Does HMC40 Output 4:2:2 Color Sampling from HDMI Connection?

D

Denniscasey

Well-known member
I read AVCCAM recording modes use 4:2:0 color sampling. I have also read 4:2:2 color sampling gives "better" (subjective term) color rendition. On HMC150 forum it was mentioned that HMC150 outputs 4:2:2 color sampling from HDMI terminal. Is this standard for all AVCHD camcorders (just another area I don't know about)? If not standard, does HMC40 output 4:2:2 from HDMI terminal or is this another feature difference between HMC150 and HMC40?

Again, this is all my "book learning" talking at this point, but reason for question is some AVCHD software convertor ads say they convert 4:2:0 to 4:2:2 color sampling "for better color rendition." I wondered how they could do this then the HMC150 post made me wonder if 4:2:2 color sampling is somehow embedded in HMC40 recording and accessible via HDMI like on HMC150? And maybe some codec convertors do have the means to access the 4:2:2 data? Also I don't know if the 4:2:2 "benefit" claimed by some convertors carries through to color you get on final output after editing--i.e. edit output to Blu-Ray and then view on HD TV?

If one can get 4:2:2 color sampling out of HMC40 HDMI terminal, will color you see on HD TV connected to HMC40 HDMI terminal always give your recorded scenes a "better" (subjective) color look than at any other time (i.e. after editing, etc)?
 
I haven't tested the HMC40 but can verify that on the AF100 (another AVCCAM camera) it absolutely does output full 4:2:2 on its HDMI, so I would guess that the HMC40 does as well.

And 4:2:2 is one of those things where you don't have to qualify it with "subjectively better" -- it just plain is better. 4:2:2 means twice the color resolution, and better color accuracy throughout the image. The difference in 24p/60p stuff won't be massive, but the improvement in 60i stuff should be substantial.
 
Thanks Barry, after your note I put a call in to Panasonic tech support to see what they can tell me about 4:2:2 output from HMC40 HDMI port (on a "call back" list now). By the way, I hope you realize I was just kidding when I said AVCHD stood for All Vital Camera History Deleted (when you answered my earlier post about retrieving iris and other info from SD card). I realize AVCHD has many recording benefits. Dennis
 
Verified. I tested using the NanoFlash, as compared to the HMC40's onboard codec, and definitely the 4:2:2 Nano footage is higher in color resolution, it does make a notable difference.
 
Barry_Green said:
Verified. I tested using the NanoFlash, as compared to the HMC40's onboard codec, and definitely the 4:2:2 Nano footage is higher in color resolution, it does make a notable difference.
Click to expand...

Great feedback, Barry. At moment I shoot 1080 60i so from your earlier note "improvement in 60i stuff should be substantial." As my experience and depth of practical knowledge still lags behind theory I am gaining --how can I best use this new information to improve quality of my video that I show others:

(1) Output video to TV via HMC40 HDMI port to see best quality--even better than plugging SD card into my Blu-Ray player to view on TV?

(2) Is there a practical way to get 4:2:2 output from HDMI terminal into NLE to gain better color from edited video vs 4:2:0 color space? Or, if I burn Blu-Ray from edited video do I effectively lose the "4:2:2 color advantage" through the conversion to Blu-Ray?

Dennis
 
The output to a TV will not yield the benefit of 4:2:2 if you've recorded footage in camera and are simply playing it back as that will be AVCHD 4:2:0 footage.

To get 4:2:2 footage into your NLE you'd either need to be tethered to your very powerful laptop w/HDMI capture device while shooting OR record from your camera into an HDMI 4:2:2 capable recorder while shooting. You must bypass the AVCHD via HDMI to get the 4:2:2. Once you have recorded the footage and edited you'll still have the benefits of the extra color space compared to 4:2:0 footage. It's always better to start with more information if you can, even if you lose something later on down the chain.
 
pulpfiction007 said:
The output to a TV will not yield the benefit of 4:2:2 if you've recorded footage in camera and are simply playing it back as that will be AVCHD 4:2:0 footage.

To get 4:2:2 footage into your NLE you'd either need to be tethered to your very powerful laptop w/HDMI capture device while shooting OR record from your camera into an HDMI 4:2:2 capable recorder while shooting. You must bypass the AVCHD via HDMI to get the 4:2:2. Once you have recorded the footage and edited you'll still have the benefits of the extra color space compared to 4:2:0 footage. It's always better to start with more information if you can, even if you lose something later on down the chain.
Click to expand...

Another example of assumption gulf between experience and inexperience. Re-reading your original post in the HMC150 section you were clear and I assumed the wrong thing---thanks for patience in clarifying.

My day job experience has been to look for bottlenecks that reduce overall output in overall production flow. I think I am beginning to understand some bottlenecks that exist in video production flow. In this case it seems HMC40 (and many other cameras) can record in 4:2:2 color space but "bottleneck" that reduces color quality is the AVCHD format (or maybe the way Panasonic's AVCCAM series manages AVCHD?)? You can remove this bottleneck by methods you explain but "investment" decision depends on what you want from final output. Dennis
 
And I should add, with benefit of more experience I know I will look back on most of my posts and say "that was obvious." Still, they do accelerate my learning curve. Dennis
 
Here is one small bit of advice and it is worth what you are going to pay for it; Reaching for higher IQ levels is a great and noble cause, but AVCHD can create some beautiful images with no improvement. To create effective video, there is a lot more to worry about like; lighting, audio, cam support and camera movement technique, etc. Not sure where you are at in learning the craft, but before I worried about improving on AVCHD recording, I would worry about the other stuff first.

Grant
 
ggrantly said:
Here is one small bit of advice and it is worth what you are going to pay for it; Reaching for higher IQ levels is a great and noble cause, but AVCHD can create some beautiful images with no improvement. To create effective video, there is a lot more to worry about like; lighting, audio, cam support and camera movement technique, etc. Not sure where you are at in learning the craft, but before I worried about improving on AVCHD recording, I would worry about the other stuff first.

Grant
Click to expand...

+1
I should say that while starting with more color information or a higher bit rate recording is good to do IF you can do it...AVCCAM will do just fine for most people and 95% of viewers won't notice the difference. A much higher percentage on DVX User can tell because they have trained eyes to see this things. (I'm not one of them yet!) It's easy to forget that we are in a bit of a bubble here compared to the general public. I was talking to a screenwriter yesterday who I might collaborate with, and he was working on a current project. I asked him if they were going to shoot 24P - His eyes glazed over.....he had no idea what I was talking about. So back to the topic....if you shoot a short film/video/doc and take care with the aspects ggrantly mentioned I honestly feel you'll blow most viewers away with even regular 4:2:0 AVCHD.
 
Grant and pulpfiction007, I totally agree. I can’t spend as much time as I would like on photography (not my day job as they say) but beginning with 35 mm and later mini-DV and Liquid editing I understand importance of essential basics like Grant mentions—still a work in process re my posts on white balance.

Not raised in digital age I try to jump right to using the technology without learning the digital stuff. Sometimes it works for me---mini-DV, tapes easily loaded into Liquid via Firewire and I learned editing, authoring and burning DVD’s without need (or desire) to learn how Liquid digitally handled data.

However, making the jump to HD, Media Composer, editing issues with AVCHD codec and Blu Ray work flow all at one time is presenting me with a lot of new choices/options—and of course many choices affect subsequent choices in work flow from when light enters lens until a person processes/perceives TV images delivered at 60 times per second (maybe not always at 60 times per second).

A bit intimidating to me at the moment, but I am learning which choices are really important in various scenarios (scenery vs race car action) and will just focus on those initially—as “day job” time allows.

Regarding my 4:2:2 HDMI digression, on page 131 of HMC Book Barry notes “the camera is always operating in 1080P mode at up to 60 frames per second” and now we know it also operates in 4:2:2 color space before it down converts all this to record and output . So, I was just trying to get someone to tell me about the hidden switch they know about that will turn the HMC40 into a full progressive 4:2:2 recording/outputting camera—like I would know what to do with a camera like that!
 
You must log in or register to reply here.
Back
Top