OHIF-20 Moving multi-frame related functionality to metaDataProvider / Created new library with parsing utilities.

Packages/viewerbase/client/components/viewer/imageViewerViewport/imageViewerViewport.js

@@ -213,15 +213,15 @@ function loadDisplaySetIntoViewport(data, templateData) {
         cornerstoneTools.addToolState(element, 'stack', stack);
 
         // Set the default CINE settings
-        var frameRate = 1000 / displaySet.images[0].frameTime;
+        var multiframeMetadata = instance.multiframeMetadata;
         var cineToolData = {
             loop: OHIF.viewer.cine.loop,
-            framesPerSecond: frameRate || OHIF.viewer.cine.framesPerSecond
+            framesPerSecond: multiframeMetadata.averageFrameRate || OHIF.viewer.cine.framesPerSecond
         };
         cornerstoneTools.addToolState(element, 'playClip', cineToolData);
 
         // Autoplay datasets that have framerates set
-        if (frameRate) {
+        if (multiframeMetadata.isMultiframeImage && multiframeMetadata.averageFrameRate > 0) {
             cornerstoneTools.playClip(element);
         }
 
@@ -386,7 +386,6 @@ function setDisplaySet(data, displaySetInstanceUid, templateData) {
     var study = data.study;
     if (!study || !study.displaySets) {
         throw 'Study does not exist or has no display sets';
-        return;
     }
 
     study.displaySets.every(displaySet => {
@@ -401,7 +400,6 @@ function setDisplaySet(data, displaySetInstanceUid, templateData) {
     // If we didn't find anything, stop here
     if (!data.displaySet) {
         throw 'Display set not found in specified study!';
-        return;
     }
 
     // Otherwise, load pass the data object into loadSeriesIntoViewport

Packages/viewerbase/lib/metaDataProvider.js

@@ -1,3 +1,5 @@
+import {parsingUtils} from './parsingUtils'
+
 var metaDataLookup = {};
 
 /**
@@ -102,6 +104,7 @@ updateMetaData = function(image) {
     imageMetaData.instance.frameIncrementPointer = imageMetaData.instance.frameIncrementPointer || image.data.string('x00280009');
     imageMetaData.instance.frameTime = imageMetaData.instance.frameTime || image.data.string('x00181063');
     imageMetaData.instance.frameTimeVector = imageMetaData.instance.frameTimeVector || image.data.string('x00181065');
+    imageMetaData.instance.multiframeMetadata = getMultiframeModuleMetaData(image.data);
 
     imageMetaData.imagePlane = imageMetaData.imagePlane || getImagePlane(imageMetaData.instance);
 };
@@ -150,6 +153,69 @@ function getImagePlane(instance) {
     };
 }
 
+/**
+ * This function extracts miltiframe information from a dicomParser.DataSet object.
+ *
+ * @param dataSet {Object} An instance of dicomParser.DataSet object where multiframe information can be found.
+ * @return {Object} An object containing multiframe image metadata (frameIncrementPointer, frameTime, frameTimeVector, etc).
+ */
+getMultiframeModuleMetaData = function(dataSet) {
+
+    var numberOfFrames,
+        frameIncrementPointer,
+        frameTime,
+        frameTimeVector,
+        imageInfo = {
+            isMultiframeImage: false,
+            frameIncrementPointer: null,
+            numberOfFrames: 0,
+            frameTime: 0,
+            frameTimeVector: null,
+            averageFrameRate: 0 // backwards compatibility only... it might be useless in the future
+        };
+
+    if (parsingUtils.isValidDataSet(dataSet)) {
+
+        // (0028,0008) = Number of Frames
+        numberOfFrames = dataSet.intString('x00280008', -1);
+        if (numberOfFrames > 0) {
+
+            // set multi-frame image indicator
+            imageInfo.isMultiframeImage = true;
+            imageInfo.numberOfFrames = numberOfFrames;
+
+            // (0028,0009) = Frame Increment Pointer
+            frameIncrementPointer = parsingUtils.attributeTag(dataSet, 'x00280009') || '';
+
+            if (frameIncrementPointer === 'x00181065') {
+                // Frame Increment Pointer points to Frame Time Vector (0018,1065) field
+                frameTimeVector = parsingUtils.floatArray(dataSet, 'x00181065');
+                if (frameTimeVector instanceof Array && frameTimeVector.length > 0) {
+                    imageInfo.frameIncrementPointer = 'frameTimeVector';
+                    imageInfo.frameTimeVector = frameTimeVector;
+                    frameTime = frameTimeVector.reduce((a, b) => a + b) / frameTimeVector.length;
+                    imageInfo.averageFrameRate = 1000 / frameTime;
+                }
+            } else if (frameIncrementPointer === 'x00181063' || frameIncrementPointer === '') {
+                // Frame Increment Pointer points to Frame Time (0018,1063) field or is not defined (for addtional flexibility).
+                // Yet another value is possible for this field (5200,9230 for Multi-frame Functional Groups)
+                // but that case is currently not supported.
+                frameTime = dataSet.floatString('x00181063', -1);
+                if (frameTime > 0) {
+                    imageInfo.frameIncrementPointer = 'frameTime';
+                    imageInfo.frameTime = frameTime;
+                    imageInfo.averageFrameRate = 1000 / frameTime;
+                }
+            }
+
+        }
+
+    }
+
+    return imageInfo;
+
+};
+
 /**
  * Looks up metaData for Cornerstone Tools given a specified type and imageId
  * A type may be, e.g. 'study', or 'patient', or 'imagePlane'. These types

Packages/viewerbase/lib/parsingUtils.js

@@ -0,0 +1,41 @@
+
+import {dicomParser} from 'meteor/cornerstone';
+
+export const parsingUtils = {
+    isValidDataSet: function(data) {
+        return (data instanceof dicomParser.DataSet);
+    },
+    attributeTag: function(data, tag) {
+        if (this.isValidDataSet(data) && tag in data.elements) {
+            let element = data.elements[tag];
+            if (element && element.length === 4) {
+                let parser = data.byteArrayParser.readUint16,
+                    bytes = data.byteArray,
+                    offset = element.dataOffset;
+                return 'x' + ('00000000' + (parser(bytes, offset) * 256 * 256 + parser(bytes, offset + 2)).toString(16)).substr(-8);
+            }
+        }
+        return null;
+    },
+    multiValue: function(data, tag, parser) {
+        if (this.isValidDataSet(data) && tag in data.elements) {
+            let element = data.elements[tag];
+            if (element && element.length > 0) {
+                let string = dicomParser.readFixedString(data.byteArray, element.dataOffset, element.length);
+                if (typeof string === 'string' && string.length > 0) {
+                    if (typeof parser !== 'function') {
+                        parser = null;
+                    }
+                    return string.split('\\').map(function(value) {
+                        value = value.trim();
+                        return parser !== null ? parser(value) : value;
+                    });
+                }
+            }
+        }
+        return null;
+    },
+    floatArray: function(data, tag) {
+        return this.multiValue(data, tag, parseFloat);
+    }
+};