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Official Low GOP topic
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  • StrayStray
    @zincoontrin It doesn't mean entirely that shadow details get discarded at longer GOPs, in fact quality of frame is not the main reason for using GOP1. The main reason is to do with how it renders motion, motion has a different look at GOP1 (or lower GOPs in general). To put simply an I-frame contains the whole frame compressed, rather than changes since, or onto, the next I-frame Which P and B frames do. Which is why B and P frames can be smaller, they need less information. This does mean however that the lower the GOP setting the higher the bitrate you're going to need, as in the case of GOP1 your compressing and storing the entire frame every frame. If, and its quite an if, running at GOP12 you can get really good I-Frame size, and B & P frames that are large enough to maintain the quality then there should be no difference between it in terms of image quality and a GOP1 stream (maintaining the bit rate is what the AQ settings are for). However, yes, the vbr codec is going to discard shadow details first (even at GOP1).

    Running a very high bitrate GOP1 kind of guarantees that your bitrate isn't going to drop substantially, meaning that your shadow detail is going to be as good as (if not better) than a comparable long GOP setting. This doesn't mean though that a longer GOP lower bitrate setting couldn't, or wouldn't have given you exactly the same image quality, and level of shadow detail. It does mean the motion in the scene however would look very different, more 'filmic' as people say here, which is understandable because the stream contains whole, singularly frames.

    Edit : I've not seen anyone say that GOP1 gives better shadow detail, its wrong, the extraordinarily high bitrate probably is.
  • ZincoontrinZincoontrin
    Question:

    What's the theoretical reason of every frame being an I-Frame gives better shadow quality?

    Is it because the B-P frame compressor decides to discard shadow detail, for some perceptual reason?
  • tobnyottobnyot
    @driftwood I tried your GOP1 220M settings and it's really looking great, but as I'm transcoding every footage to ProRes via 5DtoRGB I got some problems with those settings. Did you have further contact to @rarevision regarding the GOP1 files?
  • Ian_TIan_T
    @driftwood "... I think you missed what I was getting at - I'm showing others what this setting actually captures in the dark!"

    I get it. That's exactly what I was talking about "what it captures in the dark without smearing detail." When I said you went "extreme: I was talking about your GOP1. But, regardles of what it captures in the dark when you lift it there will be "some" noise. That's why I mentioned Neat video.
  • driftwooddriftwood
    @mbowen84 try the maximum settings thread, this is low gop :-)
  • mbowen84mbowen84
    i've been out of the office for awhile,
    could someone point me to cbrandin's 66M GOP12 AQ2 setting i keep reading about that's so good
  • driftwooddriftwood
    Its not as smooth, of course but it just looks so good at this quality.
  • HallvallaHallvalla
    @driftwood

    Slowed down how? Like 25% on the timeline of an NLE/AE? You're saying you can get better slo-mo out of high bit-rate GOP 1 24p than 60p?
  • driftwooddriftwood
    GOP1 220M slowed down is bloody amazing - better than 720p 60>30p. Simply beautiful!
  • HallvallaHallvalla
    @driftwood

    Very impressive. Glad to see there weren't any monsters hiding in the dark. ;)
  • driftwooddriftwood
    @Ian_T Yeah I read your thread and know about Neat for cleaning up noise... I think you missed what I was getting at - I'm showing others what this setting actually captures in the dark!
  • Ian_TIan_T
    @driftwood

    It's the same thing I was trying to show in this thread. But yours seems a little more extreme.:

    http://www.personal-view.com/talks/discussion/723/my-110-mbps-high-contrast-example#Item_10

    What I didn't show here is how to clean up the low frequency noise (which is done easily with Neat Video) without losing any of the extra detail.
  • B3GuyB3Guy
    this was exactly what I loved about it when I tried it out . . . it grabbed so low, and didn't smear or mush any of the details into macroblocks.
  • driftwooddriftwood
    Thought I'd show you how much room the GOP1 220M setting gives you in the shadows. Here's the original shot at ISO 800. Here is the same grab lifted in levels photoshop. See how much more information is in there! This was grabbed from chair spin movement.
    Original - Driftwood GOP1 Extreme Setting - 220M 1080p24 - shot in darkness with a single 800W Redhead on the 7-14 Wide angle - VLC screengrab.png
    1261 x 633 - 600K
    Out of the darkness - Driftwood GOP1 Extreme Setting - 220M 1080p24 - shot in darkness with a single 800W Redhead on the 7-14 Wide angle - VLC screengrab.png
    1268 x 636 - 677K
  • UlisseUlisse
    The Panasonic AVCCAM Plugin work great on MAC.
  • proaudio4proaudio4
    @driftwood "You mean total safety on pappas and trees? "

    Yes

    "Video Buffers appear fine. From high detail, I think its maxing out on other areas, thats why I need to look at harnassing the frames a bit - downwards! "

    Thanks. There's no doubt 220M GOP1 is real nice, but I'm hoping for something of this quality but at a lower bitrate. I guess I'm asking at what point is good enough and a subjective visual difference.
  • driftwooddriftwood
    Video Buffers appear fine. From high detail, I think its maxing out on other areas, thats why I need to look at harnassing the frames a bit - downwards!
  • driftwooddriftwood
    You mean total safety on pappas and trees?
  • proaudio4proaudio4
    @Driftwood
    Using 24H GOP1, what is the least bitrate you can set before it fails from maximizing the buffers?
    Sorry if you're already posted this info.



  • bannedindvbannedindv
    Try the Panasonic AVC Plugin and see if that helps playback/transcode at all?
    https://eww.pass.panasonic.co.jp/pro-av/support/dload/avccam_impt/agree_e.htm
  • B3GuyB3Guy
    yes, it must be downloaded. Vimeo obviously had trouble converting it to their specs. Also, Clip-Wrapping it (just a rewrap) caused a reordering of the frames. very strange. I need to try a convert to AIC, hopefully that will go better, as my 5dtorgb is not working at all for any clips.
  • LevICLevIC
    @Oedipax @Bueller You can just go directly to the video page and download it from there. vimeo(dot)com/29078933

    It's a gig and a half though.
  • BuellerBueller
    Cmon B3. I just did my laundry so I could watch this. Ok I had to do it anyway.
  • OedipaxOedipax
    @B3Guy, still not seeing the Vimeo clip above - is it processing? I really want to see! :)
  • StrayStray
    @Vincent_Pereira I-Frames are still compressed frames, so I guess it's because the quantizer controls the compression ratio it will also control the I-frame size, buffer usage etc.
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