Fix non-default namespace names in DASH.

XML allows namespace names to be any string. So instead of looking for the literal name 'cenc:pssh', we should be looking for the 'pssh' name in the correct namespace. Closes #1438 Change-Id: I724db3b7f0e60b4233b0fc40b1ed57698c6ce9ce
shaka-project · May 21, 2018 · 866b0e1 · 866b0e1
1 parent fc470e4
commit 866b0e1
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Showing 4 changed files with 81 additions and 10 deletions.
diff --git a/lib/dash/content_protection.js b/lib/dash/content_protection.js
@@ -109,6 +109,13 @@ shaka.dash.ContentProtection.MP4Protection_ =
     'urn:mpeg:dash:mp4protection:2011';
 
 
+/**
+ * @const {string}
+ * @private
+ */
+shaka.dash.ContentProtection.CencNamespaceUri = 'urn:mpeg:cenc:2013';
+
+
 /**
  * Parses info from the ContentProtection elements at the AdaptationSet level.
  *
@@ -302,12 +309,13 @@ shaka.dash.ContentProtection.parseElements_ = function(elems) {
        * @return {?shaka.dash.ContentProtection.Element}
        */
       function(elem) {
+        const NS = shaka.dash.ContentProtection.CencNamespaceUri;
         /** @type {?string} */
         let schemeUri = elem.getAttribute('schemeIdUri');
         /** @type {?string} */
-        let keyId = elem.getAttribute('cenc:default_KID');
+        let keyId = shaka.util.XmlUtils.getAttributeNS(elem, NS, 'default_KID');
         /** @type {!Array.<string>} */
-        let psshs = shaka.util.XmlUtils.findChildren(elem, 'cenc:pssh')
+        let psshs = shaka.util.XmlUtils.findChildrenNS(elem, NS, 'pssh')
                         .map(shaka.util.XmlUtils.getContents);
 
         if (!schemeUri) {

diff --git a/lib/dash/mpd_utils.js b/lib/dash/mpd_utils.js
@@ -83,6 +83,13 @@ shaka.dash.MpdUtils.TimeRange;
 shaka.dash.MpdUtils.SegmentInfo;
 
 
+/**
+ * @const {string}
+ * @private
+ */
+shaka.dash.MpdUtils.XlinkNamespaceUri = 'http://www.w3.org/1999/xlink';
+
+
 /**
  * Fills a SegmentTemplate URI template.  This function does not validate the
  * resulting URI.
@@ -474,18 +481,21 @@ shaka.dash.MpdUtils.handleXlinkInElement_ =
     function(element, retryParameters, failGracefully, baseUri,
              networkingEngine, linkDepth) {
   const MpdUtils = shaka.dash.MpdUtils;
+  const XmlUtils = shaka.util.XmlUtils;
   const Error = shaka.util.Error;
   const ManifestParserUtils = shaka.util.ManifestParserUtils;
+  const NS = MpdUtils.XlinkNamespaceUri;
 
-  let xlinkHref = element.getAttribute('xlink:href');
-  let xlinkActuate = element.getAttribute('xlink:actuate') || 'onRequest';
+  let xlinkHref = XmlUtils.getAttributeNS(element, NS, 'href');
+  let xlinkActuate =
+      XmlUtils.getAttributeNS(element, NS, 'actuate') || 'onRequest';
 
   // Remove the xlink properties, so it won't download again
   // when re-processed.
   for (let i = 0; i < element.attributes.length; i++) {
-    let attribute = element.attributes[i].nodeName;
-    if (attribute.indexOf('xlink:') != -1) {
-      element.removeAttribute(attribute);
+    let attribute = element.attributes[i];
+    if (attribute.namespaceURI == NS) {
+      element.removeAttributeNS(attribute.namespaceURI, attribute.localName);
       i -= 1;
     }
   }
@@ -579,8 +589,10 @@ shaka.dash.MpdUtils.processXlinks =
     function(element, retryParameters, failGracefully, baseUri,
              networkingEngine, linkDepth = 0) {
   const MpdUtils = shaka.dash.MpdUtils;
+  const XmlUtils = shaka.util.XmlUtils;
+  const NS = MpdUtils.XlinkNamespaceUri;
 
-  if (element.getAttribute('xlink:href')) {
+  if (XmlUtils.getAttributeNS(element, NS, 'href')) {
     let handled = MpdUtils.handleXlinkInElement_(
         element, retryParameters, failGracefully, baseUri,
         networkingEngine, linkDepth);
@@ -602,8 +614,8 @@ shaka.dash.MpdUtils.processXlinks =
   for (let i = 0; i < element.childNodes.length; i++) {
     let child = element.childNodes[i];
     if (child instanceof Element) {
-      let resolveToZeroString = 'urn:mpeg:dash:resolve-to-zero:2013';
-      if (child.getAttribute('xlink:href') == resolveToZeroString) {
+      const resolveToZeroString = 'urn:mpeg:dash:resolve-to-zero:2013';
+      if (XmlUtils.getAttributeNS(child, NS, 'href') == resolveToZeroString) {
         // This is a 'resolve to zero' code; it means the element should
         // be removed, as specified by the mpeg-dash rules for xlink.
         element.removeChild(child);

diff --git a/lib/util/xml_utils.js b/lib/util/xml_utils.js
@@ -56,6 +56,35 @@ shaka.util.XmlUtils.findChildren = function(elem, name) {
 };
 
 
+/**
+ * Finds namespace-qualified child XML elements.
+ * @param {!Node} elem The parent XML element.
+ * @param {string} ns The child XML element's namespace URI.
+ * @param {string} name The child XML element's local name.
+ * @return {!Array.<!Element>} The child XML elements.
+ */
+shaka.util.XmlUtils.findChildrenNS = function(elem, ns, name) {
+  return Array.prototype.filter.call(elem.childNodes, function(child) {
+    return child instanceof Element && child.localName == name &&
+        child.namespaceURI == ns;
+  });
+};
+
+
+/**
+ * Gets a namespace-qualified attribute.
+ * @param {!Element} elem The element to get from.
+ * @param {string} ns The namespace URI.
+ * @param {string} name The local name of the attribute.
+ * @return {?string} The attribute's value, or null if not present.
+ */
+shaka.util.XmlUtils.getAttributeNS = function(elem, ns, name) {
+  // Some browsers return the empty string when the attribute is missing,
+  // so check if it exists first.  See: https://mzl.la/2L7F0UK
+  return elem.hasAttributeNS(ns, name) ? elem.getAttributeNS(ns, name) : null;
+};
+
+
 /**
  * Gets the text contents of a node.
  * @param {!Node} elem The XML element.

diff --git a/test/dash/dash_parser_content_protection_unit.js b/test/dash/dash_parser_content_protection_unit.js
@@ -654,6 +654,28 @@ describe('DashParser ContentProtection', function() {
     testDashParser(done, source, expected);
   });
 
+  it('handles non-default namespace names', function(done) {
+    let source = [
+      '<MPD xmlns="urn:mpeg:DASH:schema:MPD:2011"',
+      '    xmlns:foo="urn:mpeg:cenc:2013">',
+      '  <Period duration="PT30S">',
+      '    <SegmentTemplate media="s.mp4" duration="2" />',
+      '    <AdaptationSet mimeType="video/mp4" codecs="avc1.4d401f">',
+      '      <ContentProtection',
+      '          schemeIdUri="urn:uuid:edef8ba9-79d6-4ace-a3c8-27dcd51d21ed">',
+      '        <foo:pssh>b25lIGhlYWRlciB0byBydWxlIHRoZW0gYWxs</foo:pssh>',
+      '      </ContentProtection>',
+      '      <Representation bandwidth="50" width="576" height="432" />',
+      '      <Representation bandwidth="100" width="576" height="432" />',
+      '    </AdaptationSet>',
+      '  </Period>',
+      '</MPD>'
+    ].join('\n');
+    let expected = buildExpectedManifest([buildDrmInfo(
+        'com.widevine.alpha', [], ['b25lIGhlYWRlciB0byBydWxlIHRoZW0gYWxs'])]);
+    testDashParser(done, source, expected);
+  });
+
   it('fails for no schemes common', function(done) {
     let source = buildManifestText([
       // AdaptationSet lines