remoting/codec/video_encoder_verbatim.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "remoting/codec/video_encoder_verbatim.h"
   6
   7 #include "base/logging.h"
   8 #include "base/stl_util.h"
   9 #include "base/time/time.h"
  10 #include "remoting/base/util.h"
  11 #include "remoting/proto/video.pb.h"
  12 #include "third_party/webrtc/modules/desktop_capture/desktop_frame.h"
  13 #include "third_party/webrtc/modules/desktop_capture/desktop_geometry.h"
  14 #include "third_party/webrtc/modules/desktop_capture/desktop_region.h"
  15
  16 namespace remoting {
  17
  18 static uint8_t* GetPacketOutputBuffer(VideoPacket* packet, size_t size) {
  19   packet->mutable_data()->resize(size);
  20   return reinterpret_cast<uint8_t*>(string_as_array(packet->mutable_data()));
  21 }
  22
  23 VideoEncoderVerbatim::VideoEncoderVerbatim() {}
  24 VideoEncoderVerbatim::~VideoEncoderVerbatim() {}
  25
  26 scoped_ptr<VideoPacket> VideoEncoderVerbatim::Encode(
  27     const webrtc::DesktopFrame& frame) {
  28   DCHECK(frame.data());
  29
  30   // If nothing has changed in the frame then return NULL to indicate that
  31   // we don't need to actually send anything (e.g. nothing to top-off).
  32   if (frame.updated_region().is_empty())
  33     return nullptr;
  34
  35   base::Time encode_start_time = base::Time::Now();
  36
  37   // Create a VideoPacket with common fields (e.g. DPI, rects, shape) set.
  38   scoped_ptr<VideoPacket> packet(helper_.CreateVideoPacket(frame));
  39   packet->mutable_format()->set_encoding(VideoPacketFormat::ENCODING_VERBATIM);
  40
  41   // Calculate output size.
  42   size_t output_size = 0;
  43   for (webrtc::DesktopRegion::Iterator iter(frame.updated_region());
  44        !iter.IsAtEnd(); iter.Advance()) {
  45     const webrtc::DesktopRect& rect = iter.rect();
  46     output_size += rect.width() * rect.height() *
  47         webrtc::DesktopFrame::kBytesPerPixel;
  48   }
  49
  50   uint8_t* out = GetPacketOutputBuffer(packet.get(), output_size);
  51   const int in_stride = frame.stride();
  52
  53   // Encode pixel data for all changed rectangles into the packet.
  54   for (webrtc::DesktopRegion::Iterator iter(frame.updated_region());
  55        !iter.IsAtEnd(); iter.Advance()) {
  56     const webrtc::DesktopRect& rect = iter.rect();
  57     const int row_size = webrtc::DesktopFrame::kBytesPerPixel * rect.width();
  58     const uint8_t* in = frame.data() + rect.top() * in_stride +
  59                         rect.left() * webrtc::DesktopFrame::kBytesPerPixel;
  60     for (int y = rect.top(); y < rect.top() + rect.height(); ++y) {
  61       memcpy(out, in, row_size);
  62       out += row_size;
  63       in += in_stride;
  64     }
  65   }
  66
  67   // Note the time taken to encode the pixel data.
  68   packet->set_encode_time_ms(
  69       (base::Time::Now() - encode_start_time).InMillisecondsRoundedUp());
  70
  71   return packet.Pass();
  72 }
  73
  74 }  // namespace remoting