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GH2 Flow Motion v2 - 100Mbps Fast Action Performance & Reliability for Class 10 SD cards
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  • @Frame: I don't know/use Premiere, so I cannot recommend any details on it. But generally speaking, the idea is not to avoid the first/last frames when "importing" the clips (assuming that "import" here means: telling the software about the available .mts files - without transcoding them into some different format), but to set the "in" and "out" points of your clips (afterwards, e.g. when putting them into the timeline) such that their first and last 12 frames won't be used as a source for your final output rendering.

    You mention that the part you uploaded was 30s into a larger file: Yes, and the excerpt starts with data for an I-frame, followed by data for b-frames that have a Presentation Time Stamp (PTS) that is before the PTS of the I-frame (because the file needs to contain frames in an order that allows decoding of P- and B- frames based on differences to frames that were decoded before), but the second I-frame that is needed to interpolate the 2 B-frames is not part of the file (it would have been in the part before the excerpt). So the decoder sees two B-frames that it has only one reference frame for, and at that point it may decide to discard or partially decode those frames. ffmpeg seems to opt in favor of the partial decoding under certain circumstances: when there already was at least one other decoded frame. This would explain why ffmpeg does not decode the B-frames with missing reference when cold-starting a replay, but it does decode those B-frames both when looping (using the last decoded frame from the sequence instead of the missing reference) and probably also when "seeking" in a file - e.g. when the NLE software tries to single-step to a frame where to start, but has already decoded others in the process of getting to the right position.

    The reason why I see that effect often is that my workflow starts by cutting relevant parts from the .MTS files I recorded in the compressed domain (without re-encoding). I need to do this, as I often take lots of long shots (the "actors" being animals not allowing me to request their action on command), and if I would not decimate the material quickly after shooting it, it would use up excessive amounts of harddisk space. So I live with the mentioned work-around until I can find a better solution, which could be:

    • fixing avidemux26 to get rid of the incomplete B-frames when cutting in the compressed domain
    • changing kdenlive/mlt/ffmpeg to do the "seeking to the right position" in a different way, avoiding to produce initial garbled frames.
  • I've tried again a "clean" re-install of FM2 (as suggested here: ) and no, unfortunately FM2 is definitely not stable in HBR/25p mode on highly detailed scenes shot with sharp lenses. However the changes I suggested above ( ) do work fine and by now seem to be reliable and stable (in 24H, HBRp25, FSHi50, SHp50).

    Some unsorted observations (based on 24H and HBR/25p tests)...

    FM2 shows a little less chroma noise than settings utilizing Panasonic's stock matrix... and shows in general a somewhat finer noise pattern. FM2 is also "sharper" (cleaner) and shows less artefacts on fine edges. Motion looks pretty smooth. FM2 infact shows somewhat less banding (it's not a world of a difference but it's noticable...). All in all I would say this is by far the best all-modes setting available!

    Many thanks @LPowell for your really great work!!!

    attached my modified version of FM2 for PAL users
  • @rapsoe for logging its great - rain or no - trust me even in broadcast progs - the chaps n chapesses that log and capture any ingest ... rain? Had a QC dept this week pass an audio mix (that I hadn't even laid back until the day after i.e. the all the way to 0 offline, crunchy drunk disco dancer music edit mix) on a well (multi million watched) series in it's nth series - joy. Ravensbourne where art thou with your brown cords and flares lol

  • @towi Thanks for your interest in Flow Motion v2 and your tip on the the GOPx2 settings. In fact, thanks to everyone who have posted reports of their results, they have been very helpful.

    I've been testing reliability revisions to HBR, 1080i, and 720p settings for the last few days and am planning on releasing an update soon. For those who are shooting in 1080p24, none of those settings will be altered.

  • @LPowell Looking forward! Thanks for all your great work!

  • @rapsoe for me movist works great, but one thing that is faulty is the settings about (change of )speed, just doesn't do anything to the footage. does it work on yours?

    @LPowell so far had no issues whatsoever with the 16gb 95mbs San Disk and manual lenses. maybe its just a "not all cards are made equal" issue ? the 720 50p looks great but is it a little less sharp then the 24H? i used another manual prime lens for the 720p, will try to test it again with the same lens to see if the sharpness is the same.

    to all how is the FM2 in color correction/grading/post? any examples?

  • @luxis The stability revisions I'm testing are intended to insure failsafe operation on all Class 10 cards, regardless of their rated maximum bitrates. In my experience, the advantage of the 95MB/sec Class 10 cards are primarily in their ability to support 4GB file-spanning at 100Mbps. Although standard 30MB/sec Class 10 cards are capable of reliably recording individual 4GB files at 100Mbps, they usually fail to span. With Flow Motion v2, you may see a brief write-speed error message when file-spanning fails on slower Class 10 cards, but the initial 4GB MTS file will be saved intact. FM2's 60Mbps 24L, FH, and H modes should span on standard 30MB/sec Class 10 cards, as well as higher rated SD cards.

  • @LPowell. Lee, looking forward to test your upcoming modified settings for 720P60, 1080i60. In the meantime, I modified your current FM2.0 settings by changing the high end bitrate for 720p and 1080i from 99 to 77 MB along with associated top and bottom bitrate values. I repated my tests and it worked fine with no write errors using Sandisk extreme 30MB/s, averaging 55MB for 720p and 45MB for 1080i and HBR.

  • @towi well, it was not the solution, apologies. My GH2 worked without problems for one day shooting HBR, but I emptied my card, format, and it crashed again... Shooting test charts with HBR is strange too : usually it crashes after a cold start, but if I pull out the battery and shoot again, no more crash. Thanks for sharing your settings, I'll give a try :-)

    @Lpowell : great news! And thanks for your amazing work, FM 2.0 makes the GH2 shine! 24p is simply amazing. Panning footages are so fluid and movements so smooth that it's hard to belive it's shot with the GH2 :-)

  • @5min Thanks for your enthusiam for FM2! You may be interested to check out the new sample footage I uploaded in the third post from the star of the thread. I shot a direct comparison between Flow Motion v2 in 1080p 24H mode, 1080p25 HBR mode, and 720p50 SH mode:

  • GH2 Flow Motion v2.01 Update

    This update addresses reliability issues with HBR, FSH, and SH video modes in both NTSC and PAL. It has been successfully tested for failsafe operation under all shooting conditions and options, including 80% Slow Motion and ETC zoom modes. The stability adjustments in Flow Motion v2.01 should produce little or no visible reduction in motion picture quality in any of the updated video modes.

    In response to numerous requests, I've enabled and verified reliable operation of Flow Motion v2.01 with extended ISO levels. By default, all levels up through ISO 12500 may now be selected for use with any NTSC or PAL video mode. In practice, however, levels above ISO 3200 produce considerable noise, which may require excessive bitrate and perceptibly reduce motion picture quality compared to lower ISO levels.

    Download the Flow Motion v2.01 Update at the following link:

  • @LPowell Thanks Lee! Does HBR inherit from FSH or FH? Is HBR spanning supported on this new patch on 30MB/s Class 10 cards?

  • @LPowell Thanks for the update ! I will try this with my 64g/95 card today. I will post later with results.

  • @wigginjs Regardless of which patch you install, HBR mode is always a progressively-scanned version of FSH mode. Flow Motion v2 supports 4GB file-spanning in HBR mode only with 95MB/sec Class 10 SD cards. File-spanning is also supported in 24L, FH, and H modes with standard Class 10 cards rated 30MB/sec or faster.

  • Fantastic! Thank you for this quick update. I will try it ASPA! Your samples are impressive. With FM2, I've found that an HBR footage re-encapsulated as progressive has virtually the same image quality than a 24p footage.

  • Thanks Lee!

  • @LPowell. I just tested FM2.01 in 720p60 SH mode with Sandisk Extreme 32GB 30mb/s and it failed with write errors.

  • @Zaven13 it failed with: what lens, shutter speed, iso,what scene/context,etc? are your cards genuine? have tried with another card with the same speed if you have one? also i have noticed sometimes some cards perform better in terms of storage size 16gb vs 8gb vs 64 vs 32...for different patch settings

  • Tested FM2.01 in 720p60 SH mode with Sandisk Extreme 65GB 95mb/s...all good now! even etc mode is fine. 14-140 kit lens Iso 320 card write errors this time..Yea!

    Thanks @LPowell !

  • Has anyone been editing FL2 footage, native -- particularly 24p? If so, what kind of performance are you getting, compared either to stock or intra, and on what system? Thanks.

  • @Luxis. I use two SD class 10 cards, Genuine Sandisk Extreme HD 32GB 30mb/s and Genuine Transcend SDXC 64GB. I only use Panasonic lenses for GH2, 14-140mm, pancake and 100-300mm. The scene is nature (trees, flowers in the sunlight). I tried Intelligent Auto (IA) mode and Nature setting that comes with camera and sets the various values for you. I think one of the factors effecting is the Panasonic lenses that do continuous zoom in AFC mode and OIS on. 720p H mode works fine. It is the SH mode that fails. I have found out the the limit before it fails with write error is 55 MB/s. Once details get higher and it gets close to 60MB, it fails. The way I have gotten around it in FM2.0 is to reduce the bitrate for 720p/1080 from 99/55 to 77/55 along with associated top and bottom bitrate settings. This modification keeps the SH mode to approximately 55MB therefore avoiding the write errors. I have read that others have no issues using other lenses but Panasonic lenses seem to put more stress on the sensor.

  • @Zaven13 ok,thanks for the detailed info. It helps to understand and improve. I have not tested it with the pansonic lenses yet, but its quite possible this to be reason.

  • @Zaven13 Thanks for your test report. I'll confess that I've never actually tried shooting video in Intelligent Auto mode before. As you found, Flow Motion v2.01 can fail under Intelligent Auto when used in SH mode. However, the patch does appear to work reliably under Intelligent Auto in 720p H mode, and produces bitrates comparable to your personal modifications, which have the drawback of degrading the bitrates of 1080p HBR and FSH modes as well. For users who find Intelligent Auto useful for 720p videos, I'd recommend the workaround of using 720p H mode instead of SH mode for this purpose.

  • FM 2.01 tested with HBR and SH, PAL, Panasonic 14-140, Sandisk 32MB 30mb/s, high detail ultra bight scene in nature : no more problems, all went flawlessly!!! Cool! Thank you @Lpowell, FM is now, dare I say, perfect :-)

  • @LPowell what did you exactly change from FM2.0 to FM2.01?

    As I want to use it with no Panasonic lens (Olympus 4/3) and with no AF - which both seem to put more load on the codec/cpu. Card is Sandisk 30MB/s. Will FM2.0 work or should I use 2.01? Is the picture quality lower with FM2.01?

    And thanks for your great work!

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