- From: Bernard Aboba <Bernard.Aboba@microsoft.com>
- Date: Thu, 26 Jun 2014 17:46:43 +0000
- To: "public-ortc@w3.org" <public-ortc@w3.org>
The specification needs to make clear how to lay out temporal scalabilty and turn it on. We also need an example with temporal and spatial scalability.
Here are some proposed examples of temporal scalability as well as combined temporal and spatial scalability:
Example 11
Example of 3-layer temporal scalability encoding
var encodings =[{
// Base framerate is one quarter of the input framerate
encodingId: "0",
framerateScale: 0.25
}, {
// Temporal enhancement (half the input framerate when combined with the base layer)
encodingId: "1",
dependencyEncodingIds: ["0"]
framerateScale: 0.5
}, {
// Another temporal enhancement layer (full input framerate when all layers combined)
encodingId: "2",
dependencyEncodingIds: ["0", "1"]
framerateScale: 1.0
}]
Example of 3-layer temporal scalability with all but bottom layer disabled
var encodings =[{
encodingId: "0",
framerateScale: 0.25
}, {
encodingId: "1",
dependencyEncodingIds: ["0"],
framerateScale: 0.5,
active: false
}, {
encodingId: "2",
dependencyEncodingIds: ["0", "1"],
framerateScale: 1.0,
active: false
}];
Example of 3-layer spatial scalability encoding
var encodings =[{
// Base layer with one quarter input resolution
encodingId: "0",
resolutionScale: 0.25
}, {
// Spatial enhancement layer providing half input resolution when combined with the base layer
encodingId: "1",
dependencyEncodingIds: ["0"]
resolutionScale: 0.5
}, {
// Additional spatial enhancement layer providing full input resolution when combined with all layers
encodingId: "2",
dependencyEncodingIds: ["0", "1"]
resolutionScale: 1.0
}]
Example 13
Example of 3-layer spatial scalability with all but bottom layer disabled
var encodings =[{
encodingId: "0",
resolutionScale: 0.25
}, {
encodingId: "1",
dependencyEncodingIds: ["0"],
resolutionScale: 0.5,
active: false
}, {
encodingId: "2",
dependencyEncodingIds: ["0", "1"],
resolutionScale: 1.0,
active: false
}];
Example of 2-layer spatial scalability combined with 2-layer temporal scalability
var encodings =[{
// Base layer providing half input framerate and resolution
encodingId: "0",
resolutionScale: 0.5,
framerateScale: 0.5
}, {
// Temporal enhancement to base layer providing full input framerate and half resolution
encodingId: "1",
dependencyEncodingIds: ["0"],
resolutionScale: 0.5,
framerateScale: 1.0
}, {
// Spatial enhancement to base layer providing half input framerate and full resolution
encodingId: "2",
dependencyEncodingIds: ["0"],
resolutionScale: 1.0,
framerateScale: 0.5
}, {
// Spatial enhancement to temporal enhancement providing full input framerate and resolution
encodingId: "3",
dependencyEncodingIds: ["0", "1"],
resolutionScale: 1.0,
framerateScale:1.0
}]
Received on Thursday, 26 June 2014 17:47:25 UTC