Jerky/strobing dvd playback

Discussion in 'TiVo Home Media Features & TiVoToGo' started by gthomas, Jan 23, 2006.

  1. gthomas

    gthomas New Member

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    Jan 23, 2006
    I've been reading many threads that either mention or hint at others having this problem. .tivo file plays fine on my computer, I burn it to DVD and it plays on a set top player very 'jerky'. Almost a strobe like effect, mainly in sections with a lot of motion. I've tried Nero and DVDWorkshop and had the same results. After a fair amount of trial and error, I've come to the conclusion that there is something odd (maybe intentionally) about the .tivo mpeg. I've read in various posts about improper interleaving to bad DVD blanks to incompatibility of the set top player. My last test was to use a DVD-RW and create a DVD with 2 chapters. 1 was a 10 minute clip out of a .tivo that I pulled, the other was a 10 minute DV cap from my camcorder. Both were transcoded with the DVD workshop authoring program. That way both clips have everything in common except the source of the footage. The clip from the DV source plays flawlessly, the clip from the .tivo is jerky/strobbing. Since everything is exactly the same from the media it was burned to, what transcribed the video, the set top it was played on, even the session that was burned the only conclusion I can come to is that TiVo does something to the mpeg other than including DRM. Anyone offer any other suggestions?
     
  2. fredric100

    fredric100 New Member

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    Apr 1, 2006
    Seattle, WA
    I've noticed exactly the same problem. It's super annoying. I have NOT spent a lot of time diagnosing the problem, but I've worked with many professional digital video recorders, and to me it looks likes this could be caused by a TiVo-to-MPEG transcoding bug: reversed field dominance. There are 2 interlaced video fields, called "A" and "B" in every NTSC video frame. Most professional DVRs let you choose the order in which the fields play back, "A" first, or "B" first. If you select the wrong order, on playback you get results which look very much like what I see when I play back DVDs sourced from my TiVo. Perhaps TiVo has accidently reversed the field order of their video frames in the process of transcoding to MPEG. (maybe this is what you mean by improper interleaving?). A way to test this would be to rip the sucky DVD back to MPEG, then use some software to de-interlace the fields, then re-interlace them in reverse order and write another DVD. Final Cut might have filters for this, I dunno.

    Another possibility is that somwehere in the transcoding process on the PC side there is a mismatch between the source framerate and the target framerate, and they are therefore generating interpolated ("in-between") frames. That would be something which should go away using the "best quality" setting on the DVD recorder software -- but I too have tried cranking this up, and the results still suck.

    Like I said I haven't spent much time looking at this; those are just 2 things which TiVo and/or Sonic (software I use on the PC side) may have messed up, which we could do nothing about.
     
  3. ssobol

    ssobol New Member

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    Jan 29, 2005
    VA
    I have noticed the same thing with the DVD playback of converted Tivo files. It is really annoying and makes some videos unwatchable (anything with lots of action on the screen). I have been looking for a better converter to get rid of this problem.

    It would seem to me that if there is reversed field dominance, the video would be messed up all the time. not just in scenes with lots going on (the software would set the interleave one way at the start and not change it depending on the scene content).
     

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