{"json_modified": "2016-10-19T19:40:58.279003", "uuid": "914a2138-61c3-4761-b1be-303ba7ee8ae2", "title": "Capabilities, constraints, and settings", "url": "/en-US/docs/Web/API/Media_Streams_API/Constraints", "tags": ["video", "WebRTC", "Guide", "Constraints", "Media Streams API", "Settings", "Video", "Audio", "Example", "Advanced", "Media Capture and Streams API", "Media", "audio"], "translations": [], "modified": "2016-10-19T19:40:58", "label": "Capabilities, constraints, and settings", "localization_tags": [], "locale": "en-US", "id": 196035, "last_edit": "2016-10-19T19:40:44", "summary": "The twin concepts of <strong>constraints</strong> and <strong>capabilies</strong> let the browser and Web site or app exchange information about what <strong>constrainable properties</strong> the browser's implementation supports and what values it supports for each one. This article discusses capabilities and constraints, as well as media settings, and includes an example we call the <a href=\"#Example:_Constraint_exerciser\">Example: Constraint exerciser</a>, which you can use to experiment with the results of different constraint sets being applied to the audio and video tracks coming from the computer's A/V input devices (such as its webcam and microphone).", "sections": [{"id": "Quick_Links", "title": null}, {"id": "Overview", "title": "Overview"}, {"id": "Determining_if_a_constraint_is_supported", "title": "Determining if a constraint is supported"}, {"id": "How_constraints_are_defined", "title": "How constraints are defined"}, {"id": "Requesting_a_specific_value_for_a_setting", "title": "Requesting a specific value for a setting"}, {"id": "Specifying_a_range_of_values", "title": "Specifying a range of values"}, {"id": "Advanced_constraints", "title": "Advanced constraints"}, {"id": "Checking_capabilities", "title": "Checking capabilities"}, {"id": "Applying_constraints", "title": "Applying constraints"}, {"id": "Retrieving_current_constraints_and_settings", "title": "Retrieving current constraints and settings"}, {"id": "Getting_the_constraints_in_effect", "title": "Getting the constraints in effect"}, {"id": "Getting_the_current_settings_for_a_track", "title": "Getting the current settings for a track"}, {"id": "Example_Constraint_exerciser", "title": "Example: Constraint exerciser"}, {"id": "HTML_content", "title": "HTML content"}, {"id": "CSS_content", "title": "CSS content"}, {"id": "JavaScript_content", "title": "JavaScript content"}, {"id": "Defaults_and_variables", "title": "Defaults and variables"}, {"id": "Updating_the_settings_display", "title": "Updating the settings display"}, {"id": "Building_the_track_constraint_set_objects", "title": "Building the track constraint set objects"}, {"id": "Configuring_and_starting_the_stream", "title": "Configuring and starting the stream"}, {"id": "Applying_constraint_set_updates", "title": "Applying constraint set updates"}, {"id": "Handling_the_stop_button", "title": "Handling the stop button"}, {"id": "Simple_tab_support_in_the_editor", "title": "Simple tab support in the editor"}, {"id": "Show_constrainable_properties_the_browser_supports", "title": "Show constrainable properties the browser supports"}, {"id": "Error_handling", "title": "Error handling"}, {"id": "Result", "title": "Result"}, {"id": "Specifications", "title": "Specifications"}, {"id": "Browser_compatibility", "title": "Browser compatibility"}, {"id": "See_also", "title": "See also"}], "slug": "Web/API/Media_Streams_API/Constraints", "review_tags": []}