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// Copyright 2013 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/codec/video_encoder_vpx.h"
#include "base/bind.h"
#include "base/command_line.h"
#include "base/logging.h"
#include "base/sys_info.h"
#include "remoting/base/util.h"
#include "remoting/proto/video.pb.h"
#include "third_party/libyuv/include/libyuv/convert_from_argb.h"
#include "third_party/webrtc/modules/desktop_capture/desktop_frame.h"
#include "third_party/webrtc/modules/desktop_capture/desktop_geometry.h"
#include "third_party/webrtc/modules/desktop_capture/desktop_region.h"
extern "C" {
#define VPX_CODEC_DISABLE_COMPAT 1
#include "third_party/libvpx/source/libvpx/vpx/vpx_encoder.h"
#include "third_party/libvpx/source/libvpx/vpx/vp8cx.h"
}
namespace remoting {
namespace {
// Name of command-line flag to enable VP9 to use I444 by default.
const char kEnableI444SwitchName[] = "enable-i444";
// Number of bytes in an RGBx pixel.
const int kBytesPerRgbPixel = 4;
// Defines the dimension of a macro block. This is used to compute the active
// map for the encoder.
const int kMacroBlockSize = 16;
// Magic encoder profile numbers for I420 and I444 input formats.
const int kVp9I420ProfileNumber = 0;
const int kVp9I444ProfileNumber = 1;
void SetCommonCodecParameters(vpx_codec_enc_cfg_t* config,
const webrtc::DesktopSize& size) {
// Use millisecond granularity time base.
config->g_timebase.num = 1;
config->g_timebase.den = 1000;
// Adjust default target bit-rate to account for actual desktop size.
config->rc_target_bitrate = size.width() * size.height() *
config->rc_target_bitrate / config->g_w / config->g_h;
config->g_w = size.width();
config->g_h = size.height();
config->g_pass = VPX_RC_ONE_PASS;
// Start emitting packets immediately.
config->g_lag_in_frames = 0;
// Since the transport layer is reliable, keyframes should not be necessary.
// However, due to crbug.com/440223, decoding fails after 30,000 non-key
// frames, so take the hit of an "unnecessary" key-frame every 10,000 frames.
config->kf_min_dist = 10000;
config->kf_max_dist = 10000;
// Using 2 threads gives a great boost in performance for most systems with
// adequate processing power. NB: Going to multiple threads on low end
// windows systems can really hurt performance.
// http://crbug.com/99179
config->g_threads = (base::SysInfo::NumberOfProcessors() > 2) ? 2 : 1;
}
void SetVp8CodecParameters(vpx_codec_enc_cfg_t* config,
const webrtc::DesktopSize& size) {
SetCommonCodecParameters(config, size);
// Value of 2 means using the real time profile. This is basically a
// redundant option since we explicitly select real time mode when doing
// encoding.
config->g_profile = 2;
// Clamping the quantizer constrains the worst-case quality and CPU usage.
config->rc_min_quantizer = 20;
config->rc_max_quantizer = 30;
}
void SetVp9CodecParameters(vpx_codec_enc_cfg_t* config,
const webrtc::DesktopSize& size,
bool lossless_color,
bool lossless_encode) {
SetCommonCodecParameters(config, size);
// Configure VP9 for I420 or I444 source frames.
config->g_profile =
lossless_color ? kVp9I444ProfileNumber : kVp9I420ProfileNumber;
if (lossless_encode) {
// Disable quantization entirely, putting the encoder in "lossless" mode.
config->rc_min_quantizer = 0;
config->rc_max_quantizer = 0;
} else {
// Lossy encode using the same settings as for VP8.
config->rc_min_quantizer = 20;
config->rc_max_quantizer = 30;
}
}
void SetVp8CodecOptions(vpx_codec_ctx_t* codec) {
// CPUUSED of 16 will have the smallest CPU load. This turns off sub-pixel
// motion search.
vpx_codec_err_t ret = vpx_codec_control(codec, VP8E_SET_CPUUSED, 16);
DCHECK_EQ(VPX_CODEC_OK, ret) << "Failed to set CPUUSED";
// Use the lowest level of noise sensitivity so as to spend less time
// on motion estimation and inter-prediction mode.
ret = vpx_codec_control(codec, VP8E_SET_NOISE_SENSITIVITY, 0);
DCHECK_EQ(VPX_CODEC_OK, ret) << "Failed to set noise sensitivity";
}
void SetVp9CodecOptions(vpx_codec_ctx_t* codec, bool lossless_encode) {
// Request the lowest-CPU usage that VP9 supports, which depends on whether
// we are encoding lossy or lossless.
// Note that this is configured via the same parameter as for VP8.
int cpu_used = lossless_encode ? 5 : 6;
vpx_codec_err_t ret = vpx_codec_control(codec, VP8E_SET_CPUUSED, cpu_used);
DCHECK_EQ(VPX_CODEC_OK, ret) << "Failed to set CPUUSED";
// Use the lowest level of noise sensitivity so as to spend less time
// on motion estimation and inter-prediction mode.
ret = vpx_codec_control(codec, VP9E_SET_NOISE_SENSITIVITY, 0);
DCHECK_EQ(VPX_CODEC_OK, ret) << "Failed to set noise sensitivity";
// Configure the codec to tune it for screen media.
ret = vpx_codec_control(
codec, VP9E_SET_TUNE_CONTENT, VP9E_CONTENT_SCREEN);
DCHECK_EQ(VPX_CODEC_OK, ret) << "Failed to set screen content mode";
}
void CreateImage(bool use_i444,
const webrtc::DesktopSize& size,
scoped_ptr<vpx_image_t>* out_image,
scoped_ptr<uint8[]>* out_image_buffer) {
DCHECK(!size.is_empty());
scoped_ptr<vpx_image_t> image(new vpx_image_t());
memset(image.get(), 0, sizeof(vpx_image_t));
// libvpx seems to require both to be assigned.
image->d_w = size.width();
image->w = size.width();
image->d_h = size.height();
image->h = size.height();
// libvpx should derive chroma shifts from|fmt| but currently has a bug:
// https://code.google.com/p/webm/issues/detail?id=627
if (use_i444) {
image->fmt = VPX_IMG_FMT_I444;
image->x_chroma_shift = 0;
image->y_chroma_shift = 0;
} else { // I420
image->fmt = VPX_IMG_FMT_YV12;
image->x_chroma_shift = 1;
image->y_chroma_shift = 1;
}
// libyuv's fast-path requires 16-byte aligned pointers and strides, so pad
// the Y, U and V planes' strides to multiples of 16 bytes.
const int y_stride = ((image->w - 1) & ~15) + 16;
const int uv_unaligned_stride = y_stride >> image->x_chroma_shift;
const int uv_stride = ((uv_unaligned_stride - 1) & ~15) + 16;
// libvpx accesses the source image in macro blocks, and will over-read
// if the image is not padded out to the next macroblock: crbug.com/119633.
// Pad the Y, U and V planes' height out to compensate.
// Assuming macroblocks are 16x16, aligning the planes' strides above also
// macroblock aligned them.
COMPILE_ASSERT(kMacroBlockSize == 16, macroblock_size_not_16);
const int y_rows = ((image->h - 1) & ~(kMacroBlockSize-1)) + kMacroBlockSize;
const int uv_rows = y_rows >> image->y_chroma_shift;
// Allocate a YUV buffer large enough for the aligned data & padding.
const int buffer_size = y_stride * y_rows + 2*uv_stride * uv_rows;
scoped_ptr<uint8[]> image_buffer(new uint8[buffer_size]);
// Reset image value to 128 so we just need to fill in the y plane.
memset(image_buffer.get(), 128, buffer_size);
// Fill in the information for |image_|.
unsigned char* uchar_buffer =
reinterpret_cast<unsigned char*>(image_buffer.get());
image->planes[0] = uchar_buffer;
image->planes[1] = image->planes[0] + y_stride * y_rows;
image->planes[2] = image->planes[1] + uv_stride * uv_rows;
image->stride[0] = y_stride;
image->stride[1] = uv_stride;
image->stride[2] = uv_stride;
*out_image = image.Pass();
*out_image_buffer = image_buffer.Pass();
}
} // namespace
// static
scoped_ptr<VideoEncoderVpx> VideoEncoderVpx::CreateForVP8() {
return make_scoped_ptr(new VideoEncoderVpx(false));
}
// static
scoped_ptr<VideoEncoderVpx> VideoEncoderVpx::CreateForVP9() {
return make_scoped_ptr(new VideoEncoderVpx(true));
}
VideoEncoderVpx::~VideoEncoderVpx() {}
void VideoEncoderVpx::SetLosslessEncode(bool want_lossless) {
if (use_vp9_ && (want_lossless != lossless_encode_)) {
lossless_encode_ = want_lossless;
if (codec_)
Configure(webrtc::DesktopSize(image_->w, image_->h));
}
}
void VideoEncoderVpx::SetLosslessColor(bool want_lossless) {
if (use_vp9_ && (want_lossless != lossless_color_)) {
lossless_color_ = want_lossless;
// TODO(wez): Switch to ConfigureCodec() path once libvpx supports it.
// See https://code.google.com/p/webm/issues/detail?id=913.
//if (codec_)
// Configure(webrtc::DesktopSize(image_->w, image_->h));
codec_.reset();
}
}
scoped_ptr<VideoPacket> VideoEncoderVpx::Encode(
const webrtc::DesktopFrame& frame) {
DCHECK_LE(32, frame.size().width());
DCHECK_LE(32, frame.size().height());
base::TimeTicks encode_start_time = base::TimeTicks::Now();
// Create or reconfigure the codec to match the size of |frame|.
if (!codec_ ||
!frame.size().equals(webrtc::DesktopSize(image_->w, image_->h))) {
Configure(frame.size());
}
// Convert the updated capture data ready for encode.
webrtc::DesktopRegion updated_region;
PrepareImage(frame, &updated_region);
// Update active map based on updated region.
PrepareActiveMap(updated_region);
// Apply active map to the encoder.
vpx_active_map_t act_map;
act_map.rows = active_map_height_;
act_map.cols = active_map_width_;
act_map.active_map = active_map_.get();
if (vpx_codec_control(codec_.get(), VP8E_SET_ACTIVEMAP, &act_map)) {
LOG(ERROR) << "Unable to apply active map";
}
// Do the actual encoding.
int timestamp = (encode_start_time - timestamp_base_).InMilliseconds();
vpx_codec_err_t ret = vpx_codec_encode(
codec_.get(), image_.get(), timestamp, 1, 0, VPX_DL_REALTIME);
DCHECK_EQ(ret, VPX_CODEC_OK)
<< "Encoding error: " << vpx_codec_err_to_string(ret) << "\n"
<< "Details: " << vpx_codec_error(codec_.get()) << "\n"
<< vpx_codec_error_detail(codec_.get());
// Read the encoded data.
vpx_codec_iter_t iter = NULL;
bool got_data = false;
// TODO(hclam): Make sure we get exactly one frame from the packet.
// TODO(hclam): We should provide the output buffer to avoid one copy.
scoped_ptr<VideoPacket> packet(
helper_.CreateVideoPacketWithUpdatedRegion(frame, updated_region));
packet->mutable_format()->set_encoding(VideoPacketFormat::ENCODING_VP8);
while (!got_data) {
const vpx_codec_cx_pkt_t* vpx_packet =
vpx_codec_get_cx_data(codec_.get(), &iter);
if (!vpx_packet)
continue;
switch (vpx_packet->kind) {
case VPX_CODEC_CX_FRAME_PKT:
got_data = true;
packet->set_data(vpx_packet->data.frame.buf, vpx_packet->data.frame.sz);
break;
default:
break;
}
}
// Note the time taken to encode the pixel data.
packet->set_encode_time_ms(
(base::TimeTicks::Now() - encode_start_time).InMillisecondsRoundedUp());
return packet.Pass();
}
VideoEncoderVpx::VideoEncoderVpx(bool use_vp9)
: use_vp9_(use_vp9),
lossless_encode_(false),
lossless_color_(false),
active_map_width_(0),
active_map_height_(0) {
if (use_vp9_) {
// Use I444 colour space, by default, if specified on the command-line.
if (base::CommandLine::ForCurrentProcess()->HasSwitch(
kEnableI444SwitchName)) {
SetLosslessColor(true);
}
}
}
void VideoEncoderVpx::Configure(const webrtc::DesktopSize& size) {
DCHECK(use_vp9_ || !lossless_color_);
DCHECK(use_vp9_ || !lossless_encode_);
// (Re)Create the VPX image structure and pixel buffer.
CreateImage(lossless_color_, size, &image_, &image_buffer_);
// Initialize active map.
active_map_width_ = (size.width() + kMacroBlockSize - 1) / kMacroBlockSize;
active_map_height_ = (size.height() + kMacroBlockSize - 1) / kMacroBlockSize;
active_map_.reset(new uint8[active_map_width_ * active_map_height_]);
// TODO(wez): Remove this hack once VPX can handle frame size reconfiguration.
// See https://code.google.com/p/webm/issues/detail?id=912.
if (codec_) {
// If the frame size has changed then force re-creation of the codec.
if (codec_->config.enc->g_w != static_cast<unsigned int>(size.width()) ||
codec_->config.enc->g_h != static_cast<unsigned int>(size.height())) {
codec_.reset();
}
}
// (Re)Set the base for frame timestamps if the codec is being (re)created.
if (!codec_) {
timestamp_base_ = base::TimeTicks::Now();
}
// Fetch a default configuration for the desired codec.
const vpx_codec_iface_t* interface =
use_vp9_ ? vpx_codec_vp9_cx() : vpx_codec_vp8_cx();
vpx_codec_enc_cfg_t config;
vpx_codec_err_t ret = vpx_codec_enc_config_default(interface, &config, 0);
DCHECK_EQ(VPX_CODEC_OK, ret) << "Failed to fetch default configuration";
// Customize the default configuration to our needs.
if (use_vp9_) {
SetVp9CodecParameters(&config, size, lossless_color_, lossless_encode_);
} else {
SetVp8CodecParameters(&config, size);
}
// Initialize or re-configure the codec with the custom configuration.
if (!codec_) {
codec_.reset(new vpx_codec_ctx_t);
ret = vpx_codec_enc_init(codec_.get(), interface, &config, 0);
CHECK_EQ(VPX_CODEC_OK, ret) << "Failed to initialize codec";
} else {
ret = vpx_codec_enc_config_set(codec_.get(), &config);
CHECK_EQ(VPX_CODEC_OK, ret) << "Failed to reconfigure codec";
}
// Apply further customizations to the codec now it's initialized.
if (use_vp9_) {
SetVp9CodecOptions(codec_.get(), lossless_encode_);
} else {
SetVp8CodecOptions(codec_.get());
}
}
void VideoEncoderVpx::PrepareImage(const webrtc::DesktopFrame& frame,
webrtc::DesktopRegion* updated_region) {
if (frame.updated_region().is_empty()) {
updated_region->Clear();
return;
}
// Pad each rectangle to avoid the block-artefact filters in libvpx from
// introducing artefacts; VP9 includes up to 8px either side, and VP8 up to
// 3px, so unchanged pixels up to that far out may still be affected by the
// changes in the updated region, and so must be listed in the active map.
// After padding we align each rectangle to 16x16 active-map macroblocks.
// This implicitly ensures all rects have even top-left coords, which is
// is required by ConvertRGBToYUVWithRect().
// TODO(wez): Do we still need 16x16 align, or is even alignment sufficient?
updated_region->Clear();
int padding = use_vp9_ ? 8 : 3;
for (webrtc::DesktopRegion::Iterator r(frame.updated_region());
!r.IsAtEnd(); r.Advance()) {
const webrtc::DesktopRect& rect = r.rect();
updated_region->AddRect(AlignRect(webrtc::DesktopRect::MakeLTRB(
rect.left() - padding, rect.top() - padding, rect.right() + padding,
rect.bottom() + padding)));
}
DCHECK(!updated_region->is_empty());
// Clip back to the screen dimensions, in case they're not macroblock aligned.
// The conversion routines don't require even width & height, so this is safe
// even if the source dimensions are not even.
updated_region->IntersectWith(
webrtc::DesktopRect::MakeWH(image_->w, image_->h));
// Convert the updated region to YUV ready for encoding.
const uint8* rgb_data = frame.data();
const int rgb_stride = frame.stride();
const int y_stride = image_->stride[0];
DCHECK_EQ(image_->stride[1], image_->stride[2]);
const int uv_stride = image_->stride[1];
uint8* y_data = image_->planes[0];
uint8* u_data = image_->planes[1];
uint8* v_data = image_->planes[2];
switch (image_->fmt) {
case VPX_IMG_FMT_I444:
for (webrtc::DesktopRegion::Iterator r(*updated_region); !r.IsAtEnd();
r.Advance()) {
const webrtc::DesktopRect& rect = r.rect();
int rgb_offset = rgb_stride * rect.top() +
rect.left() * kBytesPerRgbPixel;
int yuv_offset = uv_stride * rect.top() + rect.left();
libyuv::ARGBToI444(rgb_data + rgb_offset, rgb_stride,
y_data + yuv_offset, y_stride,
u_data + yuv_offset, uv_stride,
v_data + yuv_offset, uv_stride,
rect.width(), rect.height());
}
break;
case VPX_IMG_FMT_YV12:
for (webrtc::DesktopRegion::Iterator r(*updated_region); !r.IsAtEnd();
r.Advance()) {
const webrtc::DesktopRect& rect = r.rect();
int rgb_offset = rgb_stride * rect.top() +
rect.left() * kBytesPerRgbPixel;
int y_offset = y_stride * rect.top() + rect.left();
int uv_offset = uv_stride * rect.top() / 2 + rect.left() / 2;
libyuv::ARGBToI420(rgb_data + rgb_offset, rgb_stride,
y_data + y_offset, y_stride,
u_data + uv_offset, uv_stride,
v_data + uv_offset, uv_stride,
rect.width(), rect.height());
}
break;
default:
NOTREACHED();
break;
}
}
void VideoEncoderVpx::PrepareActiveMap(
const webrtc::DesktopRegion& updated_region) {
// Clear active map first.
memset(active_map_.get(), 0, active_map_width_ * active_map_height_);
// Mark updated areas active.
for (webrtc::DesktopRegion::Iterator r(updated_region); !r.IsAtEnd();
r.Advance()) {
const webrtc::DesktopRect& rect = r.rect();
int left = rect.left() / kMacroBlockSize;
int right = (rect.right() - 1) / kMacroBlockSize;
int top = rect.top() / kMacroBlockSize;
int bottom = (rect.bottom() - 1) / kMacroBlockSize;
DCHECK_LT(right, active_map_width_);
DCHECK_LT(bottom, active_map_height_);
uint8* map = active_map_.get() + top * active_map_width_;
for (int y = top; y <= bottom; ++y) {
for (int x = left; x <= right; ++x)
map[x] = 1;
map += active_map_width_;
}
}
}
} // namespace remoting