Implement runtime audio post-processing pipeline. See go/cast_audio.json

chromecast/media/cma/backend/alsa/post_processing_pipeline_parser.h

Index: chromecast/media/cma/backend/alsa/post_processing_pipeline_parser.h
diff --git a/chromecast/media/cma/backend/alsa/post_processing_pipeline_parser.h b/chromecast/media/cma/backend/alsa/post_processing_pipeline_parser.h
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index 0000000000000000000000000000000000000000..6b4f0252a9e3b262efa23dcb0ed4ff167235e7a3
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+// Copyright 2017 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_BACKEND_ALSA_POST_PROCESSING_PIPELINE_PARSER_H_
+#define CHROMECAST_MEDIA_CMA_BACKEND_ALSA_POST_PROCESSING_PIPELINE_PARSER_H_
+
+#include <memory>
+#include <string>
+
+#include "base/macros.h"
+#include "base/values.h"
+
+namespace chromecast {
+namespace media {
+
+// Helper class to parse post-processing pipeline descriptor file.
+class PostProcessingPipelineParser {
+ public:
+  PostProcessingPipelineParser();
+  ~PostProcessingPipelineParser();
+
+  // Reads the pipeline descriptor file and does preliminary parsing.
+  // Crashes with fatal log if parsing fails.
+  void Initialize();
+
+  // Gets the list of processors for a given stream type.
+  // The format will be:
+  // [
+  //   {"processor": "PATH_TO_SHARED_OBJECT",
+  //    "config": "CONFIGURATION_STRING"},
+  //   {"processor": "PATH_TO_SHARED_OBJECT",
+  //    "config": "CONFIGURATION_STRING"},
+  //    ...
+  // ]
+  base::ListValue* GetPipelineByDeviceId(const std::string& device_id);
+
+ private:
+  std::unique_ptr<base::Value> cast_audio_config_data_;
+  base::DictionaryValue* pipeline_dict_ = nullptr;
+
+  DISALLOW_COPY_AND_ASSIGN(PostProcessingPipelineParser);
+};
+
+}  // namepsace media
+}  // namespace chromecast
+
+#endif  // CHROMECAST_MEDIA_CMA_BACKEND_ALSA_POST_PROCESSING_PIPELINE_PARSER_H_