Add PeerConnectionInterface::UpdateCallBitrate.

webrtc/call/call.h

 /*
  *  Copyright (c) 2013 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_CALL_CALL_H_
 #define WEBRTC_CALL_CALL_H_
 
 #include <memory>
 #include <string>
 #include <vector>
 
+#include "webrtc/api/rtcerror.h"
 #include "webrtc/base/networkroute.h"
 #include "webrtc/base/platform_file.h"
 #include "webrtc/base/socket.h"
 #include "webrtc/call/audio_receive_stream.h"
 #include "webrtc/call/audio_send_stream.h"
 #include "webrtc/call/audio_state.h"
 #include "webrtc/call/flexfec_receive_stream.h"
 #include "webrtc/call/rtp_transport_controller_send_interface.h"
 #include "webrtc/common_types.h"
 #include "webrtc/video_receive_stream.h"
@@ skipping 34 matching lines @@
 class Call {
  public:
   struct Config {
     explicit Config(RtcEventLog* event_log) : event_log(event_log) {
       RTC_DCHECK(event_log);
     }
 
     static const int kDefaultStartBitrateBps;
 
     // Bitrate config used until valid bitrate estimates are calculated. Also
-    // used to cap total bitrate used.
+    // used to cap total bitrate used. This comes from the remote connection.
     struct BitrateConfig {
       int min_bitrate_bps = 0;
       int start_bitrate_bps = kDefaultStartBitrateBps;
       int max_bitrate_bps = -1;
     } bitrate_config;
 
+    // The local client's bitrate preferences. The actual configuration used
+    // is a combination of this and |bitrate_config|. The combination is
+    // currently more complicated than a simple mask operation (see
+    // SetBitrateConfig and SetBitrateConfigMask). Assumes that 0 <= min <=
+    // start <= max holds for set parameters.
+    struct BitrateConfigMask {
+      rtc::Optional<int> min_bitrate_bps;
+      rtc::Optional<int> start_bitrate_bps;
+      rtc::Optional<int> max_bitrate_bps;
+    };
+
     // AudioState which is possibly shared between multiple calls.
     // TODO(solenberg): Change this to a shared_ptr once we can use C++11.
     rtc::scoped_refptr<AudioState> audio_state;
 
     // Audio Processing Module to be used in this call.
     // TODO(solenberg): Change this to a shared_ptr once we can use C++11.
     AudioProcessing* audio_processing = nullptr;
 
     // RtcEventLog to use for this call. Required.
     // Use webrtc::RtcEventLog::CreateNull() for a null implementation.
@@ skipping 46 matching lines @@
 
   // All received RTP and RTCP packets for the call should be inserted to this
   // PacketReceiver. The PacketReceiver pointer is valid as long as the
   // Call instance exists.
   virtual PacketReceiver* Receiver() = 0;
 
   // Returns the call statistics, such as estimated send and receive bandwidth,
   // pacing delay, etc.
   virtual Stats GetStats() const = 0;
 
-  // TODO(pbos): Like BitrateConfig above this is currently per-stream instead
-  // of maximum for entire Call. This should be fixed along with the above.
-  // Specifying a start bitrate (>0) will currently reset the current bitrate
-  // estimate. This is due to how the 'x-google-start-bitrate' flag is currently
+  // The greater min and smaller max set by this and SetBitrateConfigMask will
+  // be used. The latest non-negative start value from either call will be used.
+  // Specifying a start bitrate (>0) will reset the current bitrate estimate.

[holmer, 2017/05/31 07:46:34]

I think it would be good to specify what start bitrate == 0 does too.

[Zach Stein, 2017/06/01 03:37:49]

start_bitrate == 0 is disallowed by DCHECK, but it will update the value to
whatever start gets clamped to. Negative values other than -1 behave similarly.
I don't think adding to this comment provides much value since this is supposed
to be an internal header now - reading the code is just as clear and can't get
out of sync. Or maybe I have just been looking at this code for too long :)

[Taylor Brandstetter, 2017/06/01 16:24:43]

The value of a comment here is that it tells you what the method is *designed*
to do, whereas reading the code only tells you what it actually does. In my
opinion, it's ideal if every method in a header file has a sufficient level of
comments that its behavior is clear and tests can be written for it without
looking at the implementation.

+  // This is due to how the 'x-google-start-bitrate' flag is currently
   // implemented.
   virtual void SetBitrateConfig(
       const Config::BitrateConfig& bitrate_config) = 0;
 
+  // The greater min and smaller max set by this and SetBitrateConfig will be
+  // used. The latest non-negative start value form either call will be used.
+  // Specifying a start bitrate will reset the current bitrate estimate.
+  // Assumes 0 <= min <= start <= max holds for set parameters.
+  virtual void SetBitrateConfigMask(
+      const Config::BitrateConfigMask& bitrate_mask) = 0;
+
   // TODO(skvlad): When the unbundled case with multiple streams for the same
   // media type going over different networks is supported, track the state
   // for each stream separately. Right now it's global per media type.
   virtual void SignalChannelNetworkState(MediaType media,
                                          NetworkState state) = 0;
 
   virtual void OnTransportOverheadChanged(
       MediaType media,
       int transport_overhead_per_packet) = 0;
 
   virtual void OnNetworkRouteChanged(
       const std::string& transport_name,
       const rtc::NetworkRoute& network_route) = 0;
 
   virtual void OnSentPacket(const rtc::SentPacket& sent_packet) = 0;
 
   virtual ~Call() {}
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_CALL_CALL_H_