[Chromecast] Pass DecoderBufferBase directly to backends.

The DecryptContext for a buffer is now available via buffer->decrypt_context(), which allows us to make the decrypt context live at least as long as the buffer. Currently it is owned by the buffer.

BUG= internal b/23751784

Review URL: https://codereview.chromium.org/1425523002

Cr-Commit-Position: refs/heads/master@{#356071}

22 files changed, 123 insertions, 214 deletions

diff --git a/chromecast/media/audio/cast_audio_output_stream.cc b/chromecast/media/audio/cast_audio_output_stream.cc
index 9ba059f1..e283ab0 100644
--- a/chromecast/media/audio/cast_audio_output_stream.cc
+++ b/chromecast/media/audio/cast_audio_output_stream.cc
@@ -12,7 +12,6 @@
 #include "chromecast/base/task_runner_impl.h"
 #include "chromecast/media/audio/cast_audio_manager.h"
 #include "chromecast/media/base/media_message_loop.h"
-#include "chromecast/media/cma/base/cast_decoder_buffer_impl.h"
 #include "chromecast/media/cma/base/decoder_buffer_adapter.h"
 #include "chromecast/public/media/decoder_config.h"
 #include "chromecast/public/media/decrypt_context.h"
@@ -67,8 +66,7 @@ class CastAudioOutputStream::Backend : public MediaPipelineBackend::Delegate {
       : audio_params_(audio_params),
         decoder_(nullptr),
         first_start_(true),
-        error_(false),
-        backend_buffer_(nullptr) {
+        error_(false) {
     thread_checker_.DetachFromThread();
   }
   ~Backend() override {}
@@ -133,11 +131,11 @@ class CastAudioOutputStream::Backend : public MediaPipelineBackend::Delegate {
       return;
     }
 
-    backend_buffer_.set_buffer(decoder_buffer);
+    backend_buffer_ = decoder_buffer;
 
     completion_cb_ = completion_cb;
     MediaPipelineBackend::BufferStatus status =
-        decoder_->PushBuffer(nullptr /* decrypt_context */, &backend_buffer_);
+        decoder_->PushBuffer(backend_buffer_.get());
     if (status != MediaPipelineBackend::kBufferPending)
       OnPushBufferComplete(decoder_, status);
   }
@@ -182,7 +180,7 @@ class CastAudioOutputStream::Backend : public MediaPipelineBackend::Delegate {
   PushBufferCompletionCallback completion_cb_;
   bool first_start_;
   bool error_;
-  CastDecoderBufferImpl backend_buffer_;
+  scoped_refptr<DecoderBufferBase> backend_buffer_;
   base::ThreadChecker thread_checker_;
   DISALLOW_COPY_AND_ASSIGN(Backend);
 };
diff --git a/chromecast/media/audio/cast_audio_output_stream_unittest.cc b/chromecast/media/audio/cast_audio_output_stream_unittest.cc
index 4c44590..608d9b6 100644
--- a/chromecast/media/audio/cast_audio_output_stream_unittest.cc
+++ b/chromecast/media/audio/cast_audio_output_stream_unittest.cc
@@ -42,15 +42,12 @@ class FakeAudioDecoder : public MediaPipelineBackend::AudioDecoder {
         pipeline_status_(PIPELINE_STATUS_OK),
         pending_push_(false),
         pushed_buffer_count_(0),
-        last_decrypt_context_(nullptr),
         last_buffer_(nullptr),
         delegate_(nullptr) {}
   ~FakeAudioDecoder() override {}
 
   // MediaPipelineBackend::AudioDecoder overrides.
-  BufferStatus PushBuffer(DecryptContext* decrypt_context,
-                          CastDecoderBuffer* buffer) override {
-    last_decrypt_context_ = decrypt_context;
+  BufferStatus PushBuffer(CastDecoderBuffer* buffer) override {
     last_buffer_ = buffer;
     ++pushed_buffer_count_;
 
@@ -93,7 +90,6 @@ class FakeAudioDecoder : public MediaPipelineBackend::AudioDecoder {
     pipeline_status_ = status;
   }
   unsigned pushed_buffer_count() const { return pushed_buffer_count_; }
-  DecryptContext* last_decrypt_context() { return last_decrypt_context_; }
   CastDecoderBuffer* last_buffer() { return last_buffer_; }
   void set_delegate(MediaPipelineBackend::Delegate* delegate) {
     delegate_ = delegate;
@@ -106,7 +102,6 @@ class FakeAudioDecoder : public MediaPipelineBackend::AudioDecoder {
   PipelineStatus pipeline_status_;
   bool pending_push_;
   int pushed_buffer_count_;
-  DecryptContext* last_decrypt_context_;
   CastDecoderBuffer* last_buffer_;
   MediaPipelineBackend::Delegate* delegate_;
 };
@@ -471,7 +466,6 @@ TEST_F(CastAudioOutputStreamTest, PushFrame) {
   ASSERT_TRUE(audio_decoder);
   // Verify initial state.
   EXPECT_EQ(0u, audio_decoder->pushed_buffer_count());
-  EXPECT_FALSE(audio_decoder->last_decrypt_context());
   EXPECT_FALSE(audio_decoder->last_buffer());
 
   scoped_ptr<FakeAudioSourceCallback> source_callback(
@@ -481,8 +475,6 @@ TEST_F(CastAudioOutputStreamTest, PushFrame) {
 
   // Verify that the stream pushed frames to the backend.
   EXPECT_LT(0u, audio_decoder->pushed_buffer_count());
-  // DecryptContext is always NULL becuase of "raw" audio.
-  EXPECT_FALSE(audio_decoder->last_decrypt_context());
   EXPECT_TRUE(audio_decoder->last_buffer());
 
   // Verify decoder buffer.
diff --git a/chromecast/media/cma/backend/audio_video_pipeline_device_unittest.cc b/chromecast/media/cma/backend/audio_video_pipeline_device_unittest.cc
index 38ea193..fb0d768 100644
--- a/chromecast/media/cma/backend/audio_video_pipeline_device_unittest.cc
+++ b/chromecast/media/cma/backend/audio_video_pipeline_device_unittest.cc
@@ -20,7 +20,6 @@
 #include "base/threading/thread.h"
 #include "base/time/time.h"
 #include "chromecast/base/task_runner_impl.h"
-#include "chromecast/media/cma/base/cast_decoder_buffer_impl.h"
 #include "chromecast/media/cma/base/decoder_buffer_adapter.h"
 #include "chromecast/media/cma/base/decoder_config_adapter.h"
 #include "chromecast/media/cma/test/frame_segmenter_for_test.h"
@@ -116,8 +115,8 @@ class AudioVideoPipelineDeviceTest : public testing::Test,
 
   scoped_ptr<TaskRunnerImpl> task_runner_;
   scoped_ptr<MediaPipelineBackend> backend_;
-  CastDecoderBufferImpl backend_audio_buffer_;
-  CastDecoderBufferImpl backend_video_buffer_;
+  scoped_refptr<DecoderBufferBase> backend_audio_buffer_;
+  scoped_refptr<DecoderBufferBase> backend_video_buffer_;
 
   // Current media time.
   base::TimeDelta pause_time_;
@@ -138,9 +137,7 @@ class AudioVideoPipelineDeviceTest : public testing::Test,
 };
 
 AudioVideoPipelineDeviceTest::AudioVideoPipelineDeviceTest()
-    : backend_audio_buffer_(nullptr),
-      backend_video_buffer_(nullptr),
-      pause_pattern_(),
+    : pause_pattern_(),
       audio_decoder_(nullptr),
       video_decoder_(nullptr),
       audio_feeding_completed_(true),
@@ -249,18 +246,16 @@ void AudioVideoPipelineDeviceTest::FeedAudioBuffer() {
   if (audio_feeding_completed_)
     return;
 
-  scoped_refptr<DecoderBufferBase> buffer = audio_buffers_.front();
-  backend_audio_buffer_.set_buffer(buffer);
+  backend_audio_buffer_ = audio_buffers_.front();
 
   MediaPipelineBackend::BufferStatus status =
-      audio_decoder_->PushBuffer(nullptr,  // decrypt_context
-                                 &backend_audio_buffer_);
+      audio_decoder_->PushBuffer(backend_audio_buffer_.get());
   EXPECT_NE(status, MediaPipelineBackend::kBufferFailed);
   audio_buffers_.pop_front();
 
   // Feeding is done, just wait for the end of stream callback.
-  if (buffer->end_of_stream() || audio_buffers_.empty()) {
-    if (audio_buffers_.empty() && !buffer->end_of_stream()) {
+  if (backend_audio_buffer_->end_of_stream() || audio_buffers_.empty()) {
+    if (audio_buffers_.empty() && !backend_audio_buffer_->end_of_stream()) {
       LOG(WARNING) << "Stream emptied without feeding EOS frame";
     }
 
@@ -280,18 +275,16 @@ void AudioVideoPipelineDeviceTest::FeedVideoBuffer() {
   if (video_feeding_completed_)
     return;
 
-  scoped_refptr<DecoderBufferBase> buffer = video_buffers_.front();
-  backend_video_buffer_.set_buffer(buffer);
+  backend_video_buffer_ = video_buffers_.front();
 
   MediaPipelineBackend::BufferStatus status =
-      video_decoder_->PushBuffer(nullptr,  // decrypt_context
-                                 &backend_video_buffer_);
+      video_decoder_->PushBuffer(backend_video_buffer_.get());
   EXPECT_NE(status, MediaPipelineBackend::kBufferFailed);
   video_buffers_.pop_front();
 
   // Feeding is done, just wait for the end of stream callback.
-  if (buffer->end_of_stream() || video_buffers_.empty()) {
-    if (video_buffers_.empty() && !buffer->end_of_stream()) {
+  if (backend_video_buffer_->end_of_stream() || video_buffers_.empty()) {
+    if (video_buffers_.empty() && !backend_video_buffer_->end_of_stream()) {
       LOG(WARNING) << "Stream emptied without feeding EOS frame";
     }
 
@@ -431,6 +424,7 @@ void AudioVideoPipelineDeviceTest::Initialize() {
   task_runner_.reset(new TaskRunnerImpl());
   MediaPipelineDeviceParams params(task_runner_.get());
   backend_.reset(CastMediaShlib::CreateMediaPipelineBackend(params));
+  DCHECK(backend_);
 }
 
 TEST_F(AudioVideoPipelineDeviceTest, Mp3Playback) {
diff --git a/chromecast/media/cma/backend/media_pipeline_backend_default.cc b/chromecast/media/cma/backend/media_pipeline_backend_default.cc
index bb0cc1e..61a3315 100644
--- a/chromecast/media/cma/backend/media_pipeline_backend_default.cc
+++ b/chromecast/media/cma/backend/media_pipeline_backend_default.cc
@@ -20,8 +20,7 @@ class MediaPipelineBackendDefault::AudioDecoderDefault
   }
 
   // MediaPipelineBackend::AudioDecoder implementation:
-  BufferStatus PushBuffer(DecryptContext* decrypt_context,
-                          CastDecoderBuffer* buffer) override {
+  BufferStatus PushBuffer(CastDecoderBuffer* buffer) override {
     if (buffer->end_of_stream())
       delegate_->OnEndOfStream(this);
     return MediaPipelineBackend::kBufferSuccess;
@@ -52,8 +51,7 @@ class MediaPipelineBackendDefault::VideoDecoderDefault
   }
 
   // MediaPipelineBackend::VideoDecoder implementation:
-  BufferStatus PushBuffer(DecryptContext* decrypt_context,
-                          CastDecoderBuffer* buffer) override {
+  BufferStatus PushBuffer(CastDecoderBuffer* buffer) override {
     if (buffer->end_of_stream())
       delegate_->OnEndOfStream(this);
     return MediaPipelineBackend::kBufferSuccess;
diff --git a/chromecast/media/cma/base/BUILD.gn b/chromecast/media/cma/base/BUILD.gn
index d3eb811..b0ebefd 100644
--- a/chromecast/media/cma/base/BUILD.gn
+++ b/chromecast/media/cma/base/BUILD.gn
@@ -14,8 +14,6 @@ source_set("base") {
     "buffering_frame_provider.h",
     "buffering_state.cc",
     "buffering_state.h",
-    "cast_decoder_buffer_impl.cc",
-    "cast_decoder_buffer_impl.h",
     "cast_decrypt_config_impl.cc",
     "cast_decrypt_config_impl.h",
     "cma_logging.h",
diff --git a/chromecast/media/cma/base/cast_decoder_buffer_impl.cc b/chromecast/media/cma/base/cast_decoder_buffer_impl.cc
deleted file mode 100644
index e958048..0000000
--- a/chromecast/media/cma/base/cast_decoder_buffer_impl.cc
+++ /dev/null
@@ -1,50 +0,0 @@
-// Copyright 2015 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 "chromecast/media/cma/base/cast_decoder_buffer_impl.h"
-
-namespace chromecast {
-namespace media {
-
-CastDecoderBufferImpl::CastDecoderBufferImpl(
-    const scoped_refptr<DecoderBufferBase>& buffer)
-    : buffer_(buffer) {}
-
-CastDecoderBufferImpl::~CastDecoderBufferImpl() {}
-
-StreamId CastDecoderBufferImpl::stream_id() const {
-  return buffer_->stream_id();
-}
-
-int64_t CastDecoderBufferImpl::timestamp() const {
-  return buffer_->timestamp().InMicroseconds();
-}
-
-const uint8* CastDecoderBufferImpl::data() const {
-  return buffer_->data();
-}
-
-size_t CastDecoderBufferImpl::data_size() const {
-  return buffer_->data_size();
-}
-
-const CastDecryptConfig* CastDecoderBufferImpl::decrypt_config() const {
-  return buffer_->decrypt_config();
-}
-
-bool CastDecoderBufferImpl::end_of_stream() const {
-  return buffer_->end_of_stream();
-}
-
-const scoped_refptr<DecoderBufferBase>& CastDecoderBufferImpl::buffer() const {
-  return buffer_;
-}
-
-void CastDecoderBufferImpl::set_buffer(
-    const scoped_refptr<DecoderBufferBase>& buffer) {
-  buffer_ = buffer;
-}
-
-}  // namespace media
-}  // namespace chromecast
diff --git a/chromecast/media/cma/base/cast_decoder_buffer_impl.h b/chromecast/media/cma/base/cast_decoder_buffer_impl.h
deleted file mode 100644
index adc663c..0000000
--- a/chromecast/media/cma/base/cast_decoder_buffer_impl.h
+++ /dev/null
@@ -1,54 +0,0 @@
-// Copyright 2015 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.
-
-#ifndef CHROMECAST_MEDIA_CMA_BASE_CAST_DECODER_BUFFER_IMPL_H_
-#define CHROMECAST_MEDIA_CMA_BASE_CAST_DECODER_BUFFER_IMPL_H_
-
-#include "chromecast/public/media/cast_decoder_buffer.h"
-#include "chromecast/media/cma/base/decoder_buffer_base.h"
-
-namespace chromecast {
-namespace media {
-
-// Implementation of public DecoderBuffer interface.
-// Holds a (refcounted) DecoderBufferBase.  This way, ownership throughout
-// the pipeline is refcounted, but without exposing RefCountedBase in
-// the public API.
-class CastDecoderBufferImpl : public CastDecoderBuffer {
- public:
-  CastDecoderBufferImpl(const scoped_refptr<DecoderBufferBase>& buffer);
-  ~CastDecoderBufferImpl() override;
-
-  // Returns the stream id of this decoder buffer belonging to. it's optional
-  // and default value is kPrimary.
-  StreamId stream_id() const override;
-
-  // Returns the PTS of the frame in microseconds.
-  int64_t timestamp() const override;
-
-  // Gets the frame data.
-  const uint8* data() const override;
-
-  // Returns the size of the frame in bytes.
-  size_t data_size() const override;
-
-  // Returns the decrypt configuration.
-  // Returns NULL if the buffer has no decrypt info.
-  const CastDecryptConfig* decrypt_config() const override;
-
-  // Indicate if this is a special frame that indicates the end of the stream.
-  // If true, functions to access the frame content cannot be called.
-  bool end_of_stream() const override;
-
-  const scoped_refptr<DecoderBufferBase>& buffer() const;
-  void set_buffer(const scoped_refptr<DecoderBufferBase>& buffer);
-
- private:
-  scoped_refptr<DecoderBufferBase> buffer_;
-};
-
-}  // namespace media
-}  // namespace chromecast
-
-#endif  // CHROMECAST_MEDIA_CMA_BASE_CAST_DECODER_BUFFER_BASE_H_
diff --git a/chromecast/media/cma/base/decoder_buffer_adapter.cc b/chromecast/media/cma/base/decoder_buffer_adapter.cc
index 10ffddc..c7de81f 100644
--- a/chromecast/media/cma/base/decoder_buffer_adapter.cc
+++ b/chromecast/media/cma/base/decoder_buffer_adapter.cc
@@ -29,8 +29,8 @@ StreamId DecoderBufferAdapter::stream_id() const {
   return stream_id_;
 }
 
-base::TimeDelta DecoderBufferAdapter::timestamp() const {
-  return buffer_->timestamp();
+int64_t DecoderBufferAdapter::timestamp() const {
+  return buffer_->timestamp().InMicroseconds();
 }
 
 void DecoderBufferAdapter::set_timestamp(base::TimeDelta timestamp) {
diff --git a/chromecast/media/cma/base/decoder_buffer_adapter.h b/chromecast/media/cma/base/decoder_buffer_adapter.h
index 5118694..9eda89c 100644
--- a/chromecast/media/cma/base/decoder_buffer_adapter.h
+++ b/chromecast/media/cma/base/decoder_buffer_adapter.h
@@ -28,9 +28,9 @@ class DecoderBufferAdapter : public DecoderBufferBase {
   DecoderBufferAdapter(
       StreamId stream_id, const scoped_refptr<::media::DecoderBuffer>& buffer);
 
-  // DecoderBufferBase implementation.
+  // DecoderBufferBase implementation:
   StreamId stream_id() const override;
-  base::TimeDelta timestamp() const override;
+  int64_t timestamp() const override;
   void set_timestamp(base::TimeDelta timestamp) override;
   const uint8* data() const override;
   uint8* writable_data() const override;
diff --git a/chromecast/media/cma/base/decoder_buffer_base.h b/chromecast/media/cma/base/decoder_buffer_base.h
index 08cf94b..d405da4 100644
--- a/chromecast/media/cma/base/decoder_buffer_base.h
+++ b/chromecast/media/cma/base/decoder_buffer_base.h
@@ -5,57 +5,57 @@
 #ifndef CHROMECAST_MEDIA_CMA_BASE_DECODER_BUFFER_BASE_H_
 #define CHROMECAST_MEDIA_CMA_BASE_DECODER_BUFFER_BASE_H_
 
-#include "base/basictypes.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
-#include "chromecast/public/media/stream_id.h"
+#include "chromecast/public/media/cast_decoder_buffer.h"
+#include "chromecast/public/media/decrypt_context.h"
 
 namespace chromecast {
 namespace media {
-class CastDecryptConfig;
 
 // DecoderBufferBase exposes only the properties of an audio/video buffer.
 // The way a DecoderBufferBase is created and organized in memory
 // is left as a detail of the implementation of derived classes.
-class DecoderBufferBase
-    : public base::RefCountedThreadSafe<DecoderBufferBase> {
+class DecoderBufferBase : public CastDecoderBuffer,
+                          public base::RefCountedThreadSafe<DecoderBufferBase> {
  public:
-  DecoderBufferBase() {}
+  // Partial CastDecoderBuffer implementation:
+  DecryptContext* decrypt_context() const override;
 
-  // Returns the stream id of this decoder buffer belonging to. it's optional
-  // and default value is kPrimary.
-  virtual StreamId stream_id() const = 0;
-
-  // Returns the PTS of the frame.
-  virtual base::TimeDelta timestamp() const = 0;
+  void set_decrypt_context(scoped_ptr<DecryptContext> context) {
+    decrypt_context_ = context.Pass();
+  }
 
   // Sets the PTS of the frame.
   virtual void set_timestamp(base::TimeDelta timestamp) = 0;
 
-  // Gets the frame data.
-  virtual const uint8* data() const = 0;
-  virtual uint8* writable_data() const = 0;
-
-  // Returns the size of the frame in bytes.
-  virtual size_t data_size() const = 0;
-
-  // Returns the decrypt configuration.
-  // Returns NULL if the buffer has no decrypt info.
-  virtual const CastDecryptConfig* decrypt_config() const = 0;
-
-  // Indicate if this is a special frame that indicates the end of the stream.
-  // If true, functions to access the frame content cannot be called.
-  virtual bool end_of_stream() const = 0;
+  // Gets a pointer to the frame data buffer.
+  virtual uint8_t* writable_data() const = 0;
 
  protected:
   friend class base::RefCountedThreadSafe<DecoderBufferBase>;
-  virtual ~DecoderBufferBase() {}
+
+  DecoderBufferBase();
+  ~DecoderBufferBase() override;
 
  private:
+  scoped_ptr<DecryptContext> decrypt_context_;
+
   DISALLOW_COPY_AND_ASSIGN(DecoderBufferBase);
 };
 
+inline DecoderBufferBase::DecoderBufferBase() {
+}
+
+inline DecoderBufferBase::~DecoderBufferBase() {
+}
+
+inline DecryptContext* DecoderBufferBase::decrypt_context() const {
+  return decrypt_context_.get();
+}
+
 }  // namespace media
 }  // namespace chromecast
 
diff --git a/chromecast/media/cma/ipc_streamer/decoder_buffer_base_marshaller.cc b/chromecast/media/cma/ipc_streamer/decoder_buffer_base_marshaller.cc
index 1bc97a5..b6af72b 100644
--- a/chromecast/media/cma/ipc_streamer/decoder_buffer_base_marshaller.cc
+++ b/chromecast/media/cma/ipc_streamer/decoder_buffer_base_marshaller.cc
@@ -27,7 +27,7 @@ class DecoderBufferFromMsg : public DecoderBufferBase {
 
   // DecoderBufferBase implementation.
   StreamId stream_id() const override;
-  base::TimeDelta timestamp() const override;
+  int64_t timestamp() const override;
   void set_timestamp(base::TimeDelta timestamp) override;
   const uint8* data() const override;
   uint8* writable_data() const override;
@@ -113,8 +113,8 @@ StreamId DecoderBufferFromMsg::stream_id() const {
   return stream_id_;
 }
 
-base::TimeDelta DecoderBufferFromMsg::timestamp() const {
-  return pts_;
+int64_t DecoderBufferFromMsg::timestamp() const {
+  return pts_.InMicroseconds();
 }
 
 void DecoderBufferFromMsg::set_timestamp(base::TimeDelta timestamp) {
@@ -154,7 +154,7 @@ void DecoderBufferBaseMarshaller::Write(
     return;
 
   CHECK(msg->WritePod(buffer->stream_id()));
-  CHECK(msg->WritePod(buffer->timestamp().InMicroseconds()));
+  CHECK(msg->WritePod(buffer->timestamp()));
 
   bool has_decrypt_config =
       (buffer->decrypt_config() != NULL &&
diff --git a/chromecast/media/cma/pipeline/audio_pipeline_impl.cc b/chromecast/media/cma/pipeline/audio_pipeline_impl.cc
index b88f686..0edd474 100644
--- a/chromecast/media/cma/pipeline/audio_pipeline_impl.cc
+++ b/chromecast/media/cma/pipeline/audio_pipeline_impl.cc
@@ -73,6 +73,11 @@ void AudioPipelineImpl::Flush(const ::media::PipelineStatusCB& status_cb) {
       base::Bind(&AudioPipelineImpl::OnFlushDone, weak_this_, status_cb));
 }
 
+void AudioPipelineImpl::BackendStopped() {
+  CMALOG(kLogControl) << __FUNCTION__;
+  av_pipeline_impl_->BackendStopped();
+}
+
 void AudioPipelineImpl::OnFlushDone(
     const ::media::PipelineStatusCB& status_cb) {
   CMALOG(kLogControl) << __FUNCTION__;
diff --git a/chromecast/media/cma/pipeline/audio_pipeline_impl.h b/chromecast/media/cma/pipeline/audio_pipeline_impl.h
index 9afe19b..014b041 100644
--- a/chromecast/media/cma/pipeline/audio_pipeline_impl.h
+++ b/chromecast/media/cma/pipeline/audio_pipeline_impl.h
@@ -46,6 +46,7 @@ class AudioPipelineImpl {
   bool StartPlayingFrom(base::TimeDelta time,
                         const scoped_refptr<BufferingState>& buffering_state);
   void Flush(const ::media::PipelineStatusCB& status_cb);
+  void BackendStopped();
   void Stop();
 
   // Update the playback statistics for this audio stream.
diff --git a/chromecast/media/cma/pipeline/av_pipeline_impl.cc b/chromecast/media/cma/pipeline/av_pipeline_impl.cc
index a8eff13..82ce75f 100644
--- a/chromecast/media/cma/pipeline/av_pipeline_impl.cc
+++ b/chromecast/media/cma/pipeline/av_pipeline_impl.cc
@@ -41,7 +41,6 @@ AvPipelineImpl::AvPipelineImpl(MediaPipelineBackend::Decoder* decoder,
       playable_buffered_time_(::media::kNoTimestamp()),
       enable_feeding_(false),
       pending_read_(false),
-      pushed_buffer_(nullptr),
       enable_time_update_(false),
       pending_time_update_task_(false),
       media_keys_(NULL),
@@ -103,14 +102,11 @@ void AvPipelineImpl::Flush(const base::Closure& done_cb) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK_EQ(state_, kFlushing);
 
-  // Note: returning to idle state aborts any pending frame push.
-  pushed_buffer_.set_buffer(nullptr);
-
   // Break the feeding loop.
   enable_feeding_ = false;
 
   // Remove any pending buffer.
-  pending_buffer_ = scoped_refptr<DecoderBufferBase>();
+  pending_buffer_ = nullptr;
 
   // Finally, remove any frames left in the frame provider.
   pending_read_ = false;
@@ -120,6 +116,13 @@ void AvPipelineImpl::Flush(const base::Closure& done_cb) {
   frame_provider_->Flush(done_cb);
 }
 
+void AvPipelineImpl::BackendStopped() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  // Note: returning to idle state aborts any pending frame push.
+  pushed_buffer_ = nullptr;
+}
+
 void AvPipelineImpl::Stop() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
@@ -149,7 +152,7 @@ void AvPipelineImpl::FetchBufferIfNeeded() {
   if (!enable_feeding_)
     return;
 
-  if (pending_read_ || pending_buffer_.get())
+  if (pending_read_ || pending_buffer_)
     return;
 
   pending_read_ = true;
@@ -179,14 +182,14 @@ void AvPipelineImpl::ProcessPendingBuffer() {
     return;
 
   // Initiate a read if there isn't already one.
-  if (!pending_buffer_.get() && !pending_read_) {
+  if (!pending_buffer_ && !pending_read_) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE,
         base::Bind(&AvPipelineImpl::FetchBufferIfNeeded, weak_this_));
     return;
   }
 
-  if (!pending_buffer_.get() || pushed_buffer_.buffer())
+  if (!pending_buffer_ || pushed_buffer_)
     return;
 
   // Break the feeding loop when the end of stream is reached.
@@ -203,13 +206,12 @@ void AvPipelineImpl::ProcessPendingBuffer() {
     std::string key_id(pending_buffer_->decrypt_config()->key_id());
     if (!media_keys_) {
       CMALOG(kLogControl) << "No CDM for frame: pts="
-                          << pending_buffer_->timestamp().InMilliseconds();
+                          << pending_buffer_->timestamp();
       return;
     }
     decrypt_context = media_keys_->GetDecryptContext(key_id);
     if (!decrypt_context.get()) {
-      CMALOG(kLogControl) << "frame(pts="
-                          << pending_buffer_->timestamp().InMilliseconds()
+      CMALOG(kLogControl) << "frame(pts=" << pending_buffer_->timestamp()
                           << "): waiting for key id "
                           << base::HexEncode(&key_id[0], key_id.size());
       return;
@@ -225,16 +227,19 @@ void AvPipelineImpl::ProcessPendingBuffer() {
   }
 
   if (!pending_buffer_->end_of_stream() && buffering_state_.get()) {
-    base::TimeDelta timestamp = pending_buffer_->timestamp();
+    base::TimeDelta timestamp =
+        base::TimeDelta::FromMicroseconds(pending_buffer_->timestamp());
     if (timestamp != ::media::kNoTimestamp())
       buffering_state_->SetMaxRenderingTime(timestamp);
   }
 
-  DCHECK(!pushed_buffer_.buffer());
-  pushed_buffer_.set_buffer(pending_buffer_);
+  DCHECK(!pushed_buffer_);
+  pushed_buffer_ = pending_buffer_;
+  if (decrypt_context && decrypt_context->GetKeySystem() != KEY_SYSTEM_NONE)
+    pushed_buffer_->set_decrypt_context(decrypt_context.Pass());
+  pending_buffer_ = nullptr;
   MediaPipelineBackend::BufferStatus status =
-      decoder_->PushBuffer(decrypt_context.release(), &pushed_buffer_);
-  pending_buffer_ = scoped_refptr<DecoderBufferBase>();
+      decoder_->PushBuffer(pushed_buffer_.get());
 
   if (status != MediaPipelineBackend::kBufferPending)
     OnBufferPushed(status);
@@ -242,7 +247,7 @@ void AvPipelineImpl::ProcessPendingBuffer() {
 
 void AvPipelineImpl::OnBufferPushed(MediaPipelineBackend::BufferStatus status) {
   DCHECK(thread_checker_.CalledOnValidThread());
-  pushed_buffer_.set_buffer(nullptr);
+  pushed_buffer_ = nullptr;
   if (status == MediaPipelineBackend::kBufferFailed) {
     LOG(WARNING) << "AvPipelineImpl: PushFrame failed";
     enable_feeding_ = false;
@@ -277,9 +282,11 @@ void AvPipelineImpl::OnDataBuffered(
   if (!buffering_state_.get())
     return;
 
-  if (!buffer->end_of_stream() && (buffered_time_ == ::media::kNoTimestamp() ||
-                                   buffered_time_ < buffer->timestamp())) {
-    buffered_time_ = buffer->timestamp();
+  if (!buffer->end_of_stream() &&
+      (buffered_time_ == ::media::kNoTimestamp() ||
+       buffered_time_ <
+           base::TimeDelta::FromMicroseconds(buffer->timestamp()))) {
+    buffered_time_ = base::TimeDelta::FromMicroseconds(buffer->timestamp());
   }
 
   if (is_at_max_capacity)
@@ -312,8 +319,10 @@ void AvPipelineImpl::UpdatePlayableFrames() {
       }
 
       if (playable_buffered_time_ == ::media::kNoTimestamp() ||
-          playable_buffered_time_ < non_playable_frame->timestamp()) {
-        playable_buffered_time_ = non_playable_frame->timestamp();
+          playable_buffered_time_ < base::TimeDelta::FromMicroseconds(
+                                        non_playable_frame->timestamp())) {
+        playable_buffered_time_ =
+            base::TimeDelta::FromMicroseconds(non_playable_frame->timestamp());
         buffering_state_->SetBufferedTime(playable_buffered_time_);
       }
     }
diff --git a/chromecast/media/cma/pipeline/av_pipeline_impl.h b/chromecast/media/cma/pipeline/av_pipeline_impl.h
index fe1a828..28a885b 100644
--- a/chromecast/media/cma/pipeline/av_pipeline_impl.h
+++ b/chromecast/media/cma/pipeline/av_pipeline_impl.h
@@ -12,7 +12,6 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/thread_checker.h"
-#include "chromecast/media/cma/base/cast_decoder_buffer_impl.h"
 #include "chromecast/public/media/media_pipeline_backend.h"
 #include "chromecast/public/media/stream_id.h"
 
@@ -64,6 +63,8 @@ class AvPipelineImpl {
   // Flush any remaining samples in the pipeline.
   // Invoke |done_cb| when flush is completed.
   void Flush(const base::Closure& done_cb);
+  // Resets any pending buffers after the backend has been stopped.
+  void BackendStopped();
 
   // Tear down the pipeline and release the hardware resources.
   void Stop();
@@ -140,7 +141,7 @@ class AvPipelineImpl {
   scoped_refptr<DecoderBufferBase> pending_buffer_;
 
   // Buffer that has been pushed to the device but not processed yet.
-  CastDecoderBufferImpl pushed_buffer_;
+  scoped_refptr<DecoderBufferBase> pushed_buffer_;
 
   // The media time is retrieved at regular intervals.
   // Indicate whether time update is enabled.
diff --git a/chromecast/media/cma/pipeline/decrypt_util.cc b/chromecast/media/cma/pipeline/decrypt_util.cc
index 7f57cec..2acd5ea 100644
--- a/chromecast/media/cma/pipeline/decrypt_util.cc
+++ b/chromecast/media/cma/pipeline/decrypt_util.cc
@@ -23,7 +23,7 @@ class DecoderBufferClear : public DecoderBufferBase {
 
   // DecoderBufferBase implementation.
   StreamId stream_id() const override;
-  base::TimeDelta timestamp() const override;
+  int64_t timestamp() const override;
   void set_timestamp(base::TimeDelta timestamp) override;
   const uint8* data() const override;
   uint8* writable_data() const override;
@@ -51,7 +51,7 @@ StreamId DecoderBufferClear::stream_id() const {
   return buffer_->stream_id();
 }
 
-base::TimeDelta DecoderBufferClear::timestamp() const {
+int64_t DecoderBufferClear::timestamp() const {
   return buffer_->timestamp();
 }
 
diff --git a/chromecast/media/cma/pipeline/media_pipeline_impl.cc b/chromecast/media/cma/pipeline/media_pipeline_impl.cc
index e741470..68df661 100644
--- a/chromecast/media/cma/pipeline/media_pipeline_impl.cc
+++ b/chromecast/media/cma/pipeline/media_pipeline_impl.cc
@@ -345,6 +345,12 @@ void MediaPipelineImpl::OnFlushDone(
     return;
   }
 
+  // Clear pending buffers.
+  if (audio_pipeline_)
+    audio_pipeline_->BackendStopped();
+  if (video_pipeline_)
+    video_pipeline_->BackendStopped();
+
   pending_flush_callbacks_.reset();
   status_cb.Run(status);
 }
diff --git a/chromecast/media/cma/pipeline/video_pipeline_impl.cc b/chromecast/media/cma/pipeline/video_pipeline_impl.cc
index e24a7f7..2d6f803 100644
--- a/chromecast/media/cma/pipeline/video_pipeline_impl.cc
+++ b/chromecast/media/cma/pipeline/video_pipeline_impl.cc
@@ -76,6 +76,11 @@ void VideoPipelineImpl::Flush(const ::media::PipelineStatusCB& status_cb) {
       base::Bind(&VideoPipelineImpl::OnFlushDone, weak_this_, status_cb));
 }
 
+void VideoPipelineImpl::BackendStopped() {
+  CMALOG(kLogControl) << __FUNCTION__;
+  av_pipeline_impl_->BackendStopped();
+}
+
 void VideoPipelineImpl::OnFlushDone(
     const ::media::PipelineStatusCB& status_cb) {
   CMALOG(kLogControl) << __FUNCTION__;
diff --git a/chromecast/media/cma/pipeline/video_pipeline_impl.h b/chromecast/media/cma/pipeline/video_pipeline_impl.h
index 9fd3071..ff18c28 100644
--- a/chromecast/media/cma/pipeline/video_pipeline_impl.h
+++ b/chromecast/media/cma/pipeline/video_pipeline_impl.h
@@ -48,6 +48,7 @@ class VideoPipelineImpl {
   bool StartPlayingFrom(base::TimeDelta time,
                         const scoped_refptr<BufferingState>& buffering_state);
   void Flush(const ::media::PipelineStatusCB& status_cb);
+  void BackendStopped();
   void Stop();
 
   // Update the playback statistics for this video stream.
diff --git a/chromecast/media/media.gyp b/chromecast/media/media.gyp
index fe0fd7c..b3a0047 100644
--- a/chromecast/media/media.gyp
+++ b/chromecast/media/media.gyp
@@ -120,8 +120,6 @@
         'cma/base/buffering_frame_provider.h',
         'cma/base/buffering_state.cc',
         'cma/base/buffering_state.h',
-        'cma/base/cast_decoder_buffer_impl.cc',
-        'cma/base/cast_decoder_buffer_impl.h',
         'cma/base/cast_decrypt_config_impl.cc',
         'cma/base/cast_decrypt_config_impl.h',
         'cma/base/cma_logging.h',
diff --git a/chromecast/public/media/cast_decoder_buffer.h b/chromecast/public/media/cast_decoder_buffer.h
index bf3d76c..f6ca422 100644
--- a/chromecast/public/media/cast_decoder_buffer.h
+++ b/chromecast/public/media/cast_decoder_buffer.h
@@ -15,12 +15,16 @@ namespace chromecast {
 namespace media {
 
 class CastDecryptConfig;
+class DecryptContext;
 
 // CastDecoderBuffer provides an interface for passing a single frame of audio
 // or video data to the pipeline backend.  End-of-stream is indicated by passing
 // a frame where end_of_stream() returns true.
-// Buffer ownership passes to backend when they are pushed (see
-// MediaComponentDevice::PushFrame).
+// The buffer's lifetime is managed by the caller code - it MUST NOT be
+// deleted by the MediaPipelineBackend implementation, and MUST NOT be
+// dereferenced after completion of buffer push (i.e.
+// kBufferSuccess/kBufferFailure for synchronous completion, OnPushComplete
+// for kBufferPending case).
 // TODO(halliwell): consider renaming functions here to camel case.
 class CastDecoderBuffer {
  public:
@@ -39,9 +43,13 @@ class CastDecoderBuffer {
   virtual size_t data_size() const = 0;
 
   // Returns the decrypt configuration.
-  // Returns NULL if and only if the buffer is unencrypted.
+  // Returns nullptr if and only if the buffer is unencrypted.
   virtual const CastDecryptConfig* decrypt_config() const = 0;
 
+  // Returns the decrypt context. Returns nullptr if and only if the buffer is
+  // unencrypted.
+  virtual DecryptContext* decrypt_context() const = 0;
+
   // Indicates if this is a special frame that indicates the end of the stream.
   // If true, functions to access the frame content cannot be called.
   virtual bool end_of_stream() const = 0;
diff --git a/chromecast/public/media/media_pipeline_backend.h b/chromecast/public/media/media_pipeline_backend.h
index 53e028b..cc497b5 100644
--- a/chromecast/public/media/media_pipeline_backend.h
+++ b/chromecast/public/media/media_pipeline_backend.h
@@ -58,13 +58,12 @@ class MediaPipelineBackend {
     // further buffers until OnPushComplete is invoked.
     // OnPushComplete should be only be invoked to indicate completion of a
     // pending buffer push - not for the immediate |kBufferSuccess| return case.
-    // The decrypt_context and buffer's lifetimes are managed by the caller code
-    // - they MUST NOT be deleted by the MediaPipelineBackend implementation,
-    // and MUST NOT be dereferenced after completion of buffer push (i.e.
+    // The buffer's lifetime is managed by the caller code - it MUST NOT be
+    // deleted by the MediaPipelineBackend implementation, and MUST NOT be
+    // dereferenced after completion of buffer push (i.e.
     // kBufferSuccess/kBufferFailure for synchronous completion, OnPushComplete
     // for kBufferPending case).
-    virtual BufferStatus PushBuffer(DecryptContext* decrypt_context,
-                                    CastDecoderBuffer* buffer) = 0;
+    virtual BufferStatus PushBuffer(CastDecoderBuffer* buffer) = 0;
 
     // Returns the playback statistics since this decoder's creation.  Only
     // called when playing or paused.