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GH2 Cake v2.3: reliability and spanning in 720p, HBR, 24p, and VMM at 2-2.5x stock bit rates
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  • @Wigginjs - love your sample clip, especially the hose part.

    I feel dumb, but is VMM = Variable Movie Mode, the one where you can go slow as 80% and upto 300%?

    I'm going to be using your Cake Codec in a gh2 im using to record our wedding. Very happy (for the wedding and the codec!)

  • Since there seems to be some demand for settings that combine Timebuster 2 + Cake 2.x, I'm willing to tailor a branch that is the best merger for both. For this I need to relax some of Timebuster's main goals, so I need those that are interested to answer a few questions:

    • Are you ready to sacrifice absolute control over IQ (either down for reaching 24h or up to get better IQ) and can you settle for the default quantizer parameter =20?

    • Must you use a 360º shutter (and therefore use HBR) or you don't mind about it and prefer to sacrifice 24p instead?

    VBR patches like Cake are already good approaches to timelapsing and all the better if they have a long GOP nature, because the temporal redundancy raises it's efficiency to a whole new level. What a specifically tailored settings definition can achieve in case of pure Cake, is a ~2.5x recording length when very low (1/2s - 1/2.5s) shutter speeds are used. And this achievement is mainly due to adjusting the GOP length.

  • @ahbleza

    Re: your test with the boats in the river.. On the Second shot of the ship passing from left to right, the high bitrate one looks much darker to me. A large difference in contrast. Have you noticed this?

  • @mrttt Yes, and that's a puzzle to me. I'll have to check if I threw in any post filters when I did the edit... I might have done some color correction. What's the timecode where you see this?

    What really puzzled me is that Cake 2.0 delivers 205 Mbps... I never expected that, although I know that water motion really increases the complexity of the visual field.

  • 205 mbps uhh what? Bitrate of cake is like 40-60 mbps right? Btw just for you guys info. Im using transcend 32 gb class 10 with cake (HBR) without any problems.

  • Cake 2.3 beta 1:

    • Improved rate control in 24H

    Cake 2.3 timelapser 1:

    • HBR 30p (NTSC) mode optimized for low bit rates with slow shutter speeds

    • 1/2.5 s shutter recommended

    • Approximately 6 Mbps

    • 30i is unusable; other modes are the same as Cake 2.3b1

    In Cake 2.3 beta 1 I've tried to keep the 24H average bit rate as close as I could to how it was set before, while keeping the max below my safe level and correcting the problem of the encoder going into fallback mode on some high detail, low motion scenes. Please test. If there are no problems, this version will become 2.3 final. With any luck, this will be my last update to Cake. We should all spend more time shooting and less time testing.

    I'm sure there are scenes in nature that can still cause the encoder with these settings to go into fallback mode, but they won't be very common. I could create settings that never go into fallback mode, but that would force me to be more conservative about how I set the bit rate. My goal was always to get the bit rate as high as I could while still having near 100% reliability and spanning. If a rare detailed scene raises the bit rate enough to force the encoder into fallback mode, that's a good thing: it means you won't get a recording error or a spanning failure.

    Cake 2.3 timelapser 1 is a tiny experiment for people who want super long recording times. The average user will be better off using regular Cake in VMM 300% mode, which is stable and gives higher quality. Timelapser 1 uses one half to one third the bit rate of VMM 300% 24H. I did not test spanning in timelapser 1. At this bit rate, you'll get about 90 minutes of recording before you reach 4 GB. If Duartix or anyone else wants to take over this line of development, be my guest.

    Edit: please see 2.3 beta 2, here: http://www.personal-view.com/talks/discussion/2123/gh2-cake-v2.2-reliability-and-spanning-in-720p-hbr-24p-and-vmm-at-2-2.5x-stock-bit-rates#Item_380

    Cake 2.3b1.zip
    857B
    Cake 2.3 timelapser 1.zip
    836B
  • @albertdros Yeah, that's what puzzled me. When I look at the original media (H.264), it shows 44 Mbps. When transcoded to high quality (ProRes 422), it shows 146 Mbps. When I export as ProRes 422 (HQ) it shows 209 Mbps.

    I'm guessing some of this must be interpolation, since the original files are only 44 Mbps.

  • @balazer great stuff, will try out cake 2.3 tomorrow morning, thanks a lot balazer. I agree, time to stop testing new settings/patches and get out shooting. Your settings mean this to me: stable and spanning settings for all shooting modes in middle/high bitrates - thats it. Cheers

  • Sorry if this is a dumb question but, how are you guys shooting HBR24p? HBR only gives me 30p and I can't figure out a way to change it...unless 24H is supposed to be the optimal setting here?

  • There is no HBR 24p. HBR is 25p or 30p. 24P Cinema is 24p. http://www.personal-view.com/faqs/gh2-usage/gh2-usage

  • (edit) moved to separate topic http://personal-view.com/talks/discussion/2935/rescuing-bad-footage

    ...because I don't want to derail attention away from @balazer's fantastic work with Cake.

  • @balazer and @duartix thank you very much for your great work with Cake and Timelapser.

    Sorry for my non-scientific approach to this, but since it's not an option for me to develope Cake+timelapser further, I'd like to give my opinion on how I think it should work. HBR30p is the best option for timelapse-mode, because 24p is way too valuable to waste. 2fps would be better in a long run instead of 2,5fps if it saves space, but quality is more important. If 2,5fps works better I can deal with it. 60min to 90min / 4GB would be enough for file-size efficiency. Spanning with standard Sandisk Extreme Class 10 30MB/s is also vital for extreme timelapses.

    I'm not sure if it is possible to develope HBR30p-timelapse completely separated from 24p, but the quality of 24p shouldn't be not compromised. However the frame quality of timelapser should be as close to the quality of 24p as possible. Combining clips shot using both modes shouldn't cause too much variation in quality for the best viewing experience. Is it even possible to achieve timelapse-mode that is as good quality as 24p without massive file-sizes?

  • (duplicated post)

  • @vstardust

    Your opinion, as well as other's willing to drop in, is highly appreciated.

    Personally, I also believe that HBR30 is the best option for timelapsing not only because it's more independent from 24p (HBR25 shares the same GOP) but mainly because it gives access to a great range of 360º shutter angles: http://www.personal-view.com/talks/discussion/2396/gh2-motion-fluidity-360%C2%BA-shutter-test-on-slow-shutter-speeds That is the reason why I endorse 2.5fps instead of 2fps.

    Plain vanilla Cake is already excellent at this and if you don't need the extra recording length, I recommend on using it as it is, because it's pretty well suited for 2.5fps, 5fps and 10fps. It just needs a few extra GOP tweaks to achieve longer Recording Length. Tweaking for 2.5fps would give ~30% of the current bitrate (~3.3x the recording length) and for 5fps it would give ~53% of the current bitrate (~1,9x the recording length). For vanilla Cake right now I'm predicting ~18m = 4GB @2.5fps.

    Now, addressing some of your questions:

    • Spanning problems and timelapsing don't make any sense when used in the same sentence.

    • Timelapsing @ 2.5fps uses 4x-8x less bitrate than normal footage with the same IQ. What do you call massive?

  • @balazer

    Thanks, I was looking for that page. 24p is an absolute necessity for me; how much of a difference would you say there is between HBR and 24H quality wise?

  • The quality difference between 24p and HBR depends on what you are shooting. Usually the difference in quality is not large. (i.e., they both have good quality)

  • @duartix I do need extra recording length. Recording sunsets from early on turning into dark nights is what I'm looking for. I don't have change to upload my clips anywhere but 1TB external hard drive. This going on for months (at least 5) and you really start to look for the best solution considering file sizes and quality. Actually @balazers new Cake 2.3 timelapser 1 seems pretty nice for both quality and file size efficiency.

    OK, so spanning is not a problem in shooting timelapse. Good to know.

    "Massive" file sizes are of course subjective, but about 7 Mbps would give 75min/4GB. That's what I'm looking for with great quality of course ;) I don't know the main principles of developing new hacks, but if it is possible to tweak the HBR30 2,5fps settings even further towards good quality and smaller file sizes I would be grateful...and I think I wouldn't be the only one. Anyways, thanks for your work so far, it has been great.

  • @vstardust : I'm still struggling to figure out if you need some tailored settings. How big is your bigger card and how long do you need to record? How much x do you want to speed up the video?

  • @all

    So far Cake 2.3b1 cadence (24h, HBR and FSH, with and w/o ex-tele) looks good to me.

  • @duartix I have 16GB cards ~ about 6 hour max with 7Mbps. I still have to study timelapses and nature to figure out what I really need. What I do know is that I like long smooth timelapses of sunsets, wandering shadows and that kind of stuff - 1-3 hours shrinked to 15-30 secs. As I have said before I'm going to take about 5 month trip and because I want to travel light I'm not going to take a computer with me, but only one 1TB external hard drive. There ain't going to be fast internet access to where I'm going and that's why I want to keep the file sizes small. I'll get back to you if I have need for more tailored settings. Thanks though.

  • @vstardust Your least case compression (1h compressed to 30s) when final outputed to 30fps still gives 10:1 frames of input:output, so it's all about efficiency. When you get back you'll still need to frame blend to get 360º shutter. Having said that and without doing the 1TB/n# of timelapses recordable math, I'd say very very very long GOP. I've searching but I can't find what was the maximum GOP I was able to achieve. Something tells me 96 or 72.

    I would take Cake 2.3 beta 1 and only change "1080i60 GOP Size" from 3 to 96 and see if it records/spans on your cards. I know what I said before about spanning, but we are talking about mega GOPs now with 3 seconds of video+audio. 7Mbps*3s = 21Mbps, it still shouldn't be an issue, but I would test it anyway...

    (edit) Apparently and according to some old tests ( http://www.personal-view.com/talks/discussion/comment/39717#Comment_39717 ) you can't go over GOP50. But at that time I was only testing on 24p, perhaps HBR30 can extend it a little further. Logic would be to try GOP60.

  • I'll be trying cake 2.3. Just loaded it, did a few clips so far and averaged 44mbps. Still seems sharp and of quality to me. I had been using mysteron but I feel like the 100mbps is wasteful for card space.

  • @ahbleza are you saying that you uploaded the 9 Gb file to youtube? It definitely looks much better than the first one, you can definitely tell in the trees above the water.

  • @Bueller Yes, it took a hell of a long time, but Youtube accepted it. According to what I've read, Youtube suggests 8 Mbps for 1080p (http://support.google.com/youtube/bin/static.py?hl=en&topic=1728588&guide=1728585&page=guide.cs) but also will accept higher.

    I checked the average download speed for Youtube for my area: http://www.youtube.com/my_speed shows an average download speed of 8 Mbps.

    Just for fun, I used the Firefox download helper to download the HBR version of my video, and checked the speed of the resulting MP4 file. The result was 257 MB in size, with a total bit rate of 6.1 Mbps.

    Bottom line: it's probably a waste of your time to upload any 1080p video to Youtube with more than 8 Mbps stream, and likely we're fooling ourselves that high bit rate makes a difference for Youtube playback -- but I could be wrong.

  • my thought is that youtube's re-encoding is destructive, and not necessarily destructive in the same way as the encoding you do before uploading, so it's probably best if it starts with the best quality you're willing to wait for, within reason, because the things it degrades might not be exactly the same things your encoding degrades, therefore the losses of quality might potentially add, rather than just "overlapping", if you get my meaning. Have not really tested this though.