Drop audio packets in the chromoting client less agressively.

remoting/client/audio_player.cc

 // Copyright (c) 2012 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.
 
 #include "remoting/client/audio_player.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/stl_util.h"
 
 // The number of channels in the audio stream (only supporting stereo audio
 // for now).
-const int kChannels = 2u;
+const int kChannels = 2;
 const int kSampleSizeBytes = 2;
 
 // If queue grows bigger than 150ms we start dropping packets.
 const int kMaxQueueLatencyMs = 150;
 
 namespace remoting {
 
 AudioPlayer::AudioPlayer()
     : sampling_rate_(AudioPacket::SAMPLING_RATE_INVALID),
       start_failed_(false),
-      queued_samples_(0),
+      queued_bytes_(0),
       bytes_consumed_(0) {
 }
 
 AudioPlayer::~AudioPlayer() {
   base::AutoLock auto_lock(lock_);
   ResetQueue();
 }
 
 void AudioPlayer::ProcessAudioPacket(scoped_ptr<AudioPacket> packet) {
   CHECK_EQ(1, packet->data_size());
@@ skipping 20 matching lines @@
     sampling_rate_ = packet->sampling_rate();
     bool success = ResetAudioPlayer(sampling_rate_);
     if (!success) {
       start_failed_ = true;
       return;
     }
   }
 
   base::AutoLock auto_lock(lock_);
 
-  if (queued_samples_ > kMaxQueueLatencyMs * sampling_rate_ /
-      base::Time::kMillisecondsPerSecond) {
-    ResetQueue();
+  queued_bytes_ += packet->data(0).size();
+  queued_packets_.push_back(packet.release());
+
+  int max_buffer_size_ =
+      kMaxQueueLatencyMs * sampling_rate_ * kSampleSizeBytes * kChannels /
+      base::Time::kMillisecondsPerSecond;
+  while (queued_bytes_ > max_buffer_size_) {
+    queued_bytes_ -= queued_packets_.front()->data(0).size() - bytes_consumed_;
+    DCHECK_GE(queued_bytes_, 0);
+    delete queued_packets_.front();
+    queued_packets_.pop_front();
+    bytes_consumed_ = 0;
   }
-
-  queued_samples_ += packet->data(0).size() / (kChannels * kSampleSizeBytes);
-  queued_packets_.push_back(packet.release());
 }
 
 // static
 void AudioPlayer::AudioPlayerCallback(void* samples,
                                       uint32 buffer_size,
                                       void* data) {
   AudioPlayer* audio_player = static_cast<AudioPlayer*>(data);
   audio_player->FillWithSamples(samples, buffer_size);
 }
 
 void AudioPlayer::ResetQueue() {
   lock_.AssertAcquired();
   STLDeleteElements(&queued_packets_);
-  queued_samples_ = 0;
+  queued_bytes_ = 0;
   bytes_consumed_ = 0;
 }
 
 void AudioPlayer::FillWithSamples(void* samples, uint32 buffer_size) {
   base::AutoLock auto_lock(lock_);
 
   const size_t bytes_needed = kChannels * kSampleSizeBytes *
       GetSamplesPerFrame();
 
   // Make sure we don't overrun the buffer.
@@ skipping 19 matching lines @@
 
     const std::string& packet_data = queued_packets_.front()->data(0);
     size_t bytes_to_copy = std::min(
         packet_data.size() - bytes_consumed_,
         bytes_needed - bytes_extracted);
     memcpy(next_sample, packet_data.data() + bytes_consumed_, bytes_to_copy);
 
     next_sample += bytes_to_copy;
     bytes_consumed_ += bytes_to_copy;
     bytes_extracted += bytes_to_copy;
-    queued_samples_ -= bytes_to_copy / kSampleSizeBytes / kChannels;
-    DCHECK_GE(queued_samples_, 0);
+    queued_bytes_ -= bytes_to_copy;
+    DCHECK_GE(queued_bytes_, 0);
   }
 }
 
 }  // namespace remoting