7 Replies Latest reply: Dec 26, 2013 11:16 AM by gkphoto RSS

    .MP4 Playback Jerky

    Dollhouse Digital Community Member

      I am working with After Effects CS 5.5, and exported a template compositition with constant moving gradients of similar colors in the background.  I needed this to play in locally in Powerpoint off the harddrive, so I exported using Media Encoder CS 5.5 1920x1080p 29.97fps, Main Concept H.264, High, Level 5.1, VBR 2 Pass, Maximum Depth, Target Bit Rate 40Mbps, Maximum Bit Rate 300Mbps, Gaussian Blur 2, Container .MP4, Maximum Render Quality Option, and this got me acceptable results.  Lowering the level even to 4.2 made the quality noticably bad and I would not want to submit this content for the client.

       

      This render took a LONG time, 10 hours to be exact, and thus I am a little disappointed by the jerky playback I am getting.  It can't be the bitrate, can it, since that setting is mostly for streaming over the internet?  To add two different soundtracks, I exported the files from Premiere to Media Encoder CS6 with the default bitrates (32 target, 40 max), all other settings the same, and the playback is still jerky (and I managed to keep the quality despite 2 encodes).

       

      I came across this thread http://forums.adobe.com/thread/489667 that seems to have my answer, but the information is old as Media Encoder now uses the MainConcept codec for H.264 encodes.  Will this help, or is there another way of editing the script to get smooth playback, without re-rendering the composition, or rendering to .mov and transcoding using quicktime or media encoder to .mp4 (.mpg)?

       

      Screen shot 2013-05-11 at 6.50.54 PM.png

      this is the code for my movie.  I am wondering what the code I need to put in for which container to make it playback more smoothly?

        • 1. Re: .MP4 Playback Jerky
          Profitic Community Member

          You could potentially transcode the existing H.264 file into an I-frame only H.264, but there would likely be a degradation of image quality in the process. Consider encoding a few short test clips with different export parameters, and then re-render the complete sequence over night.

           

          Stuttering often occurs during playback when the hardware is not fast enough to reassemble B- and P-frames in real time. As a general observation, I find QuickTime tends to stutter more often than other players. What media player are you using to play the H.264 video?

           

          Stuttering can also occur when individual frames are repeated in the export file, typcially as a result of frame rate conversions. Open the exported H.264 file in Premiere Pro or QuickTime and examime problem areas frame-by-frame to ensure there are no issues related to repeated or missing frames.

           

          Here are some of your options if the issue is related to encoding:

           

          - Encode with all intra-frames (key frame distance=1): produces high quality images that are easy to decode, but with a larger file size (may not be appropriate for streaming); this is my preferred choice for local playback from hard drive; works equally well with single-pass encoding

          - Eliminate B-Frames (Profile: Baseline); produces average image quality and data rate; easier to decode than B-frames, but stuttering may still occur depending on hardware capability

          - Select a higher quality codec: VC-1/WMV (slightly better quality, but Windows only), VC-3/DNxHD (codec must be loaded onto computer before video will play), or ProRes (on Apple computers with FCP/Compressor/etc.)

           

          Rendering time can be reduced in AME/Premiere Pro by 1) disabling Maximum Bit Depth (might not be necessary depending on whether source files and applied effects are 8-bit), 2) disabling Maximum Render Quality (unnecessary if video is not rescaled), and 3) using single-pass encoding (may impact file size and/or image quality).

          • 2. Re: .MP4 Playback Jerky
            Dollhouse Digital Community Member

            Thank you so much!  I do have a slow processor (2Ghz 1st Gen Quad core Mac Pro), and an old graphics card (ATI Radeon X1990XT 512MB) so this might be the issue.  I sent the client the file and they did not report any trouble with playback; they are using a Windows machine of consumer quality.  On my machine, I played back in QT, VLC, both stuttered, and tried to drop it into a FCP sequence which resulted in crashing the program.  I also ran it through Handbrake with the x264 settings, which seemed to make the stuttering worse, not better. 

            I'm wondering where there are resources where I can beef up my codec playback ability, ie download more codecs for QT and VLC, since I would like to have more, not less, ability to playback media than my clients, and perhaps more rendering options. I read that .mp4 uses a lot of processing speed to keep the file sizes low, which is why I might be having issues on my machine, although I can view .mp4 stock footage downloaded from the internet of a nice quality with ease, so maybe I am missing the codecs from my players and FCP.

             

            If I understand correctly, I can eliminate the extra time of 2-pass encoding whilst still getting equal quality by keyframing every frame?  Plus get smooth playback, except when streaming?

             

            I always use Pro Res and FCP; I find it to be the fastest workflow with the highest quality and ease of use.  I could not render to .mov for the Powerpoint presentation, and the .wmv wasn't an option for AME.  I am not familiar with the other codec you mentioned, but would be interested to try it.  The .mp4 seemed to be the best option, especially since I am delivering via Dropbox and the small file sizes make for timely delivery.  Now that I've been reccommended to get Handbrake, and it renders very quickly, I am probably going to render lossless to a frame based codec (.PNG or JPEG2000 or TIFF) and then transcode to multiple formats.

            • 3. Re: .MP4 Playback Jerky
              Profitic Community Member

              Yes, encoding with all I-frames will provide smoother playback. Quality is better, too, with the Adobe (MainConcept) H.264 encoder. The downside is that file size will be about 3.5 times larger (when bitrate is not a limiting constraint). Please refer to this thread for more information.

               

              DNxHD is similar to ProRes and is freely available for both Mac and Windows. It also uses a MOV wrapper.

               

              ProRes or DNxHD 10-bit 4:2:2 or 4:4:4 would be preferred as an intermediate file format. PNG and JPEG2000 work well and should meet your needs, but both are 8-bit codecs.

              • 4. Re: .MP4 Playback Jerky
                Dollhouse Digital Community Member

                Great thank you so much for the tips.  What would the compression being

                "none" yield as far as 4:4:4 or 8-bit?  It was a little better than Pro

                Res, but still seemed a bit dithered, so I thought using a lossless codec

                would be better.  I guess not.

                • 5. Re: .MP4 Playback Jerky
                  Profitic Community Member

                  Both the AVI and QuickTime None codecs are fully sampled, uncompressed 8-bit 4:4:4(:4) RGB(A) codecs. The rendered file is a three-channel RGB bitmap with optional alpha channel. These files are huge because there is no compression.

                  • 6. Re: .MP4 Playback Jerky
                    zachardoe Community Member

                    ok - picking up an old thread, but i think i have the answer - and it's taken me the better part of a day to figure it out, so i thought i'd save someone the same experience.

                     

                    after the first post it seems this thread goes on a wild goose hunt.

                     

                    namely - it seems that the problem is NOT in the compression or codec settings, but in the way that mainconcept h264 (used in the adobe media encoder, though i'm coming here from sorenson that also uses it) writes the mp4 container.

                     

                    take your output, demux, remux - and all is fine. i used "my MP4Box GUI" - but maybe there are other apps that can do that. or, if your client/deliverables allow, put the streams into an MKV container - better yet.

                     

                    keywords: jitter, jittery, jerky, stutter, pan, tilt, h264, sorenson, mainconcept, squeeze, compression.

                    • 7. Re: .MP4 Playback Jerky
                      gkphoto Community Member

                      Hello - I'm hoping some of you can help me figure out what to do to eliminate the stuttering I am seeing in playback with this short TL clip, watch the edges of the tree as the camera moves past it (and please ignore the dust spots I know I also need to fix those!):


                      https://www.dropbox.com/s/q7y3t1jxu2oel ... mp4_v3.mp4




                      The clip comes from an AE sequence of CR2 files.


                      AE sequence settings:

                      Composition size: 2880 x 1920

                      Square PAR

                      Frame rate:24

                      Resolution:full 2880x1920


                      Sequence Settings in Premiere:

                      Editing mode:DSLR

                      Timebase:24.00 frames/second

                      Frame: 1920x1080

                      Square PAR

                      Files:None (progressive Scan)

                      Display Format:24fps Timecode

                      Clip is scaled to 70%


                      Export settings from Premiere:


                      H.264

                      1920 x 1080

                      Frame Rate: 24

                      Field Order : progressive

                      Aspect : 1.0

                      NTSC

                      Profile:High

                      Level:4

                      CBR:25

                      Key frames:1


                      I can't help but wonder if the stuttering is an artifact of being too close to the tree with the camera? My settings in-camera by the way if it helps were:


                      Shutter: 0.5"

                      F/22 with lens-twist


                      I have also tried exporting as M2v, AVI, and WMV with various settings, and no matter what I do the stutter as the camera passes the tree is still evident.


                      Any ideas?