BWE allocation strategy

webrtc/rtc_base/bitrateallocationstrategy.h

+/*
+ *  Copyright 2017 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_RTC_BASE_BITRATEALLOCATIONSTRATEGY_H_
+#define WEBRTC_RTC_BASE_BITRATEALLOCATIONSTRATEGY_H_
+
+#include <map>
+#include <memory>
+#include <string>
+#include <vector>
+#include "webrtc/rtc_base/checks.h"
+#include "webrtc/rtc_base/refcount.h"
+#include "webrtc/rtc_base/refcountedobject.h"
+
+namespace rtc {
+
+// Plugable strategy allows configuration of bitrate allocation per media track
+class BitrateAllocationStrategy : public RefCountedObject<RefCountInterface> {
+ public:
+  struct TrackConfig {
+    TrackConfig(uint32_t min_bitrate_bps,
+                uint32_t max_bitrate_bps,
+                bool enforce_min_bitrate,
+                std::string track_id)
+        : min_bitrate_bps(min_bitrate_bps),
+          max_bitrate_bps(max_bitrate_bps),
+          enforce_min_bitrate(enforce_min_bitrate),
+          track_id(track_id) {}
+    TrackConfig(const TrackConfig& track_config) = default;
+    TrackConfig() {}
+
+    uint32_t min_bitrate_bps;
+    uint32_t max_bitrate_bps;
+    bool enforce_min_bitrate;
+    std::string track_id;
+  };
+
+  // Track ID to track bitrate allocation
+  typedef std::map<std::string, uint32_t> TrackAllocations;
+  typedef std::vector<std::unique_ptr<TrackConfig>> TrackConfigs;
+
+  TrackAllocations SetAllBitratesToMinimum(const TrackConfigs& track_configs);
+  TrackAllocations DistributeBitratesEvenly(const TrackConfigs& track_configs,
+                                            uint32_t available_bitrate);
+
+  virtual TrackAllocations AllocateBitrates(
+      uint32_t available_bitrate,
+      const TrackConfigs& track_configs) = 0;
+};
+
+// Simple allocation strategy giving priority to audio at low bitrates
+class AudioPriorityBitrateAllocationStrategy
+    : public BitrateAllocationStrategy {
+ public:
+  AudioPriorityBitrateAllocationStrategy(std::string audio_track_id,
+                                         uint32_t sufficient_audio_bitrate);
+  TrackAllocations AllocateBitrates(uint32_t available_bitrate,
+                                    const TrackConfigs& track_configs) override;
+
+ private:
+  std::string audio_track_id_;
+  uint32_t sufficient_audio_bitrate_;
+};
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_BITRATEALLOCATIONSTRATEGY_H_