Personal View site logo
Intraframe vs Interframe compression flame
  • 32 Replies sorted by
  • @Mark_the_Harp
    Yes, it looks great. I love this patch but unfortunately it is not possible to use it for daylight outdoor shooting with many details. At this case it makes 80-95mbps average and 130-160mbps peak bitrate, and not enough speed of class 10 card. It would be great if i could use some external recorder, but it is not possible with gh13. Or possible? What about gh13 HDMI future? Or HDMI is not good interface for huge bitrate video out?
  • @telkitachki Interesting! The low light stuff you've getting from your GH1 looks so great. Can't wait to try my GH2 when the hacks come out but I'm hugely impressed by the quality of your shots. I wouldn't have thought increasing the bitrate would give you less image noise but those are so "clean". I wonder, is that because image noise is normally "hard work" for the compressor (I assume it can't distinguish it from "wanted" motion) and is therefore working on that in addition to the "wanted" image detail? And / or maybe higher compressions do something to make the image noise look somehow more intrusive?

    BTW Sorry I don't know anything about HDMI - not something I use.
  • With GH2 having 200Mbps bitrate potential, it seems a step backward to bash B frames.
  • Here is another two gh13 GOP1 samples made at different situations. If it interesting for you, please download files, since i do not have permit to make direct HD playback at vimeo.

  • Just tried with the newest ptools v3.61d (190711)
    just set the
    Encoder setting 1 1080i/p to 2
    1080i50 and 1080p24 GOP size to 1
    then you will get a only I frames 24p video

    after some test i found that the codec is breaking,
    maybe need some more test...
  • @stonebat

    Again, we're not bashing b-frames. We're just trying to get them as low as possible, since some of us don't like the temporal motion they cause. A few of us are not solely after the highest bit-rate possible, we're also trying to improve the film-look of the camera... and the lower the b-frame count, the more film-like the image becomes. Just have a look telkitashi's examples... they're much more film-like because the encoder is not quantizing and vectoring parts of the image. The whole image should reflect the shutter speed, and IMO, inter-frame compression and b-frames make parts of the image look like it was exposed with an open-shutter instead of the regular 1/50.


    The examples are looking good! Great examples of the film-motion I'm talking about! The Shoe-Making video looks allot like the motion from a Red camera... I really hope we can get the GH2 down to GOP1!
  • Where Intra-frame encoding can make a noticeable difference is in tracking rapid object motion at fast shutter speeds. As the AVC-Intra codec demonstrates, however, very high bitrates are required to maintain high image quality - 100Mbps should be considered the minimum required bitrate at 1080p resolution. Ideally, you'd want more than 200Mbps in an intra-only AVC encoder to produce an image quality comparable to that of a B-frame-enabled 50Mbps AVCHD encoder.