EncoderZlib/DecoderZlib for chromoting

remoting/base/decoder_zlib.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_zlib.h"
+
+#include "remoting/base/decompressor_zlib.h"
+#include "remoting/base/protocol_util.h"
+
+namespace remoting {
+
+DecoderZlib::DecoderZlib()
+    : state_(kWaitingForBeginRect),
+      rect_x_(0),
+      rect_y_(0),
+      rect_width_(0),
+      rect_height_(0),
+      bytes_per_pixel_(0),
+      updated_rects_(NULL),
+      row_pos_(0),
+      row_y_(0) {
+}
+
+bool DecoderZlib::BeginDecode(scoped_refptr<media::VideoFrame> frame,
+                                  UpdatedRects* updated_rects,
+                                  Task* partial_decode_done,
+                                  Task* decode_done) {
+  DCHECK(!partial_decode_done_.get());
+  DCHECK(!decode_done_.get());
+  DCHECK(!updated_rects_);
+  DCHECK_EQ(kWaitingForBeginRect, state_);
+  CHECK(static_cast<PixelFormat>(frame->format()) == PixelFormatRgb32)
+      << "Only RGB32 is supported";
+
+  partial_decode_done_.reset(partial_decode_done);
+  decode_done_.reset(decode_done);
+  updated_rects_ = updated_rects;
+  frame_ = frame;
+
+  // Create the decompressor.
+  decompressor_.reset(new DecompressorZlib());
+  return true;
+}
+
+bool DecoderZlib::PartialDecode(HostMessage* message) {
+  scoped_ptr<HostMessage> msg_deleter(message);
+  DCHECK(message->has_update_stream_packet());
+
+  bool ret = true;
+  if (message->update_stream_packet().has_begin_rect())
+    ret = HandleBeginRect(message);
+  if (ret && message->update_stream_packet().has_rect_data())
+    ret = HandleRectData(message);
+  if (ret && message->update_stream_packet().has_end_rect())
+    ret = HandleEndRect(message);
+  return ret;
+}
+
+void DecoderZlib::EndDecode() {
+  DCHECK_EQ(kWaitingForBeginRect, state_);
+  decode_done_->Run();
+
+  partial_decode_done_.reset();
+  decode_done_.reset();
+  updated_rects_ = NULL;
+  frame_ = NULL;
+  decompressor_.reset();
+}
+
+bool DecoderZlib::HandleBeginRect(HostMessage* message) {
+  DCHECK_EQ(kWaitingForBeginRect, state_);
+  state_ = kWaitingForRectData;
+
+  rect_width_ = message->update_stream_packet().begin_rect().width();
+  rect_height_ = message->update_stream_packet().begin_rect().height();
+  rect_x_ = message->update_stream_packet().begin_rect().x();
+  rect_y_ = message->update_stream_packet().begin_rect().y();
+
+  PixelFormat pixel_format =
+      message->update_stream_packet().begin_rect().pixel_format();
+
+  if (static_cast<PixelFormat>(frame_->format()) != pixel_format) {
+    NOTREACHED() << "Pixel format of message doesn't match the video frame. "
+                    "Expected vs received = "
+                 << frame_->format() << " vs " << pixel_format
+                 << " Color space conversion required.";
+    return false;
+  }
+
+  bytes_per_pixel_ = GetBytesPerPixel(pixel_format);
+  row_pos_ = 0;
+  row_y_ = 0;
+  return true;
+}
+
+bool DecoderZlib::HandleRectData(HostMessage* message) {
+  DCHECK_EQ(kWaitingForRectData, state_);
+  DCHECK_EQ(0,
+            message->update_stream_packet().rect_data().sequence_number());
+
+  const uint8* in =
+      (const uint8*)message->update_stream_packet().rect_data().data().data();
+  const int in_size =
+      message->update_stream_packet().rect_data().data().size();
+  const int row_size = rect_width_ * bytes_per_pixel_;
+  const int stride = frame_->stride(media::VideoFrame::kRGBPlane);
+  uint8* out = frame_->data(media::VideoFrame::kRGBPlane) +
+      stride * (rect_y_ + row_y_) + bytes_per_pixel_ * rect_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;
+    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;
+    }
+  }
+  return true;
+}
+
+bool DecoderZlib::HandleEndRect(HostMessage* message) {
+  DCHECK_EQ(kWaitingForRectData, state_);
+  state_ = kWaitingForBeginRect;
+
+  updated_rects_->clear();
+  updated_rects_->push_back(gfx::Rect(rect_x_, rect_y_,
+                                      rect_width_, rect_height_));
+  partial_decode_done_->Run();
+  return true;
+}
+
+}  // namespace remoting