Play VOD streams registered with Google Cloud Video Stitcher API
This guide demonstrates how to use the IMA DAI SDK for CAF Web Receivers to request and play a Google Cloud VOD stream session .
This guide expands on the basic example from full service DAI, adding support for streams registered with the Google Cloud Video Stitcher API.
Ensure your streaming format is supported by CAF web receivers before continuing.
For information on integrating with other platforms or on using the IMA client-side SDKs, see Interactive Media Ads SDKs .
Background
Before using this guide, familiarize yourself with the Chromecast Application Framework's Web Receiver protocol.
This guide assumes a basic level of familiarity with CAF receiver concepts,
such as message
interceptors
, MediaInformation
objects, and using the Cast Command and Control
tool
to emulate a CAF sender.
App components and architecture
Implementing VOD stream playback with the Google Cloud Video Stitcher API with the IMA CAF DAI SDK involves two main components as demonstrated in this guide:
-
VideoStitcherVodStreamRequest
: An object that defines a stream request to Google's servers. -
StreamManager
: An object that handles communication between the video stream and the IMA DAI SDK, such as firing tracking pings and forwarding stream events to the publisher.
Set up a Google Cloud project
Enter the following variables for use in the IMA SDK:
-
Location- The Google Cloud region where your VOD config was created.
LOCATION
-
Project Number: The Google Cloud project number using the Video Stitcher API.
PROJECT_NUMBER
-
OAuth Token: A service account's short lived OAuth Token with the Video Stitcher user role. Read more about creating short-lived credentials for service accounts .
OAUTH_TOKEN
-
Network Code: Google Ad Manager network code for requesting ads.
NETWORK_CODE
-
VOD Config ID- The VOD config ID for the VOD stream.
VOD_CONFIG_ID
Read more about creating the VOD config ID in the Cloud stitching create a VOD config guide .
VOD_URI
Set up a custom cast receiver
To develop a custom cast receiver, you need the following:
-
A Cast Developer Console account with test devices in an allowlist.
-
A hosted web receiver app that is registered with your Cast Developer Console, and which can be modified to host the code provided by this guide.
-
A sending app configured to use your web receiver app. For the purposes of this example, this guide uses the Cast Command and Control tool as the sender.
Prepare a sender to pass stream data to the receiver
First, configure your sender app to make a load request to your web receiver,
containing the following fields in your platform's MediaInformation
object.
contentId
CONTENT_ID
contentUrl
BACKUP_STREAM_URL
contentType
BACKUP_STREAM_MIMETYPE
streamType
VOD
customData
The customData
field contains a key-value store of additional
required fields. In this case, customData
contains the DAI stream
data that you collected.
Field | Contents |
---|---|
region
|
LOCATION
|
projectNumber
|
PROJECT_NUMBER
|
oAuthToken
|
OAUTH_TOKEN
|
networkCode
|
NETWORK_CODE
|
vodConfigId
|
VOD_CONFIG_ID
|
Here are some code samples to help you get started:
Web
To configure these values in a Cast web sender, first create a MediaInfo
object with the required data, then make a load
request
to the web receiver.
// Create mediaInfo object
const
mediaInfo
=
new
chrome
.
cast
.
media
.
MediaInfo
(
" CONTENT_ID
"
);
mediaInfo
.
contentUrl
=
" BACKUP_STREAM_URL
"
;
mediaInfo
.
contentType
=
" BACKUP_STREAM_MIMETYPE
"
;
mediaInfo
.
streamType
=
chrome
.
cast
.
media
.
StreamType
.
VOD
;
mediaInfo
.
customData
=
{
region
:
" LOCATION
"
,
projectNumber
:
" PROJECT_NUMBER
"
,
oAuthToken
:
" OAUTH_TOKEN
"
,
networkCode
:
" NETWORK_CODE
"
,
vodConfigId
:
" VOD_CONFIG_ID
"
};
// Make load request to cast web receiver
const
castSession
=
cast
.
framework
.
CastContext
.
getInstance
().
getCurrentSession
();
const
request
=
new
chrome
.
cast
.
media
.
LoadRequest
(
mediaInfo
);
castSession
.
loadMedia
(
request
).
then
(
()
=
>
{
console
.
log
(
'Load succeed'
);
},
(
errorCode
)
=
>
{
console
.
log
(
'Error code: '
+
errorCode
);
});
Android
To configure these values in a Cast web sender, first create a MediaInfo
object
with the required data, then make a load
request
to the web receiver.
JSONObject
customData
=
new
JSONObject
()
.
put
(
"region"
,
" LOCATION
"
)
.
put
(
"projectNumber"
,
" PROJECT_NUMBER
"
)
.
put
(
"oAuthToken"
,
" OAUTH_TOKEN
"
)
.
put
(
"networkCode"
,
" NETWORK_CODE
"
)
.
put
(
"vodConfigId"
,
" VOD_CONFIG_ID
"
);
MediaInfo
mediaInfo
=
MediaInfo
.
Builder
(
" CONTENT_ID
"
)
.
setContentUrl
(
" BACKUP_STREAM_URL
"
)
.
setContentType
(
" BACKUP_STREAM_MIMETYPE
"
)
.
setStreamType
(
MediaInfo
.
STREAM_TYPE_VOD
)
.
setCustomData
(
customData
)
.
build
();
RemoteMediaClient
remoteMediaClient
=
mCastSession
.
getRemoteMediaClient
();
remoteMediaClient
.
load
(
new
MediaLoadRequestData
.
Builder
().
setMediaInfo
(
mediaInfo
).
build
());
iOS (Obj-C)
To configure these values in a Cast web sender, first create a GCKMediaInformation
object with the required data, then make a load
request
to the web receiver.
NSURL
url
=
[
NSURL
URLWithString
:
@" BACKUP_STREAM_URL
"
];
NSDictionary
*
customData
=
@{
@"region"
:
@" LOCATION
"
,
@"projectNumber"
:
@" PROJECT_NUMBER
"
,
@"oAuthToken"
:
@" OAUTH_TOKEN
"
,
@"networkCode"
:
@" NETWORK_CODE
"
,
@"vodConfigId"
:
@" VOD_CONFIG_ID
"
}
;
GCKMediaInformationBuilder
*
mediaInfoBuilder
=
[[
GCKMediaInformationBuilder
alloc
]
initWithContentID
:
@" CONTENT_ID
"
];
mediaInfoBuilder
.
contentURL
=
url
;
mediaInfoBuilder
.
contentType
=
@" BACKUP_STREAM_MIMETYPE
"
;
mediaInfoBuilder
.
streamType
=
GCKMediaStreamTypeNone
;
mediaInfoBuilder
.
customData
=
customData
;
self
.
mediaInformation
=
[
mediaInfoBuilder
build
];
GCKRequest
*
request
=
[
self
.
sessionManager
.
currentSession
.
remoteMediaClient
loadMedia
:
self
.
mediaInformation
];
if
(
request
!=
nil
)
{
request
.
delegate
=
self
;
}
iOS (Swift)
To configure these values in a Cast web sender, first create a GCKMediaInformation
object with the required data, then make a load
request
to the web receiver.
let
url
=
URL
.
init
(
string
:
" BACKUP_STREAM_URL
"
)
guard
let
mediaURL
=
url
else
{
print
(
"invalid mediaURL"
)
return
}
let
customData
=
[
"region"
:
" LOCATION
"
,
"projectNumber"
:
" PROJECT_NUMBER
"
,
"oAuthToken"
:
" OAUTH_TOKEN
"
,
"networkCode"
:
" NETWORK_CODE
"
,
"vodConfigId"
:
" VOD_CONFIG_ID
"
]
let
mediaInfoBuilder
=
GCKMediaInformationBuilder
.
init
(
contentId
:
" CONTENT_ID
"
)
mediaInfoBuilder
.
contentURL
=
mediaUrl
mediaInfoBuilder
.
contentType
=
" BACKUP_STREAM_MIMETYPE
"
mediaInfoBuilder
.
streamType
=
GCKMediaStreamType
.
none
mediaInfoBuilder
.
customData
=
customData
mediaInformation
=
mediaInfoBuilder
.
build
()
guard
let
mediaInfo
=
mediaInformation
else
{
print
(
"invalid mediaInformation"
)
return
}
if
let
request
=
sessionManager
.
currentSession
?.
remoteMediaClient
?.
loadMedia
(
mediaInfo
)
{
request
.
delegate
=
self
}
CAC tool
To configure these values in the Cast Command and Control tool , click the Load Media tab, and set the custom load request type to LOAD. Then replace the JSON data in the text area with this JSON:
{
"media"
:
{
"contentId"
:
" CONTENT_ID
"
,
"contentUrl"
:
" BACKUP_STREAM_URL
"
,
"contentType"
:
" BACKUP_STREAM_MIMETYPE
"
,
"streamType"
:
"VOD"
,
"customData"
:
{
"region"
:
" LOCATION
"
,
"projectNumber"
:
" PROJECT_NUMBER
"
,
"oAuthToken"
:
" OAUTH_TOKEN
"
,
"networkCode"
:
" NETWORK_CODE
"
,
"vodConfigId"
:
" VOD_CONFIG_ID
"
}
}
}
This custom load request can be sent to the receiver to test the rest of the steps.
Create a custom CAF web receiver
Create a custom web receiver, as seen in the CAF SDK Custom Web Receiver Guide .
Your receiver's code should look like the following:
<html>
<head>
<script
src="//www.gstatic.com/cast/sdk/libs/caf_receiver/v3/cast_receiver_framework.js">
</script>
</head>
<body>
<cast-media-player></cast-media-player>
<script>
const castContext = cast.framework.CastReceiverContext.getInstance()
castContext.start();
</script>
</body>
</html>
Import the IMA DAI SDK and get the Player Manager
Add a script tag to import the IMA DAI SDK for CAF to your web receiver, just after the script loading CAF. Then in the script tag that follows, store the receiver context and player manager as constants before starting the receiver.
<html>
<head> <script
src="//www.gstatic.com/cast/sdk/libs/caf_receiver/v3/cast_receiver_framework.js"></script><script src="//imasdk.googleapis.com/js/sdkloader/cast_dai.js"></script>
</head>
<body>
<cast-media-player></cast-media-player>
<script>
const castContext = cast.framework.CastReceiverContext.getInstance(); const playerManager = castContext.getPlayerManager();castContext.start();
</script>
</body>
</html>
Initialize the IMA Stream Manager
Initialize the IMA Stream Manager.
<html>
<head>
<script type="text/javascript"
src="//www.gstatic.com/cast/sdk/libs/caf_receiver/v3/cast_receiver_framework.js"></script>
<script src="//imasdk.googleapis.com/js/sdkloader/cast_dai.js"></script>
</head>
<body>
<cast-media-player></cast-media-player>
<script>
const castContext = cast.framework.CastReceiverContext.getInstance();
const playerManager = castContext.getPlayerManager(); const streamManager = new google.ima.cast.dai.api.StreamManager();castContext.start();
</script>
</body>
</html>
Create the Stream Manager Load Interceptor
Before your media items are passed to CAF, create your stream request in a LOAD message interceptor .
const
castContext
=
cast
.
framework
.
CastReceiverContext
.
getInstance
();
const
playerManager
=
castContext
.
getPlayerManager
();
const
streamManager
=
new
google
.
ima
.
cast
.
dai
.
api
.
StreamManager
();
/**
* Creates a VOD stream request object for the Video Stitcher API.
* @param {!LoadRequestData} castRequest The request object from the cast sender
* @return {StreamRequest} an IMA stream request
*/
const
createStreamRequest
=
(
castRequest
)
=
>
{
/* ... */
};
/**
* Initates a DAI stream request for the final stream manifest.
* @param {!LoadRequestData} castRequest The request object from the cast sender
* @return {Promise<LoadRequestData>} a promise that resolves to an updated castRequest, containing the DAI stream manifest
*/
const
createDAICastRequest
=
(
castRequest
)
=
>
{
return
streamManager
.
requestStream
(
castRequest
,
createStreamRequest
(
castRequest
))
.
then
((
castRequestWithStreamData
)
=
>
{
console
.
log
(
'Successfully made DAI stream request.'
);
return
castRequestWithStreamData
;
})
.
catch
((
error
)
=
>
{
console
.
log
(
'Failed to make DAI stream request.'
);
// CAF will automatically fallback to the content URL
// that it can read from the castRequest object.
return
castRequest
;
});
};
playerManager
.
setMessageInterceptor
(
cast
.
framework
.
messages
.
MessageType
.
LOAD
,
createDAICastRequest
);
castContext
.
start
();
Create the stream request
Complete the createStreamRequest
function to create a Video Stitcher API VOD
stream request, based on the CAF load request.
/**
* Creates a VOD stream request object for the Video Stitcher API.
* @param {!LoadRequestData} castRequest The request object from the cast sender
* @return {StreamRequest} an IMA stream request
*/
const
createStreamRequest
=
(
castRequest
)
=
>
{
const
streamRequest
=
new
google
.
ima
.
cast
.
dai
.
api
.
VideoStitcherVodStreamRequest
();
const
customData
=
castRequest
.
media
.
customData
;
streamRequest
.
region
=
customData
.
region
;
streamRequest
.
projectNumber
=
customData
.
projectNumber
;
streamRequest
.
oAuthToken
=
customData
.
oAuthToken
;
streamRequest
.
networkCode
=
customData
.
networkCode
;
streamRequest
.
vodConfigId
=
customData
.
vodConfigId
;
streamRequest
.
videoStitcherSessionOptions
=
{};
return
streamRequest
;
};
(Optional) Add streaming session options
Customize your stream request by adding session options to override the default
Cloud Video Stitcher API configuration using VideoStitcherVodStreamRequest.videoStitcherSessionOptions
.
If you provide an unrecognized option, the Cloud
Video Stitcher API will respond with an HTTP 400 error. Consult the troubleshooting guide
for assistance.
For example, you can override the manifest options with the following code snippet, which requests two stream manifests with renditions ordered from lowest bitrate to highest.
...
// The following session options are examples. Use session options
// that are compatible with your video stream.
streamRequest
.
videoStitcherSessionOptions
=
{
"manifestOptions"
:
{
"bitrateOrder"
:
"ascending"
}
};
streamManager
.
requestStream
(
streamRequest
);