Is it confirmed DiscoveryHD accepts XDCAM?
 

I have heard that XDCAMHD does not have the same 15% content restriction as HDV for DiscoveryHD,,,can someone confirm this? I am producing a pilot I'd like to shop around and I can save a grip working in XDCAM over HDCAM for my workflow.

Has anyone had experience shooting 100% XDCAMHD for any other HD network?

Thanks in advance....

Take a look at this PDF document.

Discovery HD Specifications

Greetings!

Thanks Ivan!

Now I'm new to XDCAM so no one please get upset by this question: XDCAMHD is NOT considered HDV at 35mbs, right? (since they use similar GOP MPEG2 encoding, its a little confusing)

XDCAM HD is not the HDV format in 18, 25 or 35 mbps mode. It is called MPEG-HD.

Thanks for the clarification!

XDCAM HD at 35Mb uses a variable bit rate codec as opposed to HDV's constant bit rate codec. This allows XDCAM to adjust how the data is allocated to each frame, thus frame that need extra bandwidth get it. This results in a much more efficient use of the data and thus far fewer artifacts and better performance overall.

and XDCAM HD at 25mbps is a constant bit rate that is very much the same thing as HDV.

Nope, still not the same as HDV because of the higher quality front end on a camera. It is able to put a lot better image into the MPEG encoder even at 25mb CBR. It may be spec'd the same, but the video from the F350/330 would still look better upon close inspection. Larger chips are a big part of the reason allowing for wider dynamic range and lower noise.

Also, from the audio side, the XDCAM HD produces 4 channel uncompressed audio in all modes of shooting, whereas HDV is using MPEG compression on the audio. That's not to say that HDV audio doesn't sound very good when handled correctly.

-gb-

and "the video specs" for XDCAM HD at 25mbps is a constant bit rate that is very much the same thing as HDV.

The same, only different.

So no, they're not the same. Read the specs, Bob.

Incidentally, there is not a "very much" the same. .There is merely the same and not. This... is not.

They are not at all the same. The common bit rate is meaningless in this regard.

We cleared up this misconception back in April: http://www.dvinfo.net/conf/showthread.php?t=90898

I have read the specs and I use both HDV and XDCAM HD. I am only refering to the recording specs, not the difference in camera lenses or chip size. I see no information in the link you provided to the contrary, Chris.

There is no question that the 35mbps of XDCAM is a different animal, but at 25mbps and a constant bit rate, it shows the same issues as HDV. Don't get me wrong, I find the HDV footage from a Sony Z1 to be quite amazing. It will also cut quite well with the XDCAM footage (from the F350) if it is handled properly.

The 2 cameras have been a great compliment to each other. I do look forward to the new Sony EX when it is released, as it will allow an even better match and can record at 24p and variable frame rates.

I see this statement a lot I have used the setup a lot also. But I have not edited the footage that I have shot with this setup. So when people say when you set the Z1 up correctly it will cut together well. What is this magic setup that people are talking about? Because most of the time we just leave the Z1 at its default settings and go. I have not heard anything from the post house that the footage is drastically different as a matter of fact they have not said anything to me about the footage at all. But that is a whole other story in itself.

I'm following this discussion with interest.

Can someone clear something up for me?

Is the audio sampling rate is not taken up in the quoted figures of HDV's 25 CBR mbps. compared to XDCam's 35 VBR mbps?

Not knowing the precise figures, I would have thought that 4 uncompressed audio tracks would take up lot of mbits more than two tracks of MPEG audio.

Or is it all video compression that is talked about here, with audio added on, or is audio included in the figures, if so, how much room does the 4 channels PCM take up?

Cheers all,

Vaughan

Looks like a key fact here is that XDCAM HD source footage is only accepted in the 35 Mbps recording mode, which makes sense. Also interesting that footage from the Panasonic HVX200 is accepted with the same restrictions as HDV, which shows that the overall quality of a camera is at least as important as the recording format it uses.

P.S. An interesting question here is whether broadcasters will come to accept footage from the XDCAM EX camera without restrictions, once that camera is shipping.

I imagine that Discovery specified a 35mbps variable rate over the constant 25mbps rate because there was a difference in the quality of the footage. They decided they needed a starting point for their specs.

But, they also allowed the show "The Deadliest Catch" to shoot the majority (if not 100%) of their show in HDV with Sony small cameras. I have noticed that all of the cameras that are mentioned in these forums are finding use in various productions by different photographers. I did not want to start debating the merits of specific cameras.

The reference to setting up a Z1 to match a F350 was limited to the camera setting itself. There is not a lot of adjustments that can be made with the Z1, so depending on how your F350 is setup you can only adjust detail and chroma saturation and then try to match white balance in the field. The rest has to be done in post. Most of what I have had to adjust is in the gamma and the blacks.

I thought I read somewhere that "The Deadliest Catch" is shot mostly with PD170s, but I can't find that reference now. Also, as far as I can know the show isn't airing in HD, so the HD technical requirements wouldn't be relevant.

Getting back to the original topic, the point seems to be that XDCAM HD at the 35 Mbps bit rate is considered good enough for Discovery HD, so there's the answer.

Here's a reference:
http://www.avid.com/profiles/070521_...atch_dnxhd.asp

Thanks Bob, that's useful info. Something to mention to customers if they wonder about the viability of HDV...

P.S. Could it be that they shot earlier seasons on PD170s? I'm almost sure I saw that in an article somewhere.

Don't know. Could be.

Also in that article they mention that the XDCAM HD format was used for the program "Icy Roads" on the History Channel. I have read an interview with the DP in which he stated the cameras were chosen for the picture quality and ruggedness in those conditions.

Slight correction, Bob. That show is called, "Ice Road Truckers". A job, BTW, that the few truck drivers I know say they would never do!

-gb-