Add PpapiDecryptor which wraps a CDM plugin.

webkit/media/crypto/key_systems.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "webkit/media/crypto/key_systems.h"
 
-#include "media/base/decryptor.h"
-#include "media/crypto/aes_decryptor.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebString.h"
 
 namespace webkit_media {
 
 namespace {
 
 const char kClearKeyKeySystem[] = "webkit-org.w3.clearkey";
+const char kExternalClearKeyKeySystem[] = "org.chromium.external-clearkey";

[ddorwin, 2012/07/19 01:12:34]

Not sure whether we should use a '-'. I guess it's fine.

[xhwang, 2012/07/19 15:54:34]

Done.

 
 struct MediaFormatAndKeySystem {
   const char* mime_type;
   const char* codec;
   const char* key_system;
 };
 
+struct KeySystemPluginTypePair {
+  const char* key_system;
+  const char* plugin_type;
+};
+
 static const MediaFormatAndKeySystem

[xhwang, 2012/07/19 15:54:34]

We have both anonymous namespace and static function in this file. I plan to
remove anonymous namespace and use static exclusively in this file. Please let
me know if it sounds good.

[ddorwin, 2012/07/19 20:50:09]

SG. I guess both are allowed (last paragraph):
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Nonmem...

[xhwang, 2012/07/19 21:54:03]

Done.

 supported_format_key_system_combinations[] = {
   // TODO(ddorwin): Reconsider based on how usage of this class evolves.
   // For now, this class is stateless, so we do not have the opportunity to
   // build a list using ParseCodecString() like
-  // net::MimeUtil::InitializeMimeTypeMaps(). Therfore, the following line must
+  // net::MimeUtil::InitializeMimeTypeMaps(). Therefore, the following line must
   // be separate entries.
   // { "video/webm", "vorbis,vp8,vp8.0", kClearKeyKeySystem },
   { "video/webm", "vorbis", kClearKeyKeySystem },
   { "video/webm", "vp8", kClearKeyKeySystem },
   { "video/webm", "vp8.0", kClearKeyKeySystem },
   { "audio/webm", "vorbis", kClearKeyKeySystem },
   { "video/webm", "", kClearKeyKeySystem },
-  { "audio/webm", "", kClearKeyKeySystem }
+  { "audio/webm", "", kClearKeyKeySystem },
+  { "video/webm", "vorbis", kExternalClearKeyKeySystem },
+  { "video/webm", "vp8", kExternalClearKeyKeySystem },
+  { "video/webm", "vp8.0", kExternalClearKeyKeySystem },
+  { "audio/webm", "vorbis", kExternalClearKeyKeySystem },
+  { "video/webm", "", kExternalClearKeyKeySystem },
+  { "audio/webm", "", kExternalClearKeyKeySystem }
+};
+
+static const KeySystemPluginTypePair key_system_to_plugin_type_mapping[] = {
+  // TODO(xhwang): Update this with the real plugin name.
+  { kExternalClearKeyKeySystem, "application/x-ppapi-example" }
 };
 
 bool IsSupportedKeySystemWithContainerAndCodec(const std::string& mime_type,
                                                const std::string& codec,
                                                const std::string& key_system) {
   for (size_t i = 0;
        i < arraysize(supported_format_key_system_combinations);
        ++i) {
     const MediaFormatAndKeySystem& combination =
         supported_format_key_system_combinations[i];
     if (combination.mime_type == mime_type &&
         combination.codec == codec &&
         combination.key_system == key_system)
       return true;
   }
 
   return false;
 }
 
 }  // namespace
 
 bool IsSupportedKeySystem(const WebKit::WebString& key_system) {
-  if (key_system == kClearKeyKeySystem)
+  if (key_system == kClearKeyKeySystem ||

[ddorwin, 2012/07/19 01:12:34]

We _could_ replace this with:
  if (CanUseAesDecryptor || GetPluginType()).
This avoids code duplication and maintenance costs. Thoughts?

[xhwang, 2012/07/19 15:54:34]

Done.

+      key_system == kExternalClearKeyKeySystem)
     return true;
   return false;
 }
 
 bool IsSupportedKeySystemWithMediaMimeType(
     const std::string& mime_type,
     const std::vector<std::string>& codecs,
     const std::string& key_system) {
   if (codecs.empty())
     return IsSupportedKeySystemWithContainerAndCodec(mime_type, "", key_system);
 
   for (size_t i = 0; i < codecs.size(); ++i) {
     if (!IsSupportedKeySystemWithContainerAndCodec(
             mime_type, codecs[i], key_system))
       return false;
   }
 
   return true;
 }
 
-scoped_ptr<media::Decryptor> CreateDecryptor(const std::string& key_system,
-                                             media::DecryptorClient* client) {
-  if (key_system == kClearKeyKeySystem)
-    return scoped_ptr<media::Decryptor>(new media::AesDecryptor(client));
-  return scoped_ptr<media::Decryptor>();
+bool CanUseAesDecryptor(const std::string& key_system) {
+  return key_system == kClearKeyKeySystem;
+}
+
+const char* GetPluginType(const std::string& key_system) {
+  for (size_t i = 0; i < arraysize(key_system_to_plugin_type_mapping); ++i) {
+    if (key_system_to_plugin_type_mapping[i].key_system == key_system)
+      return key_system_to_plugin_type_mapping[i].plugin_type;
+  }
+
+  return NULL;
 }
 
 }  // namespace webkit_media