Added orientation-dependent constraints; extended constrain-matching;

example/live_w_locator.js

@@ -146,12 +146,21 @@ $(function() {
             inputStream: {
                 type : "LiveStream",
                 constraints: {
-                    width: {ideal: 480},
-                    height: {ideal: 480},
-                    zoom: {exact: 2},
+                    width: {ideal: 800},
+                    height: {ideal: 800},
                     facingMode: "environment",
+                    landscape: {
+                        width: {ideal: 640},
+                        height: {ideal: 480},
+                        zoom: 1.5,
+                    },
+                    portrait: {
+                        width: {ideal: 640},
+                        height: {ideal: 640},
+                        zoom: 1.5,
                         aspectRatio: 1,
                     }
+                }
             },
             locator: {
                 patchSize: "medium",

src/common/device.js

@@ -1,5 +1,6 @@
 export const PORTRAIT = "portrait";
 export const LANDSCAPE = "landscape";
+export const SQUARE = "square";
 
 const matchingScreens = {
     [PORTRAIT]: /portrait/i,

src/input/Source.js

@@ -1,8 +1,81 @@
 import {clone} from 'lodash';
-import {determineOrientation, PORTRAIT} from '../common/device';
+import {determineOrientation, PORTRAIT, LANDSCAPE, SQUARE} from '../common/device';
 import CameraAccess from './camera_access';
 import {getViewport} from '../common/utils';
 
+const ConstraintPresets = [
+    {
+        width: 720,
+        height: 1280,
+    }, {
+        width: 540,
+        height: 960,
+    }, {
+        width: 600,
+        height: 800,
+    }, {
+        width: 480,
+        height: 640,
+    }, {
+        width: 1280,
+        height: 720,
+    }, {
+        width: 960,
+        height: 540,
+    }, {
+        width: 800,
+        height: 600,
+    }, {
+        width: 640,
+        height: 480,
+    }, {
+        width: 1280,
+        height: 1280,
+    }, {
+        width: 1080,
+        height: 1080,
+    }, {
+        width: 960,
+        height: 960,
+    }, {
+        width: 800,
+        height: 800,
+    }, {
+        width: 640,
+        height: 640,
+    },
+].map((preset) => Object.assign({}, preset, {aspectRatio: preset.width / preset.height}));
+
+function getFilter(aspectRatio) {
+    if (aspectRatio === 1) {
+        return pre => pre.aspectRatio === aspectRatio;
+    } else if (aspectRatio > 1) {
+        return pre => pre.aspectRatio > 1;
+    }
+    return pre => pre.aspectRatio < 1;
+}
+
+function resolveMinWidthToAdvanced({aspectRatio, minPixels}) {
+    return [...ConstraintPresets]
+    .filter(getFilter(aspectRatio))
+    .map((pre) => {
+        return {
+            error: Math.abs((pre.width * pre.height) - minPixels),
+            pre,
+        };
+    })
+    .sort(({error: errorA}, {error: errorB}) => {
+        if (errorB > errorA) {
+            return -1;
+        }
+        if (errorB < errorA) {
+            return 1;
+        }
+        return 0;
+    })
+    .map(({pre}) => pre);
+}
+
 function getOrCreateVideo(source, target) {
     const $viewport = getViewport(target);
     if ($viewport) {
@@ -16,21 +89,70 @@ function getOrCreateVideo(source, target) {
     return document.createElement("video");
 }
 
-export function fromCamera(constraints) {
-    var orientation = determineOrientation();
-    var videoConstraints = clone(constraints);
-    if (orientation === PORTRAIT) {
-        videoConstraints = Object.assign({}, videoConstraints, {
-            width: videoConstraints.height,
-            height: videoConstraints.width,
-        });
+function constraintToNumber(constraint) {
+    if (!constraint) {
+        return null;
+    }
+    if (typeof constraint === 'number') {
+        return constraint;
+    }
+    const {ideal, exact, min, max} = constraint;
+    if (typeof exact !== 'undefined') {
+        return exact;
+    }
+    if (typeof ideal !== 'undefined') {
+        return ideal;
     }
+    if (typeof min !== 'undefined') {
+        return min;
+    }
+    if (typeof max !== 'undefined') {
+        return max;
+    }
+
+    return null;
+}
+
+function adjustWithZoom(videoConstraints) {
+    const constraints = clone(videoConstraints);
+    const orientation = determineOrientation();
+
+    let zoom = constraintToNumber(constraints.zoom) || 1,
+        width = constraintToNumber(constraints.width),
+        height = constraintToNumber(constraints.height),
+        aspectRatio = constraintToNumber(constraints.aspectRatio) || (width / height);
+
+    if (constraints[orientation]) {
+        zoom = constraintToNumber(constraints[orientation].zoom) || zoom;
+        width = constraintToNumber(constraints[orientation].width) || width;
+        height = constraintToNumber(constraints[orientation].height) || height;
+        aspectRatio = constraintToNumber(constraints[orientation].aspectRatio) || (width / height);
+    }
+
+    if (zoom > 1) {
+        width = Math.floor(width * zoom);
+        height = Math.floor(height * zoom);
+    }
+
+    delete constraints.zoom;
+    delete constraints.orientation;
+    delete constraints.landscape;
+    delete constraints.portrait;
 
-    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;
+    const advanced = resolveMinWidthToAdvanced({minPixels: (width * height), aspectRatio});
+    return {
+        zoom,
+        video: Object.assign({}, constraints, {
+            width: {ideal: advanced[0].width},
+            height: {ideal: advanced[0].height},
+            aspectRatio: {exact: advanced[0].aspectRatio || aspectRatio},
+            advanced,
+        }),
+    };
 }
+
+export function fromCamera(constraints) {
+    var {video: videoConstraints, zoom} = adjustWithZoom(constraints);
     console.log(videoConstraints);
 
     const video = getOrCreateVideo();
@@ -46,9 +168,7 @@ export function fromCamera(constraints) {
                     width: video.videoWidth,
                     height: video.videoHeight,
                 };
-
-                if (constraints.zoom && constraints.zoom.exact > 1) {
-                    const zoom = constraints.zoom.exact;
+                if (zoom > 1) {
                     viewport.width = Math.floor(video.videoWidth / zoom);
                     viewport.height = Math.floor(video.videoHeight / zoom);
                     viewport.x = Math.floor((video.videoWidth - viewport.width) / 2);

src/quagga.js

@@ -8,6 +8,7 @@ import {merge} from 'lodash';
 import CameraAccess from './input/camera_access';
 import * as PixelCapture from './input/PixelCapture';
 import * as Source from './input/Source';
+import {PORTRAIT, LANDSCAPE, SQUARE} from './common/device';
 
 function fromConfig(pixelCapturer, config) {
     const scanner = createScanner(pixelCapturer);
@@ -162,6 +163,11 @@ function createApi() {
         ResultCollector,
         _worker: {
             createScanner
+        },
+        Orientation: {
+            PORTRAIT,
+            LANDSCAPE,
+            SQUARE,
         }
     };
 }