[Chromecast] Move CastAudioDecoder out to chromecast/media/cma/decoder

chromecast/media/cma/decoder/cast_audio_decoder.h

+// Copyright 2015 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 CHROMECAST_MEDIA_CMA_DECODER_CAST_AUDIO_DECODER_H_
+#define CHROMECAST_MEDIA_CMA_DECODER_CAST_AUDIO_DECODER_H_
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+
+namespace base {
+class SingleThreadTaskRunner;
+}  // namespace base
+
+namespace chromecast {
+namespace media {
+struct AudioConfig;
+class DecoderBufferBase;
+
+// Audio decoder interface.
+class CastAudioDecoder {
+ public:
+  enum Status {
+    kDecodeOk,
+    kDecodeError,
+  };
+
+  enum OutputFormat {
+    kOutputSigned16,     // Output signed 16-bit interleaved samples.
+    kOutputPlanarFloat,  // Output planar float samples.
+  };
+
+  // The callback that is called when the decoder initialization is complete.
+  // |success| is true if initialization was successful; if |success| is false
+  // then the CastAudioDecoder instance is unusable and should be destroyed.
+  typedef base::Callback<void(bool success)> InitializedCallback;
+  typedef base::Callback<void(
+      Status status,
+      const scoped_refptr<media::DecoderBufferBase>& decoded)> DecodeCallback;
+
+  // Creates a CastAudioDecoder instance for the given |config|. Decoding must
+  // occur on the same thread as |task_runner|. Returns an empty scoped_ptr if
+  // the decoder could not be created.
+  static scoped_ptr<CastAudioDecoder> Create(
+      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
+      const media::AudioConfig& config,
+      OutputFormat output_format,
+      const InitializedCallback& initialized_callback);
+
+  // Given a CastAudioDecoder::OutputFormat, return the size of each sample in
+  // that OutputFormat in bytes.
+  static int OutputFormatSizeInBytes(CastAudioDecoder::OutputFormat format);
+
+  CastAudioDecoder() {}
+  virtual ~CastAudioDecoder() {}
+
+  // Converts encoded data to the |output_format|. Must be called on the same
+  // thread as |task_runner|. Decoded data will be passed to |decode_callback|.
+  // It is OK to call Decode before the |initialized_callback| has been called;
+  // those buffers will be queued until initialization completes, at which point
+  // they will be decoded in order (if initialization was successful), or
+  // ignored if initialization failed.
+  // It is OK to pass an end-of-stream DecoderBuffer as |data|.
+  // Returns |false| if the decoder is not ready yet.
+  virtual bool Decode(const scoped_refptr<media::DecoderBufferBase>& data,
+                      const DecodeCallback& decode_callback) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CastAudioDecoder);
+};
+
+}  // namespace media
+}  // namespace chromecast
+
+#endif  // CHROMECAST_MEDIA_CMA_DECODER_CAST_AUDIO_DECODER_H_