Extract bitrate allocation of spatial/temporal layers out of codec impl.

webrtc/modules/video_coding/include/video_codec_initializer.h

+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_MODULES_VIDEO_CODING_INCLUDE_VIDEO_CODEC_INITIALIZER_H_
+#define WEBRTC_MODULES_VIDEO_CODING_INCLUDE_VIDEO_CODEC_INITIALIZER_H_
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "webrtc/video_send_stream.h"
+
+namespace webrtc {
+
+class TemporalLayersFactory;
+class VideoBitrateAllocator;
+class VideoCodec;
+class VideoEncoderConfig;
+
+class VideoCodecInitializer {
+ public:
+  // Takes an EncoderSettings, a VideoEncoderConfig and the VideoStream
+  // configuration and translated them into the old school VideoCodec type.
+  // It also creates a VideoBitrateAllocator instance, suitable for the codec
+  // type used. For instance, VP8 will create an allocator than can handle
+  // simulcast and temporal layering.
+  // GetBitrateAllocator is called implicitly from here, no need to call again.
+  static bool SetupCodec(
+      const VideoEncoderConfig& config,
+      const VideoSendStream::Config::EncoderSettings settings,
+      const std::vector<VideoStream>& streams,
+      VideoCodec* codec,
+      std::unique_ptr<VideoBitrateAllocator>* bitrate_allocator);
+
+  // Create a bitrate allocator for the specified codec. |tl_factory| is
+  // optional, if it is populated, ownership of that instance will be
+  // transferred to the VideoBitrateAllocator instance.
+  static std::unique_ptr<VideoBitrateAllocator> GetBitrateAllocator(
+      const VideoCodec& codec,
+      std::unique_ptr<TemporalLayersFactory> tl_factory);
+
+ private:
+  static VideoCodec VideoEncoderConfigToVideoCodec(
+      const VideoEncoderConfig& config,
+      const std::vector<VideoStream>& streams,
+      const std::string& payload_name,
+      int payload_type);
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_VIDEO_CODING_INCLUDE_VIDEO_CODEC_INITIALIZER_H_