Pass delay and timestamp to AudioSourceCallback::OnMoreData.

media/audio/android/opensles_output.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 "media/audio/android/opensles_output.h"
 
 #include "base/logging.h"
 #include "base/macros.h"
+#include "base/time/time.h"
 #include "base/trace_event/trace_event.h"
 #include "media/audio/android/audio_manager_android.h"
 
 #define LOG_ON_FAILURE_AND_RETURN(op, ...)      \
   do {                                          \
     SLresult err = (op);                        \
     if (err != SL_RESULT_SUCCESS) {             \
       DLOG(ERROR) << #op << " failed: " << err; \
       return __VA_ARGS__;                       \
     }                                           \
@@ skipping 314 matching lines @@
 }
 
 void OpenSLESOutputStream::FillBufferQueueNoLock() {
   // Ensure that the calling thread has acquired the lock since it is not
   // done in this method.
   lock_.AssertAcquired();
 
   // Calculate the position relative to the number of frames written.
   uint32_t position_in_ms = 0;
   SLresult err = (*player_)->GetPosition(player_, &position_in_ms);
-  const int delay =
-      err == SL_RESULT_SUCCESS
-          ? -delay_calculator_.GetFramesToTarget(
-                base::TimeDelta::FromMilliseconds(position_in_ms)) *
-                bytes_per_frame_
-          : 0;
+  // Given the position of the playback head, compute the approximate number of
+  // frames that have been queued to the buffer but not yet played out.
+  // This will be added to the system reference time below to compute the target
+  // playout time to pass to OnMoreData().
+  // Note that the value returned by GetFramesToTarget() is negative because
+  // more frames have been added to |delay_calculator_| than have been played
+  // out and thus the target timestamp is earlier than the current timestamp of
+  // |delay_calculator_|.
+  const int delay = err == SL_RESULT_SUCCESS
+                        ? -delay_calculator_.GetFramesToTarget(
+                              base::TimeDelta::FromMilliseconds(position_in_ms))
+                        : 0;
   DCHECK_GE(delay, 0);
 
+  // Calculate when the requested data will be played by converting the delay to
+  // time and adding it to the current time.
+  const base::TimeTicks target_playout_time =
+      base::TimeTicks::Now() +
+      base::TimeDelta::FromMicroseconds(
+          delay * base::Time::kMicrosecondsPerSecond / format_.samplesPerSec);
+
   // Read data from the registered client source.
-  const int frames_filled = callback_->OnMoreData(audio_bus_.get(), delay, 0);
+  const int frames_filled =
+      callback_->OnMoreData(target_playout_time, 0, audio_bus_.get());
   if (frames_filled <= 0) {
     // Audio source is shutting down, or halted on error.
     return;
   }
 
   // Note: If the internal representation ever changes from 16-bit PCM to
   // raw float, the data must be clipped and sanitized since it may come
   // from an untrusted source such as NaCl.
   audio_bus_->Scale(muted_ ? 0.0f : volume_);
   audio_bus_->ToInterleaved(frames_filled, format_.bitsPerSample / 8,
@@ skipping 31 matching lines @@
   }
 }
 
 void OpenSLESOutputStream::HandleError(SLresult error) {
   DLOG(ERROR) << "OpenSLES Output error " << error;
   if (callback_)
     callback_->OnError(this);
 }
 
 }  // namespace media