View Full Version : Recording via HDMI


Thad Donovan
March 3rd, 2014, 09:50 PM
I have a Canon 5Diii and plan to use the O7Q with it when I order one. Unfortunately, the 5Diii is limited to the HDMI output. As I understand it, there is a bit of quality to be gained by recording to the O7Q instead of the camera's native h264, but not much generally speaking.

Is recording in RAW over HDMI a viable option for noticeably higher quality recordings? More dynamic range? Or is all of that lost by virtue of the HDMI connection? Doesn't HDMI just support 8-bit color?

The Atomos Ninja, for example, records to ProRes 4:2:2, but people continually point out that there isn't much gained by doing so unless you're doing compositing or unless you film something where banding is apparent (like a sky or plain wall or something).

In short, will the O7Q offer any considerable advantage (via RAW, DNxHD or the unnamed codec) to native H264 assuming that HDMI is a bottleneck?

On a similar note, it's also my understanding that the 5Diii only pipes 30P via HDMI (not 60P). SO again, HDMI is the bottleneck for obtaining higher frame rate capture, even though the O7Q is capable, right?

I just want to make sure I'm not missing something. It's frustrating having this excellent camera, but being choked by inferior audio recording and consumer grade video output. Grrrrr.

Dan Keaton
March 5th, 2014, 06:32 AM
Dear Thad,

Almost all HDMI is 8-Bit, thus the HDMI outputs of almost all cameras are 8-Bit.

The Odyssey7Q supports 1080p, up to 1080p30 over HDMI.

Respectfully,

Amir Qureshi
March 7th, 2014, 09:26 PM
As I understand it, there is a bit of quality to be gained by recording to the O7Q instead of the camera's native h264, but not much generally speaking.

Is recording in RAW over HDMI a viable option for noticeably higher quality recordings? More dynamic range? Or is all of that lost by virtue of the HDMI connection? Doesn't HDMI just support 8-bit color?

In short, will the O7Q offer any considerable advantage (via RAW, DNxHD or the unnamed codec) to native H264 assuming that HDMI is a bottleneck?

On a similar note, it's also my understanding that the 5Diii only pipes 30P via HDMI (not 60P). SO again, HDMI is the bottleneck for obtaining higher frame rate capture, even though the O7Q is capable, right?



Hi Thad,

It all depends on whats intended to be done in post/edit, by you or your client, what type of turn around time and budget your business models affords you, and whats ultimately going to happen to the delivered master once it leaves the post/edit house (final broadcast/social media, further broadcast/youtube/vimeo compression, etc.), with the potential of all of the above being inter-related some how. Now having said that:

Lets say that the camera' output is HDMI and 8 bit (as is probably the case with your camera) and the external recording format is also 8 bit.

Technically, in terms of sheer amount of information being acquired right off the camera's output, even within an 8 bit universe, there is a huge difference between recording to H264 or directly to one of the originally-designed-for-post/edit formats (DNxHD, ProRes, RAW, or uncompressed DPX). If you read/hear anything otherwise, thats just simply incorrect. You will need this additional information that you get with the above mentioned external recording formats if you plan to do any color or effects work. But again it is all relative to your business requirements. H264 quicktimes for a color session are perfectly adequate for some business models but the same source format maybe considered a joke for others.

Visually, depending on the type of shots/footage, when watched on a properly calibrated 23 or 24 inch broadcast monitor from three to five or six feet away, you may or may not see any difference right away between the in camera' H264 or an externally recorded format from the above mentioned bunch. You are however most likely to notice the artifacts if the footage consists of fast moving objects or camera pans, etc. On bigger displays, the artifacts can be fairly noticeable.

Its not until you begin to affect the footage in post/edit/effects when you really start to appreciate the merits of recording externally with one of the above mentioned formats. The extra information affords you more control, yes even in an 8 bit world. There could be other scenarios aside from just grading or keying where you could use this extra information and artifact-free sources. I have not done any scientific tests but based on my experience with various type sources in post/effects in general, I am inclined to say that certain speed-change plug-ins or algorithms, for example, may deal better with the cleaner, artifact-free (visually apparent or not) pixels, hence performing better when interpolating/creating extra frames if you are slowing your footage down. This instance alone could be a difference between a headache and huge time savings.

Mark Watson
March 8th, 2014, 12:52 AM
I have a Canon 5Diii and plan to use the O7Q with it when I order one. Unfortunately, the 5Diii is limited to the HDMI output. As I understand it, there is a bit of quality to be gained by recording to the O7Q instead of the camera's native h264, but not much generally speaking.

Is recording in RAW over HDMI a viable option for noticeably higher quality recordings? More dynamic range? Or is all of that lost by virtue of the HDMI connection? Doesn't HDMI just support 8-bit color?

The Atomos Ninja, for example, records to ProRes 4:2:2, but people continually point out that there isn't much gained by doing so unless you're doing compositing or unless you film something where banding is apparent (like a sky or plain wall or something).

In short, will the O7Q offer any considerable advantage (via RAW, DNxHD or the unnamed codec) to native H264 assuming that HDMI is a bottleneck?

On a similar note, it's also my understanding that the 5Diii only pipes 30P via HDMI (not 60P). SO again, HDMI is the bottleneck for obtaining higher frame rate capture, even though the O7Q is capable, right?

I just want to make sure I'm not missing something. It's frustrating having this excellent camera, but being choked by inferior audio recording and consumer grade video output. Grrrrr.



For the HDMI output you're limited to 24p or 60i/50i.

From the Canon web-site:

To benefit DSLR cinematographers, the EOS 5D Mark III will now be able to record clean, uncompressed digital video with embedded time code over HDMI output while simultaneously displaying the video on the rear LCD display and recording to internal CF or SD cards. Combined with an improved color sampling of YCbCr 4:2:2 8-bit video, this firmware update adds efficiency to video editing, improves color grading options, and enhances on-set monitoring.

The new “mirroring” feature via the HDMI output allows video to be displayed on the rear LCD screen with or without scene and camera information while also outputting a clean video signal to a monitor or external recorder. An external recorder not only enables a video signal devoid of compression artifacts, but also allows a choice of preferred edit-ready codec, the ability to shoot in a variety of frame rates and bit rates, and longer record time. Combined with the heightened color correction capabilities as a result of the expanded color space, post-production workflows will be smoother and offer users greater control and quality. With external recorders it is also possible to use a variety of on-set monitoring solutions, which facilitate real-time viewing of EOS 5D Mark III video with the Rec. ITU-R BT. 709 color matrix. Additionally, it will now be possible to synchronize the start and stop of EOS 5D Mark III video capture with the start and stop of the external recorder.

There's always the C500.

Mark

Thad Donovan
March 15th, 2014, 12:36 PM
Thanks for the great info.

SPECIFIC QUESTIONS HERE:
What about recording high frame rates via HD-SDI from the C100? Even though the C100 seems to max out at 60i internally, can you get like 60P or even 120P using the O7Q via HDMI? I'm thinking the answer is no, but I figured I'd ask.

Are LUTs an additional add-on to the O7Q. My LUT button is grayed out. I haven't had a chance to really dig around through everything, so sorry for dumping questions here before I really learn the tool. My O7Q doesn't currently match my 5Dii screen or my Zacuto EVF very well. I assume I need to somehow calibrate the O7Q?

Finally, I can't get the O7Q to be triggered by the 5Diii for record. It seems I have it set up correctly in the menus, but it simply doesn't work.


RAMBLING RANTS HERE:
I have come to hate HDMI. It's super finicky. I can't count how many cables I've ruined because I accidentally tugged on it the wrong way. I bought this wonderful O7Q and it only works with my very short HDMI cable with a Type A to Type C converter. I tried a longer cable (3') and it doesn't work. I'm going from the Canon 5Diii, which has mini HDMI to the O7Q which also has mini. I really wish the O7Q had full size HDMI.

So now I'm almost forced to get something like a C300 or even 500 so I can get a real video output and real audio connections. This is getting very frustrating.

WISH LIST:
Here's what I really want. Perhaps you'd all have some insight:

1. Full frame sensor
2. At least 60fps at 1080P (120 ideally)
3. EF mount since I've got a bunch of Canon lenses
4. Professional audio inputs
5. Professional video out so I can really use the O7Q without the garbage HDMI connector
6. Something that can be used run and gun as well as in a studio setting

My dream camera is the forthcoming Arri Amira. It's absolutely perfect (for me) except the price.

Second in line is the Canon C500. It seems to hit all my checkmarks, but I'd be curious about things people don't like about it. I hear it's got kind of a plasticky feel. Also, I'm not sure how comfortable it would be for run and gun.

The Sony FS700 looks solid. The high frame rates are great. Some complain of goofy form factor. Also, the 4:2:0 internal recording almost demands going to external recording. Plus, I'm not sure how well my canon lenses will cooperate with the Sony.

Thoughts?

Dan Keaton
March 21st, 2014, 05:55 AM
Dear Thad,

The HDMI input on the Odyssey7Q supports up to 1080p30.

Triggering over HDMI, via Timecode, is not yet enabled on the Odysssey7Q.

Custom LUT's will be added later.

Respectfully,