EME: Require codecs parameter for audio/videoCapabilities

media/blink/key_system_config_selector.cc

 // Copyright 2014 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 "media/blink/key_system_config_selector.h"
 
 #include <stddef.h>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 288 matching lines @@
                             const std::string& codecs,
                             bool use_aes_decryptor) {
   std::vector<std::string> codec_vector;
   ParseCodecString(codecs, &codec_vector, false);
   // AesDecryptor decrypts the stream in the demuxer before it reaches the
   // decoder so check whether the media format is supported when clear.
   SupportsType support_result =
       use_aes_decryptor
           ? IsSupportedMediaFormat(container_mime_type, codec_vector)
           : IsSupportedEncryptedMediaFormat(container_mime_type, codec_vector);
-  switch (support_result) {
-    case IsSupported:
-      return true;
-    case MayBeSupported:
-      // If no codecs were specified, the best possible result is
-      // MayBeSupported, indicating support for the container.
-      return codec_vector.empty();
-    case IsNotSupported:
-      return false;
-  }
-  NOTREACHED();
-  return false;
+  return (support_result == IsSupported);
 }
 
 // TODO(sandersd): Move contentType parsing from Blink to here so that invalid
 // parameters can be rejected. http://crbug.com/417561

[xhwang, 2017/02/09 20:07:55]

The link is wrong.

Does this TODO still make sense?

[jrummell, 2017/02/09 23:36:08]

Updated link(s). The debate continues on what to do with invalid parameters.

 bool KeySystemConfigSelector::IsSupportedContentType(
     const std::string& key_system,
     EmeMediaType media_type,
     const std::string& container_mime_type,
     const std::string& codecs,
     KeySystemConfigSelector::ConfigState* config_state) {
   // From RFC6838: "Both top-level type and subtype names are case-insensitive."
   std::string container_lower = base::ToLowerASCII(container_mime_type);
 
   // contentTypes must provide a codec string unless the container implies a
   // particular codec. For EME, none of the currently supported containers
   // imply a codec, so |codecs| must be provided.
-  if (codecs.empty()) {
-    // Since the spec didn't initially require this, add an exemption for
-    // some existing containers to give clients time to adapt.
-    // TODO(jrummell): Remove this exemption once the number of contentTypes
-    // without codecs drops low enough (UMA added in the blink code).
-    // http://crbug.com/605661.
-    if (container_lower != "audio/webm" && container_lower != "video/webm" &&
-        container_lower != "audio/mp4" && container_lower != "video/mp4") {
-      return false;
-    }
-  }
+  if (codecs.empty())
+    return false;
 
   // Check that |container_mime_type| and |codecs| are supported by Chrome. This
   // is done primarily to validate extended codecs, but it also ensures that the
   // CDM cannot support codecs that Chrome does not (which could complicate the
   // robustness algorithm).
   if (!IsSupportedMediaFormat(container_lower, codecs,
                               CanUseAesDecryptor(key_system))) {
     return false;
   }
 
@@ skipping 590 matching lines @@
 
 void KeySystemConfigSelector::OnPermissionResult(
     std::unique_ptr<SelectionRequest> request,
     bool is_permission_granted) {
   request->was_permission_requested = true;
   request->is_permission_granted = is_permission_granted;
   SelectConfigInternal(std::move(request));
 }
 
 }  // namespace media