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

services/media/framework/models/packet_transform.h

+// 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.
+
+#ifndef MOJO_MEDIA_MODELS_PACKET_TRANSFORM_H_
+#define MOJO_MEDIA_MODELS_PACKET_TRANSFORM_H_
+
+#include <memory>
+
+#include "services/media/framework/allocator.h"
+#include "services/media/framework/packet.h"
+
+namespace mojo {
+namespace media {
+
+// Synchronous packet transform.
+class PacketTransform {
+ public:
+  virtual ~PacketTransform() {}
+
+  // Processes a packet. Returns true to indicate the transform is done
+  // processing the input packet. Returns false to indicate the input
+  // packet should be processed again. new_input indicates whether the input
+  // packet is new (true) or is being processed again (false). An output packet
+  // may or may not be generated for any given invocation of this method.
+  virtual bool TransformPacket(
+      const PacketPtr& input,
+      bool new_input,
+      Allocator* allocator,
+      PacketPtr* output) = 0;

[jeffbrown, 2016/02/02 05:35:47]

So is this allocating a new packet each time?

[dalesat, 2016/02/02 21:46:39]

Yes, whenever the transform wants to produce a packet. My intention is to
optimize Packet allocation using a lookaside.

+};
+
+typedef std::shared_ptr<PacketTransform> PacketTransformPtr;
+
+}  // namespace media
+}  // namespace mojo
+
+#endif // MOJO_MEDIA_MODELS_PACKET_TRANSFORM_H_