Chromecast: adds a media pipeline feeding data to CMA device backends.

chromecast/media/cma/pipeline/av_pipeline_impl.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 "chromecast/media/cma/pipeline/av_pipeline_impl.h"
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/message_loop/message_loop_proxy.h"
+#include "base/strings/string_number_conversions.h"
+#include "chromecast/media/base/decrypt_context.h"
+#include "chromecast/media/cdm/browser_cdm_cast.h"
+#include "chromecast/media/cma/backend/media_clock_device.h"
+#include "chromecast/media/cma/backend/media_component_device.h"
+#include "chromecast/media/cma/base/buffering_frame_provider.h"
+#include "chromecast/media/cma/base/buffering_state.h"
+#include "chromecast/media/cma/base/cma_logging.h"
+#include "chromecast/media/cma/base/coded_frame_provider.h"
+#include "chromecast/media/cma/base/decoder_buffer_base.h"
+#include "chromecast/media/cma/pipeline/decrypt_util.h"
+#include "media/base/audio_decoder_config.h"
+#include "media/base/decrypt_config.h"
+
+namespace chromecast {
+namespace media {
+
+namespace {
+
+const int kNoCallbackId = -1;
+
+}  // namespace
+
+AvPipelineImpl::AvPipelineImpl(
+    MediaComponentDevice* media_component_device,
+    const UpdateConfigCB& update_config_cb)
+    : update_config_cb_(update_config_cb),
+      media_component_device_(media_component_device),
+      state_(kUninitialized),
+      buffered_time_(::media::kNoTimestamp()),
+      playable_buffered_time_(::media::kNoTimestamp()),
+      enable_feeding_(false),
+      pending_read_(false),
+      pending_push_(false),
+      enable_time_update_(false),
+      pending_time_update_task_(false),
+      media_keys_(NULL),
+      media_keys_callback_id_(kNoCallbackId),
+      weak_factory_(this) {
+  DCHECK(media_component_device);
+  weak_this_ = weak_factory_.GetWeakPtr();
+  thread_checker_.DetachFromThread();
+}
+
+AvPipelineImpl::~AvPipelineImpl() {
+  // If there are weak pointers in the wild, they must be invalidated
+  // on the right thread.
+  DCHECK(thread_checker_.CalledOnValidThread());
+  media_component_device_->SetClient(MediaComponentDevice::Client());
+
+  if (media_keys_ && media_keys_callback_id_ != kNoCallbackId) {

[damienv1, 2014/11/20 17:08:26]

nit: remove curly brace

[gunsch, 2014/11/20 19:50:27]

Done.

+    media_keys_->UnregisterPlayer(media_keys_callback_id_);
+  }
+}
+
+void AvPipelineImpl::TransitionToState(State state) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  state_ = state;
+}
+
+void AvPipelineImpl::SetCodedFrameProvider(
+    scoped_ptr<CodedFrameProvider> frame_provider,
+    size_t max_buffer_size,
+    size_t max_frame_size) {
+  DCHECK_EQ(state_, kUninitialized);
+  DCHECK(frame_provider);
+
+  // Wrap the incoming frame provider to add some buffering capabilities.
+  frame_provider_.reset(
+      new BufferingFrameProvider(
+          frame_provider.Pass(),
+          max_buffer_size,
+          max_frame_size,
+          base::Bind(&AvPipelineImpl::OnFrameBuffered, weak_this_)));
+}
+
+void AvPipelineImpl::SetClient(const AvPipelineClient& client) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK_EQ(state_, kUninitialized);
+  client_ = client;
+}
+
+bool AvPipelineImpl::Initialize() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK_EQ(state_, kUninitialized);
+
+  MediaComponentDevice::Client client;
+  client.eos_cb = base::Bind(&AvPipelineImpl::OnEos, weak_this_);
+  media_component_device_->SetClient(client);
+  if (!media_component_device_->SetState(MediaComponentDevice::kStateIdle))
+    return false;
+
+  return true;
+}
+
+bool AvPipelineImpl::StartPlayingFrom(
+    base::TimeDelta time,
+    const scoped_refptr<BufferingState>& buffering_state) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK_EQ(state_, kFlushed);
+
+  // Media time where rendering should start
+  // and switch to a state where the audio device accepts incoming buffers.
+  if (!media_component_device_->SetStartPts(time) ||
+      !media_component_device_->SetState(MediaComponentDevice::kStatePaused)) {
+    return false;
+  }
+
+  // Buffering related initialization.
+  DCHECK(frame_provider_);
+  buffering_state_ = buffering_state;
+  if (buffering_state_.get())
+    buffering_state_->SetMediaTime(time);
+
+  // Start feeding the pipeline.
+  enable_feeding_ = true;
+  base::MessageLoopProxy::current()->PostTask(
+      FROM_HERE,
+      base::Bind(&AvPipelineImpl::FetchBufferIfNeeded, weak_this_));
+
+  if (!media_component_device_->SetState(MediaComponentDevice::kStateRunning))
+    return false;

[damienv1, 2014/11/20 17:08:26]

StartPlayingFrom used to be 2 different actions (Preroll + Play) where Play was
done *only* if Preroll was successful.

I think we should move this state transition before starting feeding the
pipeline (if there is an error, feeding the pipeline should not be done).

[gunsch, 2014/11/20 19:50:27]

Strictly speaking, this code is in order from when Preroll/Play were separate,
but that SGTM. Done.

+
+  return true;
+}
+
+bool AvPipelineImpl::Pause() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK_EQ(state_, kPlaying);
+
+  DCHECK_EQ(
+      media_component_device_->GetState(), MediaComponentDevice::kStateRunning);

[damienv1, 2014/11/20 17:08:26]

Can you add a comment for this block of code to mention that returning to the
idle state aborts any pending frame push operation.

[gunsch, 2014/11/20 19:50:27]

Done.

+  media_component_device_->SetState(MediaComponentDevice::kStateIdle);
+  pending_push_ = false;
+
+  // Break the feeding loop.
+  enable_feeding_ = false;
+
+  return true;
+}
+
+void AvPipelineImpl::Flush(const base::Closure& done_cb) {

[damienv1, 2014/11/20 17:33:39]

Could you merge Pause and Flush (always used together in
Audio/VideoPipelineImpl) ?

[gunsch, 2014/11/20 19:50:27]

Done.

+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK_EQ(state_, kFlushing);
+
+  // Remove any pending buffer.
+  pending_buffer_ = scoped_refptr<DecoderBufferBase>();
+
+  // Finally, remove any frames left in the frame provider.
+  pending_read_ = false;
+  buffered_time_ = ::media::kNoTimestamp();
+  playable_buffered_time_ = ::media::kNoTimestamp();
+  non_playable_frames_.clear();
+  frame_provider_->Flush(done_cb);
+}
+
+void AvPipelineImpl::Stop() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  // Stop can be called from any state.
+  if (state_ == kUninitialized || state_ == kStopped)
+    return;
+
+  // Stop feeding the pipeline.
+  enable_feeding_ = false;
+
+  // Release hardware resources on Stop.
+  if (media_component_device_->GetState() ==
+          MediaComponentDevice::kStatePaused ||
+      media_component_device_->GetState() ==
+          MediaComponentDevice::kStateRunning) {
+    media_component_device_->SetState(MediaComponentDevice::kStateIdle);
+  }
+  if (media_component_device_->GetState() == MediaComponentDevice::kStateIdle) {
+    media_component_device_->SetState(
+        MediaComponentDevice::kStateUninitialized);
+  }
+}
+
+void AvPipelineImpl::SetCdm(BrowserCdmCast* media_keys) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(media_keys);
+
+  if (media_keys_ && media_keys_callback_id_ != kNoCallbackId) {

[damienv1, 2014/11/20 17:08:26]

nit: remove curly braces.

[gunsch, 2014/11/20 19:50:27]

Done.

+    media_keys_->UnregisterPlayer(media_keys_callback_id_);
+  }
+
+  media_keys_ = media_keys;
+  media_keys_callback_id_ = media_keys_->RegisterPlayer(
+      base::Bind(&AvPipelineImpl::OnCdmStateChanged, weak_this_),
+      base::Bind(&AvPipelineImpl::OnCdmDestroyed, weak_this_));
+}
+
+void AvPipelineImpl::OnEos() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  CMALOG(kLogControl) << __FUNCTION__;
+  if (state_ != kPlaying)
+    return;
+
+  if (!client_.eos_cb.is_null())
+    client_.eos_cb.Run();
+}
+
+void AvPipelineImpl::FetchBufferIfNeeded() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (!enable_feeding_)
+    return;
+
+  if (pending_read_ || pending_buffer_.get())
+    return;
+
+  pending_read_ = true;
+  frame_provider_->Read(
+      base::Bind(&AvPipelineImpl::OnNewFrame, weak_this_));
+}
+
+void AvPipelineImpl::OnNewFrame(
+    const scoped_refptr<DecoderBufferBase>& buffer,
+    const ::media::AudioDecoderConfig& audio_config,
+    const ::media::VideoDecoderConfig& video_config) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  pending_read_ = false;
+
+  if (audio_config.IsValidConfig() || video_config.IsValidConfig()) {

[damienv1, 2014/11/20 17:08:26]

nit: remove curly braces.

[gunsch, 2014/11/20 19:50:27]

Done.

+    update_config_cb_.Run(audio_config, video_config);
+  }
+
+  pending_buffer_ = buffer;
+  ProcessPendingBuffer();
+
+  base::MessageLoopProxy::current()->PostTask(
+      FROM_HERE,
+      base::Bind(&AvPipelineImpl::FetchBufferIfNeeded, weak_this_));
+}
+
+void AvPipelineImpl::ProcessPendingBuffer() {
+  if (!enable_feeding_)
+    return;
+
+  // Initiate a read if there isn't already one.
+  if (!pending_buffer_.get() && !pending_read_) {
+    base::MessageLoopProxy::current()->PostTask(
+        FROM_HERE,
+        base::Bind(&AvPipelineImpl::FetchBufferIfNeeded, weak_this_));
+    return;
+  }
+
+  if (!pending_buffer_.get() || pending_push_)
+    return;
+
+  // Break the feeding loop when the end of stream is reached.
+  if (pending_buffer_->end_of_stream()) {
+    CMALOG(kLogControl) << __FUNCTION__ << ": EOS reached, stopped feeding";
+    enable_feeding_ = false;
+  }
+
+  scoped_refptr<DecryptContext> decrypt_context;
+  if (!pending_buffer_->end_of_stream() &&
+      pending_buffer_->decrypt_config()) {
+    // Verify that CDM has the key ID.
+    // Should not send the frame if the key ID is not available yet.
+    std::string key_id(pending_buffer_->decrypt_config()->key_id());
+    if (!media_keys_) {
+      CMALOG(kLogControl) << "No CDM for frame: pts="
+                          << pending_buffer_->timestamp().InMilliseconds();
+      return;
+    }
+    decrypt_context = media_keys_->GetDecryptContext(key_id);
+    if (!decrypt_context.get()) {
+      CMALOG(kLogControl) << "frame(pts="
+                          << pending_buffer_->timestamp().InMilliseconds()
+                          << "): waiting for key id "
+                          << base::HexEncode(&key_id[0], key_id.size());
+      return;
+    }
+
+    // If we do have the clear key, decrypt the pending buffer
+    // and reset the decryption context (not needed anymore).
+    crypto::SymmetricKey* key = decrypt_context->GetKey();
+    if (key != NULL) {
+      pending_buffer_ = DecryptDecoderBuffer(pending_buffer_, key);
+      decrypt_context = scoped_refptr<DecryptContext>();
+    }
+  }
+
+  MediaComponentDevice::FrameStatus status = media_component_device_->PushFrame(
+      decrypt_context,
+      pending_buffer_,
+      base::Bind(&AvPipelineImpl::OnFramePushed, weak_this_));
+  pending_buffer_ = scoped_refptr<DecoderBufferBase>();
+
+  pending_push_ = (status == MediaComponentDevice::kFramePending);
+  if (!pending_push_)
+    OnFramePushed(status);
+}
+
+void AvPipelineImpl::OnFramePushed(MediaComponentDevice::FrameStatus status) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  pending_push_ = false;
+  if (status == MediaComponentDevice::kFrameFailed) {
+    LOG(WARNING) << "AvPipelineImpl: PushFrame failed";
+    enable_feeding_ = false;
+    state_ = kError;
+    return;
+  }
+  base::MessageLoopProxy::current()->PostTask(
+      FROM_HERE,
+      base::Bind(&AvPipelineImpl::ProcessPendingBuffer, weak_this_));
+}
+
+void AvPipelineImpl::OnCdmStateChanged() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  // Update the buffering state if needed.
+  if (buffering_state_.get())
+    UpdatePlayableFrames();
+
+  // Process the pending buffer in case the CDM now has the frame key id.
+  ProcessPendingBuffer();
+}
+
+void AvPipelineImpl::OnCdmDestroyed() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  media_keys_ = NULL;
+}
+
+void AvPipelineImpl::OnFrameBuffered(
+    const scoped_refptr<DecoderBufferBase>& buffer,
+    bool is_at_max_capacity) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  if (!buffering_state_.get())
+    return;
+
+  if (!buffer->end_of_stream() &&
+      (buffered_time_ == ::media::kNoTimestamp() ||
+       buffered_time_ < buffer->timestamp())) {
+    buffered_time_ = buffer->timestamp();
+  }
+
+  if (is_at_max_capacity)
+    buffering_state_->NotifyMaxCapacity(buffered_time_);
+
+  // No need to update the list of playable frames,
+  // if we are already blocking on a frame.
+  bool update_playable_frames = non_playable_frames_.empty();
+  non_playable_frames_.push_back(buffer);
+  if (update_playable_frames)
+    UpdatePlayableFrames();
+}
+
+void AvPipelineImpl::UpdatePlayableFrames() {
+  while (!non_playable_frames_.empty()) {
+    const scoped_refptr<DecoderBufferBase>& non_playable_frame =
+        non_playable_frames_.front();
+
+    if (non_playable_frame->end_of_stream()) {
+      buffering_state_->NotifyEos();
+    } else {
+      const ::media::DecryptConfig* decrypt_config =
+          non_playable_frame->decrypt_config();
+      if (decrypt_config &&
+          !(media_keys_ &&
+            media_keys_->GetDecryptContext(decrypt_config->key_id()).get())) {
+        // The frame is still not playable. All the following are thus not
+        // playable.
+        break;
+      }
+
+      if (playable_buffered_time_ == ::media::kNoTimestamp() ||
+          playable_buffered_time_ < non_playable_frame->timestamp()) {
+        playable_buffered_time_ = non_playable_frame->timestamp();
+        buffering_state_->SetBufferedTime(playable_buffered_time_);
+      }
+    }
+
+    // The frame is playable: remove it from the list of non playable frames.
+    non_playable_frames_.pop_front();
+  }
+}
+
+}  // namespace media
+}  // namespace chromecast