AVCHD and panning. HDV too?

Discussion in 'Digital Video' started by computerjunkie, Nov 25, 2008.

  1. computerjunkie macrumors member

    Joined:
    Mar 31, 2008
    #1
    Well I was just about ready to pull the trigger on a new HD camera...and had been through all the pros and cons of AVCHD in terms of editing, file size, storage, blah blah blah. Then I checked some sample vids to see what all the talk was about on panning and how not to do it.

    Short question is this: Does HDV suffer from that as well, or is it simply a limitation of AVCHD? Cause what I saw was really bad...bad enough to make me re-think.

    Regards,

    G.

    Edit: Well it seems I asked before I searched...bad I know. Seems as though HDV is just as bad...at least one person thinks worse. So, let me change the question. Would the panning issue go away with HDV if using something like a Canon XH-A1?
     
  2. Courtaj macrumors 6502a

    Courtaj

    Joined:
    Jul 3, 2008
    Location:
    Edinburgh, U.K.
    #2
    Were the "sample vids" you looked at raw AVCHD clips or flash video on Vimeo? If the latter, then half the problem is down to the fact that you're only seeing half of the frames - possibly a quarter of the original fields by the time the 60i source is deinterlaced and converted to 15fps .flv.

    Andrew.
     
  3. computerjunkie thread starter macrumors member

    Joined:
    Mar 31, 2008
    #3
    Yea Vimeo is where I was looking at samples. And I guess that could be part of the issue. But I have read lots of posts where people were complaining that thier edited footage (as opposed to raw AVCHD footage which looked fine) had the jaggy business going on.

    So I just assumed that what I was seeing on Vimeo was the same jaggy effect everyone complains about.

    For me, if its Vimeo that is the culprit then I can live with that. But I would at least want to be able to EDIT footage and view it locally and it be good (ie not jaggy).

    Regards,

    G.
    Critic
     
  4. KeithPratt macrumors 6502a

    Joined:
    Mar 6, 2007
    #4
    Would you use "jaggy" and "stuttery" as interchangeable terms? Because I think of 'jaggies' as a lack of smoothness or aliasing (often to do with watching interlaced material on a computer LCD) that can be seen in a single frame or paused video; whereas 'stuttering' is something only seen in watching a moving video.

    If you've read posts referencing 'jaggy' or 'jaggies' they might not be referring to what you are thinking of.

    People see jaggies when they watch interlaced material on their progressive computer LCD in something like Quicktime, and see both interlaced fields at the same time. Objects where the edges should be straight have a sort of "comb" look to them.

    The stuttering a lot of people are talking about happens when they move or pan too fast in 30p or 24p. (It may also have something to do with the GoP structure of AVCHD or HDV.) Where there is disparity between the source footage coming out of the camera straight to an HDTV and what they're seeing in iMovie, it could be that iMovie is dropping one set of fields whilst editing. Or it could be that when iMovie converts to AIC it deinterlaces. Someone else may be able to detail what iMovie does to footage in its conversion from AVCHD to AIC. Either way it would be that they are going from 60i to 30p (permanently or temporarily).
     
  5. Courtaj macrumors 6502a

    Courtaj

    Joined:
    Jul 3, 2008
    Location:
    Edinburgh, U.K.
    #5
    I don't think iMovie deinterlaces when "transcoding" (ugh) AVCHD to AIC (i.e. importing AVCHD into iMovie), as deinterlacing is still an option when exporting using QuickTime and there is a noticeable difference between deinterlaced and interlaced (non-deinterlaced!) exported video: one with "combs," one without.

    Nonetheless, I do notice a lack of smoothness in even slow pans once AVCHD clips have been converted to AIC - more so than in the source video. Why? Ask Apple - I really haven't a clue.

    I agree with the distinction to be made between "jaggies" and "stutters" however. Useful when all we have to go on here is words!

    Andrew.
     
  6. computerjunkie thread starter macrumors member

    Joined:
    Mar 31, 2008
    #6
    Jaggy vs stuttery...you guys are exactly correct. I used a very poor choice of words. And I see exactly the differences you describe.

    "Stutter" is clearly a better choice to describe what I was talking about. The thing I see that I dislike, is the stutter (mostly the background) seen when panning. For me, the subject matter will be mostly fast action sports, and when looking at some samples I was really not impressed. I hate that too, cause I really "wanted" to be.

    So would it be fair to say that the stutter or lack of smoothness while panning seems to be present in both AVCHD and HDV?

    Regards,

    G.
     

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