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Official Low GOP topic
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  • @kae

    Just applied your July 27 "65M extreme 1080 24 3 GOP settings WITH stable settings for the other modes"

    No problems shooting and playing back in camera using Transcend Class 10 SDHC card. Clips play perfectly off the card on my Panasonic DMP-BD35 Blu-Ray player's SD card slot too.

    Nice! I'll stick with these settings for now even though I don't use anything but 24p
  • 720p30 gop3. It didn't crash, but the bitrate looks funny. Rapid bitrate drop after first 30 frames.
    gh2-720p60gop3.png
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  • @stonebat I like your rig. What is it? Where did you get it? and How much was it?
  • I don't wanna digress this thread. See http://www.personal-view.com/talks/discussion/comment/2795 for the rig.
  • @stonebat

    You've just uncovered the issue with low GOP 720P and 1080i modes, it'll look like it's writing fine, but streamparser reveals the flaw. This is why I stuck with 12 GOP in those modes in my combo patch above. I only get an average stable write speed of only 35-40Mb/s in 720P but I don't use those modes much anyway.
  • @shrigg

    Good know about the transcend, but what is the data rate on your clip? The 65 extreme settings only seems to choke them at high rates like 61Mb/s and above.
  • @kae I modified your latest setting.
    Video Bitrate FSH/SH=54000000
    720p60 GOP Size=3

    It didn't crash either. It began like 54Mbps, but it quickly drops to 34Mbps. Here's my wild guess. 720p Top Setting=31878 and 720p Bottom Setting=22314 are a way too high for gop3. That's 20 i-frames per sec... kinda overkill.
    image

    720p60 GOP6 & Video Bitrate FSH/SH=54000000 didn't crash either. Similar behavior. From 54Mbps to 34Mbps. Notice the high bits sized i-frames in every 12th and 13th positions. If all i-frames were that high, it would have given close to 54Mbps bitrate.
    image
    gh2-720p60gop3-540-timemode.png
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    gh2-720p60gop6-timemode.png
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  • @kae

    I don't know the data rates, I'm on Mac so no Streamparser for me. If only it'd would run under Wine...
  • @kae

    I shot with your settings all day. 50 or so clips including some driving all in 24p. Driving was flawless.
    Data rate on clips was 45000000 mps up to 69000000 mbs.

    No data write errors on the 2 transcend cat 10 16gb cards I used. I have 3 others to test but don't expect issues.

    The only thing that happened today, is the last 40clips or so were of hanging out near the water and me, gh2, & tripod playing. Lots of 1-2 minute clips. No read errors, but I started playing every clip I shot and on occasion I'd get "can't play this clip. I'd have to shut down/restart camera to be able to play. This seem to happen every 3-4 clips.

    Will try again tomorrow. I'm going to check and see if the clips playback issues were on the higher data rate clips as I was up and down today.

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  • get virtual box. works really well. its free.
  • @jfro

    Great to hear! These are the results I'm getting. I too, get the clip cannot play error once in awhile. Turning cam off and on resolves it immediately. I'm assuming your long drive files span???
  • @ Kai

    Have you checked your roll over images after the 4GB limit. Go frame by frame in an editor and check it out. I didn't get low bit rate frames on the rollover first few frames, but it appears i got 2-3 of the same frame (repeated) while I was driving. When I trim the extra frames off and butt the clips together, I get what appears to be a slight exposure shift on the trailing or rollover clip.. Will do some more checking as it's late and I'm too tired to chase this.

  • 65 MB/s Extreme Motion Test Footage

    I'm a bit stunned at how crappy the Vimeo decoder is when transcoding MTS files that have a high data rate and heavy motion. The Vimeo transcode strobes and stutters like crazy and the motion is far from the original. Perhaps this is why GH2 24P is getting a bad name, people aren't watching the original .mts files.

    Anyway, I have shot a 30 sec test clip to demo the 3 GOP 65Mb/s settings with heavy motion. It looks very much like what I see hand held with film with a fast shutter like we use for fight sequences. If this was shot at a lower data rate and a long GOP the results would be noticeably different (worse). To me, this is the strength of 3GOP or lower AVCHD.

    Footage is ungraded original, dynamic mode at 0 for all so the blacks are a bit crushed, 14-140mm panny lens set at 14mm, hand held, auto focus (it hunts a bit), F4, ISO 640, WB at 7500K, my guess is the auto shutter is at 80-120 throughout, OIS is OFF, shaky cam is intentional, I see some edge blurring when shaking the cereal bin but not much and bearable. This clip is not meant to be high art but strictly a demo of 3GOP high data AVCHD for those who can't wrap their heads around the benefits of it for heavy motion.

    It was shot with the combo 65Mb/s 1080 24P settings I posted a couple days ago and have attached again below on a Dane-Elect 32GB averaging roughly a 61Mb/s data stream.

    Original MTS File is here at Filesonic: http://www.filesonic.com/file/1564573944/KAE65extremeMotiontest.MTS

    It's 248 megs, about a 10 minute download.

    YOU WILL NEED POWERFUL CPU to play this back because it is a non-standard 3 GOP file. WMP on windows works great it may stutter with VLC.

    If you like this look and want to use these settings please DONATE to Vitaliy at Personal View, he needs all the support and gratitude we can give him for this incredible hack.
    KAEExtreme65Mbs108024P3GOPMotionTest.JPG
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    KAEExtreme65Mbs108024P3GOPMotionTestA.JPG
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    KAE65M1080_24P_3GOPand42M720_1080i_12GOP.zip
    511B
  • I can vouch for jfro's experiences. Flawless writes for me with the occasional playback in cam error (about every 1 in 4 tries) remedied by a power up/down. I'm using a Transcend C10/16GB. Running on VLC through my Mid 2010 13" Macbook Pro - get some hang ups with heavy motion shots. Clips play back beautifully on my Sony BDP-S470 through USB slot - really stunning quality.
  • @last_SHIFT

    Then maybe Transcends are ok? Perhaps people have just been mixing and matching settings and screwing up the 65MB extreme ones.
  • @jfro

    'Have you checked your roll over images after the 4GB limit'

    I will do this. When watching in WMP the whole sequence plays fine and I don't notice. When plugging them into a Sony Blu-ray player each file plays separately so I wouldn't notice there. I could live with it as 7-10 minute takes are more than I ever need but i realize a lot of folks want the 30 minute or so capability. BTW: Have you shot longer than 30 minutes with these settings?

  • @kae

    Both my Transcend C10/16GB cards work as reported above - however I notice the in cam playback errors are more frequent now as to when I first applied your 65GB settings (maybe coz I'm shooting more?).
  • @last_SHIFT

    What I do, especially when recording a long clip, is cycle the cam off and on before I even try playback. Also, watch the red 'write' icon carefully, it seems to take a lot more time to finish writing at these settings and sometimes I find myself pulling out the SD card like an idiot before it's through.
  • @Kae: I have one Trancend that works well, another that hangs up... so maybe a bad batch on the one, maybe a counterfit... who knows? But there seems to be a consistency problem.
  • @kae: What shutter speed ws that shot on? It looks darn good by the way.
  • @Ian_T
    See above - shutter was auto. My guess is 80-120. Let's make sure we keep on the low gop settings topic or Vitaliy will bump us ;-)
  • Kae: Great video, but one word:

    DECAF man! That was a fantastically frantic video!!! Well done.
  • That was kinda nice. Weird... but nice demo.
  • Another motion test demo of the 3 GOP hack using the 'jfro' technique --

    This was hammered at 10:1 by the You Tube codec ( the 1080P you tube file is 20 megs, original is 218 megs) but it's a nice demo of the 3 GOP hack's ability to capture an insane amount of detail at 61 mb/s. A long GOP and lower data rate would have just blurred the trees as they whipped by and banding in the sky would be evident. I shot in dynamic mode so the blacks are a bit crushed. There's also a reflection on the window. For best results watch in 1080P and let it download all the way before you hit play:

  • @kae:
    any comments on my weirdly bad results? I did not change a thing in your preset. edit: okay did use 3.60 with 3.61 and the added options, it works great!!
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