Refactor the AudioDevice for iOS and improve the performance and stability

webrtc/modules/audio_device/fine_audio_buffer.cc

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#include "webrtc/modules/audio_device/android/fine_audio_buffer.h"
+#include "webrtc/modules/audio_device/fine_audio_buffer.h"
 
 #include <memory.h>
 #include <stdio.h>
 #include <algorithm>
 
 #include "webrtc/base/checks.h"
+#include "webrtc/base/logging.h"
 #include "webrtc/modules/audio_device/audio_device_buffer.h"
 
 namespace webrtc {
 
 FineAudioBuffer::FineAudioBuffer(AudioDeviceBuffer* device_buffer,
                                  size_t desired_frame_size_bytes,
                                  int sample_rate)
     : device_buffer_(device_buffer),
       desired_frame_size_bytes_(desired_frame_size_bytes),
       sample_rate_(sample_rate),
       samples_per_10_ms_(static_cast<size_t>(sample_rate_ * 10 / 1000)),
       bytes_per_10_ms_(samples_per_10_ms_ * sizeof(int16_t)),
       cached_buffer_start_(0),
-      cached_bytes_(0) {
+      cached_bytes_(0),

[tkchin_webrtc, 2015/09/01 20:54:49]

nit: consider naming this playout_cached_bytes_

[henrika_webrtc, 2015/09/03 13:44:41]

Done.

+      record_cached_bytes_(0) {
   cache_buffer_.reset(new int8_t[bytes_per_10_ms_]);

[tkchin_webrtc, 2015/09/01 20:54:49]

nit: consider naming this playout_cache_buffer_ to match record_cache_buffer_

[henrika_webrtc, 2015/09/03 13:44:41]

Done.

+  record_cache_buffer_.reset(
+      new int8_t[desired_frame_size_bytes + bytes_per_10_ms_]);

[tkchin_webrtc, 2015/09/01 20:54:49]

nit: pull out size into a local var since it's the same in two places, can call
RequiredPlayoutBufferSizeBytes() too if that makes sense

[henrika_webrtc, 2015/09/03 13:44:41]

Thanks. Done.

+  memset(record_cache_buffer_.get(), 0,
+         desired_frame_size_bytes + bytes_per_10_ms_);
 }
 
 FineAudioBuffer::~FineAudioBuffer() {
 }
 
-size_t FineAudioBuffer::RequiredBufferSizeBytes() {
+size_t FineAudioBuffer::RequiredPlayoutBufferSizeBytes() {
   // It is possible that we store the desired frame size - 1 samples. Since new
   // audio frames are pulled in chunks of 10ms we will need a buffer that can
   // hold desired_frame_size - 1 + 10ms of data. We omit the - 1.
   return desired_frame_size_bytes_ + bytes_per_10_ms_;
 }
 
-void FineAudioBuffer::GetBufferData(int8_t* buffer) {
+void FineAudioBuffer::ResetPlayout() {
+  cached_buffer_start_ = 0;
+  cached_bytes_ = 0;
+  memset(cache_buffer_.get(), 0, bytes_per_10_ms_);
+}
+
+void FineAudioBuffer::ResetRecord() {
+  record_cached_bytes_ = 0;
+  memset(record_cache_buffer_.get(), 0,
+         desired_frame_size_bytes_ + bytes_per_10_ms_);
+}
+
+void FineAudioBuffer::GetPlayoutData(int8_t* buffer) {
   if (desired_frame_size_bytes_ <= cached_bytes_) {
     memcpy(buffer, &cache_buffer_.get()[cached_buffer_start_],
            desired_frame_size_bytes_);
     cached_buffer_start_ += desired_frame_size_bytes_;
     cached_bytes_ -= desired_frame_size_bytes_;
     CHECK_LT(cached_buffer_start_ + cached_bytes_, bytes_per_10_ms_);
     return;
   }
   memcpy(buffer, &cache_buffer_.get()[cached_buffer_start_], cached_bytes_);
   // Push another n*10ms of audio to |buffer|. n > 1 if
   // |desired_frame_size_bytes_| is greater than 10ms of audio. Note that we
   // write the audio after the cached bytes copied earlier.
   int8_t* unwritten_buffer = &buffer[cached_bytes_];
   int bytes_left = static_cast<int>(desired_frame_size_bytes_ - cached_bytes_);
   // Ceiling of integer division: 1 + ((x - 1) / y)
   size_t number_of_requests = 1 + (bytes_left - 1) / (bytes_per_10_ms_);
   for (size_t i = 0; i < number_of_requests; ++i) {
     device_buffer_->RequestPlayoutData(samples_per_10_ms_);
     int num_out = device_buffer_->GetPlayoutData(unwritten_buffer);
     if (static_cast<size_t>(num_out) != samples_per_10_ms_) {
       CHECK_EQ(num_out, 0);
       cached_bytes_ = 0;
       return;
     }
     unwritten_buffer += bytes_per_10_ms_;
     CHECK_GE(bytes_left, 0);
-    bytes_left -= bytes_per_10_ms_;
+    bytes_left -= static_cast<int>(bytes_per_10_ms_);
   }
   CHECK_LE(bytes_left, 0);
   // Put the samples that were written to |buffer| but are not used in the
   // cache.
   size_t cache_location = desired_frame_size_bytes_;
   int8_t* cache_ptr = &buffer[cache_location];
   cached_bytes_ = number_of_requests * bytes_per_10_ms_ -
-      (desired_frame_size_bytes_ - cached_bytes_);
+                  (desired_frame_size_bytes_ - cached_bytes_);
   // If cached_bytes_ is larger than the cache buffer, uninitialized memory
   // will be read.
   CHECK_LE(cached_bytes_, bytes_per_10_ms_);
   CHECK_EQ(static_cast<size_t>(-bytes_left), cached_bytes_);
   cached_buffer_start_ = 0;
   memcpy(cache_buffer_.get(), cache_ptr, cached_bytes_);
 }
 
+void FineAudioBuffer::DeliverRecordedData(const int8_t* buffer,
+                                          size_t size_in_bytes,
+                                          int playout_delay_ms,
+                                          int record_delay_ms) {
+  CHECK_EQ(size_in_bytes, desired_frame_size_bytes_);
+  // Store the recorded sampled in a temporary buffer.
+  memcpy(record_cache_buffer_.get() + record_cached_bytes_, buffer,
+         size_in_bytes);
+  record_cached_bytes_ += size_in_bytes;
+  // Ensure that we don't write outside the boundaries.
+  CHECK_LE(record_cached_bytes_, desired_frame_size_bytes_ + bytes_per_10_ms_);
+  // Consume samples in temporary buffer in chunks of 10ms until there is not
+  // enough data left. Any remaining part is moved to the beginning of the
+  // temporary buffer and |record_cached_bytes_| points to the first byte where
+  // new data can be stored.
+  while (record_cached_bytes_ >= bytes_per_10_ms_) {
+    device_buffer_->SetRecordedBuffer(record_cache_buffer_.get(),
+                                      samples_per_10_ms_);
+    device_buffer_->SetVQEData(playout_delay_ms, record_delay_ms, 0);
+    device_buffer_->DeliverRecordedData();
+    memmove(record_cache_buffer_.get(),

[tkchin_webrtc, 2015/09/01 20:54:49]

Isn't this expensive? Performs a copy of all remaining bytes each iteration. Or
are the sizes small enough that it doesn't matter?

[henrika_webrtc, 2015/09/03 13:44:41]

I have modified the existing scheme by extending the size of the temporary
buffer with a factor of 5.
On my iPhone 6, it results in a total cache size of 9920 bytes but now we only
do a memmove() once every tenth call, i.e.,
store & send
... 7 more
store & send 
memmove()
store & send
... 7 more
store & send
ec.
and the largest block we move is 896 bytes (smallest is 64)

+            record_cache_buffer_.get() + bytes_per_10_ms_,
+            record_cached_bytes_ - bytes_per_10_ms_);
+    record_cached_bytes_ -= bytes_per_10_ms_;
+  }
+}
+
 }  // namespace webrtc