600D GOP and Slice control FAQ + settings, for beginners.

[Sam Makes Movies]

For my likings i don't get good Results with any Settings.
Most of the Time it's just too noisy and finally you lose
detail in Post-Production.

@N/A
Thanks for the link. Really interessting. Camera Sharpening
may help, but if you have bad luck in some Situations you
and up with oversharped Footage.

[Bosnik]

Hi all,

First, thanks a lot for working on the EOS cameras I have installed the 2.3 ml on my 600 and it's working great.

I thought that it already came with RAW video but as I understand it having browsed around,
that it's not stable yet, hardly in HD and definitely not stable enough to shoot a short film with it.

So my questions are:
Is tragic lantern part of your team, or others, but in the end, are they complementary to your work or rival?
did you develop with tragic lantern a better control of the bit rate, to make better videos in spite of not having the raw stable yet?

And also, I'm lost with the different files they offer on the website: the six thirty, the new system and what you offer in this thread the bitrateback.

Lastly, sorry for being annoying, if i want to install these, do i install them on the sd card already containing magic lantern or this should go on a separate SD? And shall i just forget about the new system and just stick to the better bit rate?

Thank you  

[1%]

Is basically my repo. Code flows back and forth. It just frees me up to put 600D only stuff without worrying about breaking other cameras.

i.e. Movie mode remap isn't good for 60D but it works on 600D so it won't be in unified.

[vicnaum]

Do you plan returning all the GOP/Slice parameters to some newest build?

[Luzestudio]

Improved sharpness

Due the high quality achieved with those settings I'm able to apply kernel convultion sharpening to the footable without visible artifacts and that gives, for my eye, a great sharpness, highly improved from my previous footage.

It's an improvised shoot w/o tripod. Tell me what you think about sharpness.

Best

Xermán

[deletedAcc.0021]

Improved sharpness

Due the high quality achieved with those settings I'm able to apply kernel convultion sharpening to the footable without visible artifacts and that gives, for my eye, a great sharpness, highly improved from my previous footage.

It's an improvised shoot w/o tripod. Tell me what you think about sharpness.

Best

Xermán

Looks Good!  Where was this filmed?

[MD87]

The surface of the water looks great!

[vicnaum]

Maybe it's sharper that usual, but... still looks 720p. You can judge this from the logo in the end, which is supersharp (compared to the footage).

[Luzestudio]

To make a comparison, the same exact video in 2 versions:

without convulsion sharpening:

with:

I see them very different, the second one sharper, at 1080 it's very noticeable.

Best,

Xermán

ps - It's in Galicia, Spain.

[Luzestudio]

This post is designed to answer questions about the H264 codec control in one version of Tragic Lantern in a simple and practical way.

After a few posts I made about using bitrate control on the 600D I had a bunch of messages about settings, and development threads were getting busy, so here's a new thread.

Though one could explain these concepts in greater detail, it's of no real practical use to the average user, so here they in plain English.

They are simplified, so lease don't fill the thread with highly technical responses on video encoding, that information is available elsewhere for those who are curious.

WHAT IS IT?

A balancing act of sorts. High bitrate means nicer footage but bigger files. You can adjust the colours more and remove noise more easily. Advanced control of the H264 encoder that tries to make it use as high a bitrate as possible, without fluctuating wildly or stopping recording.

WHY NOT USE RAW?

Raw can be lovely but there are also a lot of compromises (crop sensor, lower resolution, longer workflow) so perfecting H264 is a great way to get higher quality footage from your beloved camera.

H264 is limited because the encoder uses a rather soft image, but these settings will let you get the best from that image.

WHAT DO I NEED?

A 600D, a fast SD card of 45 or 95MBs will guarantee speed, and (currently) this build of 1%'s Tragic Lantern:

https://bitbucket.org/OtherOnePercent/tragic-lantern/downloads/autoexec.bin-bitrateback

The build is a little older than ones you may be used to so a few things are missing or different. GOP and slice control aren't in the new builds yet but may be at some point, and when they are let me know and alter this thread.

Some other useful things for the 600D are:

The Mosaic Engineering TXi filter, which removes most aliasing and moire, allowing you to make better use of the bitrate. Sometimes it gives Err30 butmost of the time it's amazing. You will still get some moire with exceedingly fine cloth and so on.

The Technicolor Cinestyle Picture Profile and it's LUT, which allows a flatter picture for grading. It's free.

The VisionColor picture profile, which is quite flat but has a nice natural film like tone. It's $6.99. That's a bargain, don't pirate it!

Neat Video denoising plug-in, which can make very high ISOs like 6400 usable when combined with the higher bitrates.

  THE SETTINGS

SOUND OFF *For maximum image quality, don't bother recording sound in camera, deactivate it in Canon menus. Use separate sound.*

IF YOU NEED SOUND use 25p mode and set GOP to 3 instead of 1.

IN SLICE CBR

Lock Slice: Disabled
Min BR: 130
Max BR: 160
Drop by 1: 140
Drop by 3: 145
Taper Rates: Enabled.

IN BITRATE MENU
Mode: CBR
DblockA: -6
Dblockb: -6
PicPC: 0
GOP: 1
Bitrate Info: On (I find it interesting)
BuffWarnLevel: 70% (just in case)


BUT WHAT DOES IT MEAN?!!

If you don't need to know, it's probably best to to worry. Hey, the important thing is it works! But here's some simplified explanations:

SLICE
Quality. The numbers used are weird, but not that confusing. The lowest numbers (86, 87) try and use as many bits as possible for encoding. The trouble is, if you lock the slice to 87 and give the camera a hugely complex picture the bitrate goes too high, the buffer fills up and recording stops, or quality has to drop for a while. The second of these situation makes the bitrate "bounce" up and down between loads and 40 or so, which means your image goes pixelly every so often.

Slice control lets the camera raise the slice (drop the bitrate) gradually and in a controlled manner if things get too much.

The settings I've provided here have been stress tested very heavily. They keep things at 87 a lot of  the time, but reign it in if the scene becomes too complex. The settings are designed to keep the bitrate below 160 but as high as the camera can keep it without overflowing the buffer in complex scenes.

You can push it harder, but it won't be as stable. These setting have, for me so far, been the most consistant. I recently shot for 15 hours on a fashion video and never had any buffer drops. The average bitrate of the footage was around 100mbps I-frame, which is a lot better than stock.

The buffer can still get too full (resulting in a drop to a very low bitrate and some pixellation) if you shoot a very complex high ISO scene with the slice starting at 87 or so. If you are shooting a complex scene start the slice at 115 or so using the first setting in Slice Control, and the camera will quickly level itself.

GOP

GOP is "group of pictures". To compress more video into less space, some codecs look at one frame, then compare a lot of subsequent frames to it, only storing the bits that have changed. The GOP number is how many are in this group.

So what's the practical result? A long GOP is more efficient, but to my eye tend to look more video like, motion can be a little smeared. I prefer GOP 1, also known as I-frame, as each picture is a whole picture, like a piece of film. The downside here is that file sizes are big, but hey, it looks the best and memory cheap.

GOP 3 is a good compromise and allows sound recording in 25p mode with these settings.

BUFFER

A small memory where the camera stores things before they are written to the SD card. If this fills up, recording will stop. You can use GOP 1 to let frames be written straight to the card, but for some reason GOP 3 seems less hard on buffer. This is reaching the limit of my knowledge. GOP 1 probably stresses the card a lot, but your card will probably be obsolete before it matters. Just format it ater shoots.

Hi, as other users suggested before a Dblock of 1 gives less noise.

Best,

Xermán

[jgharding]

Yes you can get away with more sharpening,

I like the sharpening in Neat Video due to frequency and channel specific...

What's kernel convolution sharpening mean?

I still need to test that deblock...

[Luzestudio]

Yes you can get away with more sharpening,

I like the sharpening in Neat Video due to frequency and channel specific...

What's kernel convolution sharpening mean?

I still need to test that deblock...

Convolution Kernel effect
The Convolution Kernel effect changes the brightness values of each pixel in the clip according to a mathematical operation known as a convolution. A convolution overlays a matrix of numbers onto a matrix of pixels, multiplies each underlying pixel's value by the number that overlays it, and replaces the central pixel's value with the sum of all of these multiplications. This is performed for each pixel in the image.

The Convolution Kernel Settings include a set of controls that represent cells in a 3x3 grid of pixel brightness multipliers. Labels on the controls, which begin with the letter “M,” indicate their position in the matrix. The M11 control, for example, affects the cell in the first row and first column of the grid; the M32 control affects the cell in the third row and second column. The pixel being evaluated falls in the center of the grid, at the M22 location. Use this effect for fine control over the properties of various emboss, blur, and sharpen effects. For a given effect, it is easier to apply one of the Convolution Kernel presets and to modify it, than to create the effect from scratch using the Convolution Kernel effect itself.

http://help.adobe.com/en_US/premierepro/cs/using/images/ae_ConvKernGrid.png
Convolution Kernel pixel grid, showing the position of each control in the matrix

from http://help.adobe.com/en_US/premierepro/cs/using/WS1E7C690B-2342-43c3-9253-2BAAFF4168EF.html
If you are into maths: http://homepages.inf.ed.ac.uk/rbf/HIPR2/convolve.htm

I read about it on this forum, don't remember where, but an user was recommending it. I like the results a lot.

[jgharding]

I just tried Convolution Kernel but I really can't understand what's going on enough to tweak it in a way that is beneficial...

I put the preset in and tried changing things but I can't find a logic to it. It seems easy to make things ugly but I'm struggling to get the subtle results shown in the youtube video above.

I think it could do with a more friendly set of controls...

The sharpen preset is a bit excessive but I don't know how to reduce it...

For me nothing beats Neat Video yet. The luminance only, high-frequency only sharpening is great and almost artifact free. add a bit of mid frequency sometimes and you're good to go! easy and quick.

[Luzestudio]

I just tried Convolution Kernel but I really can't understand what's going on enough to tweak it in a way that is beneficial...

I put the preset in and tried changing things but I can't find a logic to it. It seems easy to make things ugly but I'm struggling to get the subtle results shown in the youtube video above.

I think it could do with a more friendly set of controls...

The sharpen preset is a bit excessive but I don't know how to reduce it...

For me nothing beats Neat Video yet. The luminance only, high-frequency only sharpening is great and almost artifact free. add a bit of mid frequency sometimes and you're good to go! easy and quick.

Hi, Im using the default sharpen preset, it looks better with the lower Dblock (I think that makes the video "less blocky" in a way) and also everything becomes more natural when the video is exported to h.264

Best!

Xermán

[J_C_B]

I once saw the idea of changing the compression from h264 to mjpeg or something.
So we could get 4:2:2 or even better.
Is there still anyone working on that? maybe 1%?

RAW doesn't look like a proper solution on the smaller cameras like 600D

[jgharding]

Hi, Im using the default sharpen preset, it looks better with the lower Dblock (I think that makes the video "less blocky" in a way) and also everything becomes more natural when the video is exported to h.264

Best!

Xermán

Cool I'll give it a try! I was trying on some stock 5D ii footage

[Zao]

RAW doesn't look like a proper solution on the smaller cameras like 600D

This topic is not about RAW but about getting the most out of the existing compression.

This build is my favourite build, but it doesnt allow for modules. Would be awesome if this was combined with the other builds to allow for some of the other stuff, dual iso especially.

That way we wont have to switch builds for different purposes.

[Bosnik]

hello again, can anyone explain me how to install the GOP and Slice control on my 600D? I currently have the ML 2.3 running on the camera and the bitrate running at 3* but I would like to know how to go beyond that (my card is a lexar pro 95mo/s). Thanks

[deletedAcc.0021]

hello again, can anyone explain me how to install the GOP and Slice control on my 600D? I currently have the ML 2.3 running on the camera and the bitrate running at 3* but I would like to know how to go beyond that (my card is a lexar pro 95mo/s). Thanks

See the first post in this thread. 

download and replace your current autoexec.bin from link in post.

[Bosnik]

Thanks ! 

I didn't work at first because the filename is autoexec.bitrate and the original file is autoexec but it worked when I renamed it

[jgharding]

I edited the original post slightly to reflect the findings of more testers, rather than just my own

[ru31jan]

Thanks for all the hard work! Great quality with these settings.

[AvdS]

Hi, first of all I want to thank you all for the amazing job you have done with Magic Lantern! It's amazing how the filmmaking world has changed these last few years, professional filmmaking has become affordable and it's also thanks to you!
These settings are great I use them on my 600d with vision tech and sandisk extrem and it's super stable it gives just what you need for a more advanced color grading.
I've got one issue though, the playback on the camera doesn't work anymore. It's greenish laggy and it shows only one second then stop. If I don't record the sound it plays but still with weird artifacts and laggy images. Am I the only one to have that I don't see any post about it? Does anyone have a solution?
Thanks

[1%]

The player can't play high rate videos.

[AvdS]

Thanks for your quick answer. That's bad, how do you do when you want to check quickly your shot on location?