Adaptive Bitrate Packaging
Package
An output package is a group of containers each representing an Adaptive Bitrate (ABR) variant. Media streams are routed from the input containers to the variant containers in the output package.
For example the following composition creates an HTTP Live Streaming (HLS) package with two variant containers hi and lo:
---
input:
container:
- name: 360p
video:
- name: v1
- name: 720p
video:
- name: v2
- name: aac
audio:
- name: a1
output:
package:
- name: output1
type: 'hls '
properties:
SegmentDuration: 10.0
container:
- name: lo
type: 'mpg2'
video:
- name: v1
audio:
- name: a1
- name: hi
type: 'mpg2'
video:
- name: v2
audio:
- name: a1
{
"input": {
"container": [
{
"name": "360p",
"video": [
{
"name": "v1"
}
]
},
{
"name": "720p",
"video": [
{
"name": "v2"
}
]
},
{
"name": "aac",
"audio": [
{
"name": "a1"
}
]
}
]
},
"output": {
"package": [
{
"name": "output1",
"type": "hls ",
"properties":{
"SegmentDuration": 10
},
"container": [
{
"name": "lo",
"type": "mpg2",
"video": [
{
"name": "v1"
}
],
"audio": [
{
"name": "a1"
}
]
},
{
"name": "hi",
"type": "mpg2",
"video": [
{
"name": "v2"
}
],
"audio": [
{
"name": "a1"
}
]
}
]
}
]
}
}
Note that this example simply re-packages the encoded v1, v2 and a1 input streams.
Supported Formats
Transform supports most common ABR package formats. Each type of package supports different variant container formats, encryption algorithms and DRM protection systems.
See the Package Reference page for additional details.
Path Templates
A package produces multiple output files. The file paths for a package are specified using a template dictionary. Each entry has a name and a corresponding path template. Template names are defined for each package type.
For example the following composition provides a template dictionary for an HLS package. In this case the path property sets the parent directory. Sub-directories can be created with the / character.
---
output:
package:
- type: 'hls '
name: output1
path: "$job_id$"
template:
- name: key
path: "$kid$.bin"
- name: manifest
path: "$package$.m3u8"
- name: playlist
path: "$container$/$container$.m3u8"
- name: media
path: "$container$/$container$_$segment$.$extension$"
container:
- name: lo
- name: hi
{
"output": {
"package": [
{
"type": "hls ",
"name": "output1",
"path":"$job_id$",
"template": [
{
"name": "key",
"path": "$kid$.bin"
},
{
"name": "manifest",
"path": "$package$.m3u8"
},
{
"name": "playlist",
"path": "$container$/$container$.m3u8"
},
{
"name": "media",
"path": "$container$/$container$_$segment$.$extension$"
}
],
"container": [
{
"name": "lo"
},
{
"name": "hi"
}
]
}
]
}
}
Stream Encoding
In a typical package the media streams are encoded at different resolutions and bit rates, for example:
---
input:
container:
- name: input1
video:
- name: v1
output:
package:
- name: output1
type: 'hls '
properties:
SegmentDuration: 3
container:
- name: lo
type: mpg2
video:
- route:
name: v1
width: 640
height: 480
encode:
type: h264
properties:
BitRate: 500000
- name: hi
type: mpg2
video:
- route:
name: v1
width: 1280
height: 720
encode:
type: h264
properties:
BitRate: 1000000
{
"input": {
"container": [
{
"name": "input1",
"video": [
{
"name": "v1"
}
]
}
]
},
"output": {
"package": [
{
"name": "output1",
"type": "hls ",
"properties":{
"SegmentDuration": 3
},
"container": [
{
"name": "lo",
"type": "mpg2",
"video": [
{
"route": {
"name": "v1"
},
"width": 640,
"height": 480,
"encode": {
"type": "h264",
"properties": {
"BitRate": 500000
}
}
}
]
},
{
"name": "hi",
"type": "mpg2",
"video": [
{
"route": {
"name": "v1"
},
"width": 1280,
"height": 720,
"encode": {
"type": "h264",
"properties": {
"BitRate": 1000000
}
}
}
]
}
]
}
]
}
}
Stream Replication
A media stream (typically audio) can be encoded and routed to multiple variant containers, for example:
---
input:
container:
- name: input1
video:
- name: v1
audio:
- name: a1
output:
package:
- name: output1
type: 'hls '
properties:
SegmentDuration: 3
audio:
- name: a2
route:
name: a1
encode:
type: mcac
properties:
BitRate: 128000
container:
- name: lo
type: mpg2
video:
- route:
name: v1
width: 640
height: 480
encode:
type: h264
properties:
BitRate: 500000
audio:
- route:
name: a2
- name: hi
type: mpg2
video:
- route:
name: v1
width: 1280
height: 720
encode:
type: h264
properties:
BitRate: 1000000
audio:
- route:
name: a2
{
"input":{
"container":[
{
"name":"input1",
"video":[
{
"name":"v1"
}
],
"audio":[
{
"name":"a1"
}
]
}
]
},
"output":{
"package":[
{
"name":"output1",
"type":"hls ",
"properties":{
"SegmentDuration":3
},
"audio":[
{
"name":"a2",
"route":{
"name":"a1"
},
"encode":{
"type":"mcac",
"properties":{
"BitRate":128000
}
}
}
],
"container":[
{
"name":"lo",
"type":"mpg2",
"video":[
{
"route":{
"name":"v1"
},
"width":640,
"height":480,
"encode":{
"type":"h264",
"properties":{
"BitRate":500000
}
}
}
],
"audio":[
{
"route":{
"name":"a2"
}
}
]
},
{
"name":"hi",
"type":"mpg2",
"video":[
{
"route":{
"name":"v1"
},
"width":1280,
"height":720,
"encode":{
"type":"h264",
"properties":{
"BitRate":1000000
}
}
}
],
"audio":[
{
"route":{
"name":"a2"
}
}
]
}
]
}
]
}
}
Digital Rights Management (DRM)
A composition is protected by applying encryption to each output package using one or more encryption keys.
Each encryption key has a unique public id and a private value. The key identifier is assigned by the DRM provider when a key is created. A protection system allows a player to securely request the key from the DRM provider.
For example the following composition is encrypted using a single key and protected using both Microsoft PlayReady and Google Widevine:
output:
package:
- type: 'dash'
encryption:
key:
- id: a9f4d51bf8d342c78de5ebeb2b6c512e
value: 1809764c9860ea32ab370242ac130002
protection:
- type: 'play'
- type: 'vine'
container:
- type: 'mpg4'
encryption:
key:
- id: a9f4d51bf8d342c78de5ebeb2b6c512e
{
"output": {
"package": [
{
"type": "dash",
"encryption": {
"key": [
{
"id": "a9f4d51bf8d342c78de5ebeb2b6c512e",
"value": "1809764c9860ea32ab370242ac130002"
}
],
"protection": [
{
"type": "play"
},
{
"type": "vine"
}
]
},
"container": [
{
"type": "mpg4",
"encryption": {
"key": [
{
"id": "a9f4d51bf8d342c78de5ebeb2b6c512e"
}
]
}
}
]
}
]
}
}
Updated about 1 year ago