Motown in-proc streaming framework used to implement media services.

services/media/framework/stages/lpcm_stage_output.cc

Index: services/media/framework/stages/lpcm_stage_output.cc
diff --git a/services/media/framework/stages/lpcm_stage_output.cc b/services/media/framework/stages/lpcm_stage_output.cc
new file mode 100644
index 0000000000000000000000000000000000000000..87cb0331cd7db7a8dc2359d22e4d059bdf5498de
--- /dev/null
+++ b/services/media/framework/stages/lpcm_stage_output.cc
@@ -0,0 +1,85 @@
+// Copyright 2016 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 "services/media/framework/engine.h"
+#include "services/media/framework/stages/lpcm_stage_input.h"
+#include "services/media/framework/stages/lpcm_stage_output.h"
+#include "services/media/framework/stages/stage.h"
+
+namespace mojo {
+namespace media {
+
+LpcmStageOutput::LpcmStageOutput() :
+    buffer_(nullptr),
+    frame_count_(0),
+    mix_(false),
+    synchronous_(false),
+    next_presentation_time_(0) {}
+
+LpcmStageOutput::~LpcmStageOutput() {}
+
+void LpcmStageOutput::set_stream_type(const LpcmStreamType& stream_type) {
+  lpcm_demand_.set_bytes_per_frame(stream_type.bytes_per_frame());
+}
+
+void LpcmStageOutput::SupplyFrames(bool end_of_stream, Engine* engine) {
+  DCHECK(engine);
+  DCHECK(connected());
+  DCHECK(end_of_stream || buffer_);
+
+  uint64_t duration = frame_count_ - lpcm_demand_.frame_count();
+  if (allocator_ != nullptr) {
+    SupplyPacketInternal(
+        Packet::Create(
+            next_presentation_time_,
+            duration,
+            end_of_stream,
+            duration * lpcm_demand_.bytes_per_frame(),
+            duration == 0 ? nullptr : buffer_,
+            allocator_),
+        engine);
+  } else {
+    SupplyPacketInternal(
+        Packet::CreateNoAllocator(
+            next_presentation_time_,
+            duration,
+            end_of_stream,
+            duration * lpcm_demand_.bytes_per_frame(),
+            duration == 0 ? nullptr : buffer_),
+        engine);
+  }
+
+  next_presentation_time_ += duration;
+
+  buffer_ = nullptr;
+  frame_count_ = 0;
+  mix_ = false;
+  synchronous_ = false;
+  lpcm_demand_.Reset();
+}
+
+Allocator* LpcmStageOutput::Prepare(bool can_accept_allocator) {
+  // The stage isn't concerned with allocators, but we'll need one if our mate
+  // isn't LPCM.
+  Allocator* allocator = StageOutput::Prepare(true);
+  DCHECK(!connected_to_lpcm() || allocator == nullptr);
+  if (!connected_to_lpcm()) {
+    // Our mate isn't lpcm, so we'll need an allocator to create packet buffers.
+    // Use the provided one or the default.
+    allocator_ = allocator == nullptr ? Allocator::GetDefault() : allocator;
+  }
+
+  return nullptr;
+}
+
+LpcmStageOutput* LpcmStageOutput::get_lpcm() {
+  return this;
+}
+
+bool LpcmStageOutput::connected_to_lpcm() {
+  return mate().get_lpcm() != nullptr;
+}
+
+}  // namespace media
+}  // namespace mojo