Motown: Remove LPCM optimizations, fix prepare, add flush, add ActiveMultistreamSink model/stage

services/media/framework/stages/transform_stage.cc

Index: services/media/framework/stages/transform_stage.cc
diff --git a/services/media/framework/stages/transform_stage.cc b/services/media/framework/stages/transform_stage.cc
new file mode 100644
index 0000000000000000000000000000000000000000..dce82545d8eec7cb2273052ebbd0079ebe28792d
--- /dev/null
+++ b/services/media/framework/stages/transform_stage.cc
@@ -0,0 +1,104 @@
+// 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/stages/transform_stage.h"
+
+namespace mojo {
+namespace media {
+
+TransformStage::TransformStage(
+    std::shared_ptr<Transform> transform) :
+    transform_(transform),
+    allocator_(nullptr),
+    input_packet_is_new_(true) {
+  DCHECK(transform_);
+}
+
+TransformStage::~TransformStage() {}
+
+size_t TransformStage::input_count() const {
+  return 1;
+};
+
+Input& TransformStage::input(size_t index) {
+  DCHECK_EQ(index, 0u);
+  return input_;
+}
+
+size_t TransformStage::output_count() const {
+  return 1;
+}
+
+Output& TransformStage::output(size_t index) {
+  DCHECK_EQ(index, 0u);
+  return output_;
+}
+
+PayloadAllocator* TransformStage::PrepareInput(size_t index) {
+  DCHECK_EQ(index, 0u);
+  return nullptr;
+}
+
+void TransformStage::PrepareOutput(
+    size_t index,
+    PayloadAllocator* allocator,
+    const UpstreamCallback& callback) {
+  DCHECK_EQ(index, 0u);
+
+  allocator_ =
+      allocator == nullptr ? PayloadAllocator::GetDefault() : allocator;
+
+  callback(0);
+}
+
+void TransformStage::UnprepareOutput(
+    size_t index,
+    const UpstreamCallback& callback) {
+  allocator_ = nullptr;
+  callback(0);
+}
+
+void TransformStage::Update(Engine* engine) {
+  DCHECK(engine);
+  DCHECK(allocator_);
+
+  if (input_.packet_from_upstream() && output_.demand() != Demand::kNegative) {
+    PacketPtr output_packet;
+    if (transform_->TransformPacket(
+        input_.packet_from_upstream(),
+        input_packet_is_new_,
+        allocator_,
+        &output_packet)) {
+      input_.packet_from_upstream().reset();
+      input_packet_is_new_ = true;
+    } else {
+      input_packet_is_new_ = false;
+    }
+
+    if (output_packet) {
+      output_.SupplyPacket(std::move(output_packet), engine);
+    }
+  }
+
+  input_.SetDemand(output_.demand(), engine);
+}
+
+void TransformStage::FlushInput(
+    size_t index,
+    const DownstreamCallback& callback) {
+  DCHECK_EQ(index, 0u);
+  input_.Flush();
+  callback(0);
+}
+
+void TransformStage::FlushOutput(size_t index) {
+  DCHECK_EQ(index, 0u);
+  DCHECK(transform_);
+  output_.Flush();
+  transform_->Flush();
+  input_packet_is_new_ = true;
+}
+
+}  // namespace media
+}  // namespace mojo