Move decoder into separate thread, clean up API layering, and redo update protocl

remoting/base/decoder_row_based.cc

+// Copyright (c) 2010 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 "remoting/base/decoder_row_based.h"
+
+#include "remoting/base/decompressor.h"
+#include "remoting/base/decompressor_zlib.h"
+#include "remoting/base/decompressor_verbatim.h"
+#include "remoting/base/protocol_util.h"
+
+namespace remoting {
+
+DecoderRowBased* DecoderRowBased::CreateZlibDecoder() {
+  return new DecoderRowBased(new DecompressorZlib(), EncodingZlib);
+}
+
+DecoderRowBased* DecoderRowBased::CreateVerbatimDecoder() {
+  return new DecoderRowBased(new DecompressorVerbatim(), EncodingNone);
+}
+
+DecoderRowBased::DecoderRowBased(Decompressor* decompressor,
+                                 UpdateStreamEncoding encoding)
+    : state_(kUninitialized),
+      decompressor_(decompressor),
+      encoding_(encoding),
+      bytes_per_src_pixel_(0),
+      row_pos_(0),
+      row_y_(0),
+      // TODO(hclam): We should use the information from the update stream
+      // to determine whether we should reverse the rows or not.
+      // But for simplicity we set to be always true.
+      reverse_rows_(true) {
+}
+
+DecoderRowBased::~DecoderRowBased() {
+}
+
+void DecoderRowBased::Reset() {
+  frame_ = NULL;
+  decompressor_->Reset();
+  state_ = kUninitialized;
+}
+
+bool DecoderRowBased::IsReadyForData() {
+  return state_ == kReady;
+}
+
+void DecoderRowBased::Initialize(scoped_refptr<media::VideoFrame> frame,
+                                 const gfx::Rect& clip,
+                                 int bytes_per_src_pixel) {
+  // Make sure we are not currently initialized.
+  CHECK_EQ(kUninitialized, state_);
+
+  if (static_cast<PixelFormat>(frame->format()) != PixelFormatRgb32) {
+    LOG(WARNING) << "DecoderRowBased only supports RGB32.";
+    state_ = kError;
+    return;
+  }
+
+  frame_ = frame;
+
+  // Reset the buffer location status variables.
+  clip_ = clip;
+  row_pos_ = 0;
+  row_y_ = 0;
+  bytes_per_src_pixel_ = bytes_per_src_pixel;
+
+  state_ = kReady;
+}
+
+void DecoderRowBased::DecodeBytes(const std::string& encoded_bytes) {
+  DCHECK_EQ(kReady, state_);
+
+  const uint8* in = reinterpret_cast<const uint8*>(encoded_bytes.data());
+  const int in_size = encoded_bytes.size();
+  const int row_size = clip_.width() * bytes_per_src_pixel_;
+  int stride = frame_->stride(media::VideoFrame::kRGBPlane);
+  uint8* rect_begin = frame_->data(media::VideoFrame::kRGBPlane);
+
+  if (reverse_rows_) {
+    // Advance the pointer to the last row.
+    rect_begin += (frame_->height() - 1) * stride;
+
+    // And then make the stride negative.
+    stride = -stride;
+  }
+
+  // TODO(ajwong): This should be bytes_per_dst_pixel shouldn't this.?
+  uint8* out = rect_begin +
+      stride * (clip_.y() + row_y_) +
+      bytes_per_src_pixel_ * clip_.x();
+
+  // Consume all the data in the message.
+  bool decompress_again = true;
+  int used = 0;
+  while (decompress_again && used < in_size) {
+    int written = 0;
+    int consumed = 0;
+    // TODO(ajwong): This assume source and dest stride are the same, which is
+    // incorrect.
+    decompress_again = decompressor_->Process(
+        in + used, in_size - used, out + row_pos_, row_size - row_pos_,
+        &consumed, &written);
+    used += consumed;
+    row_pos_ += written;
+
+    // If this row is completely filled then move onto the next row.
+    if (row_pos_ == row_size) {
+      ++row_y_;
+      row_pos_ = 0;
+      out += stride;
+    }
+  }
+}
+
+}  // namespace remoting