XDCAM SHD

[FranceBB]

Hi,
I noticed that the "SHD" standard has not been implemented in the XDCAM node.
The SHD standard is just a normal XDCAM 1080i but with 85Mbit/s.

Format: XDCAM SHD
VideoFormat: MPEG-2 ES (ISO/IEC 13818-2)
Level/Profile: 422Profile High Level
GOP: Long GOP; N=12; M=3; pattern: IBBPBBPBBPBB
Chroma Sampling: 4:2:2 planar (yv16)
Bit Rate: 85 Mbit/s
Constant Bit Rate: Yes
Picture Size (active): 1920 x1080
Aspect Ratio: 16:9
Frame Rate: 25i
Scan Type: Interlaced
Sequence Header: Before each GOP
Field Encoding: Top field first
Bit Depth: 8 bit
Timecode in GOP header: Not in use
Color Range: Limited
Color Matrix: BT.709

XDCAM SHD (Super HD) is not very common, still it's used by some companies.
I think you should add the possibility to increase bitrate from 50Mbit/s to 85Mbit/s and leave the rest of the node as it is.
I could just use the custom ffmpeg node, but I don't think it's worth it 'cause I would lose all the conditionals you set inside the XDCAM node to handle all the kind of conversions.

Kind regards,
Frank.

[momocampo]

Hello FranceBB,

I think there is a mistake in your SHD description, the bitrate should be 85 Mbits/s I suppose
I don't know this SHD, are you sure it exists?
Cheers.

Benjamin

[FranceBB]

Yep, sorry, I meant 85 Mbit/s.
Yes, XDCAM Super HD actually exists and it's officially supported by the Omneon Playout Ports, but it's not very common.

[admin]

FranceBB, do you have any official documentation describing this XDCAM flavor? I have looked but a simple search like "XDCAM SHD" or "XDCAM HD 85" gives nothing of value.

-steinar

[jordanh]

Hey FranceBB,

I had a look in the 3 RDD9 standards up to 2013 and did not find any reference to 85Mbps either. Are you sure this is connected to XDCAM?

[admin]

FranceBB,

It might be as trivial as to just pump up all the video bit rate values to accommodate to the (non existing) 85 Mbit/s variant but I'm a bit hesitant to create support for something based on guesses. That's why it's important to get some documentation.

-steinar

[FranceBB]

I tried to gather some docs, but the only place in which I've found it is the Omneon specs provided by Harmonic (check the MPEG-2 Long GOP next to "XDCAM"): https://www.harmonicinc.com/media/2016/ ... ormats.pdf

What about a warning on the bitrate saying that it may not be supported?

[admin]

Thanks! So according to this documentation Quantel supports MPEG-2 l-gop up tp 85 Mbit/s, which is totally different from being a standard. I don't think making a special 85 Mbit/s template in the existing XDCAM-HD encoder is the right way to go. How about the i-frame HD variants also supported by Quantel. Should that also be considered a XDCAM-HD format and supported in FFAStrans? The only sane way to solve this is to create a new generic MPEG-2 encoders that lets you set parameters like gop-structure and bit-rate yourself.

-steinar

[jordanh]

Dear FranceBB, what is your reason to want to play some generic MPEG2 on such an expensive Device? From experience such experiments only lead to tears. Wouldn't it be possible for you to just use some standardized Format e.g. AVC-I 100 standard instead?

The number problems you can experience with non standard material on a hardware decoder is indefinite. Starting with the vendor not defining ALL possible MPEG parameters they support, e.g. what is the maximum frame Size?
You can easily bring your playout server into a state only a reboot can repair the issue when experimenting with different Formats.

[FranceBB]

Dear FranceBB, what is your reason to want to play some generic MPEG2 on such an expensive Device? From experience such experiments only lead to tears. Wouldn't it be possible for you to just use some standardized Format e.g. AVC-I 100 standard instead?

The number problems you can experience with non standard material on a hardware decoder is indefinite. Starting with the vendor not defining ALL possible MPEG parameters they support, e.g. what is the maximum frame Size?
You can easily bring your playout server into a state only a reboot can repair the issue when experimenting with different Formats.

Of course I would use H.264 10bit if I had to choose, but unfortunately, those specs were selected by someone else and I had no say on them whatsoever, so MPEG-2 it is (which is old, unoptimised and has a lot of banding due to it being 8bit, but hey, I didn't choose the specs).