Revert of Moved ring-buffer related files from common_audio to audio_processing

webrtc/common_audio/blocker.cc

Index: webrtc/common_audio/blocker.cc
diff --git a/webrtc/common_audio/blocker.cc b/webrtc/common_audio/blocker.cc
new file mode 100644
index 0000000000000000000000000000000000000000..13432f2e7a89fd990debd0f59cd12b4528c79c75
--- /dev/null
+++ b/webrtc/common_audio/blocker.cc
@@ -0,0 +1,236 @@
+/*
+ *  Copyright (c) 2014 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/common_audio/blocker.h"
+
+#include <string.h>
+
+#include "webrtc/base/checks.h"
+
+namespace {
+
+// Adds |a| and |b| frame by frame into |result| (basically matrix addition).
+void AddFrames(const float* const* a,
+               size_t a_start_index,
+               const float* const* b,
+               int b_start_index,
+               size_t num_frames,
+               size_t num_channels,
+               float* const* result,
+               size_t result_start_index) {
+  for (size_t i = 0; i < num_channels; ++i) {
+    for (size_t j = 0; j < num_frames; ++j) {
+      result[i][j + result_start_index] =
+          a[i][j + a_start_index] + b[i][j + b_start_index];
+    }
+  }
+}
+
+// Copies |src| into |dst| channel by channel.
+void CopyFrames(const float* const* src,
+                size_t src_start_index,
+                size_t num_frames,
+                size_t num_channels,
+                float* const* dst,
+                size_t dst_start_index) {
+  for (size_t i = 0; i < num_channels; ++i) {
+    memcpy(&dst[i][dst_start_index],
+           &src[i][src_start_index],
+           num_frames * sizeof(dst[i][dst_start_index]));
+  }
+}
+
+// Moves |src| into |dst| channel by channel.
+void MoveFrames(const float* const* src,
+                size_t src_start_index,
+                size_t num_frames,
+                size_t num_channels,
+                float* const* dst,
+                size_t dst_start_index) {
+  for (size_t i = 0; i < num_channels; ++i) {
+    memmove(&dst[i][dst_start_index],
+            &src[i][src_start_index],
+            num_frames * sizeof(dst[i][dst_start_index]));
+  }
+}
+
+void ZeroOut(float* const* buffer,
+             size_t starting_idx,
+             size_t num_frames,
+             size_t num_channels) {
+  for (size_t i = 0; i < num_channels; ++i) {
+    memset(&buffer[i][starting_idx], 0,
+           num_frames * sizeof(buffer[i][starting_idx]));
+  }
+}
+
+// Pointwise multiplies each channel of |frames| with |window|. Results are
+// stored in |frames|.
+void ApplyWindow(const float* window,
+                 size_t num_frames,
+                 size_t num_channels,
+                 float* const* frames) {
+  for (size_t i = 0; i < num_channels; ++i) {
+    for (size_t j = 0; j < num_frames; ++j) {
+      frames[i][j] = frames[i][j] * window[j];
+    }
+  }
+}
+
+size_t gcd(size_t a, size_t b) {
+  size_t tmp;
+  while (b) {
+     tmp = a;
+     a = b;
+     b = tmp % b;
+  }
+  return a;
+}
+
+}  // namespace
+
+namespace webrtc {
+
+Blocker::Blocker(size_t chunk_size,
+                 size_t block_size,
+                 size_t num_input_channels,
+                 size_t num_output_channels,
+                 const float* window,
+                 size_t shift_amount,
+                 BlockerCallback* callback)
+    : chunk_size_(chunk_size),
+      block_size_(block_size),
+      num_input_channels_(num_input_channels),
+      num_output_channels_(num_output_channels),
+      initial_delay_(block_size_ - gcd(chunk_size, shift_amount)),
+      frame_offset_(0),
+      input_buffer_(num_input_channels_, chunk_size_ + initial_delay_),
+      output_buffer_(chunk_size_ + initial_delay_, num_output_channels_),
+      input_block_(block_size_, num_input_channels_),
+      output_block_(block_size_, num_output_channels_),
+      window_(new float[block_size_]),
+      shift_amount_(shift_amount),
+      callback_(callback) {
+  RTC_CHECK_LE(num_output_channels_, num_input_channels_);
+  RTC_CHECK_LE(shift_amount_, block_size_);
+
+  memcpy(window_.get(), window, block_size_ * sizeof(*window_.get()));
+  input_buffer_.MoveReadPositionBackward(initial_delay_);
+}
+
+// When block_size < chunk_size the input and output buffers look like this:
+//
+//                      delay*             chunk_size    chunk_size + delay*
+//  buffer: <-------------|---------------------|---------------|>
+//                _a_              _b_                 _c_
+//
+// On each call to ProcessChunk():
+// 1. New input gets read into sections _b_ and _c_ of the input buffer.
+// 2. We block starting from frame_offset.
+// 3. We block until we reach a block |bl| that doesn't contain any frames
+//    from sections _a_ or _b_ of the input buffer.
+// 4. We window the current block, fire the callback for processing, window
+//    again, and overlap/add to the output buffer.
+// 5. We copy sections _a_ and _b_ of the output buffer into output.
+// 6. For both the input and the output buffers, we copy section _c_ into
+//    section _a_.
+// 7. We set the new frame_offset to be the difference between the first frame
+//    of |bl| and the border between sections _b_ and _c_.
+//
+// When block_size > chunk_size the input and output buffers look like this:
+//
+//                   chunk_size               delay*       chunk_size + delay*
+//  buffer: <-------------|---------------------|---------------|>
+//                _a_              _b_                 _c_
+//
+// On each call to ProcessChunk():
+// The procedure is the same as above, except for:
+// 1. New input gets read into section _c_ of the input buffer.
+// 3. We block until we reach a block |bl| that doesn't contain any frames
+//    from section _a_ of the input buffer.
+// 5. We copy section _a_ of the output buffer into output.
+// 6. For both the input and the output buffers, we copy sections _b_ and _c_
+//    into section _a_ and _b_.
+// 7. We set the new frame_offset to be the difference between the first frame
+//    of |bl| and the border between sections _a_ and _b_.
+//
+// * delay here refers to inintial_delay_
+//
+// TODO(claguna): Look at using ring buffers to eliminate some copies.
+void Blocker::ProcessChunk(const float* const* input,
+                           size_t chunk_size,
+                           size_t num_input_channels,
+                           size_t num_output_channels,
+                           float* const* output) {
+  RTC_CHECK_EQ(chunk_size, chunk_size_);
+  RTC_CHECK_EQ(num_input_channels, num_input_channels_);
+  RTC_CHECK_EQ(num_output_channels, num_output_channels_);
+
+  input_buffer_.Write(input, num_input_channels, chunk_size_);
+  size_t first_frame_in_block = frame_offset_;
+
+  // Loop through blocks.
+  while (first_frame_in_block < chunk_size_) {
+    input_buffer_.Read(input_block_.channels(), num_input_channels,
+                       block_size_);
+    input_buffer_.MoveReadPositionBackward(block_size_ - shift_amount_);
+
+    ApplyWindow(window_.get(),
+                block_size_,
+                num_input_channels_,
+                input_block_.channels());
+    callback_->ProcessBlock(input_block_.channels(),
+                            block_size_,
+                            num_input_channels_,
+                            num_output_channels_,
+                            output_block_.channels());
+    ApplyWindow(window_.get(),
+                block_size_,
+                num_output_channels_,
+                output_block_.channels());
+
+    AddFrames(output_buffer_.channels(),
+              first_frame_in_block,
+              output_block_.channels(),
+              0,
+              block_size_,
+              num_output_channels_,
+              output_buffer_.channels(),
+              first_frame_in_block);
+
+    first_frame_in_block += shift_amount_;
+  }
+
+  // Copy output buffer to output
+  CopyFrames(output_buffer_.channels(),
+             0,
+             chunk_size_,
+             num_output_channels_,
+             output,
+             0);
+
+  // Copy output buffer [chunk_size_, chunk_size_ + initial_delay]
+  // to output buffer [0, initial_delay], zero the rest.
+  MoveFrames(output_buffer_.channels(),
+             chunk_size,
+             initial_delay_,
+             num_output_channels_,
+             output_buffer_.channels(),
+             0);
+  ZeroOut(output_buffer_.channels(),
+          initial_delay_,
+          chunk_size_,
+          num_output_channels_);
+
+  // Calculate new starting frames.
+  frame_offset_ = first_frame_in_block - chunk_size_;
+}
+
+}  // namespace webrtc