MPEGStreamclip and/or JES Deinterlacer issue

Discussion in 'Digital Video' started by Leo D, May 21, 2010.

  1. Leo D macrumors newbie

    Joined:
    Apr 20, 2010
    #1
    I am trying to edit MPEG2 home movies in imovie 09 to make DVD's to enjoy when I get old. I'm starting to wonder if I'm going to get old before I am able to make a decent DVD. Apple software designers obviously don't care much about people who want to edit MPEG2's, or people who want to create DVD's. Unfortunately, I want to make DVD's, and my camcorder records in MPEG2 format, so that's what I'm working with. The AC3 audio format used by my camcorder is just another obstacle which, for whatever reason, Apple software designers don't like.

    I've pretty much devoted the past month of my life trying to find a way to work around these problems, not to mention imovie 09's single field processing of interlaced video, and I finally found what seems to be the best workflow that might result in a DVD of acceptable quality.

    First, I run the clips through MPEGStreamclip to convert the audio to something Quicktime likes, which apparently is anything other than AC3. I leave the video in MPEG2. No conversion, no quality loss, and now I have sound.

    Next step is to run that video clip through JES Deinterlacer to convert to 60p, making a frame out of each field. This step actually doesn't degrade the quality of the video noticeably, and allows me to edit in imovie 09 without suffering the shortcomings of single field processing. I export from JES in Apple Intermediate Codec, since extensive testing has proven that AIC produces the best results for me.

    Having finally discovered the best workflow to accomplish my goals, I was now prepared to begin editing the video clips from a vacation I took last year. Step 1 went quickly and efficiently. I now had 136 video clips, with audio, ready to be deinterlaced. When JES completed the task, I was eagerly anticipating the joy of finally being able to get on with editing and completing my vacation DVD.

    I quickly discovered, however, that some of the clips weren't right. Very jerky, 27 clips to be exact. The other 108 clips looked fine. All the clips went through the same steps. The clips that were "jerky" after exporting from JES looked fine going in. Also, if I ran the original (before MPEGStreamclip) of one of the jerky clips through JES, it came out fine...no audio, of course, but the video quality was fine, not jerky at all.

    I don't get it. It looks like JES is dropping frames on about 20% of the clips. The other 80% of the clips are smooth. Spent the whole day trying to figure this out, to no avail. It appears that something is happening to some of the clips in MPEGStreamClip, although whatever is happening doesn't become apparent until the deinterlacing step. But if I run the same "original" clip through JES, skipping MPEGStreamClip, it comes out smooth, not jerky.

    If anyone can shed any light on this, or offer any suggestions, I would greatly appreciate it.
     
  2. -DH macrumors 65816

    Joined:
    Nov 28, 2006
    Location:
    Nashville Tennessee
    #2
    Yeah ... it's all Apple's fault. Don't blame the camcorder manufacturers that use a final delivery codec to record in ... naaaa, it couldn't be their fault.

    Why not just use MPEG Streamclip to convert the video AND audio at the same time?

    -DH
     
  3. Leo D thread starter macrumors newbie

    Joined:
    Apr 20, 2010
    #3
    While MPEGStreamclip is a very useful software, it's deinterlacer does a poor job in comparison with JES. Apple's decision to go with single field processing for interlaced material has forced me to deinterlace all my clips before editing in imovie 09...I've tried it without deinterlacing, and the results are horrible. You're right, I could transcode in MPEGStreamclip, but I get better results transcoding while deinterlacing in JES, and since I have to use JES anyway (to deinterlace), there's no reason not to do it that way.

    BTW, I'm not defending camcorder manufacturers who decided that MPEG2 is the codec they want their camcorders to record in. Probably not a wise choice, and if I had known more about video several years ago when I bought my camcorder, I might have chosen a different model. None of that is Apple's fault, certainly.

    But the fact remains, there are many camcorders that use MPEG2, and there are times when people may have to edit MPEG2's. The fact that MPEG2 was never intended for editing doesn't mean that it can't, or shouldn't be done. It can be done, and sometimes there is no other choice. Apple offers no support for those of us in that boat. In fact, if it wasn't for third party softwares, it would be impossible for me to edit my videos at a quality level that would be acceptable, or worth the effort.

    Before I switched from PC a couple months ago, there were many options available to me for editing my MPEG2's. The difficulty posed by editing MPEG2's on my iMac, and the resulting frustration, are for me a big stain on an otherwise beautiful machine.
     

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