115 mbp/s??? CANON DSLR

[FilmMan]

There has been talk about 4:2:2 mjpeg, whether this comes to reality is questionable. If 4:2:2 mjpeg is a possible as thought, it would be nice to see this get the top priority as it could open the majority of Canon cheaper model cameras to alot better video. It would be disruptive. We'll have to wait and see. Alot more work needs to be done (according to a key ML programmer). The bitrate testing looks to be positive so far.

[P4INKiller]

I'm using a 64GB 95MB/s sandisk card, and I can't go above CBR 1.4.
I don't see these noise improvements people keep mentioning.

I really hope it's just me messing up.

[FilmMan]

I find using a higher CBR is helping with color grading - can push the image more in color grading. With alot of the prior posts, some Magic Lantern guys are trying new programming which isn't released. Hoping it becomes stable and is eventually released. Still early. Cheers.

[jgharding]

[quote name='P4INKiller' timestamp='1347567267' post='17921']
I'm using a 64GB 95MB/s sandisk card, and I can't go above CBR 1.4.
I don't see these noise improvements people keep mentioning.

I really hope it's just me messing up.
[/quote]

It is ;)

You have to switch off sound recording in the normal Canon menus, then you can get to 2.8 or 2.9 with that card.

[FilmMan]

Beta testing of new bitrate program. Andy600's video.

[url="http://vimeo.com/groups/superneutral/videos/49436519"]http://vimeo.com/groups/superneutral/videos/49436519[/url]

[FilmMan]

[url="http://vimeo.com/groups/superneutral/videos/49436519"]http://vimeo.com/groups/superneutral/videos/49436519[/url]

[P4INKiller]

[quote name='jgharding' timestamp='1347573091' post='17934']


It is ;)

You have to switch off sound recording in the normal Canon menus, then you can get to 2.8 or 2.9 with that card.
[/quote]

D'oh! Of course. Thanks for reminding me.

[FilmMan]

This has really got me glued to this. The bitrate beta testing has been moving along really good so far. It seems a buffer issue needs to be tweaked. If so, we may have some top bitrates coming from the Canons!

Programmer JasonATL says,
[color=#ff0000][i]2. I think that, if this feature can be further refined (and it is darn near good enough for me already), that most will find this one of the best features of ML. People want clean HDMI out to be able to get 4:2:2 or increase bitrate. This satisfies the latter. And, seeing the results that I'm seeing, would really call into question the need for 4:2:2 for most people, I suspect.[/i][/color]

[color=#000000]Programmer 1% responded about the merits of MJPEG422,[/color]
[i][color=#0000ff]I do a bit of chroma key stuff and seeing the color on the demo vid was great. Also you gain some zoom out of it like in crop mode but lose the in camera uprezing. Also would kill 30 minute limit which nobody has been able to so far.[/color][/i]

[jgharding]

No sooner do I open my mouth to say 7D probably won't be hacked at this rate, than...

[url="http://blog.planet5d.com/2012/09/hot-update-magic-lantern-team-has-cracked-the-canon-eos-7d-yes/"]http://blog.planet5d.com/2012/09/hot-update-magic-lantern-team-has-cracked-the-canon-eos-7d-yes/[/url]

I spoke too soon ;)

[FilmMan]

Donating and letting Alex know you are interested in better bitrate, etc., must have perked some of the Magic Lantern guys. Some new posts by different programmers including Alex on the bitrate investigation.

[b]Here's a post by a programmer named Marvin. Read below, quite interesting. [/b]

Let me share with you my findings with the H264 parameters in the .ini file, I did tons of experiments with Alex back in May, during the quiet days after the "Hello World" :-)

I'll start with ALL-I.


Code: [url="javascript:void(0);"][Select][/url]
Transform8x8Flag = 2
Profile = 100
Level = 51
It seems that these parameters can't be changed (ERR70 if modified). Profile 100 and Level 51 means "High Profile, Level 5.1" in H264 specifications, this is even more advanced than standard Bluray codec which is High Profile Level 4.1.


Code: [url="javascript:void(0);"][Select][/url]
BitRate = 90000000
This parameter might interest most of the people here [img]http://www.magiclantern.fm/forum/Smileys/default/tongue.gif[/img] yes it can be changed to maximum 300000000, which is 300Mbps (specified in H264 standards), compared to original 90Mbps default by Canon. But please note that this value is currently only a cap and does not keep the video file at this bitrate. More on this later.


Code: [url="javascript:void(0);"][Select][/url]
EntropyCodingMode = 0
Another interesting parameter, there are two modes which are "Context-Adaptive Variable Length Coding (CAVLC), Context-Adaptive Binary Arithmetic Coding (CABAC)". default 0 is CAVLC which is lower encoding efficiency but easier for playback. value of 1 enables CABAC which is said to bring 10%-15% quality increase under the same given bitrate.


Code: [url="javascript:void(0);"][Select][/url]
IntraPicInitQP = 20
InterPicInitQP = 20
QpOffsetForB = 0
can't be changed if I remember correctly, seems related to initial Quantitization Parameter, more on this later...


Code: [url="javascript:void(0);"][Select][/url]
MinQpI = 10
MinQpP = 10
MinQpB = 10
MaxQpI = 51
MaxQpP = 51
MaxQpB = 51
an important set of parameters, these values affect the actual video bitrate, for ALL-I, after numerous ERR70s I found out that the three "MinQp" values can be changed up to 7, and "MaxQp" values can be changed up to 20. QP stands for Quantitization Parameter which is the lower the number the better, a value of "0" means lossless encoding :-)

Video shot with these values changed/unchanged did show a noticeable difference in bitrate. Under the same scene and same exposure, I got 70Mbps compared to 40Mbps with Canon default value. Together with the previous "Bitrate" parameter set to 300Mbps I was able to get 151Mbps under ISO12800 compared to 92Mbps default.


Code: [url="javascript:void(0);"][Select][/url]
MinBitrate = 0
MaxBitrate = 0
can't be changed.


Code: [url="javascript:void(0);"][Select][/url]
SarWidth = 0
SarHeight = 0
AspectRatioIdc = 1
VideoFmtAndVspFlag = 81
VideoFullRangeFlag = 1
TimingInfoPresentFlag = 0
not very important parameters, doesn't affect the video much.


Code: [url="javascript:void(0);"][Select][/url]
RateControlEnable = 2
A mysterious parameter and worth looking into, according to some documents, a value of 0 => CBR, 1 => VBR, 2 = Fixed QP. with 0 I get very small video files from 1Mbps to 5Mbps, 1 gives ERR70, 2 is Canon default which must be Canon's secret of manipulating bitrate.


Code: [url="javascript:void(0);"][Select][/url]
ScalingMatrices = 0
pScalingMatrixAddr[0] = 0
pScalingMatrixAddr[1] = 0
pScalingMatrixAddr[2] = 0
pScalingMatrixAddr[3] = 0
pScalingMatrixAddr[4] = 0
pScalingMatrixAddr[5] = 0
Not sure about the exact meanings but don't seem to affect the video much.

For IPB there is only a few differences.


Code: [url="javascript:void(0);"][Select][/url]
Profile = 100
Level = 41
BitRate = 10000000
IPB uses High Profile Level 4.1, the same as Bluray codec. Bitrate can be changed to maximum 62000000.


Code: [url="javascript:void(0);"][Select][/url]
MinQpI = 10
MinQpP = 10
MinQpB = 10
MaxQpI = 35
MaxQpP = 51
MaxQpB = 51
Alex are you sure these are default values? I don't remember LOL, but for IPB, MinQp and MaxQp can be changed to 6 and 30. resulting bitrate can easily hit 62Mbps which is the upper limit set by H264 specifications.

If you look at the metadata of 5D Mark III's .MOV file, it will tell you that the video is encoded by "EOS encoder", which I think it might be talking to the above parameters directly, if a value is not present, for example, if I change "Profile" to 122 which stands for High 4:2:2 encoding, it will give an ERR70... or if I change the MinQP to something like 2 or 3, video recording will be stuck at "BUSY".

Hope this information is helpful and can save you some time, good luck folks!

[jgharding]

A nice test showing 160mbps All-I on 600D

[url="https://vimeo.com/49730388"]https://vimeo.com/49730388[/url]

[FilmMan]

Latest with Bitrates: Programmer/tester Jason.
[color=#FF0000][i]1% - Still working with this latest build and tried GOP=3. It looks to be absolutely awesome. The buffer save is clearly working more effectively now. I gave it quite a workout for about 15 minutes. I'm trying to look at the footage now to see if I can see the difference. My first pass through, I couldn't see when the save function kicks in - so this is great! No more "breathing". I tried to overflow the buffer many times and haven't been able to yet. The recording didn't stop on me in my few tries.

Also, I assume you're seeing this: peak bitrate at 250 Mbps on the i-frames! Craziness![/i][/color]

[TC]

[quote name='jgharding' timestamp='1348061748' post='18583']
A nice test showing 160mbps All-I on 600D
[/quote]

Much as I would like to see a higher bitrate option available, to my eye, all three panels in that video look more or less the same. Still, good to see the Magic Lantern development team chipping away at this issue, even if they perhaps have not completely cracked it.

[galenb]

I watched that clip over and over again and I really can't tell the difference between them. Am I missing something?

[jgharding]

Have you downloade the original clip from Vimeo?

Practically speaking, a Big reduction in macro blocking compared to firmware default means much better response to grading, color banding and sharpening. also, actual moving shots with proper subjects (not locked off "tests") show nicer movement cadence with I-frame.

High bitrate High ISO shots keep the noise more separated and clear so it can be removed more efficiently

The cameras only have something like 700 or so lines of resolution so the bitrate won't add that back. But take a look at some of the shots in the magic Lantern thread, still a lot more detail from what's there before encoding.

[kabuto1138]

If you download the video you can really see the difference. When VIMEO encodes it, it ALL looks the same because vimeo is like 7mbs... which is really crappy.