what is the minimum resolution we can set for webrtc video?

Question

I am testing a peer to peer video chat app using webrtc. when I set the video contraints as

var video_constraints = {
    mandatory: {
        maxHeight: 120,
        maxWidth: 160 
    },
    optional: []
};

window.navigator.webkitGetUserMedia({
    audio: true,
    video: video_constraints
}, onSuccess, onError);

this fires onError. what could be the reason?

Answer 1

To quote from code.google.com/p/chromium/issues/detail?id=143631#c9:

GetUserMedia constraints are matched with a fixed list of resolutions independent on what the camera actually support. The list is fixed and used on all platforms.

1280, 720,
960, 720,
640, 360,
640, 480,
320, 240,
320, 180

This means your constraints will fail.

Constraints are also documented in Harald Alvestrand's IETF draft.