development towards 1080p50/60
 

Dear Dan / CF team,
With the panasonic AF100/101 on the market, 1080p50/60 is now available for many of us, however not with the nano. Is there any devolpments foreseen for an upgrade making this possible with a nano?

Cees

Re: development towards 1080p50/60
 

Dear Cees,

In the specific case of the AF100, which uses single-link HD-SDI at 1.485 Gbps, there is not enough bandwidth to output 1080p50, 1080p59.94 or 1080p29.97.

Thus, the nanoFlash never sees these framerates nor does that AF100 output them over HD-SDI.

Re: development towards 1080p50/60
 

Dear Dan,

Thanks for your reply. I did not make my question clear, I also don't own the specific camera I mentioned. It is the general development of camera's moving towards 1080p50/60 that made me wonder if CD is moving the same way.

Cees

Re: development towards 1080p50/60
 

Dear Cees,

I am most interested in the development of 1080p50, 1080p59.94, and 1080p60 cameras.

Many professionals shoot in 1080 for the outstanding images that can be obtained, especially with the nanoFlash.

However, with single-link HD-SDI, no camera can output 1080p60 over the link. Dual-Link or HD-SDI 3G is required.

But, 720p60 can be transmitted over an HD-SDI single link.

Thus, for slo-mo, 720p60 is typically used.

But, again, I am very interested in 1080p60 over dual-link or 3G as then one can shoot in 1080 and have outstanding slow-mo, such as 1080p24 timeline with a crank speed of 60. This is very desirable.

Re: development towards 1080p50/60
 

1080p50/60 has recently been set as standard for 3D filming.
Please don't miss this important document ( the 274M SMPTE/ EBU standard):
http://tech.ebu.ch/docs/tech/tech3299.pdf
rafael

Re: development towards 1080p50/60
 

Dear Rafael,

Thank you for posting that document.

It is a very nice reference document, which emphasis on frame rates used in PAL areas.

Re: development towards 1080p50/60
 

Hmmm... Strange... Page 8, Table 3, Item 2, states:

I wonder if it is a typo, or if it truly means R rather than R’. Why would it use the linear value of red (R) but the gamma corrected values of green (G’) and blue (B’).

Re: development towards 1080p50/60
 

You are right Adam; that's a typo on the BT.709 Y' formula..
As Dan points the paper are for PAL-land time-bases, but much on the information can be extrapolated to NTSC-land.
About 1080p60/50, I don't see the need to going there unless you are making Slow-mow for a BIG screen.
The

Re: development towards 1080p50/60
 

Thanks for confirming that.

Re: development towards 1080p50/60
 

Dan, just wondering, is 720p120 a possibility for a single HDSDI lane?

Scarlet will have this framerate and it would be quite nice to be able to record using the Nano.

Thanks

Re: development towards 1080p50/60
 

Dear Tim,

I do not know if 720p120 is possible via 1.485 Gbps Single Link HD-SDI.

I will ask our engineers if this is possible with the Sony Codec Module.

It is a very interesting question.

Re: development towards 1080p50/60
 

Thanks. Lets hope it is possible.

Re: development towards 1080p50/60
 

720p120 contains 921,600 pixels per frame. Multiplied by 120 gives us 110,592,000 pixels per second. With three color channels, we get 331,776,000 colored pixels per second. With 8 bits each, we get 2,654,208,000 bits per second. That is slightly more than 2.654 Gb/s. Even without any overhead, 2.654 is more than 1.485.

As far as I know, SD-HDI transfers uncompressed 4:4:4 video. If that is the case, the answer to the question is: No, it is not possible.

Re: development towards 1080p50/60
 

On second thought, I think it uses 4:2:2, so we need to take 2/3 of that, giving us 1,769,472,000 bits per second, or slightly more than 1.769 Gbps. Still too much.

Re: development towards 1080p50/60
 

Dear Friends,

Do anyone know of a camera that outputs 720p120 via HD-SDI, single-link, dual-link, or 3G?

It is one thing to record internally at 720p120, quite another to send this out via HD-SDI.

Re: development towards 1080p50/60
 

How about over the HDMI input?

Re: development towards 1080p50/60
 

Dear Tim,

That may be possible.

Re: development towards 1080p50/60
 

HDMI can transfer that data in RT, but whatever we put out of the HDMI/SDI, I don't think any of these signal can't be recorded as MPEG-2. Those frames rates are off the specs of the MPEG-2 norm.
Beside needing a new MPEG-2 flavor, I guess we would need a new processor more than a Firmware update.
rafael

Re: development towards 1080p50/60
 

Dear Friends,

I should have been clearer in my reply to Tim.

Yes, I feel that 1080p60 is technically possible over HDMI.

No, the nanoFlash is not designed to handle 1080p60. For one, the Sony Codec can not handle 1080p60 as far as I know.

Re: development towards 1080p50/60
 

If it's possible to specify upper field or lower field first w/ 60i encoding, then there seems to be at least a hypothetical solution to this.

You could split the signal and send it to two encoders. One encoder is set to 60i upper field first. The other is set to 60i lower field first. Combining the streams coming out of these two encoders (similar to detinterlacing PsF material) could create true 60P.

Now how practical any of this is, I of course have no idea.

Re: development towards 1080p50/60
 

ARM Cortex or Nvidia Tegra are (IMO) two types of processors showing promise of raw encode power for 1080p60.

The problem at the moment is: The codec.

MPEG-2 cannot efficiently take in 1080p60. H.264 may be an option, but royalties could get in the way.

AVC-Ultra, the vaporware codec from Panasonic, was to be the definitive 1080p60 codec. Unfortunately, we haven't heard of any products using it.

What we need is an open source codec that encodes well for acquisition in 1080p60 and fits within mobile processor specs for encode/decode. VP8 is what I had in mind, but it's (as expected) under attack from the MPEG-LA.

nanoFlash could offer a Cineform option for 1080p60 if a partnership ever arises down the line. But that's wishful thinking.