rhubarb-lip-sync/lib/webrtc-8d2248ff/webrtc/media/base/videoadapter.cc

270 lines
9.4 KiB
C++

/*
* Copyright (c) 2010 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "webrtc/media/base/videoadapter.h"
#include <algorithm>
#include <cstdlib>
#include <limits>
#include "webrtc/base/checks.h"
#include "webrtc/base/logging.h"
#include "webrtc/media/base/mediaconstants.h"
#include "webrtc/media/base/videocommon.h"
namespace {
struct Fraction {
int numerator;
int denominator;
};
// Scale factors optimized for in libYUV that we accept.
// Must be sorted in decreasing scale factors for FindScaleLargerThan to work.
const Fraction kScaleFractions[] = {
{1, 1},
{3, 4},
{1, 2},
{3, 8},
{1, 4},
{3, 16},
};
// Round |valueToRound| to a multiple of |multiple|. Prefer rounding upwards,
// but never more than |maxValue|.
int roundUp(int valueToRound, int multiple, int maxValue) {
const int roundedValue = (valueToRound + multiple - 1) / multiple * multiple;
return roundedValue <= maxValue ? roundedValue
: (maxValue / multiple * multiple);
}
Fraction FindScaleLessThanOrEqual(int input_num_pixels, int target_num_pixels) {
float best_distance = std::numeric_limits<float>::max();
Fraction best_scale = {0, 1}; // Default to 0 if nothing matches.
for (const auto& fraction : kScaleFractions) {
const float scale =
fraction.numerator / static_cast<float>(fraction.denominator);
float test_num_pixels = input_num_pixels * scale * scale;
float diff = target_num_pixels - test_num_pixels;
if (diff < 0) {
continue;
}
if (diff < best_distance) {
best_distance = diff;
best_scale = fraction;
if (best_distance == 0) { // Found exact match.
break;
}
}
}
return best_scale;
}
Fraction FindScaleLargerThan(int input_num_pixels,
int target_num_pixels,
int* resulting_number_of_pixels) {
float best_distance = std::numeric_limits<float>::max();
Fraction best_scale = {1, 1}; // Default to unscaled if nothing matches.
// Default to input number of pixels.
float best_number_of_pixels = input_num_pixels;
for (const auto& fraction : kScaleFractions) {
const float scale =
fraction.numerator / static_cast<float>(fraction.denominator);
float test_num_pixels = input_num_pixels * scale * scale;
float diff = test_num_pixels - target_num_pixels;
if (diff <= 0) {
break;
}
if (diff < best_distance) {
best_distance = diff;
best_scale = fraction;
best_number_of_pixels = test_num_pixels;
}
}
*resulting_number_of_pixels = static_cast<int>(best_number_of_pixels + .5f);
return best_scale;
}
Fraction FindScale(int input_num_pixels,
int max_pixel_count_step_up,
int max_pixel_count) {
// Try scale just above |max_pixel_count_step_up_|.
if (max_pixel_count_step_up > 0) {
int resulting_pixel_count;
const Fraction scale = FindScaleLargerThan(
input_num_pixels, max_pixel_count_step_up, &resulting_pixel_count);
if (resulting_pixel_count <= max_pixel_count)
return scale;
}
// Return largest scale below |max_pixel_count|.
return FindScaleLessThanOrEqual(input_num_pixels, max_pixel_count);
}
} // namespace
namespace cricket {
VideoAdapter::VideoAdapter()
: frames_in_(0),
frames_out_(0),
frames_scaled_(0),
adaption_changes_(0),
previous_width_(0),
previous_height_(0),
resolution_request_max_pixel_count_(std::numeric_limits<int>::max()),
resolution_request_max_pixel_count_step_up_(0) {}
VideoAdapter::~VideoAdapter() {}
bool VideoAdapter::KeepFrame(int64_t in_timestamp_ns) {
rtc::CritScope cs(&critical_section_);
if (!requested_format_ || requested_format_->interval == 0)
return true;
if (next_frame_timestamp_ns_) {
// Time until next frame should be outputted.
const int64_t time_until_next_frame_ns =
(*next_frame_timestamp_ns_ - in_timestamp_ns);
// Continue if timestamp is withing expected range.
if (std::abs(time_until_next_frame_ns) < 2 * requested_format_->interval) {
// Drop if a frame shouldn't be outputted yet.
if (time_until_next_frame_ns > 0)
return false;
// Time to output new frame.
*next_frame_timestamp_ns_ += requested_format_->interval;
return true;
}
}
// First timestamp received or timestamp is way outside expected range, so
// reset. Set first timestamp target to just half the interval to prefer
// keeping frames in case of jitter.
next_frame_timestamp_ns_ =
rtc::Optional<int64_t>(in_timestamp_ns + requested_format_->interval / 2);
return true;
}
bool VideoAdapter::AdaptFrameResolution(int in_width,
int in_height,
int64_t in_timestamp_ns,
int* cropped_width,
int* cropped_height,
int* out_width,
int* out_height) {
rtc::CritScope cs(&critical_section_);
++frames_in_;
// The max output pixel count is the minimum of the requests from
// OnOutputFormatRequest and OnResolutionRequest.
int max_pixel_count = resolution_request_max_pixel_count_;
if (requested_format_) {
max_pixel_count = std::min(
max_pixel_count, requested_format_->width * requested_format_->height);
}
// Drop the input frame if necessary.
if (max_pixel_count == 0 || !KeepFrame(in_timestamp_ns)) {
// Show VAdapt log every 90 frames dropped. (3 seconds)
if ((frames_in_ - frames_out_) % 90 == 0) {
// TODO(fbarchard): Reduce to LS_VERBOSE when adapter info is not needed
// in default calls.
LOG(LS_INFO) << "VAdapt Drop Frame: scaled " << frames_scaled_
<< " / out " << frames_out_
<< " / in " << frames_in_
<< " Changes: " << adaption_changes_
<< " Input: " << in_width
<< "x" << in_height
<< " timestamp: " << in_timestamp_ns
<< " Output: i"
<< (requested_format_ ? requested_format_->interval : 0);
}
// Drop frame.
return false;
}
// Calculate how the input should be cropped.
if (!requested_format_ ||
requested_format_->width == 0 || requested_format_->height == 0) {
*cropped_width = in_width;
*cropped_height = in_height;
} else {
// Adjust |requested_format_| orientation to match input.
if ((in_width > in_height) !=
(requested_format_->width > requested_format_->height)) {
std::swap(requested_format_->width, requested_format_->height);
}
const float requested_aspect =
requested_format_->width /
static_cast<float>(requested_format_->height);
*cropped_width =
std::min(in_width, static_cast<int>(in_height * requested_aspect));
*cropped_height =
std::min(in_height, static_cast<int>(in_width / requested_aspect));
}
// Find best scale factor.
const Fraction scale =
FindScale(*cropped_width * *cropped_height,
resolution_request_max_pixel_count_step_up_, max_pixel_count);
// Adjust cropping slightly to get even integer output size and a perfect
// scale factor.
*cropped_width = roundUp(*cropped_width, scale.denominator, in_width);
*cropped_height = roundUp(*cropped_height, scale.denominator, in_height);
RTC_DCHECK_EQ(0, *cropped_width % scale.denominator);
RTC_DCHECK_EQ(0, *cropped_height % scale.denominator);
// Calculate final output size.
*out_width = *cropped_width / scale.denominator * scale.numerator;
*out_height = *cropped_height / scale.denominator * scale.numerator;
++frames_out_;
if (scale.numerator != scale.denominator)
++frames_scaled_;
if (previous_width_ && (previous_width_ != *out_width ||
previous_height_ != *out_height)) {
++adaption_changes_;
LOG(LS_INFO) << "Frame size changed: scaled " << frames_scaled_ << " / out "
<< frames_out_ << " / in " << frames_in_
<< " Changes: " << adaption_changes_ << " Input: " << in_width
<< "x" << in_height
<< " Scale: " << scale.numerator << "/" << scale.denominator
<< " Output: " << *out_width << "x" << *out_height << " i"
<< (requested_format_ ? requested_format_->interval : 0);
}
previous_width_ = *out_width;
previous_height_ = *out_height;
return true;
}
void VideoAdapter::OnOutputFormatRequest(const VideoFormat& format) {
rtc::CritScope cs(&critical_section_);
requested_format_ = rtc::Optional<VideoFormat>(format);
next_frame_timestamp_ns_ = rtc::Optional<int64_t>();
}
void VideoAdapter::OnResolutionRequest(
rtc::Optional<int> max_pixel_count,
rtc::Optional<int> max_pixel_count_step_up) {
rtc::CritScope cs(&critical_section_);
resolution_request_max_pixel_count_ =
max_pixel_count.value_or(std::numeric_limits<int>::max());
resolution_request_max_pixel_count_step_up_ =
max_pixel_count_step_up.value_or(0);
}
} // namespace cricket