Official Low GOP topic, series 5

towi

Maybe a little breakthrough re spanning …

I've just succesfully tested spanning in HBR mode on a SanDisk 30MB/s with a modified GOP3ZILLA version (tested in PAL mode). Bitrate actually utilized in this test was 76M!

I remembered @balazer somewhere said he thinks the camera is writing a GOP table at a time.

If true, I thought we maybe have to "tell" the firmware the actual GOP length.

This is why I tried to modify the "GOPx2" tables (PTools->patches for testers->AVCHD Movie Mode->GOP related).

The default GOPx2 value for instance for 1080p24 is 24. This is twice the default GOP length (12x2). So if we use a 3GOP setting apparently we have to set twice the modified GOP length… so 6 (3x2) instead of the default 24.

1080i and 720p default values show four times the default GOP length (4x15=60 for 1080i60 and 4x12=48 for 1080i50). Running 1080i at 3GOP we have to set 4x3=12. Running 720p at 6GOP we have to set 4x6=24.

Now … I've just made a first test. But it seems to work as supposed to. At least in HBR mode (tested in PAL mode). At 24H I think the bitrate is just too high … the settings do not span (neither on a SanDisk 30MB/s nor on a 95MB/s, 32GB card).

I think the 2xGOP length settings do not affect how the settings work otherwise … so I assume it's quite safe to just test with adapted values.

Other than that I've modifed the PAL GOP tables in GOP3ZILLA. At 720p50 I feel it's a major improvement. HBR/25p also seems to be improved, though I think the 1080i50 table could need further adjustment (however even in it's present form it works good… just try it). I've also modified the 720p60 GOP tables… but they have not been tested yet by me…

The settings are not ready for primetime … need more testing!

Test away…

Streamparser grabs from a death chart (static) shot off a monitor:

rikyxxx

@towi

I confirm that @balazer says it in the second post of Cake's thread (I reported it to you a couple of pages ago on this thread).

If your theory turns out to be true I think we'll see big improvements in a lot of settings' spanning capability.

Bonzai

blazer, bkmcwd... Interlace mystery solved. It's a video player issue. Thanks blazer for taking the time to analyze the video file posted to Vimeo. I was a VLC fan a few years back but it tended to be buggy. After evaluating the MPC-HC platform I never looked back. In my case the Windows Media Player also plays HBR 30P files with artifacts however VLC plays 'em back just fine - including those posted by bkmcwd. And yes bkmcwd, your screen capture isnot interlaced :-)

towi

@Bonzai

there's still something wrong (with the settings in HBR/30p mode) ... when you look at the moving blades of grass on the left side you'll notice that the background (the little stones in the flower bed) is also "moving" ...

minger

@towi Thanx for your efforts in the 25p arena. It really seems that you are succeeding. My 25 minutes test run outside went fine. I was using a 32GB 45mbs SanDisk and a manual lens at aperture 5.6 and ISO 320. Keep up your good work.

chromekoda

Thank you towi, GOP3ZILLA_modified.zip seems to work pretty well both hbr and 720 in my pal cam. SanDisk 30 MB/s. So far it seems to be the best for 720 for me... all the others settings have freezed the camera. Great !!!

konjow

great news towi, cant wait to test new pal option... not sooner then tuesday:(

chromekoda

Hmmphh, sorry,I had wrong settings (they were 1080)... 720 freezes the camera immediately with GOP3ZILLA_modified.zip with my cards.. Motion recording was cancelled due.. The battery has to be removed to get it back to working condition.

towi

Updated version of the modified GOP3ZILLA

improved 720p50 (thanks to @bkmcwd )
stable performance on SanDisk 20MB/s cards (in all modes / camera set to PAL)
spans in HBR/25p mode on SanDisk 30MB/s (and faster, of course)

Preliminary setting aimed at PAL users. bkmcwd will release a final version for all modes soon.

attached a screenshot of a 16GB SanDisk 30MB/s card. First clip was a short test in 24H. The other 4 clips are HBR/25p spanning until the card was full. Average bitrate utilized in this spanning test: 75M. Streams look healthy all over the clips.

chromekoda

=( , 720 freezes everything ... maybe tomorrow :) . Thanks for fighting... bkmcwdrocks !

towi

720 what? 50 or 60? Which card?

720p50 survives EVERYTHING here even on my old class 6 SanDisk20MB/s. I am talking really heavy torture tests with ultra sharp lenses ...

Don't forget to reformat the cards when a new patch was installed ...

balazer

Bonzi, Media Player Classic Home Cinema does a great job using its built-in filters. The problem is that it uses DirectShow, and any random DirectShow filters installed on your system could be doing the wrong thing for interlaced video. (the wrong thing of course being the right thing: de-interlacing interlaced video that doesn't need to be de-interlaced) Make sure that all of MPCHC's internal filters are enabled, and then check to see which filters are actually being used during playback. If other filters are being used, you'll need to reduce their merit or unregister them. It's a little more complicated than I care to talk about here. Google probably has info. Personally I use MPCHC and ffdshow tryouts.

minger

@towi How would you call this setting? "Iron Sky"? Again this grew better. How far can you go?

towi

Well, I would call it GOP3ZILLA :-) It's bkmcwd's setting after all. I've just optimized the GOP tables for PAL modes. I have no buffer analyzer software, though. I need feedback from bkmcwd. So it takes time. But it seems we are getting close. GOLGOP13 looks georgeous! (soon to be released). GOLGOP13 doesn't span in HBR/25p mode, though.

minger

Please help me out: What was the intension of GOLGOP13?

Stray

@towi What are the changes to GOLGOP the same as the ones made to GOP3ZILLA ?

towi

GOLGOP13 is actually aimed at lowlight shooting as the noise looks very, very smooth. In comparision to GOP3ZILLA it produces much larger B-Frames (in all modes) ... at the price of much higher bitrates beeing utilized (and therefore larger filesize). I also use GOLGOP13 in daylight as motion looks somewhat smoother. But GOP3ZILLA spanning in HBR/25p mode on 30MB/s cards is definitely a keeper for me!

towi

@Stray

yes, the changes are all in the GOP related settings. But bkmcwd is still working on the NTSC mode tables... so be patient :-)

Stray

Yep indeed, I have to shoot HBR all day in a couple of weeks, and I can't praise you highly enough for the changes. I use GOLGOP13 for everything 24p pretty much myself.

minger

@towi thank you for your immediate answer.

bkmcwd

@towi

Thanks mate! :-)

Although I am adjusting NTSC now, since I have an appointment with my son today, it may take time more.

Your explanation about my settings is perfect. In addition, I have raised one more and "natural" as a safest and economical setting.

@chromekoda

Thanks always! :-)

Bonzai

balazer, Re: MPC-HC interlace settings... I set MPC-HC up to use LAV filters (external filters) and configured LAV Video Decoder to use "Treat as Progressive" under "Settings for Deinterlacing". The latest version (0.50.1) supports ATI hardware acceleration via DXAV2 (native). Works the ballz:-) Thanks for pointing me in the right direction to get interlacing working properly in MPC-HC.

bkmcwd

@towi

Please check, although I think that it is probably OK now. :-)

@ someone

Please check especially NTSC 60p. :-)

chromekoda

YEEEE !!!!! First impressions... bkmcwd GOP3ZILLA_V2.12_BETA.zip seems to work with my configuration in all modes very well. I am shooting everything in PAL mode....

konjow

Does towis modyfied V2 and bkmcwd V2.12 beta have both the same settings for PAL?

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