Interlaced timing indication in /sinks/{sinkId}/properties
N-Nagorny opened this issue · 3 comments
BCP-005-01 says
Each video timing SHOULD be present in the Receiver’s Capabilities as a Constraint Set with a non-empty
urn:x-nmos:cap:format:frame_width
urn:x-nmos:cap:format:frame_height
urn:x-nmos:cap:format:grain_rate which MUST be the exact frame rate of the signal
The timing descriptors MAY include one or more of the following mappings:
urn:x-nmos:cap:format:interlace_mode
urn:x-nmos:cap:meta:preference
The first three properties are reflected in edid_timing.json. What do you think about adding an optional interlace_mode property?
BCP-005-01 does not dictate how to map an interlaced timing to video Flow interlace_mode. Does anybody know if it's appropriate to expose all three interlaced_* in this case?
I am in favor of adding it, it would be nice to match it to https://specs.amwa.tv/is-04/releases/v1.3.1/APIs/NodeAPI.html#flows__flowid__get
interlace_mode" : {
"description" : "Interlaced video mode for frames in this Flow",
"type" : "string",
"default": "progressive",
"enum" : [
"progressive",
"interlaced_tff",
"interlaced_bff",
"interlaced_psf"
]
Are we saying we are adding interlaced_mode to the video media profiles as optional and it will follow from the BCP-004-01 / Capabilities defined in the parameter register which actually will result in an enum with values taken from the flow interlace_mode?
From the parameter register capabilities:
Name: urn:x-nmos:cap:format:interlace_mode
Description: Identifies the acceptable interlace mode of a video stream.
Specification: per AMWA BCP-004-01
Type: string (enumerated values as per AMWA IS-04)
Target: (a) video Flow ‘interlace_mode’, (b) SDP attribute ‘a=fmtp:’ format-specific parameters ‘interlace’, ‘segmented’ and ‘top-field-first’
Applicability: AMWA IS-04
interlaced_mode is already an optional property of video Media Profile. There is also edid.json on the Sink side which lists timings supported by the Sink. Each timing consists of frame size and rate and I propose to add optional interlace_mode to it.