chrome.tabCapture.capture returned stream is undefined
I've got some js code in a chrome background extension of the following :
function handleCapture(stream) {
console.log('content captured');
console.log("backround.js stream: ", stream);
alert(stream);
// localStream = stream; // used by RTCPeerConnection addStream();
// initialize(); // start signalling and peer connection process
}
function captureCurrentTab() {
console.log('reqeusted current tab');
chrome.tabs.getSelected(null, function(tab) {
console.log('got current tab');
var selectedTabId = tab.id;
chrome.tabCapture.capture({
audio : false,
video : true
}, handleCapture);
});
}
However, when this is ran, the "handleCapture" variable "stream" that is passed in is always undefined? Is this to be expected or is there something that I am missing here?
Also, I've confirmed that my manifest.json contains the capture permission and I am using chrome canary Version 31.0.1607.1 canary Aura.
Thanks, Mike
You should probably provide some constraints to make it work. See: http://developer.chrome.com/extensions/tabCapture.html#type-MediaStreamConstraint
The capture param you provided is a MediaTrackConstraint, see: http://dev.w3.org/2011/webrtc/editor/getusermedia.html#mediastreamconstraints
that is also a simple JS object, where you should set some mandatory options, see: http://dev.w3.org/2011/webrtc/editor/getusermedia.html#idl-def-MediaTrackConstraints
So the following should help, if you set all the needed settings in mandatory object:
chrome.tabCapture.capture({
audio : false,
video : true,
{
mandatory: {
width: { min: 640 },
height: { min: 480 }
}
}
}, handleCapture);
I had this same issue when I was trying to drive a tabCapture purely from a background script, I found this on the tabCapture reference page:
Captures the visible area of the currently active tab. This method can only be used on the currently active page after the extension has been invoked , similar to the way that activeTab works. Note that Chrome internal pages cannot be captured.
My understanding is that this means you need to drive it from a browserAction for your extension, like so:
chrome.browserAction.onClicked.addListener(function(request) {
chrome.tabs.getSelected(null, function(tab) {
chrome.tabCapture.capture({audio: true, video: true}, callback);
});
});
That's what worked for me.
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