Pass delay and timestamp to AudioSourceCallback::OnMoreData.

media/audio/cras/cras_unified.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/audio/cras/cras_unified.h"
 
 #include "base/logging.h"
 #include "base/macros.h"
 #include "media/audio/cras/audio_manager_cras.h"
 
@@ skipping 43 matching lines @@
     : client_(NULL),
       stream_id_(0),
       params_(params),
       bytes_per_frame_(0),
       is_playing_(false),
       volume_(1.0),
       manager_(manager),
       source_callback_(NULL),
       stream_direction_(CRAS_STREAM_OUTPUT) {
   DCHECK(manager_);
-  DCHECK(params_.channels()  > 0);
+  DCHECK_GT(params_.channels(), 0);
 
   output_bus_ = AudioBus::Create(params);
 }
 
 CrasUnifiedStream::~CrasUnifiedStream() {
   DCHECK(!is_playing_);
 }
 
 bool CrasUnifiedStream::Open() {
   // Sanity check input values.
@@ skipping 151 matching lines @@
   if (!client_)
     return;
   volume_ = static_cast<float>(volume);
   cras_client_set_stream_volume(client_, stream_id_, volume_);
 }
 
 void CrasUnifiedStream::GetVolume(double* volume) {
   *volume = volume_;
 }
 
-uint32_t CrasUnifiedStream::GetBytesLatency(const struct timespec& latency_ts) {
-  uint32_t latency_usec;
-
-  // Treat negative latency (if we are too slow to render) as 0.
-  if (latency_ts.tv_sec < 0 || latency_ts.tv_nsec < 0) {
-    latency_usec = 0;
-  } else {
-    latency_usec = (latency_ts.tv_sec * base::Time::kMicrosecondsPerSecond) +
-        latency_ts.tv_nsec / base::Time::kNanosecondsPerMicrosecond;
-  }
-
-  double frames_latency =
-      latency_usec * params_.sample_rate() / base::Time::kMicrosecondsPerSecond;
-
-  return static_cast<unsigned int>(frames_latency * bytes_per_frame_);
-}
-
 // Static callback asking for samples.
 int CrasUnifiedStream::UnifiedCallback(cras_client* client,
                                        cras_stream_id_t stream_id,
                                        uint8_t* input_samples,
                                        uint8_t* output_samples,
                                        unsigned int frames,
                                        const timespec* input_ts,
                                        const timespec* output_ts,
                                        void* arg) {
   CrasUnifiedStream* me = static_cast<CrasUnifiedStream*>(arg);
@@ skipping 35 matching lines @@
 
 uint32_t CrasUnifiedStream::WriteAudio(size_t frames,
                                        uint8_t* buffer,
                                        const timespec* sample_ts) {
   DCHECK_EQ(frames, static_cast<size_t>(output_bus_->frames()));
 
   // Determine latency and pass that on to the source.
   timespec latency_ts  = {0, 0};
   cras_client_calc_playback_latency(sample_ts, &latency_ts);
 
+  // Treat negative latency (if we are too slow to render) as 0.
+  const base::TimeDelta delay = latency_ts.tv_sec > 0 && latency_ts.tv_nsec > 0

[miu, 2016/09/28 23:04:41]

Is it possible for tv_sec to be greater than zero, but tv_nsec to be negative?

Might be simpler to just:

  const base::TimeDelta delay =
std::max(base::TimeDelta::FromTimeSpec(latency_ts), base::TimeDelta());

[jameswest, 2016/09/29 00:52:24]

That shouldn't happen, and even if it does, using a TimeDelta of zero isn't
necessary more correct than computing it from the values as given. I changed it
as suggested.

+                                    ? base::TimeDelta::FromTimeSpec(latency_ts)
+                                    : base::TimeDelta();
+
   int frames_filled = source_callback_->OnMoreData(
-      output_bus_.get(), GetBytesLatency(latency_ts), 0);
+      delay, base::TimeTicks::Now(), 0, output_bus_.get());
 
   // Note: If this ever changes to output raw float the data must be clipped and
   // sanitized since it may come from an untrusted source such as NaCl.
   output_bus_->ToInterleaved(
       frames_filled, bytes_per_frame_ / params_.channels(), buffer);
 
   return frames_filled;
 }
 
 void CrasUnifiedStream::NotifyStreamError(int err) {
   // This will remove the stream from the client.
   if (source_callback_)
     source_callback_->OnError(this);
 }
 
 }  // namespace media