canon rumors FORUM

Gear Talk => EOS Bodies - For Video => Topic started by: cayenne on November 30, 2012, 04:01:54 PM

Title: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: cayenne on November 30, 2012, 04:01:54 PM
Hi all,

I've been looking about and I can't figure out if the latest Magic Lantern out there, supports the clean HDMI out....I thought I heard it would/could but I can't find confirmation on  this.

If so...has anyone used it? If so..can you tell your set up, what are you using to record externally?

Another question I have about this...in this set up..what format is the video coming off? Would this be the equivalent of RAW video out?  I'm wondering if anyone can fill in the blanks for me to let me know what can and cannot be done with the 5D3 and clean HDMI out (if not out already).

Would this be the equivalent of the Blackmagic camera shooting RAW video?

Anyway, hoping to start a discussion here to learn what exactly is needed to capture this (external recorder hardware), what it means for using and Post Production of footage captured this way...advantages and disadvantages...

And if it is available now...

Thanks in advance,

cayenne
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: Axilrod on December 01, 2012, 02:13:27 PM
No it's not at all the same as shooting RAW video, most external recorders will record ProRes 422 (which is a more edit friendly format).  I don't know of anyone using the magic lantern clean HDMI, but I know Canon has a firmware update coming out in April that will enable clean HDMI on the 5D3, I'm waiting for that one.  I would expect a huge difference in image quality, but the footage will respond much better to color grading and keying, and your editor will run much more smoothly (since prores is much more optimized for editing).  The file sizes are much bigger of course. 

From what I've heard the Magic Lantern clean HDMI produced poor results, I don't think it was implemented perfectly.  Hopefully Canon's firmware update will do a better job for it.  But honestly, unless you are doing a whole lot of green screen work and/or heavy grading I don't think it's worth the trouble.
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: HurtinMinorKey on December 01, 2012, 04:39:25 PM
It depends what the sensor readout is. It's quite possible it will do next to nothing for the IQ.  It will still be 8-bit.

Isn't possible that even though you can record in ProRes422 the readout will still only contain the 420 color info?
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: syder on December 01, 2012, 06:14:35 PM
The ML HDMI sounds a bit sketchy, but for the latest follow the 5Dmiii thread on their forum. The upcoming Canon firmware upgrade will likely be not only more stable, but will allow hardware manufacturers to design around its implementation (Atmos did this with the D800 for example), something they wont do for a project like ML.

We don't know what the Canon HDMI out will be, but it sure as hell wont be CinemaDNG. You'll need an external recorder - something like an Atmos Ninja or Blackmagic Hypershuttle, both of which will record to ProRes (for FCP) or DnxHd for Avid, at up to 220mb/s.
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: jonathanlang on December 01, 2012, 06:15:53 PM
"When shooting video, HDMI Output makes possible the recording of High Definition uncompressed video data (YCbCr 4:2:2, 8 bit) from the EOS 5D Mark III to an external recorder via the camera’s HDMI terminal. "
- Canon Australia Website.

I'm looking forward to using it for green-screen work with my BlackMagic Design HyperDeck Shuttle II which can do Prores HQ and Uncompressed.
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: LetTheRightLensIn on December 01, 2012, 11:37:56 PM
Hi all,

I've been looking about and I can't figure out if the latest Magic Lantern out there, supports the clean HDMI out....I thought I heard it would/could but I can't find confirmation on  this.

If so...has anyone used it? If so..can you tell your set up, what are you using to record externally?

Another question I have about this...in this set up..what format is the video coming off? Would this be the equivalent of RAW video out?  I'm wondering if anyone can fill in the blanks for me to let me know what can and cannot be done with the 5D3 and clean HDMI out (if not out already).

Would this be the equivalent of the Blackmagic camera shooting RAW video?

Anyway, hoping to start a discussion here to learn what exactly is needed to capture this (external recorder hardware), what it means for using and Post Production of footage captured this way...advantages and disadvantages...

And if it is available now...

Thanks in advance,

cayenne

Sadly, it is totally worthless. I got a Ninja 2 and was all excited, but the ML clean HDMI, while clean, is really bad. I guess Canon figured ML might try something  :D so they not only didn't put out clean HDMI but also put it out at some sort of weird semi-downsized resolution which is something ML simply can't get around (unless they figured how to access things at a deeper layer, but that gets to be really tricky without documentation, which of course, is kept secret). Whatever res it is it is lower enough that it looks worse than just sticking with the internal recorder.  :(

I sure hope the version from Canon gives the full 1920x1080 output and isn't the same as the clean HDMI from ML otherwise it will be totally useless.
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: gloch on December 02, 2012, 01:19:03 AM
Canon has promised this via firmware update in Spring for the MKIII.

It will come, just not soon.

-gl
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: peederj on December 02, 2012, 10:55:19 AM
On the topic I can confirm that the C100's HDMI output is clean uncompressed 8 bit 422, with timecode and record start/stop control. So with the Ninja 2, the ProRes 422 HQ 220Mbit is a very high quality image to my eyes, the noise floor does show the one dimension of chroma subsampling (444 would be better) but is fine and very even without much banding and no macroblocking.

The C100's compressed internal video is fairly ugly in comparison, I'm just using the SDXCs as safeties and doing all recording onto the Ninja. I strictly use Canon Log gamma to get the 12 stops of dynamic range this way, I don't notice banding in color gradients as 12 stops over 8 bits is still very high fidelity even though 10 bit would be optimal for 12 stops. ISO 20000 is quite usable...I think I will use the NDs instead of going below the native ISO of 850, but going below that does crush out the noise floor at the expense of recoverable dynamic range. I'd rather use NR in post to taste.

I would say the C100 is at least a stop better low light than the 5D3 video, though I will want to see what the Ninja does with the 5D3 clean HDMI output, which Canon said would be uncompressed 8 bit 422. Noise is a very complex thing for a codec to handle of course, and chroma subsampling makes color edges the other main concern. I have great hopes for the 5D3's clean HDMI out, it will still not be as comfortable a video camera as the C100, nor will the downsampling be as sharp. But it will have the full frame look and DOF and be free of moire and aliasing, and the noise floor should be quite fine and color edges resolved well. The dynamic range might be OK with Cinestyle gamma in that case, right now I don't use that because of the codec. Canon Log is still going to be better I predict...would be nice if Canon released Canon Log for the 5D3 along with the clean HDMI.

I'm sure Canon delayed the 5D3 clean HDMI till April just so people interested in doing films would give the C100 a try...I think the C100 will be my A cam workhorse for years even if the 5D3 video lives up to my greatest hopes. But I do want the good B cam, and I don't mind picking up a second Ninja if in April things work as I hope. Enjoy your shooting, Canon is being less and less evil these days, and the C100 + Ninja + Canon Log is a dream come true for me anyway.
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: cayenne on December 02, 2012, 12:18:39 PM
I'm thinking more on this.

Would you not be able to, with "clean HDMI out" when either ML or Canon has it working for us....just be able to plug the HDMI cable out of the camera into just about any computer out there and record the footage off it??

I've heard Ninja and other digital recorders mentioned in this thread, and while I've not looked, I'm guessing they're somewhat pricey.

Why could you not run the cable out of the camera to your laptop and just record the image data there directly?
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: peederj on December 02, 2012, 12:52:47 PM
The Atomos Ninja 2 costs $1000 and comes with everything you need, and also provides a very useful 2nd monitor with peaking, false color etc. It's small and the batteries and media are cheap as chips. Six hours of recording ProRes HQ onto a bog standard 500GB 2.5" laptop drive. SSD optional. Pressing record on the C100 starts and stops recording automatically on the Ninja. Your laptop is going to be a complete pain in comparison, plus you will need some form of HDMI capture ability for it.

The only minor annoyance with the Ninja 2 is it needs to analyze a moving image to properly deinterlace to 23.98fps 1080p. The HDMI standard is 1080i60, and the C100 (and 5D3) are going to have to send that format out regardless. You can record that directly but deinterlacing in post is a pain. So instead with the Ninja 2, you can have it deinterlace and record 23.98 fps directly, which is wonderful, but every time you power both the camera and the recorder on, you will have to wave your hand in front of the lens a bit for it to figure out how to do the 3:2 pulldown.

A nuisance but that is the only nuisance...everything else is beautifully optimized and integrated. You can name the project, camera, scene and shot directly on the Ninja and the take number will auto-increment. Timecode is fully supported. It's a professional solution. The Hyperdeck Shuttle 2 is actually bigger and far less featured, and while it's half the price (with the needed mount plate) it mandates the use of SSDs which make up for the difference. Also, for the 5D3, they may continue to insist on turning off the internal LCD when using HDMI, so with the Hyperdeck you won't be able to see what you're shooting. Get the Ninja.

But if you don't care at all about ergonomics and workflow, why are you caring so much about image quality? Do you just shoot product shots or something in one studio?
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: cayenne on December 02, 2012, 01:57:51 PM
The Atomos Ninja 2 costs $1000 and comes with everything you need, and also provides a very useful 2nd monitor with peaking, false color etc. It's small and the batteries and media are cheap as chips. Six hours of recording ProRes HQ onto a bog standard 500GB 2.5" laptop drive. SSD optional. Pressing record on the C100 starts and stops recording automatically on the Ninja. Your laptop is going to be a complete pain in comparison, plus you will need some form of HDMI capture ability for it.

The only minor annoyance with the Ninja 2 is it needs to analyze a moving image to properly deinterlace to 23.98fps 1080p. The HDMI standard is 1080i60, and the C100 (and 5D3) are going to have to send that format out regardless. You can record that directly but deinterlacing in post is a pain. So instead with the Ninja 2, you can have it deinterlace and record 23.98 fps directly, which is wonderful, but every time you power both the camera and the recorder on, you will have to wave your hand in front of the lens a bit for it to figure out how to do the 3:2 pulldown.

A nuisance but that is the only nuisance...everything else is beautifully optimized and integrated. You can name the project, camera, scene and shot directly on the Ninja and the take number will auto-increment. Timecode is fully supported. It's a professional solution. The Hyperdeck Shuttle 2 is actually bigger and far less featured, and while it's half the price (with the needed mount plate) it mandates the use of SSDs which make up for the difference. Also, for the 5D3, they may continue to insist on turning off the internal LCD when using HDMI, so with the Hyperdeck you won't be able to see what you're shooting. Get the Ninja.

But if you don't care at all about ergonomics and workflow, why are you caring so much about image quality? Do you just shoot product shots or something in one studio?

No, right now, I'm just a hobbyist learning all the tools, but hoping to move into doing some stuff to make some $$.

I come from the IT world, and I was thinking this is all just about basically computer signal capturing...hence my questions on just plugging it into a laptop.

I am quite puzzled about one of your statements...where you went on about deinterlacing...etc.

I was under the assumption (yes, I know what you get for assuming  :) )....that this was shot at full HD, which to me means 1080p....progressive, not interlaced...? Your mentioning of having to deinterlace stuff shot with my 5D3 if coming directly out of HDMI port confused me..?

Can you give a bit more detail on this aspect of your post?

Anyway..I'll look into the ninja.  But I just pulled the trigger on the 70-200 L f/2.8...and once that is paid off, I was going for the 50L next. So, during all this lens buying, the Canon update with the clean HDMI out (or maybe ML will get it right first)...I was wanting to think about capturing this which equipment I had on hand...

If it would do for going straight to say, my laptop, I was thinking that maybe I could hook the HDMI out of the camera to a device to stream video wirelessly to my laptop, and could use that as a nice monitor, and not have too much hanging on my tripod...?

Thoughts? Comments?

TIA,

cayenne
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: peederj on December 02, 2012, 04:00:31 PM
HDMI is a data transfer protocol standard, just like TCP/IP or USB. And it's a dumb consumer-level standard...its professional sibling is called SDI. And on the C300 you get both options, and Atomos makes a higher end Ninja they call the Samurai that just does SDI instead of HDMI. HDMI was for HDTV, which for legacy reasons uses 1080i60, sending half the lines 30 times per second, alternating with the other half (all interlaced together) also 30 times per second. There is nothing a camera or anything else can do to alter the protocol...that's how the machines have all agreed to talk, and because it's so dumb a standard, you can expect any HDMI monitor or whatever to understand it.

But we don't want to shoot 30p or 60i (both are offered on the C100 btw), for cinema the standard frame rate is 24p, which gives a nice familiar texture and blur to motion when captured at a shutter angle of 180 degrees (1/48th of a second or 1/50th on the 5D3 is close enough). So how does one send a 24fps signal over a 60i protocol? I forget the technical term (you can google all of this of course, and please do) but they essentially just repeat frames alternating 3 repeats and 2 repeats to match the timing difference of 30:24. And the receiver, to deinterlace that redundant 1080i60 stream to 24p (23.98 is the actual rate on the Ninja also due to legacy concerns with synchronization) must figure out the cadence of repeats and drop the appropriate redundancies, leaving a steady and even stream of progressive frames.

The Ninja has to do this empirically off a moving image being sent so it can see which images are repeats and which are new and drop the proper ones. HDMI can't communicate that information sadly, meaning the Ninja waits with record disabled until it gets enough contrasty motion to see what to do.

As for your growth plans, I understand dipping your toe in, but a lot of this only makes sense when you have the full professional rig in front of you and understood, and then you can learn to make do with less. Good luck with your exploration however you go about it.
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: cayenne on December 02, 2012, 05:59:11 PM
HDMI is a data transfer protocol standard, just like TCP/IP or USB. And it's a dumb consumer-level standard...its professional sibling is called SDI. And on the C300 you get both options, and Atomos makes a higher end Ninja they call the Samurai that just does SDI instead of HDMI. HDMI was for HDTV, which for legacy reasons uses 1080i60, sending half the lines 30 times per second, alternating with the other half (all interlaced together) also 30 times per second. There is nothing a camera or anything else can do to alter the protocol...that's how the machines have all agreed to talk, and because it's so dumb a standard, you can expect any HDMI monitor or whatever to understand it.

But we don't want to shoot 30p or 60i (both are offered on the C100 btw), for cinema the standard frame rate is 24p, which gives a nice familiar texture and blur to motion when captured at a shutter angle of 180 degrees (1/48th of a second or 1/50th on the 5D3 is close enough). So how does one send a 24fps signal over a 60i protocol? I forget the technical term (you can google all of this of course, and please do) but they essentially just repeat frames alternating 3 repeats and 2 repeats to match the timing difference of 30:24. And the receiver, to deinterlace that redundant 1080i60 stream to 24p (23.98 is the actual rate on the Ninja also due to legacy concerns with synchronization) must figure out the cadence of repeats and drop the appropriate redundancies, leaving a steady and even stream of progressive frames.

The Ninja has to do this empirically off a moving image being sent so it can see which images are repeats and which are new and drop the proper ones. HDMI can't communicate that information sadly, meaning the Ninja waits with record disabled until it gets enough contrasty motion to see what to do.

As for your growth plans, I understand dipping your toe in, but a lot of this only makes sense when you have the full professional rig in front of you and understood, and then you can learn to make do with less. Good luck with your exploration however you go about it.

Interesting...thank you for the reply.

I do have one other thing that I don't understand.  If I have all my AV gear hooked with HDMI....how do I have 1080p images on my big plasma tv....if the protocol of HDMI as you mention can only handle 1080i information?

Thanks in advance,

C
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: syder on December 02, 2012, 06:03:50 PM

But we don't want to shoot 30p or 60i (both are offered on the C100 btw), for cinema the standard frame rate is 24p,

This really depends on what your output is going to be. And of course where you are. In the UK we don't use 30p - its 25 - and because it's what material is broadcast at, its what most clients will ask for.

And the BBC requires intraframe HD material to be 100mb/s+ (50 for long gop material) so using the hdmi out of 5dmiii should be acceptable.

...and you're describing a reverse 3:2 pulldown - reverse as the tendency was always to go from film (high quality 35/16mm material) to video rather than vice-versa (crap low quality video to film)

Thanks for the 4:2:2 link - that should mean you have a lot more leeway to grade footage harder. Will be very interesting to see what emerges in April... And also thanks for the C100 thoughts, I've don't know anyone with one yet.
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: peederj on December 02, 2012, 06:48:13 PM

I do have one other thing that I don't understand.  If I have all my AV gear hooked with HDMI....how do I have 1080p images on my big plasma tv....if the protocol of HDMI as you mention can only handle 1080i information?

It is deinterlaced by the TV, though usually the TVs are displaying 30p and so it doesn't need to do the 3:2 pulldown, just every other frame.

This really depends on what your output is going to be. And of course where you are. In the UK we don't use 30p - its 25 - and because it's what material is broadcast at, its what most clients will ask for.

And the BBC requires intraframe HD material to be 100mb/s+ (50 for long gop material) so using the hdmi out of 5dmiii should be acceptable.

...and you're describing a reverse 3:2 pulldown - reverse as the tendency was always to go from film (high quality 35/16mm material) to video rather than vice-versa (crap low quality video to film)

Thanks for the 4:2:2 link - that should mean you have a lot more leeway to grade footage harder. Will be very interesting to see what emerges in April... And also thanks for the C100 thoughts, I've don't know anyone with one yet.

Right, there are two regions of the world based on the frequency of AC power used. 240V (e.g. in the UK) is usually 50Hz and 120V (e.g. in the USA) is usually 60Hz. The streetlights and other things flicker at the rate of the alternating current, so they match the frame rates (or make perfect halves e.g. 25fps for 50Hz) to avoid the flicker. Canon cameras are world cameras and can shoot at both frame rate standards.

The C100 (also switchable to 50Hz) is really just a dream camera, better I think than the C300 unless you need the SDI and the internal recording to 50mbit or the odd frame rates. It's as if the C100 was designed around the Ninja, the Ninja solves all its problems beautifully... Anyone criticizing the C100 that isn't recording onto a Ninja and using Canon Log (cinema lock is the most foolproof way, though they could still screw up white balance and exposure given the competence of some of these online reviewers) really missed the boat. Canon should just slip a Ninja into the C100 box and prevent such adverse opinions.

I think I'll post a thread on the C100 covering it in more detail.
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: JasonATL on December 03, 2012, 07:54:59 AM
You can see the Magic Lantern HDMI results here: https://vimeo.com/52822486 (https://vimeo.com/52822486)

Some have said above that ML's implementation is lacking. That seems to misplace the blame on ML. They are working with what they have in terms of the current limitations. The primary limitations are: 1) The resolution that the Canon firmware makes available to HDMI (1620x1080); 2) The fact that the HDMI out is 1080i.

Because of 1, the same frame that is internally recorded must be cropped (zoomed) from the HDMI output, so the resulting resolution is 1620x911 (and does not even appear to perfectly resolve that resolution, just as the native 5D3 footage does not resolve the full 1920x1080 resolution).

The interlacing is a real pain and limitation. While there could be a limitation in the Hyperdeck Shuttle that I used in recording the interlaced signal, I simply could not reliably reconstruct the 24p signal. I could reconstruct it with a lot of effort, but it was a bit soft. Even the 30p signal was a bit soft after deinterlacing.

My own testing using a resolution chart shows that the HDMI out from ML does seem to resolve about the same resolution as the internal recording, albeit with pillar bars (since it is only 1620x1080). Oddly, though, the shot must be framed differently, since you must zoom in. Thus, with a very good deinterlacer, this might be useful for greenscreen work (assuming you don't need the full 16x9 frame).

In short, while the ML clean HDMI out might be useful for some purposes, it doesn't work for me right now in its current implementation to yield any significant benefits. There is a chance that ML can improve their HDMI out. However, I suspect that the 1080i HDMI output is something that they simply cannot overcome.

I don't think the ML implementation gives us any indication of what Canon's firmware will be. If Canon were going to do what ML did, they could have released clean HDMI already. This gives me hope that they will 1) give us at least as good a resolution as currently is recorded internally; and 2) provide a true 24p signal or at least have the 1080i embed the 24p information so that it is easily and cleanly recoverable. If they do these things, then the externally recorded material should show significant benefits, even if it is 8 bits. The benefits will be in less compression artifacts on highly detailed and dynamic (in motion) material from the higher available bit rates and less color compression from 4:2:2 vs. 4:2:0.
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: HurtinMinorKey on December 03, 2012, 09:16:36 AM
HDMI is a data transfer protocol standard, just like TCP/IP or USB. And it's a dumb consumer-level standard...its professional sibling is called SDI. And on the C300 you get both options, and Atomos makes a higher end Ninja they call the Samurai that just does SDI instead of HDMI. HDMI was for HDTV, which for legacy reasons uses 1080i60, sending half the lines 30 times per second, alternating with the other half (all interlaced together) also 30 times per second. There is nothing a camera or anything else can do to alter the protocol...that's how the machines have all agreed to talk, and because it's so dumb a standard, you can expect any HDMI monitor or whatever to understand it.

HDMI is capable of delivering progressive frame formats. I you use one with a blue ray player, that's what it's doing.  In fact, if I don't use HDMI and instead use component cables, then it delivers it in 1080-60i (and it looks way too smooth)
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: peederj on December 03, 2012, 10:52:24 AM
Well the camera HDMI outs are 1080i60 and not progressive for whatever reason.

Thank you Jason for your detailed reports and example video. To test whether something is 420 or 422 I suggest shooting red & white text next to black & white text in the same frame, using text printed with enough resolution and zoomed out enough for its edge to be beyond the limit of sensor resolution. If the red & white (I actually like white on red, stop signs are often used for this) is significantly blockier looking than the black & white when zoomed 300% then you are at 420 but if it's close in resolution you are at 422. Equal in resolution would be 444. This way I have confirmed the HDMI out of the C100 is 422 and Canon announced the 5D3 clean HDMI firmware will indeed be 422.

422 is a bigger win than a lot of people seem to think, 420 is a massive thwack to color quality ime. If you only care about 720p web video then just shoot internal codec and be happy.
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: JasonATL on December 03, 2012, 11:04:37 AM
peederj - In my test video, I looked for that. The resolution makes this a not-so-clear test. However, it does appear that there is a benefit to using the HDMI out in color resolution. Therefore, my best guess right now is that the current HDMI out is 4:2:2. And, I agree, having 4:2:2 is a very nice step up when trying to color grade or even add sharpness.

By the way, you can see the red effect that you describe in another video I did. It shows a way to greatly help with the type of blocking that you describe around red, especially when applying a sharpening filter. The solution is to use a very weak color blur filter prior to sharpening. https://vimeo.com/42314148 (https://vimeo.com/42314148)
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: peederj on December 03, 2012, 12:02:11 PM
By the way, you can see the red effect that you describe in another video I did. It shows a way to greatly help with the type of blocking that you describe around red, especially when applying a sharpening filter. The solution is to use a very weak color blur filter prior to sharpening. https://vimeo.com/42314148 (https://vimeo.com/42314148)

Handy...thank you again Jason. The era of struggling with codecs and artifacts is thankfully coming to a close but we will still have situations where these techniques help. Educating each other about where this damage is coming from will put a lot of pressure on the manufacturers to fix it as we see with the 5D3 announcement. Canon wouldn't have given in on that last year.
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: LetTheRightLensIn on December 06, 2012, 02:36:05 AM
HDMI is a data transfer protocol standard, just like TCP/IP or USB. And it's a dumb consumer-level standard...its professional sibling is called SDI. And on the C300 you get both options, and Atomos makes a higher end Ninja they call the Samurai that just does SDI instead of HDMI. HDMI was for HDTV, which for legacy reasons uses 1080i60, sending half the lines 30 times per second, alternating with the other half (all interlaced together) also 30 times per second. There is nothing a camera or anything else can do to alter the protocol...that's how the machines have all agreed to talk, and because it's so dumb a standard, you can expect any HDMI monitor or whatever to understand it.

But we don't want to shoot 30p or 60i (both are offered on the C100 btw), for cinema the standard frame rate is 24p, which gives a nice familiar texture and blur to motion when captured at a shutter angle of 180 degrees (1/48th of a second or 1/50th on the 5D3 is close enough). So how does one send a 24fps signal over a 60i protocol? I forget the technical term (you can google all of this of course, and please do) but they essentially just repeat frames alternating 3 repeats and 2 repeats to match the timing difference of 30:24. And the receiver, to deinterlace that redundant 1080i60 stream to 24p (23.98 is the actual rate on the Ninja also due to legacy concerns with synchronization) must figure out the cadence of repeats and drop the appropriate redundancies, leaving a steady and even stream of progressive frames.

The Ninja has to do this empirically off a moving image being sent so it can see which images are repeats and which are new and drop the proper ones. HDMI can't communicate that information sadly, meaning the Ninja waits with record disabled until it gets enough contrasty motion to see what to do.

As for your growth plans, I understand dipping your toe in, but a lot of this only makes sense when you have the full professional rig in front of you and understood, and then you can learn to make do with less. Good luck with your exploration however you go about it.

24p works perfectly fine over HDMI, many HDTVs handle 24p signals just fine and many computers and blu-rays players can output it as well as some gaming systems for disc output

you can send all sorts of signals over HDMI, my computer can send 1920x1080x60p over it too just fine

Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: peederj on December 06, 2012, 10:14:22 AM
Herp derp shows how much I know...  :o

But regardless of what's possible with HDMI, the Canons and external recorders are limited to 1080i60 8 bit 4:2:2, and a benefit of the Ninja is, given a sharp, contrasty signal to evaluate, it can deinterlace and pull down 23.98p out of it. With other systems (e.g. Blackmagic Hyperdeck Shuttle) you have to deinterlace and find the proper cadence to do the pulldown manually in post. Win for the Ninja.
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: cayenne on December 07, 2012, 03:38:21 PM
You know...

Just occured to me...this is all just DATA...wonder why there isn't some way to just stream off the image data via the USB port straight to computer or via a usb wireless dongle to a computer, and just bypass HDMI altogether?

Just a thought...

C
Title: Re: Canon 5D3 - ML: Is Clean HDMI out working? Using it? Info...?
Post by: Policar on December 07, 2012, 04:58:53 PM
You know...

Just occured to me...this is all just DATA...wonder why there isn't some way to just stream off the image data via the USB port straight to computer or via a usb wireless dongle to a computer, and just bypass HDMI altogether?

Just a thought...

C

USB2 has a theoretical maximum sustained transfer rate of 480mb/sec. In practice, it's closer to half that.

HDMI video (8 bit NTSC) is 30fps*1080 vertical pixels*1920 horizontal pixels*8 bit color*3 channels=about 1500mb/sec.

Way too much data.