remoting/codec/video_encoder_vpx.cc

   1 // Copyright 2013 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_vpx.h"
   6
   7 #include "base/bind.h"
   8 #include "base/command_line.h"
   9 #include "base/logging.h"
  10 #include "base/sys_info.h"
  11 #include "remoting/base/util.h"
  12 #include "remoting/proto/video.pb.h"
  13 #include "third_party/libyuv/include/libyuv/convert_from_argb.h"
  14 #include "third_party/webrtc/modules/desktop_capture/desktop_frame.h"
  15 #include "third_party/webrtc/modules/desktop_capture/desktop_geometry.h"
  16 #include "third_party/webrtc/modules/desktop_capture/desktop_region.h"
  17
  18 extern "C" {
  19 #define VPX_CODEC_DISABLE_COMPAT 1
  20 #include "third_party/libvpx/source/libvpx/vpx/vpx_encoder.h"
  21 #include "third_party/libvpx/source/libvpx/vpx/vp8cx.h"
  22 }
  23
  24 namespace remoting {
  25
  26 namespace {
  27
  28 // Name of command-line flag to enable VP9 to use I444 by default.
  29 const char kEnableI444SwitchName[] = "enable-i444";
  30
  31 // Number of bytes in an RGBx pixel.
  32 const int kBytesPerRgbPixel = 4;
  33
  34 // Defines the dimension of a macro block. This is used to compute the active
  35 // map for the encoder.
  36 const int kMacroBlockSize = 16;
  37
  38 // Magic encoder profile numbers for I420 and I444 input formats.
  39 const int kVp9I420ProfileNumber = 0;
  40 const int kVp9I444ProfileNumber = 1;
  41
  42 void SetCommonCodecParameters(const webrtc::DesktopSize& size,
  43                               vpx_codec_enc_cfg_t* config) {
  44   // Use millisecond granularity time base.
  45   config->g_timebase.num = 1;
  46   config->g_timebase.den = 1000;
  47
  48   // Adjust default target bit-rate to account for actual desktop size.
  49   config->rc_target_bitrate = size.width() * size.height() *
  50       config->rc_target_bitrate / config->g_w / config->g_h;
  51
  52   config->g_w = size.width();
  53   config->g_h = size.height();
  54   config->g_pass = VPX_RC_ONE_PASS;
  55
  56   // Start emitting packets immediately.
  57   config->g_lag_in_frames = 0;
  58
  59   // Since the transport layer is reliable, keyframes should not be necessary.
  60   // However, due to crbug.com/440223, decoding fails after 30,000 non-key
  61   // frames, so take the hit of an "unnecessary" key-frame every 10,000 frames.
  62   config->kf_min_dist = 10000;
  63   config->kf_max_dist = 10000;
  64
  65   // Using 2 threads gives a great boost in performance for most systems with
  66   // adequate processing power. NB: Going to multiple threads on low end
  67   // windows systems can really hurt performance.
  68   // http://crbug.com/99179
  69   config->g_threads = (base::SysInfo::NumberOfProcessors() > 2) ? 2 : 1;
  70 }
  71
  72 ScopedVpxCodec CreateVP8Codec(const webrtc::DesktopSize& size) {
  73   ScopedVpxCodec codec(new vpx_codec_ctx_t);
  74
  75   // Configure the encoder.
  76   vpx_codec_enc_cfg_t config;
  77   const vpx_codec_iface_t* algo = vpx_codec_vp8_cx();
  78   CHECK(algo);
  79   vpx_codec_err_t ret = vpx_codec_enc_config_default(algo, &config, 0);
  80   if (ret != VPX_CODEC_OK)
  81     return ScopedVpxCodec();
  82
  83   SetCommonCodecParameters(size, &config);
  84
  85   // Value of 2 means using the real time profile. This is basically a
  86   // redundant option since we explicitly select real time mode when doing
  87   // encoding.
  88   config.g_profile = 2;
  89
  90   // Clamping the quantizer constrains the worst-case quality and CPU usage.
  91   config.rc_min_quantizer = 20;
  92   config.rc_max_quantizer = 30;
  93
  94   if (vpx_codec_enc_init(codec.get(), algo, &config, 0))
  95     return ScopedVpxCodec();
  96
  97   // Value of 16 will have the smallest CPU load. This turns off subpixel
  98   // motion search.
  99   if (vpx_codec_control(codec.get(), VP8E_SET_CPUUSED, 16))
 100     return ScopedVpxCodec();
 101
 102   // Use the lowest level of noise sensitivity so as to spend less time
 103   // on motion estimation and inter-prediction mode.
 104   if (vpx_codec_control(codec.get(), VP8E_SET_NOISE_SENSITIVITY, 0))
 105     return ScopedVpxCodec();
 106
 107   return codec.Pass();
 108 }
 109
 110 ScopedVpxCodec CreateVP9Codec(const webrtc::DesktopSize& size,
 111                               bool lossless_color,
 112                               bool lossless_encode) {
 113   ScopedVpxCodec codec(new vpx_codec_ctx_t);
 114
 115   // Configure the encoder.
 116   vpx_codec_enc_cfg_t config;
 117   const vpx_codec_iface_t* algo = vpx_codec_vp9_cx();
 118   CHECK(algo);
 119   vpx_codec_err_t ret = vpx_codec_enc_config_default(algo, &config, 0);
 120   if (ret != VPX_CODEC_OK)
 121     return ScopedVpxCodec();
 122
 123   SetCommonCodecParameters(size, &config);
 124
 125   // Configure VP9 for I420 or I444 source frames.
 126   config.g_profile =
 127       lossless_color ? kVp9I444ProfileNumber : kVp9I420ProfileNumber;
 128
 129   if (lossless_encode) {
 130     // Disable quantization entirely, putting the encoder in "lossless" mode.
 131     config.rc_min_quantizer = 0;
 132     config.rc_max_quantizer = 0;
 133   } else {
 134     // Lossy encode using the same settings as for VP8.
 135     config.rc_min_quantizer = 20;
 136     config.rc_max_quantizer = 30;
 137   }
 138
 139   if (vpx_codec_enc_init(codec.get(), algo, &config, 0))
 140     return ScopedVpxCodec();
 141
 142   // Request the lowest-CPU usage that VP9 supports, which depends on whether
 143   // we are encoding lossy or lossless.
 144   // Note that this is configured via the same parameter as for VP8.
 145   int cpu_used = lossless_encode ? 5 : 6;
 146   if (vpx_codec_control(codec.get(), VP8E_SET_CPUUSED, cpu_used))
 147     return ScopedVpxCodec();
 148
 149   // Use the lowest level of noise sensitivity so as to spend less time
 150   // on motion estimation and inter-prediction mode.
 151   if (vpx_codec_control(codec.get(), VP9E_SET_NOISE_SENSITIVITY, 0))
 152     return ScopedVpxCodec();
 153
 154   return codec.Pass();
 155 }
 156
 157 void CreateImage(bool use_i444,
 158                  const webrtc::DesktopSize& size,
 159                  scoped_ptr<vpx_image_t>* out_image,
 160                  scoped_ptr<uint8[]>* out_image_buffer) {
 161   DCHECK(!size.is_empty());
 162
 163   scoped_ptr<vpx_image_t> image(new vpx_image_t());
 164   memset(image.get(), 0, sizeof(vpx_image_t));
 165
 166   // libvpx seems to require both to be assigned.
 167   image->d_w = size.width();
 168   image->w = size.width();
 169   image->d_h = size.height();
 170   image->h = size.height();
 171
 172   // libvpx should derive chroma shifts from|fmt| but currently has a bug:
 173   // https://code.google.com/p/webm/issues/detail?id=627
 174   if (use_i444) {
 175     image->fmt = VPX_IMG_FMT_I444;
 176     image->x_chroma_shift = 0;
 177     image->y_chroma_shift = 0;
 178   } else { // I420
 179     image->fmt = VPX_IMG_FMT_YV12;
 180     image->x_chroma_shift = 1;
 181     image->y_chroma_shift = 1;
 182   }
 183
 184   // libyuv's fast-path requires 16-byte aligned pointers and strides, so pad
 185   // the Y, U and V planes' strides to multiples of 16 bytes.
 186   const int y_stride = ((image->w - 1) & ~15) + 16;
 187   const int uv_unaligned_stride = y_stride >> image->x_chroma_shift;
 188   const int uv_stride = ((uv_unaligned_stride - 1) & ~15) + 16;
 189
 190   // libvpx accesses the source image in macro blocks, and will over-read
 191   // if the image is not padded out to the next macroblock: crbug.com/119633.
 192   // Pad the Y, U and V planes' height out to compensate.
 193   // Assuming macroblocks are 16x16, aligning the planes' strides above also
 194   // macroblock aligned them.
 195   DCHECK_EQ(16, kMacroBlockSize);
 196   const int y_rows = ((image->h - 1) & ~(kMacroBlockSize-1)) + kMacroBlockSize;
 197   const int uv_rows = y_rows >> image->y_chroma_shift;
 198
 199   // Allocate a YUV buffer large enough for the aligned data & padding.
 200   const int buffer_size = y_stride * y_rows + 2*uv_stride * uv_rows;
 201   scoped_ptr<uint8[]> image_buffer(new uint8[buffer_size]);
 202
 203   // Reset image value to 128 so we just need to fill in the y plane.
 204   memset(image_buffer.get(), 128, buffer_size);
 205
 206   // Fill in the information for |image_|.
 207   unsigned char* uchar_buffer =
 208       reinterpret_cast<unsigned char*>(image_buffer.get());
 209   image->planes[0] = uchar_buffer;
 210   image->planes[1] = image->planes[0] + y_stride * y_rows;
 211   image->planes[2] = image->planes[1] + uv_stride * uv_rows;
 212   image->stride[0] = y_stride;
 213   image->stride[1] = uv_stride;
 214   image->stride[2] = uv_stride;
 215
 216   *out_image = image.Pass();
 217   *out_image_buffer = image_buffer.Pass();
 218 }
 219
 220 } // namespace
 221
 222 // static
 223 scoped_ptr<VideoEncoderVpx> VideoEncoderVpx::CreateForVP8() {
 224   return make_scoped_ptr(new VideoEncoderVpx(false));
 225 }
 226
 227 // static
 228 scoped_ptr<VideoEncoderVpx> VideoEncoderVpx::CreateForVP9() {
 229   return make_scoped_ptr(new VideoEncoderVpx(true));
 230 }
 231
 232 VideoEncoderVpx::~VideoEncoderVpx() {}
 233
 234 void VideoEncoderVpx::SetLosslessEncode(bool want_lossless) {
 235   if (use_vp9_ && (want_lossless != lossless_encode_)) {
 236     lossless_encode_ = want_lossless;
 237     codec_.reset(); // Force encoder re-initialization.
 238   }
 239 }
 240
 241 void VideoEncoderVpx::SetLosslessColor(bool want_lossless) {
 242   if (use_vp9_ && (want_lossless != lossless_color_)) {
 243     lossless_color_ = want_lossless;
 244     codec_.reset(); // Force encoder re-initialization.
 245   }
 246 }
 247
 248 scoped_ptr<VideoPacket> VideoEncoderVpx::Encode(
 249     const webrtc::DesktopFrame& frame) {
 250   DCHECK_LE(32, frame.size().width());
 251   DCHECK_LE(32, frame.size().height());
 252
 253   base::TimeTicks encode_start_time = base::TimeTicks::Now();
 254
 255   if (!codec_ ||
 256       !frame.size().equals(webrtc::DesktopSize(image_->w, image_->h))) {
 257     bool ret = Initialize(frame.size());
 258     // TODO(hclam): Handle error better.
 259     CHECK(ret) << "Initialization of encoder failed";
 260
 261     // Set now as the base for timestamp calculation.
 262     timestamp_base_ = encode_start_time;
 263   }
 264
 265   // Convert the updated capture data ready for encode.
 266   webrtc::DesktopRegion updated_region;
 267   PrepareImage(frame, &updated_region);
 268
 269   // Update active map based on updated region.
 270   PrepareActiveMap(updated_region);
 271
 272   // Apply active map to the encoder.
 273   vpx_active_map_t act_map;
 274   act_map.rows = active_map_height_;
 275   act_map.cols = active_map_width_;
 276   act_map.active_map = active_map_.get();
 277   if (vpx_codec_control(codec_.get(), VP8E_SET_ACTIVEMAP, &act_map)) {
 278     LOG(ERROR) << "Unable to apply active map";
 279   }
 280
 281   // Do the actual encoding.
 282   int timestamp = (encode_start_time - timestamp_base_).InMilliseconds();
 283   vpx_codec_err_t ret = vpx_codec_encode(
 284       codec_.get(), image_.get(), timestamp, 1, 0, VPX_DL_REALTIME);
 285   DCHECK_EQ(ret, VPX_CODEC_OK)
 286       << "Encoding error: " << vpx_codec_err_to_string(ret) << "\n"
 287       << "Details: " << vpx_codec_error(codec_.get()) << "\n"
 288       << vpx_codec_error_detail(codec_.get());
 289
 290   // Read the encoded data.
 291   vpx_codec_iter_t iter = NULL;
 292   bool got_data = false;
 293
 294   // TODO(hclam): Make sure we get exactly one frame from the packet.
 295   // TODO(hclam): We should provide the output buffer to avoid one copy.
 296   scoped_ptr<VideoPacket> packet(
 297       helper_.CreateVideoPacketWithUpdatedRegion(frame, updated_region));
 298   packet->mutable_format()->set_encoding(VideoPacketFormat::ENCODING_VP8);
 299
 300   while (!got_data) {
 301     const vpx_codec_cx_pkt_t* vpx_packet =
 302         vpx_codec_get_cx_data(codec_.get(), &iter);
 303     if (!vpx_packet)
 304       continue;
 305
 306     switch (vpx_packet->kind) {
 307       case VPX_CODEC_CX_FRAME_PKT:
 308         got_data = true;
 309         packet->set_data(vpx_packet->data.frame.buf, vpx_packet->data.frame.sz);
 310         break;
 311       default:
 312         break;
 313     }
 314   }
 315
 316   // Note the time taken to encode the pixel data.
 317   packet->set_encode_time_ms(
 318       (base::TimeTicks::Now() - encode_start_time).InMillisecondsRoundedUp());
 319
 320   return packet.Pass();
 321 }
 322
 323 VideoEncoderVpx::VideoEncoderVpx(bool use_vp9)
 324     : use_vp9_(use_vp9),
 325       lossless_encode_(false),
 326       lossless_color_(false),
 327       active_map_width_(0),
 328       active_map_height_(0) {
 329   if (use_vp9_) {
 330     // Use I444 colour space, by default, if specified on the command-line.
 331     if (CommandLine::ForCurrentProcess()->HasSwitch(kEnableI444SwitchName)) {
 332       SetLosslessColor(true);
 333     }
 334   }
 335 }
 336
 337 bool VideoEncoderVpx::Initialize(const webrtc::DesktopSize& size) {
 338   DCHECK(use_vp9_ || !lossless_color_);
 339   DCHECK(use_vp9_ || !lossless_encode_);
 340
 341   codec_.reset();
 342
 343   // (Re)Create the VPX image structure and pixel buffer.
 344   CreateImage(lossless_color_, size, &image_, &image_buffer_);
 345
 346   // Initialize active map.
 347   active_map_width_ = (image_->w + kMacroBlockSize - 1) / kMacroBlockSize;
 348   active_map_height_ = (image_->h + kMacroBlockSize - 1) / kMacroBlockSize;
 349   active_map_.reset(new uint8[active_map_width_ * active_map_height_]);
 350
 351   // (Re)Initialize the codec.
 352   if (use_vp9_) {
 353     codec_ = CreateVP9Codec(size, lossless_color_, lossless_encode_);
 354   } else {
 355     codec_ = CreateVP8Codec(size);
 356   }
 357
 358   return codec_;
 359 }
 360
 361 void VideoEncoderVpx::PrepareImage(const webrtc::DesktopFrame& frame,
 362                                    webrtc::DesktopRegion* updated_region) {
 363   if (frame.updated_region().is_empty()) {
 364     updated_region->Clear();
 365     return;
 366   }
 367
 368   // Align the region to macroblocks, to avoid encoding artefacts.
 369   // This also ensures that all rectangles have even-aligned top-left, which
 370   // is required for ConvertRGBToYUVWithRect() to work.
 371   std::vector<webrtc::DesktopRect> aligned_rects;
 372   for (webrtc::DesktopRegion::Iterator r(frame.updated_region());
 373        !r.IsAtEnd(); r.Advance()) {
 374     const webrtc::DesktopRect& rect = r.rect();
 375     aligned_rects.push_back(AlignRect(webrtc::DesktopRect::MakeLTRB(
 376         rect.left(), rect.top(), rect.right(), rect.bottom())));
 377   }
 378   DCHECK(!aligned_rects.empty());
 379   updated_region->Clear();
 380   updated_region->AddRects(&aligned_rects[0], aligned_rects.size());
 381
 382   // Clip back to the screen dimensions, in case they're not macroblock aligned.
 383   // The conversion routines don't require even width & height, so this is safe
 384   // even if the source dimensions are not even.
 385   updated_region->IntersectWith(
 386       webrtc::DesktopRect::MakeWH(image_->w, image_->h));
 387
 388   // Convert the updated region to YUV ready for encoding.
 389   const uint8* rgb_data = frame.data();
 390   const int rgb_stride = frame.stride();
 391   const int y_stride = image_->stride[0];
 392   DCHECK_EQ(image_->stride[1], image_->stride[2]);
 393   const int uv_stride = image_->stride[1];
 394   uint8* y_data = image_->planes[0];
 395   uint8* u_data = image_->planes[1];
 396   uint8* v_data = image_->planes[2];
 397
 398   switch (image_->fmt) {
 399     case VPX_IMG_FMT_I444:
 400       for (webrtc::DesktopRegion::Iterator r(*updated_region); !r.IsAtEnd();
 401            r.Advance()) {
 402         const webrtc::DesktopRect& rect = r.rect();
 403         int rgb_offset = rgb_stride * rect.top() +
 404                          rect.left() * kBytesPerRgbPixel;
 405         int yuv_offset = uv_stride * rect.top() + rect.left();
 406         libyuv::ARGBToI444(rgb_data + rgb_offset, rgb_stride,
 407                            y_data + yuv_offset, y_stride,
 408                            u_data + yuv_offset, uv_stride,
 409                            v_data + yuv_offset, uv_stride,
 410                            rect.width(), rect.height());
 411       }
 412       break;
 413     case VPX_IMG_FMT_YV12:
 414       for (webrtc::DesktopRegion::Iterator r(*updated_region); !r.IsAtEnd();
 415            r.Advance()) {
 416         const webrtc::DesktopRect& rect = r.rect();
 417         int rgb_offset = rgb_stride * rect.top() +
 418                          rect.left() * kBytesPerRgbPixel;
 419         int y_offset = y_stride * rect.top() + rect.left();
 420         int uv_offset = uv_stride * rect.top() / 2 + rect.left() / 2;
 421         libyuv::ARGBToI420(rgb_data + rgb_offset, rgb_stride,
 422                            y_data + y_offset, y_stride,
 423                            u_data + uv_offset, uv_stride,
 424                            v_data + uv_offset, uv_stride,
 425                            rect.width(), rect.height());
 426       }
 427       break;
 428     default:
 429       NOTREACHED();
 430       break;
 431   }
 432 }
 433
 434 void VideoEncoderVpx::PrepareActiveMap(
 435     const webrtc::DesktopRegion& updated_region) {
 436   // Clear active map first.
 437   memset(active_map_.get(), 0, active_map_width_ * active_map_height_);
 438
 439   // Mark updated areas active.
 440   for (webrtc::DesktopRegion::Iterator r(updated_region); !r.IsAtEnd();
 441        r.Advance()) {
 442     const webrtc::DesktopRect& rect = r.rect();
 443     int left = rect.left() / kMacroBlockSize;
 444     int right = (rect.right() - 1) / kMacroBlockSize;
 445     int top = rect.top() / kMacroBlockSize;
 446     int bottom = (rect.bottom() - 1) / kMacroBlockSize;
 447     DCHECK_LT(right, active_map_width_);
 448     DCHECK_LT(bottom, active_map_height_);
 449
 450     uint8* map = active_map_.get() + top * active_map_width_;
 451     for (int y = top; y <= bottom; ++y) {
 452       for (int x = left; x <= right; ++x)
 453         map[x] = 1;
 454       map += active_map_width_;
 455     }
 456   }
 457 }
 458
 459 }  // namespace remoting