Add more rendition properties CR 10-18

[jolla56]

Description of the change: (free-text)

ninjs launched with a concise set of rendition properties, that were felt to be universally applicable to all non-text rendition types.

"href" : {
    "description" : "The URL for accessing the rendition as a resource",
    "type" : "string",
    "format" : "uri"
},
"mimetype" : {
    "description" : "A MIME type which applies to the rendition",
    "type" : "string"
},
"title" : {
    "description" : "A title for the link to the rendition resource",
    "type" : "string"
},
"height" : {
    "description" : "For still and moving images: the height of the display area measured in pixels",
    "type" : "number"
},
"width" : {
    "description" : "For still and moving images: the width of the display area measured in pixels",
    "type" : "number"
},
"sizeinbytes" : {
    "description" : "The size of the rendition resource in bytes",
    "type" : "number"
}

I propose adding the following properties for renditions, which are variously applicable to audio, video and image rendition types:

• format
• fileextension
• digest
• originalfilename
• orientation
• duration
• resolution
• samplerate
• averagebitrate
• videocodec
• framerate
• aspectratio
• colourspace
• videoscaling

[jolla56]

JAYSON:

Hmmm the schema is starting to look like a Controlled Vocabulary if we do this. Maybe use a scheme like in some of the other proposals?

[jolla56]

duration and format was added in 1.2