diff --git a/example/file_input.html b/example/file_input.html
index dee9aae..06ca78b 100644
--- a/example/file_input.html
+++ b/example/file_input.html
@@ -77,7 +77,7 @@
             </label>
             <label>
                 <span>Half-Sample</span>
-                <input type="checkbox" name="locator_half-sample" />
+                <input checked="checked" type="checkbox" name="locator_half-sample" />
             </label>
             <label>
                 <span>Single Channel</span>
diff --git a/example/live_w_locator.js b/example/live_w_locator.js
index 8d4fd9e..fd9892b 100644
--- a/example/live_w_locator.js
+++ b/example/live_w_locator.js
@@ -3,24 +3,29 @@ $(function() {
         init : function() {
             this.overlay = document.querySelector('#interactive canvas.drawing');
 
-            this.scanner = Quagga
-                .fromConfig(this.state);
-
-            this.scanner
-                .addEventListener("processed", drawResult.bind(this, this.scanner))
-                .addEventListener("detected", addToResults.bind(this, this.scanner));
-
-            this.scanner.start()
-            .then(function (){
-                console.log("started");
-                this.attachListeners();
-            }.bind(this))
-            .catch(function(err) {
-                console.log("Error: " + err);
-            });
+            this.state.inputStream.constraints.zoom = {exact: 2};
+            Quagga.fromCamera({
+                constraints: this.state.inputStream.constraints,
+                locator: this.state.locator,
+                decoder: this.state.decoder,
+            }).then(function(scanner) {
+                this.scanner = scanner;
+                this.scanner
+                    .addEventListener("processed", drawResult.bind(this, this.scanner))
+                    .addEventListener("detected", addToResults.bind(this, this.scanner));
+
+                this.scanner.start()
+                .then(function (){
+                    console.log("started");
+                    this.attachListeners();
+                }.bind(this))
+                .catch(function(err) {
+                    console.error(err);
+                });
+            }.bind(this));
         },
-        initCameraSelection: function(){
-            var streamLabel = Quagga.CameraAccess.getActiveStreamLabel();
+        initCameraSelection: function() {
+            var streamLabel = this.scanner.getSource().getLabel();
 
             return Quagga.CameraAccess.enumerateVideoDevices()
             .then(function(devices) {
@@ -106,8 +111,8 @@ $(function() {
                     if (/^(\d+)x(\d+)$/.test(value)) {
                         var values = value.split('x');
                         return {
-                            width: {min: parseInt(values[0])},
-                            height: {min: parseInt(values[1])}
+                            width: {ideal: parseInt(values[0])},
+                            height: {ideal: parseInt(values[1])}
                         };
                     }
                     return {
@@ -141,8 +146,8 @@ $(function() {
             inputStream: {
                 type : "LiveStream",
                 constraints: {
-                    width: {min: 640},
-                    height: {min: 480},
+                    width: {ideal: 640},
+                    height: {ideal: 480},
                     facingMode: "environment",
                     aspectRatio: {min: 1, max: 2}
                 }
diff --git a/src/common/utils.js b/src/common/utils.js
index 1b9c4af..f1cb666 100644
--- a/src/common/utils.js
+++ b/src/common/utils.js
@@ -4,3 +4,13 @@ export function sleep(millis) {
         window.setTimeout(resolve, millis);
     });
 }
+
+export function getViewport(target) {
+    if (target && target.nodeName && target.nodeType === 1) {
+        return target;
+    } else {
+        // Use '#interactive.viewport' as a fallback selector (backwards compatibility)
+        var selector = typeof target === 'string' ? target : '#interactive.viewport';
+        return document.querySelector(selector);
+    }
+}
diff --git a/src/config/config.dev.js b/src/config/config.dev.js
index cd039fa..f388b7e 100644
--- a/src/config/config.dev.js
+++ b/src/config/config.dev.js
@@ -30,7 +30,7 @@ module.exports = {
         }
     },
     locator: {
-        halfSample: false,
+        halfSample: true,
         patchSize: "medium", // x-small, small, medium, large, x-large
         debug: {
             showCanvas: false,
diff --git a/src/input/PixelCapture.js b/src/input/PixelCapture.js
index 690c898..0a49591 100644
--- a/src/input/PixelCapture.js
+++ b/src/input/PixelCapture.js
@@ -2,6 +2,7 @@ import {
     computeGray
 } from '../common/cv_utils';
 import {sleep} from '../common/utils';
+import {getViewport} from '../common/utils';
 
 function adjustCanvasSize(input, canvas) {
     if (input instanceof HTMLVideoElement) {
@@ -25,18 +26,8 @@ function adjustCanvasSize(input, canvas) {
     }
 }
 
-function getViewPort(target) {
-    if (target && target.nodeName && target.nodeType === 1) {
-        return target;
-    } else {
-        // Use '#interactive.viewport' as a fallback selector (backwards compatibility)
-        var selector = typeof target === 'string' ? target : '#interactive.viewport';
-        return document.querySelector(selector);
-    }
-}
-
 function getOrCreateCanvas(source, target) {
-    const $viewport = getViewPort(target);
+    const $viewport = getViewport(target);
     let $canvas = $viewport.querySelector("canvas.imgBuffer");
     if (!$canvas) {
         $canvas = document.createElement("canvas");
diff --git a/src/input/Source.js b/src/input/Source.js
index 0e34535..474c843 100644
--- a/src/input/Source.js
+++ b/src/input/Source.js
@@ -1,21 +1,40 @@
+import {clone} from 'lodash';
 import {determineOrientation, PORTRAIT} from '../common/device';
 import CameraAccess from './camera_access';
+import {getViewport} from '../common/utils';
 
-export function fromCamera(constraints) {
-    if (!constraints) {
-        constraints = {width: {ideal: 540}, height: {ideal: 540}, aspectRatio: {ideal: 1}, facingMode: 'environment'};
+function getOrCreateVideo(source, target) {
+    const $viewport = getViewport(target);
+    if ($viewport) {
+        let $video = $viewport.querySelector("video");
+        if (!$video) {
+            $video = document.createElement("video");
+            $viewport.appendChild($video);
+        }
+        return $video;
     }
+    return document.createElement("video");
+}
+
+export function fromCamera(constraints) {
     var orientation = determineOrientation();
-    var videoConstraints = constraints;
+    var videoConstraints = clone(constraints);
     if (orientation === PORTRAIT) {
-        constraints = Object.assign({}, constraints, {
-            width: constraints.height,
-            height: constraints.width,
+        videoConstraints = Object.assign({}, videoConstraints, {
+            width: videoConstraints.height,
+            height: videoConstraints.width,
         });
     }
 
-    const video = document.querySelector('video');
-    CameraAccess.request(videoConstraints, video)
+    if (videoConstraints.zoom && videoConstraints.zoom.exact > 1) {
+        videoConstraints.width.ideal = Math.floor(videoConstraints.width.ideal * videoConstraints.zoom.exact);
+        videoConstraints.height.ideal = Math.floor(videoConstraints.height.ideal * videoConstraints.zoom.exact);
+        delete videoConstraints.zoom;
+    }
+    console.log(videoConstraints);
+
+    const video = getOrCreateVideo();
+    return CameraAccess.request(video, videoConstraints)
     .then(function(mediastream) {
         const track = mediastream.getVideoTracks()[0];
         return {
@@ -39,8 +58,8 @@ export function fromCamera(constraints) {
                 return {
                     viewport,
                     canvas: {
-                        width: constraints.width,     // AR
-                        height: constraints.height,   // AR
+                        width: viewport.width,     // AR
+                        height: viewport.height,   // AR
                     },
                 };
             },
@@ -65,7 +84,7 @@ export function fromCamera(constraints) {
                     constraints.height.ideal = Math.floor(constraints.height.ideal * constraints.zoom.exact);
                     delete constraints.zoom;
                 }
-                return CameraAccess.request(videoConstraints, video);
+                return CameraAccess.request(video, videoConstraints);
             },
             getLabel: function() {
                 return track.label;
diff --git a/src/input/camera_access.js b/src/input/camera_access.js
index 13fbe7f..abb7c21 100644
--- a/src/input/camera_access.js
+++ b/src/input/camera_access.js
@@ -10,7 +10,7 @@ var streamRef;
 
 function waitForVideo(video, stream) {
     return new Promise((resolve, reject) => {
-        let attempts = 10;
+        let attempts = 20;
 
         function checkVideo() {
             if (attempts > 0) {
@@ -20,7 +20,7 @@ function waitForVideo(video, stream) {
                     }
                     resolve(stream);
                 } else {
-                    window.setTimeout(checkVideo, 500);
+                    window.setTimeout(checkVideo, 200);
                 }
             } else {
                 reject('Unable to play video stream. Is webcam working?');
diff --git a/src/quagga.js b/src/quagga.js
index d51098e..6892610 100644
--- a/src/quagga.js
+++ b/src/quagga.js
@@ -5,13 +5,14 @@ import ImageDebug from './common/image_debug';
 import ResultCollector from './analytics/result_collector';
 import Config from './config/config';
 import {merge} from 'lodash';
-import {createConfigForImage} from './input/config_factory';
+import CameraAccess from './input/camera_access';
 import * as PixelCapture from './input/PixelCapture';
 import * as Source from './input/Source';
 
 function fromConfig(pixelCapturer, config) {
     const scanner = createScanner(pixelCapturer);
     const source = pixelCapturer.getSource();
+    let currentConfig = config;
     let pendingStart = null;
     let initialized = false;
     return {
@@ -35,7 +36,7 @@ function fromConfig(pixelCapturer, config) {
                 return Promise.resolve(true);
             }
             pendingStart = new Promise((resolve, reject) => {
-                scanner.init(config, (error) => {
+                scanner.init(currentConfig, (error) => {
                     if (error) {
                         console.log(error);
                         reject(error);
@@ -80,7 +81,7 @@ function fromConfig(pixelCapturer, config) {
                 };
             } else {
                 return new Promise((resolve, reject) => {
-                    scanner.decodeSingle(config, (result) => {
+                    scanner.decodeSingle(currentConfig, (result) => {
                         if (result && result.codeResult && result.codeResult.code) {
                             return resolve(result);
                         }
@@ -95,6 +96,21 @@ function fromConfig(pixelCapturer, config) {
         getCanvas() {
             return pixelCapturer.getCanvas();
         },
+        applyConfig(newConfig) {
+            // during runtime?
+            // running scanners must know that!
+            // apply constraints to source, only if changed
+
+            const normalizedConfig = merge({}, Config, newConfig);
+            this.stop();
+            currentConfig = normalizedConfig;
+
+            return source.applyConstraints(currentConfig.constraints)
+            .then(() => this.start());
+        },
+        getSource() {
+            return pixelCapturer.getSource();
+        }
     };
 }
 
@@ -116,6 +132,12 @@ function createApi() {
                 .fromImage(image, config.constraints)
                 .then(fromSource.bind(null, config));
         },
+        fromCamera(options) {
+            const config = merge({}, Config, options);
+            return Source
+                .fromCamera(config.constraints)
+                .then(fromSource.bind(null, config));
+        },
         fromSource(src, inputConfig) {
             return fromSource(configuration, src, inputConfig);
         },
@@ -134,6 +156,7 @@ function createApi() {
         config(conf) {
             return createApi(merge({}, configuration, conf));
         },
+        CameraAccess,
         ImageWrapper,
         ImageDebug,
         ResultCollector,
diff --git a/src/scanner.js b/src/scanner.js
index f9042b1..372a0d8 100644
--- a/src/scanner.js
+++ b/src/scanner.js
@@ -209,10 +209,11 @@ function createScanner(pixelCapturer) {
             } else {
                 //_framegrabber.attachData(_inputImageWrapper.data);
             }
-            pixelCapturer.grabFrameData()
+
+            return pixelCapturer.grabFrameData()
             .then((bitmap) => {
-                _inputImageWrapper.data = bitmap.data;
                 if (bitmap) {
+                    _inputImageWrapper.data = bitmap.data;
                     if (availableWorker) {
                         availableWorker.busy = true;
                         availableWorker.worker.postMessage({
@@ -226,15 +227,15 @@ function createScanner(pixelCapturer) {
             })
             .catch(err => {
                 console.error(err);
-            })
-        } else {
-            locateAndDecode();
+            });
         }
+
+        return locateAndDecode();
     }
 
     function startContinuousUpdate() {
         var next = null,
-            delay = 1000 / (_config.frequency === 0 ? 60 : (_config.frequency || 60));
+            delay = 1000 / (_config.frequency === 0 ? 10 : (_config.frequency || 10));
 
         _stopped = false;
         (function frame(timestamp) {
@@ -242,9 +243,12 @@ function createScanner(pixelCapturer) {
             if (!_stopped) {
                 if (timestamp >= next) {
                     next += delay;
-                    update();
+                    update().then(() => {
+                        window.requestAnimFrame(frame);
+                    });
+                } else {
+                    window.requestAnimFrame(frame);
                 }
-                window.requestAnimFrame(frame);
             }
         }(performance.now()));
     }