Cast: Merge common functionality from audio/video sender into frame_sender.

media/cast/sender/video_sender.cc

Index: media/cast/sender/video_sender.cc
diff --git a/media/cast/sender/video_sender.cc b/media/cast/sender/video_sender.cc
index 1552749015d14c0bf45779520f930fcfc8ddde08..bc2d3e2907fd4aca2f6c7700ebe390e79d93ee11 100644
--- a/media/cast/sender/video_sender.cc
+++ b/media/cast/sender/video_sender.cc
@@ -19,22 +19,10 @@
 namespace media {
 namespace cast {
 
-const int kNumAggressiveReportsSentAtStart = 100;
-
-namespace {
-
-// Returns a fixed bitrate value when external video encoder is used.
+// Note, we use a fixed bitrate value when external video encoder is used.
 // Some hardware encoder shows bad behavior if we set the bitrate too
 // frequently, e.g. quality drop, not abiding by target bitrate, etc.
 // See details: crbug.com/392086.
-size_t GetFixedBitrate(const VideoSenderConfig& video_config) {
-  if (!video_config.use_external_encoder)
-    return 0;
-  return (video_config.min_bitrate + video_config.max_bitrate) / 2;
-}
-
-}  // namespace
-
 VideoSender::VideoSender(
     scoped_refptr<CastEnvironment> cast_environment,
     const VideoSenderConfig& video_config,
@@ -43,18 +31,16 @@ VideoSender::VideoSender(
     CastTransportSender* const transport_sender)
     : FrameSender(
         cast_environment,
+        false,
         transport_sender,
         base::TimeDelta::FromMilliseconds(video_config.rtcp_interval),
         kVideoFrequency,
         video_config.ssrc,
         video_config.max_frame_rate,
-        video_config.target_playout_delay),
-      fixed_bitrate_(GetFixedBitrate(video_config)),
-      frames_in_encoder_(0),
-      congestion_control_(cast_environment->Clock(),
-                          video_config.max_bitrate,
-                          video_config.min_bitrate,
-                          max_unacked_frames_),
+        video_config.target_playout_delay,
+        NewFixedCongestionControl(
+            (video_config.min_bitrate + video_config.max_bitrate) / 2)),
+      last_bitrate_(0),
       weak_factory_(this) {
   cast_initialization_status_ = STATUS_VIDEO_UNINITIALIZED;
   VLOG(1) << "max_unacked_frames is " << max_unacked_frames_
@@ -69,6 +55,11 @@ VideoSender::VideoSender(
                                                   create_vea_cb,
                                                   create_video_encode_mem_cb));
   } else {
+    congestion_control_.reset(
+        NewAdaptiveCongestionControl(cast_environment->Clock(),
+                                     video_config.max_bitrate,
+                                     video_config.min_bitrate,
+                                     max_unacked_frames_));
     video_encoder_.reset(new VideoEncoderImpl(
         cast_environment, video_config, max_unacked_frames_));
   }
@@ -124,23 +115,17 @@ void VideoSender::InsertRawVideoFrame(
     return;
   }
 
-  uint32 bitrate = fixed_bitrate_;
-  if (!bitrate) {
-    bitrate = congestion_control_.GetBitrate(
+  uint32 bitrate = congestion_control_->GetBitrate(
         capture_time + target_playout_delay_, target_playout_delay_);
-    DCHECK(bitrate);
-    video_encoder_->SetBitRate(bitrate);
-  } else if (last_send_time_.is_null()) {
-    // Set the fixed bitrate value to codec until a frame is sent. We might
-    // set this value a couple times at the very beginning of the stream but
-    // it is not harmful.
+  if (bitrate != last_bitrate_) {
     video_encoder_->SetBitRate(bitrate);
+    last_bitrate_ = bitrate;
   }
 
   if (video_encoder_->EncodeVideoFrame(
           video_frame,
           capture_time,
-          base::Bind(&VideoSender::SendEncodedVideoFrame,
+          base::Bind(&FrameSender::SendEncodedFrame,
                      weak_factory_.GetWeakPtr(),
                      bitrate))) {
     frames_in_encoder_++;
@@ -149,179 +134,8 @@ void VideoSender::InsertRawVideoFrame(
   }
 }
 
-void VideoSender::SendEncodedVideoFrame(
-    int requested_bitrate_before_encode,
-    scoped_ptr<EncodedFrame> encoded_frame) {
-  DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
-
-  DCHECK_GT(frames_in_encoder_, 0);
-  frames_in_encoder_--;
-
-  const uint32 frame_id = encoded_frame->frame_id;
-
-  const bool is_first_frame_to_be_sent = last_send_time_.is_null();
-  last_send_time_ = cast_environment_->Clock()->NowTicks();
-  last_sent_frame_id_ = frame_id;
-  // If this is the first frame about to be sent, fake the value of
-  // |latest_acked_frame_id_| to indicate the receiver starts out all caught up.
-  // Also, schedule the periodic frame re-send checks.
-  if (is_first_frame_to_be_sent) {
-    latest_acked_frame_id_ = frame_id - 1;
-    ScheduleNextResendCheck();
-  }
-
-  VLOG_IF(1, encoded_frame->dependency == EncodedFrame::KEY)
-      << "Send encoded key frame; frame_id: " << frame_id;
-
-  cast_environment_->Logging()->InsertEncodedFrameEvent(
-      last_send_time_, FRAME_ENCODED, VIDEO_EVENT, encoded_frame->rtp_timestamp,
-      frame_id, static_cast<int>(encoded_frame->data.size()),
-      encoded_frame->dependency == EncodedFrame::KEY,
-      requested_bitrate_before_encode);
-
-  RecordLatestFrameTimestamps(frame_id,
-                              encoded_frame->reference_time,
-                              encoded_frame->rtp_timestamp);
-
-  // Used by chrome/browser/extension/api/cast_streaming/performance_test.cc
-  TRACE_EVENT_INSTANT1(
-      "cast_perf_test", "VideoFrameEncoded",
-      TRACE_EVENT_SCOPE_THREAD,
-      "rtp_timestamp", encoded_frame->rtp_timestamp);
-
-  // At the start of the session, it's important to send reports before each
-  // frame so that the receiver can properly compute playout times.  The reason
-  // more than one report is sent is because transmission is not guaranteed,
-  // only best effort, so send enough that one should almost certainly get
-  // through.
-  if (num_aggressive_rtcp_reports_sent_ < kNumAggressiveReportsSentAtStart) {
-    // SendRtcpReport() will schedule future reports to be made if this is the
-    // last "aggressive report."
-    ++num_aggressive_rtcp_reports_sent_;
-    const bool is_last_aggressive_report =
-        (num_aggressive_rtcp_reports_sent_ == kNumAggressiveReportsSentAtStart);
-    VLOG_IF(1, is_last_aggressive_report) << "Sending last aggressive report.";
-    SendRtcpReport(is_last_aggressive_report);
-  }
-
-  congestion_control_.SendFrameToTransport(
-      frame_id, encoded_frame->data.size() * 8, last_send_time_);
-
-  if (send_target_playout_delay_) {
-    encoded_frame->new_playout_delay_ms =
-        target_playout_delay_.InMilliseconds();
-  }
-  transport_sender_->InsertFrame(ssrc_, *encoded_frame);
-}
-
-void VideoSender::OnReceivedCastFeedback(const RtcpCastMessage& cast_feedback) {
-  DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
-
-  base::TimeDelta rtt;
-  base::TimeDelta avg_rtt;
-  base::TimeDelta min_rtt;
-  base::TimeDelta max_rtt;
-  if (is_rtt_available()) {
-    rtt = rtt_;
-    avg_rtt = avg_rtt_;
-    min_rtt = min_rtt_;
-    max_rtt = max_rtt_;
-
-    congestion_control_.UpdateRtt(rtt);
-
-    // Don't use a RTT lower than our average.
-    rtt = std::max(rtt, avg_rtt);
-
-    // Having the RTT values implies the receiver sent back a receiver report
-    // based on it having received a report from here.  Therefore, ensure this
-    // sender stops aggressively sending reports.
-    if (num_aggressive_rtcp_reports_sent_ < kNumAggressiveReportsSentAtStart) {
-      VLOG(1) << "No longer a need to send reports aggressively (sent "
-              << num_aggressive_rtcp_reports_sent_ << ").";
-      num_aggressive_rtcp_reports_sent_ = kNumAggressiveReportsSentAtStart;
-      ScheduleNextRtcpReport();
-    }
-  } else {
-    // We have no measured value use default.
-    rtt = base::TimeDelta::FromMilliseconds(kStartRttMs);
-  }
-
-  if (last_send_time_.is_null())
-    return;  // Cannot get an ACK without having first sent a frame.
-
-  if (cast_feedback.missing_frames_and_packets.empty()) {
-    video_encoder_->LatestFrameIdToReference(cast_feedback.ack_frame_id);
-
-    // We only count duplicate ACKs when we have sent newer frames.
-    if (latest_acked_frame_id_ == cast_feedback.ack_frame_id &&
-        latest_acked_frame_id_ != last_sent_frame_id_) {
-      duplicate_ack_counter_++;
-    } else {
-      duplicate_ack_counter_ = 0;
-    }
-    // TODO(miu): The values "2" and "3" should be derived from configuration.
-    if (duplicate_ack_counter_ >= 2 && duplicate_ack_counter_ % 3 == 2) {
-      VLOG(1) << "Received duplicate ACK for frame " << latest_acked_frame_id_;
-      ResendForKickstart();
-    }
-  } else {
-    // Only count duplicated ACKs if there is no NACK request in between.
-    // This is to avoid aggresive resend.
-    duplicate_ack_counter_ = 0;
-  }
-
-  base::TimeTicks now = cast_environment_->Clock()->NowTicks();
-  congestion_control_.AckFrame(cast_feedback.ack_frame_id, now);
-
-  cast_environment_->Logging()->InsertFrameEvent(
-      now,
-      FRAME_ACK_RECEIVED,
-      VIDEO_EVENT,
-      GetRecordedRtpTimestamp(cast_feedback.ack_frame_id),
-      cast_feedback.ack_frame_id);
-
-  const bool is_acked_out_of_order =
-      static_cast<int32>(cast_feedback.ack_frame_id -
-                             latest_acked_frame_id_) < 0;
-  VLOG(2) << "Received ACK" << (is_acked_out_of_order ? " out-of-order" : "")
-          << " for frame " << cast_feedback.ack_frame_id;
-  if (!is_acked_out_of_order) {
-    // Cancel resends of acked frames.
-    std::vector<uint32> cancel_sending_frames;
-    while (latest_acked_frame_id_ != cast_feedback.ack_frame_id) {
-      latest_acked_frame_id_++;
-      cancel_sending_frames.push_back(latest_acked_frame_id_);
-    }
-    transport_sender_->CancelSendingFrames(ssrc_, cancel_sending_frames);
-    latest_acked_frame_id_ = cast_feedback.ack_frame_id;
-  }
-}
-
-bool VideoSender::ShouldDropNextFrame(base::TimeTicks capture_time) const {
-  DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
-  int frames_in_flight = 0;
-  base::TimeDelta duration_in_flight;
-  if (!last_send_time_.is_null()) {
-    frames_in_flight =
-        static_cast<int32>(last_sent_frame_id_ - latest_acked_frame_id_);
-    if (frames_in_flight > 0) {
-      const uint32 oldest_unacked_frame_id = latest_acked_frame_id_ + 1;
-      duration_in_flight =
-          capture_time - GetRecordedReferenceTime(oldest_unacked_frame_id);
-    }
-  }
-  frames_in_flight += frames_in_encoder_;
-  VLOG(2) << frames_in_flight
-          << " frames in flight; last sent: " << last_sent_frame_id_
-          << "; latest acked: " << latest_acked_frame_id_
-          << "; frames in encoder: " << frames_in_encoder_
-          << "; duration in flight: "
-          << duration_in_flight.InMicroseconds() << " usec ("
-          << (target_playout_delay_ > base::TimeDelta() ?
-                  100 * duration_in_flight / target_playout_delay_ :
-                  kint64max) << "%)";
-  return frames_in_flight >= max_unacked_frames_ ||
-      duration_in_flight >= target_playout_delay_;
+void VideoSender::OnAck(uint32 frame_id) {
+  video_encoder_->LatestFrameIdToReference(frame_id);
 }
 
 }  // namespace cast