EncoderZlib/DecoderZlib for chromoting

remoting/base/encoder_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/encoder_zlib.h"
+
+#include "gfx/rect.h"
+#include "media/base/data_buffer.h"
+#include "remoting/base/capture_data.h"
+#include "remoting/base/compressor_zlib.h"
+#include "remoting/base/protocol_util.h"
+#include "remoting/base/protocol/chromotocol.pb.h"
+
+namespace remoting {
+
+static const int kPacketSize = 1024 * 1024;
+
+EncoderZlib::EncoderZlib() : packet_size_(kPacketSize) {
+}
+
+EncoderZlib::EncoderZlib(int packet_size) : packet_size_(packet_size) {
+}
+
+void EncoderZlib::Encode(scoped_refptr<CaptureData> capture_data,
+                         bool key_frame,
+                         DataAvailableCallback* data_available_callback) {
+  CHECK(capture_data->pixel_format() == PixelFormatRgb32)
+      << "Zlib Encoder only works with RGB32";
+  capture_data_ = capture_data;
+  callback_.reset(data_available_callback);
+
+  CompressorZlib compressor;
+  for (current_rect_ = 0; current_rect_ < capture_data->dirty_rects().size();
+       ++current_rect_) {
+    EncodeRect(&compressor);
+  }
+
+  capture_data_ = NULL;
+  callback_.reset();
+  current_rect_ = 0;
+}
+
+void EncoderZlib::EncodeRect(CompressorZlib* compressor) {
+  CHECK(capture_data_->data_planes().data[0]);
+  const gfx::Rect rect = capture_data_->dirty_rects()[current_rect_];
+  const int strides = capture_data_->data_planes().strides[0];
+  const int bytes_per_pixel = GetBytesPerPixel(capture_data_->pixel_format());
+  const int row_size = bytes_per_pixel * rect.width();
+
+  HostMessage* message = PrepareMessage(true);
+  const uint8 * in = capture_data_->data_planes().data[0] +
+                     rect.y() * strides +
+                     rect.x() * bytes_per_pixel;
+  // TODO(hclam): Fill in the sequence number.
+  uint8* out = (uint8*)message->mutable_update_stream_packet()->
+      mutable_rect_data()->mutable_data()->data();
+  int filled = 0;
+  int row_x = 0;
+  int row_y = 0;
+  bool compress_again = true;
+  while (compress_again) {
+    // Prepare a message for sending out.
+    if (!message) {
+      message = PrepareMessage(false);
+      out = (uint8*)(message->mutable_update_stream_packet()->
+                     mutable_rect_data()->mutable_data()->data());
+      filled = 0;
+    }
+
+    Compressor::CompressorFlush flush = Compressor::CompressorNoFlush;
+    if (row_y == rect.height() - 1) {
+      if (current_rect_ == capture_data_->dirty_rects().size() - 1)
+        flush = Compressor::CompressorFinish;
+      else
+        flush = Compressor::CompressorSyncFlush;
+    }
+
+    int consumed = 0;
+    int written = 0;
+    compress_again = compressor->Process(in + row_x, row_size - row_x,
+                                         out + filled, packet_size_ - filled,
+                                         flush, &consumed, &written);
+    row_x += consumed;
+    filled += written;
+
+    // We have reached the end of stream.
+    if (!compress_again) {
+      message->mutable_update_stream_packet()->mutable_end_rect();
+    }
+
+    // If we have filled the message or we have reached the end of stream.
+    if (filled == packet_size_ || !compress_again) {
+      message->mutable_update_stream_packet()->mutable_rect_data()->
+          mutable_data()->resize(filled);
+      SubmitMessage(message);
+      message = NULL;
+    }
+
+    // Reached the end of input row and we're not at the last row.
+    if (row_x == row_size && row_y < rect.height() - 1) {
+      row_x = 0;
+      in += strides;
+      ++row_y;
+    }
+  }
+}
+
+HostMessage* EncoderZlib::PrepareMessage(bool new_rect) {
+  HostMessage* message = new HostMessage();
+  UpdateStreamPacketMessage* packet = message->mutable_update_stream_packet();
+
+  // Prepare the begin rect content.
+  if (new_rect) {
+    gfx::Rect rect = capture_data_->dirty_rects()[current_rect_];
+    packet->mutable_begin_rect()->set_x(rect.x());
+    packet->mutable_begin_rect()->set_y(rect.y());
+    packet->mutable_begin_rect()->set_width(rect.width());
+    packet->mutable_begin_rect()->set_height(rect.height());
+    packet->mutable_begin_rect()->set_encoding(EncodingZlib);
+    packet->mutable_begin_rect()->set_pixel_format(
+        capture_data_->pixel_format());
+  }
+
+  packet->mutable_rect_data()->mutable_data()->resize(packet_size_);
+  return message;
+}
+
+void EncoderZlib::SubmitMessage(HostMessage* message) {
+  EncodingState state = EncodingInProgress;
+  if (current_rect_ == 0 && message->update_stream_packet().has_begin_rect())
+    state |= EncodingStarting;
+  if (current_rect_ == capture_data_->dirty_rects().size() - 1 &&
+      message->update_stream_packet().has_end_rect())
+    state |= EncodingEnded;
+  callback_->Run(message, state);
+}
+
+}  // namespace remoting