Get PlayReady PSSH from <mspr:pro> in DASH (#2106)

Creates "pssh" init data based on the <mspr:pro> element in the DASH manifest. Closes #2058
shaka-project · Aug 23, 2019 · 5a5864c · 5a5864c
1 parent 47db0cf
commit 5a5864c
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Showing 3 changed files with 108 additions and 2 deletions.
diff --git a/lib/dash/content_protection.js b/lib/dash/content_protection.js
@@ -22,6 +22,7 @@ goog.require('shaka.log');
 goog.require('shaka.util.BufferUtils');
 goog.require('shaka.util.Error');
 goog.require('shaka.util.ManifestParserUtils');
+goog.require('shaka.util.Pssh');
 goog.require('shaka.util.Uint8ArrayUtils');
 goog.require('shaka.util.XmlUtils');
 
@@ -321,6 +322,36 @@ shaka.dash.ContentProtection = class {
     return ContentProtection.getLaurl_(rootElement);
   }
 
+  /**
+   * Gets a PlayReady initData from a content protection element
+   * containing a PlayReady Pro Object
+   *
+   * @param {shaka.dash.ContentProtection.Element} element
+   * @return {?Array.<shaka.extern.InitDataOverride>}
+   * @private
+   */
+  static getInitDataFromPro_(element) {
+    const proNode = shaka.util.XmlUtils.findChildNS(
+        element.node, 'urn:microsoft:playready', 'pro');
+    if (!proNode) {
+      return null;
+    }
+    const Uint8ArrayUtils = shaka.util.Uint8ArrayUtils;
+    const data = Uint8ArrayUtils.fromBase64(proNode.textContent);
+    const systemId = new Uint8Array([
+      0x9a, 0x04, 0xf0, 0x79, 0x98, 0x40, 0x42, 0x86,
+      0xab, 0x92, 0xe6, 0x5b, 0xe0, 0x88, 0x5f, 0x95,
+    ]);
+    const pssh = shaka.util.Pssh.createPssh(data, systemId);
+    return [
+      {
+        initData: pssh,
+        initDataType: 'cenc',
+        keyId: element.keyId,
+      },
+    ];
+  }
+
   /**
    * Creates DrmInfo objects from the given element.
    *
@@ -346,7 +377,8 @@ shaka.dash.ContentProtection = class {
             !element.init || element.init.length,
             'Init data must be null or non-empty.');
 
-        const initData = element.init || defaultInit;
+        const proInitData = ContentProtection.getInitDataFromPro_(element);
+        const initData = element.init || defaultInit || proInitData;
         const info = ManifestParserUtils.createDrmInfo(keySystem, initData);
         const licenseParser = licenseUrlParsers.get(keySystem);
         if (licenseParser) {

diff --git a/lib/util/pssh.js b/lib/util/pssh.js
@@ -109,4 +109,44 @@ shaka.util.Pssh = class {
       shaka.log.warning('Mismatch between box size and data size!');
     }
   }
+
+  /**
+   * Creates a pssh blob from the given system ID and data.
+   *
+   * @param {!Uint8Array} data
+   * @param {!Uint8Array} systemId
+   * @return {!Uint8Array}
+   */
+  static createPssh(data, systemId) {
+    const dataLength = data.length;
+    const psshSize = 0x4 + 0x4 + 0x4 + systemId.length + 0x4 + dataLength;
+
+    /** @type {!ArrayBuffer} */
+    const psshBoxBuffer = new ArrayBuffer(psshSize);
+
+    /** @type {!Uint8Array} */
+    const psshBox = new Uint8Array(psshBoxBuffer);
+
+    /** @type {!DataView} */
+    const psshData = new DataView(psshBoxBuffer);
+
+    let byteCursor = 0;
+    psshData.setUint32(byteCursor, psshSize);
+    byteCursor += 0x4;
+    psshData.setUint32(byteCursor, 0x70737368);  // 'pssh'
+    byteCursor += 0x4;
+    psshData.setUint32(byteCursor, 0);  // flags
+    byteCursor += 0x4;
+    psshBox.set(systemId, byteCursor);
+    byteCursor += systemId.length;
+    psshData.setUint32(byteCursor, dataLength);
+    byteCursor += 0x4;
+    psshBox.set(data, byteCursor);
+    byteCursor += dataLength;
+
+    goog.asserts.assert(byteCursor === psshSize,
+        'MS PRO invalid length.');
+
+    return psshBox;
+  }
 };
diff --git a/test/dash/dash_parser_content_protection_unit.js b/test/dash/dash_parser_content_protection_unit.js
@@ -68,7 +68,8 @@ describe('DashParser ContentProtection', () => {
       adaptationSetLines, representation1Lines, representation2Lines) {
     const template = [
       '<MPD xmlns="urn:mpeg:DASH:schema:MPD:2011"',
-      '    xmlns:cenc="urn:mpeg:cenc:2013">',
+      '    xmlns:cenc="urn:mpeg:cenc:2013"',
+      '    xmlns:mspr="urn:microsoft:playready">',
       '  <Period duration="PT30S">',
       '    <SegmentTemplate media="s.mp4" duration="2" />',
       '    <AdaptationSet mimeType="video/mp4" codecs="avc1.4d401f">',
@@ -299,6 +300,39 @@ describe('DashParser ContentProtection', () => {
     await testDashParser(source, expected);
   });
 
+  it('extracts embedded PSSHs with mspr:pro', async () => {
+    const source = buildManifestText([
+      // AdaptationSet lines
+      '<ContentProtection',
+      '  schemeIdUri="urn:uuid:9a04f079-9840-4286-ab92-e65be0885f95">',
+      '  <mspr:pro>UGxheXJlYWR5</mspr:pro>',
+      '</ContentProtection>',
+    ], [], []);
+    const expected = buildExpectedManifest([
+      buildDrmInfo('com.microsoft.playready', [], [
+        'AAAAKXBzc2gAAAAAmgTweZhAQoarkuZb4IhflQAAAAlQbGF5cmVhZHk=',
+      ]),
+    ]);
+    await testDashParser(source, expected);
+  });
+
+  it('extracts embedded PSSHs and prefer cenc:pssh over mspr:pro', async () => {
+    const source = buildManifestText([
+      // AdaptationSet lines
+      '<ContentProtection',
+      '  schemeIdUri="urn:uuid:9a04f079-9840-4286-ab92-e65be0885f95">',
+      '  <cenc:pssh>bm8gaHVtYW4gY2FuIHJlYWQgYmFzZTY0IGRpcmVjdGx5</cenc:pssh>',
+      '  <mspr:pro>ZmFrZSBQbGF5cmVhZHkgUFJP</mspr:pro>',
+      '</ContentProtection>',
+    ], [], []);
+    const expected = buildExpectedManifest([
+      buildDrmInfo('com.microsoft.playready', [], [
+        'bm8gaHVtYW4gY2FuIHJlYWQgYmFzZTY0IGRpcmVjdGx5',
+      ]),
+    ]);
+    await testDashParser(source, expected);
+  });
+
   it('assumes all known key systems for generic CENC', async () => {
     const source = buildManifestText([
       // AdaptationSet lines