media: Allow config change between clear and encrypted streams

media/filters/decrypting_video_decoder.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 "media/filters/decrypting_video_decoder.h"
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/location.h"
 #include "base/logging.h"
@@ skipping 34 matching lines @@
                                         const OutputCB& output_cb) {
   DVLOG(2) << __func__ << ": " << config.AsHumanReadableString();
 
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(state_ == kUninitialized ||
          state_ == kIdle ||
          state_ == kDecodeFinished) << state_;
   DCHECK(decode_cb_.is_null());
   DCHECK(reset_cb_.is_null());
   DCHECK(config.IsValidConfig());
-  DCHECK(config.is_encrypted());
 
   init_cb_ = BindToCurrentLoop(init_cb);
   output_cb_ = BindToCurrentLoop(output_cb);
   weak_this_ = weak_factory_.GetWeakPtr();
   config_ = config;
 
   if (state_ == kUninitialized) {
+    // DecoderSelector only chooses |this| when the stream is encrypted.
+    // TODO(xhwang): We may also select this decoder for clear stream if a CDM
+    // is attached. Then we need to update this. See http://crbug.com/597443
+    DCHECK(config.is_encrypted());
     DCHECK(cdm_context);
     if (!cdm_context->GetDecryptor()) {
       MEDIA_LOG(DEBUG, media_log_) << GetDisplayName() << ": no decryptor";
       base::ResetAndReturn(&init_cb_).Run(false);
       return;
     }
 
     decryptor_ = cdm_context->GetDecryptor();
   } else {
-    // Reinitialization.
+    // Reinitialization (i.e. upon a config change). The new config can be
+    // encrypted or clear.
     decryptor_->DeinitializeDecoder(Decryptor::kVideo);
   }
 
   state_ = kPendingDecoderInit;
   decryptor_->InitializeVideoDecoder(
       config_, BindToCurrentLoop(base::Bind(
                    &DecryptingVideoDecoder::FinishInitialization, weak_this_)));
 }
 
 void DecryptingVideoDecoder::Decode(const scoped_refptr<DecoderBuffer>& buffer,
@@ skipping 226 matching lines @@
 }
 
 void DecryptingVideoDecoder::DoReset() {
   DCHECK(init_cb_.is_null());
   DCHECK(decode_cb_.is_null());
   state_ = kIdle;
   base::ResetAndReturn(&reset_cb_).Run();
 }
 
 }  // namespace media