Connect WebMediaPlayerImpl to WebContentDecryptionModuleImpl for EME WD (Chromium side)

content/renderer/media/webmediaplayer_impl.cc

 // Copyright 2013 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 "content/renderer/media/webmediaplayer_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <string>
 #include <vector>
@@ skipping 32 matching lines @@
 #include "media/filters/audio_renderer_impl.h"
 #include "media/filters/chunk_demuxer.h"
 #include "media/filters/ffmpeg_audio_decoder.h"
 #include "media/filters/ffmpeg_demuxer.h"
 #include "media/filters/ffmpeg_video_decoder.h"
 #include "media/filters/gpu_video_accelerator_factories.h"
 #include "media/filters/gpu_video_decoder.h"
 #include "media/filters/opus_audio_decoder.h"
 #include "media/filters/video_renderer_impl.h"
 #include "media/filters/vpx_video_decoder.h"
+#include "third_party/WebKit/public/platform/WebContentDecryptionModule.h"
 #include "third_party/WebKit/public/platform/WebMediaSource.h"
 #include "third_party/WebKit/public/platform/WebRect.h"
 #include "third_party/WebKit/public/platform/WebSize.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/public/platform/WebURL.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
 #include "third_party/WebKit/public/web/WebRuntimeFeatures.h"
 #include "third_party/WebKit/public/web/WebView.h"
 #include "v8/include/v8.h"
 #include "webkit/renderer/compositor_bindings/web_layer_impl.h"
@@ skipping 98 matching lines @@
       frames_dropped_before_paint_(0),
       pending_repaint_(false),
       pending_size_change_(false),
       video_frame_provider_client_(NULL),
       text_track_index_(0) {
   media_log_->AddEvent(
       media_log_->CreateEvent(media::MediaLogEvent::WEBMEDIAPLAYER_CREATED));
 
   pipeline_.reset(new media::Pipeline(media_loop_, media_log_.get()));
 
+  // Grab a copy of the current CDM. This may be updated at any time by calls

[ddorwin, 2013/12/18 23:47:35]

It's not really a copy.

+  // to mediaKeysChanged().
+  cdm_ = client_->getWebContentDecryptionModule();

[ddorwin, 2013/12/18 23:47:35]

A WebContentDecryptionModule is not that interesting - it has no useful
interfaces. We really need the Decryptor from the MediaKeys from the
WebContentDecryptionModuleImpl.

It seems WebContentDecryptionModuleImpl is going to require a static_cast. Is
there a better way to do that?

We may still want to save the WebContentDecryptionModule for detaching, but we
should demonstrate in this CL how we are getting to something interesting so we
can evaluate whether the Blink APIs make sense.

[ddorwin, 2013/12/19 00:26:27]

I don't think this is the right time to set cdm_ (other than to NULL in the
initializer list). We should get it when we need it, which is when initializing
the pipeline. It might make more sense to be getting these objects there too.

We may end up with code that needs to be shared with mediaKeysChanged, in which
case we should consider a helper function if things get complicated.

+
   // |gpu_factories_| requires that its entry points be called on its
   // |GetMessageLoop()|.  Since |pipeline_| will own decoders created from the
   // factories, require that their message loops are identical.
   DCHECK(!gpu_factories_ || (gpu_factories_->GetMessageLoop() == media_loop_));
 
   // Let V8 know we started new thread if we did not do it yet.
   // Made separate task to avoid deletion of player currently being created.
   // Also, delaying GC until after player starts gets rid of starting lag --
   // collection happens in parallel with playing.
   //
@@ skipping 665 matching lines @@
   if (!IsConcreteSupportedKeySystem(key_system))
     return WebMediaPlayer::MediaKeyExceptionKeySystemNotSupported;
 
   if (current_key_system_.isEmpty() || key_system != current_key_system_)
     return WebMediaPlayer::MediaKeyExceptionInvalidPlayerState;
 
   decryptor_->CancelKeyRequest(session_id.utf8());
   return WebMediaPlayer::MediaKeyExceptionNoError;
 }
 
+void WebMediaPlayerImpl::mediaKeysChanged(
+    blink::WebContentDecryptionModule* cdm) {
+  cdm_ = cdm;

[ddorwin, 2013/12/18 23:47:35]

We need to stop any current uses of the old one (unless the pointers are the
same for whatever reason - might be a DCHECK here and Blink should prevent
that).

That makes things interesting because that operation will be asynchronous.
Therefore:

We also need to ensure that the previous CDM is not destroyed while the pipeline
is still using them. We should probably maintain a reference count to the
objects (MediaKeys/Decryptor?) that the pipeline is using in the pipeline
(Decoders?) and in WebCDMImpl.

We also need to figure out a way to prevent applications from attaching the
still-in-use MediaKeys implementation to another HTMLMediaElement. I'm going to
pursue this in a spec bug. Regardless, we will probably need some way to
indicate this is complete.

+}
+
 void WebMediaPlayerImpl::OnDestruct() {
   Destroy();
 }
 
 void WebMediaPlayerImpl::Repaint() {
   DCHECK(main_loop_->BelongsToCurrentThread());
   TRACE_EVENT0("media", "WebMediaPlayerImpl:repaint");
 
   bool size_changed = false;
   {
@@ skipping 443 matching lines @@
   // The |current_frame_| wasn't painted, it is being replaced, and we haven't
   // even gotten the chance to request a repaint for it yet. Mark it as dropped.
   TRACE_EVENT0("media", "WebMediaPlayerImpl:frameDropped");
   DVLOG(1) << "Frame dropped before being painted: "
            << current_frame_->GetTimestamp().InSecondsF();
   if (frames_dropped_before_paint_ < kuint32max)
     frames_dropped_before_paint_++;
 }
 
 }  // namespace content