PDA

View Full Version : NDI spec?



ebuddington
10-16-2016, 12:43 PM
I'm new to NDI, and trying to get a handle on what it does.

NDI is promoted as an "open standard" - where can I find a formal specification?

What does NDI provide that was not available with preexisting standards (e.g. RTP or MPEG-DASH)?

Thanks for any pointers.

PIZAZZ
10-16-2016, 03:21 PM
This is a great basic place to start:

http://www.newtek.com/solutions/advanced-ip-workflow.html

NDI is not really comparable to streaming technology like rtp and MpegDash. Different items altogether.

ebuddington
10-17-2016, 08:40 AM
Thanks - that's a very broad overview. I'm looking for information like:
- does NDI run over TCP, UDP, IP, IPv6, raw ethernet, or something else entirely?
- is NDI unicast or multicast?
- how is NDI bitrate determined, and how does it handle packet loss?
- what codecs does it support?
- How do NDI devices discover each other?

kanep
10-17-2016, 09:01 AM
There are two parts to how NDI 'works'.

First is discovery, this operates using the mDNS protocol which operates on port 5353/UDP via a multicast protocol.

Once you connect to a NDI source, the connection itself is a TCP and unicast that can be on any port between the range of 4915265535. It can run over IPv4 or IPv6.

NDI bitrate depends on frame size and frame rate. 1080i video can peak at around 100Mbits/sec, with typical datarate in the 50MBit to 80Mbit range. As long as you have adequate bandwidth, packet loss isn't a worry because the TCP protocol makes sure that all packets arrive.

NDI uses it's own codec, it is DCT based like ProRes and DNxHD.

ebuddington
10-17-2016, 12:08 PM
thanks - that's helpful.

ocrete
04-27-2017, 05:47 PM
NDI is promoted as an "open standard" - where can I find a formal specification?


I see claims that NDI is an open protocol, is there a published specification somewhere? Or an Open Source implementation?

SBowie
04-27-2017, 06:48 PM
I see claims that NDI is an open protocol, is there a published specification somewhere? Or an Open Source implementation?See http://pages.newtek.com/NDI-Developers/

livepad
04-28-2017, 02:01 AM
I'm new to NDI, and trying to get a handle on what it does.

NDI is promoted as an "open standard" - where can I find a formal specification?

What does NDI provide that was not available with preexisting standards (e.g. RTP or MPEG-DASH)?

Thanks for any pointers.

https://en.wikipedia.org/wiki/Network_Device_Interface

ocrete
05-01-2017, 11:40 AM
See http://pages.newtek.com/NDI-Developers/

I tried registering there, but I never get an email.. Also, this seems to be only a proprietary SDK?

jcupp
05-01-2017, 08:26 PM
The NDI standard is open (the license is free) the source code is not.

ocrete
05-02-2017, 12:45 PM
The NDI standard is open (the license is free) the source code is not.

I can't find a standard? All I see is a proprietary SDK. Is there a specification somewhere?

kanep
05-02-2017, 01:54 PM
Standard in this case is being used to say that all off the products that are using NDI allows compatibility and interoperability between software & systems. NDI is not something that is overviewed by a standards body.

I think from the point of view are you looking for, the SDK is a binary from NewTek which owns the specification. It is not open source. It is open for anyone to implement in their software.