Cast: end2end bug fixes

media/cast/audio_sender/audio_encoder.cc

 // Copyright 2013 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 "media/cast/audio_sender/audio_encoder.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 57 matching lines @@
                           uint32 frame_id,
                           CastLoggingEvent type) {
     cast_environment_->Logging()->InsertFrameEvent(
         cast_environment_->Clock()->NowTicks(), type, rtp_timestamp, frame_id);
   }
 
   void EncodeAudio(const AudioBus* audio_bus,
                    const base::TimeTicks& recorded_time,
                    const base::Closure& done_callback) {
     int src_pos = 0;
+    int packet_count = 0;
     while (audio_bus && src_pos < audio_bus->frames()) {
       const int num_samples_to_xfer = std::min(
           samples_per_10ms_ - buffer_fill_end_, audio_bus->frames() - src_pos);
       DCHECK_EQ(audio_bus->channels(), num_channels_);
       TransferSamplesIntoBuffer(
           audio_bus, src_pos, buffer_fill_end_, num_samples_to_xfer);
       src_pos += num_samples_to_xfer;
       buffer_fill_end_ += num_samples_to_xfer;
 
       if (src_pos == audio_bus->frames()) {
@@ skipping 29 matching lines @@
                                                  audio_frame->rtp_timestamp,
                                                  audio_frame->frame_id,
                                                  kAudioFrameEncoded));
           // Compute an offset to determine the recorded time for the first
           // audio sample in the buffer.
           const base::TimeDelta buffer_time_offset =
               (buffer_fill_end_ - src_pos) *
               base::TimeDelta::FromMilliseconds(10) / samples_per_10ms_;
           // TODO(miu): Consider batching EncodedAudioFrames so we only post a
           // at most one task for each call to this method.
-          cast_environment_->PostTask(
+          // Postpone every packet by 10mS with respect to the previous. Playout
+          // is postponed already by 10mS, and this will better correlate with
+          // the pacer's expectations.
+          //TODO(mikhal): Turn this into a list of packets.
+          // Update the end2end allowed error once this is fixed.
+          cast_environment_->PostDelayedTask(
               CastEnvironment::MAIN,
               FROM_HERE,
               base::Bind(callback_,
                          base::Passed(&audio_frame),
-                         recorded_time - buffer_time_offset));
+                         recorded_time - buffer_time_offset),
+              base::TimeDelta::FromMilliseconds(packet_count * 10));
+          ++packet_count;
         }
         buffer_fill_end_ = 0;
       }
     }
   }
 
  protected:
   virtual void TransferSamplesIntoBuffer(const AudioBus* audio_bus,
                                          int source_offset,
                                          int buffer_fill_offset,
@@ skipping 216 matching lines @@
 
 void AudioEncoder::EncodeAudio(const AudioBus* audio_bus,
                                const base::TimeTicks& recorded_time,
                                const base::Closure& done_callback) {
   DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::AUDIO_ENCODER));
   impl_->EncodeAudio(audio_bus, recorded_time, done_callback);
 }
 
 }  // namespace cast
 }  // namespace media