. Re: H.264 .mp4 file playback issue ...
                joneisele Level 1

                Ok - good call to check the settings more closely.  I expanded the settings window vertically and noticed that when I switch between level 4.0 and 4.1 PP changes other settings automatically.   Anyway, once I corrected those settings, the level 4.0 version has the same issue as 4.1, so it isn't a level issue.   I posted the sequence settings and export settings for a .mp4 file below for review.  

                 

                I noticed that if I downscale to 1280x720, still keep it upper first interlaced and 29.97fps, the export has the same issue.  However, changing to 59.94fps alleviates the issue.   I realize a 720i, 59.94 isn't really a common format, but perhaps this export will tell us something.   I could not test a 1920x1080i, 59.94 - PP would not allow me to enter those settings.

                 

                Summary:

                • Original 1920x1080i, 29.97 .mts clip plays fine.
                • H.264 .mp4, DNxHD, Matrox I-Frame all exiting the interlaced combing artifacts on plabyack on the PC, but not the PS3.  
                • H.264 Blu-ray .m2t and MPEG2 look ok on PC.   Here are export settings and sequence settings:

                 

                Capture Sequence.JPG

                 

                Capture 4.1 Settings.JPG

                • 5. Re: H.264 .mp4 file playback issue ...
                  Jim_Simon Level 8

                  Any interlaced exports are likely to display those artifacts when viewed on a computer screen, which can only display progressive signals.  If the goal is computer playback, export out a progressive format.  For TV, Blu-ray or DVD, export out interlaced to match the original.

                   

                  In short, two exports.