Add the frame provider base class used in cast media.

chromecast/media/cma/filters/demuxer_stream_adapter.cc

Index: chromecast/media/cma/filters/demuxer_stream_adapter.cc
diff --git a/chromecast/media/cma/filters/demuxer_stream_adapter.cc b/chromecast/media/cma/filters/demuxer_stream_adapter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b5735723d13490e7590766653510f1efd870f2f1
--- /dev/null
+++ b/chromecast/media/cma/filters/demuxer_stream_adapter.cc
@@ -0,0 +1,182 @@
+// 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/filters/demuxer_stream_adapter.h"
+
+#include "base/bind.h"
+#include "base/callback_helpers.h"
+#include "base/single_thread_task_runner.h"
+#include "chromecast/media/cma/base/balanced_media_task_runner_factory.h"
+#include "chromecast/media/cma/base/cma_logging.h"
+#include "chromecast/media/cma/base/decoder_buffer_adapter.h"
+#include "chromecast/media/cma/base/media_task_runner.h"
+#include "media/base/bind_to_current_loop.h"
+#include "media/base/buffers.h"
+#include "media/base/decoder_buffer.h"
+#include "media/base/demuxer_stream.h"
+
+namespace chromecast {
+namespace media {
+
+namespace {
+
+class DummyMediaTaskRunner : public MediaTaskRunner {
+ public:
+  DummyMediaTaskRunner(
+      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner);
+
+  // MediaTaskRunner implementation.
+  virtual bool PostMediaTask(
+      const tracked_objects::Location& from_here,
+      const base::Closure& task,
+      base::TimeDelta timestamp) OVERRIDE;
+
+ private:
+  virtual ~DummyMediaTaskRunner();
+
+  scoped_refptr<base::SingleThreadTaskRunner> const task_runner_;
+
+  DISALLOW_COPY_AND_ASSIGN(DummyMediaTaskRunner);
+};
+
+DummyMediaTaskRunner::DummyMediaTaskRunner(
+    const scoped_refptr<base::SingleThreadTaskRunner>& task_runner)
+  : task_runner_(task_runner) {
+}
+
+DummyMediaTaskRunner::~DummyMediaTaskRunner() {
+}
+
+bool DummyMediaTaskRunner::PostMediaTask(
+    const tracked_objects::Location& from_here,
+    const base::Closure& task,
+    base::TimeDelta timestamp) {
+  return task_runner_->PostTask(from_here, task);
+}
+
+}  // namespace
+
+DemuxerStreamAdapter::DemuxerStreamAdapter(
+    const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
+    const scoped_refptr<BalancedMediaTaskRunnerFactory>&
+    media_task_runner_factory,
+    ::media::DemuxerStream* demuxer_stream)
+    : task_runner_(task_runner),
+      media_task_runner_factory_(media_task_runner_factory),
+      media_task_runner_(new DummyMediaTaskRunner(task_runner)),
+      demuxer_stream_(demuxer_stream),
+      is_pending_read_(false),
+      weak_factory_(new base::WeakPtrFactory<DemuxerStreamAdapter>(this)) {
+  ResetMediaTaskRunner();
+  weak_this_ = weak_factory_->GetWeakPtr();
+  thread_checker_.DetachFromThread();
+}
+
+DemuxerStreamAdapter::~DemuxerStreamAdapter() {
+  // Needed since we use weak pointers:
+  // weak pointers must be invalidated on the same thread.
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+void DemuxerStreamAdapter::Read(const ReadCb& read_cb) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  // Support only one read at a time.
+  DCHECK(!is_pending_read_);
+
+  is_pending_read_ = true;
+  bool may_run_in_future = media_task_runner_->PostMediaTask(
+      FROM_HERE,
+      base::Bind(&DemuxerStreamAdapter::RequestBuffer, weak_this_, read_cb),
+      max_pts_);
+  DCHECK(may_run_in_future);
+}
+
+void DemuxerStreamAdapter::Flush(const base::Closure& flush_cb) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  CMALOG(kLogControl) << __FUNCTION__;
+
+  // Invalidate all the weak pointers so that we don't receive anymore buffers
+  // from |demuxer_stream_| that are associated with the current media
+  // timeline.
+  is_pending_read_ = false;
+  weak_factory_->InvalidateWeakPtrs();
+  weak_factory_.reset(new base::WeakPtrFactory<DemuxerStreamAdapter>(this));
+  weak_this_ = weak_factory_->GetWeakPtr();
+
+  // Reset the decoder configurations.
+  audio_config_ = ::media::AudioDecoderConfig();
+  video_config_ = ::media::VideoDecoderConfig();
+
+  // Create a new media task runner for the upcoming media playback.
+  ResetMediaTaskRunner();
+
+  CMALOG(kLogControl) << "Flush done";
+  flush_cb.Run();
+}
+
+void DemuxerStreamAdapter::ResetMediaTaskRunner() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  max_pts_ = ::media::kNoTimestamp();
+  if (media_task_runner_factory_.get()) {
+    media_task_runner_ =
+        media_task_runner_factory_->CreateMediaTaskRunner(task_runner_);
+  }
+}
+
+void DemuxerStreamAdapter::RequestBuffer(const ReadCb& read_cb) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  demuxer_stream_->Read(::media::BindToCurrentLoop(
+      base::Bind(&DemuxerStreamAdapter::OnNewBuffer, weak_this_, read_cb)));
+}
+
+void DemuxerStreamAdapter::OnNewBuffer(
+    const ReadCb& read_cb,
+    ::media::DemuxerStream::Status status,
+    const scoped_refptr< ::media::DecoderBuffer>& input) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  is_pending_read_ = false;
+
+  if (status == ::media::DemuxerStream::kAborted) {
+    DCHECK(input.get() == NULL);
+    return;
+  }
+
+  if (status == ::media::DemuxerStream::kConfigChanged) {
+    DCHECK(input.get() == NULL);
+    if (demuxer_stream_->type() == ::media::DemuxerStream::VIDEO)
+      video_config_ = demuxer_stream_->video_decoder_config();
+    if (demuxer_stream_->type() == ::media::DemuxerStream::AUDIO)
+      audio_config_ = demuxer_stream_->audio_decoder_config();
+
+    // Got a new config, but we still need to get a frame.
+    Read(read_cb);
+    return;
+  }
+
+  DCHECK_EQ(status, ::media::DemuxerStream::kOk);
+
+  // Updates the timestamp used for task scheduling.
+  if (!input->end_of_stream() &&
+      input->timestamp() != ::media::kNoTimestamp() &&
+      (max_pts_ == ::media::kNoTimestamp() || input->timestamp() > max_pts_)) {
+    max_pts_ = input->timestamp();
+  }
+
+  // Provides the buffer as well as possibly valid audio and video configs.
+  scoped_refptr<DecoderBufferBase> buffer(new DecoderBufferAdapter(input));
+  read_cb.Run(buffer, audio_config_, video_config_);
+
+  // Back to the default audio/video config:
+  // an invalid audio/video config means there is no config update.
+  if (audio_config_.IsValidConfig())
+    audio_config_ = ::media::AudioDecoderConfig();
+  if (video_config_.IsValidConfig())
+    video_config_ = ::media::VideoDecoderConfig();
+}
+
+}  // namespace media
+}  // namespace chromecast