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// Copyright 2022 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 "content/browser/media/capture/io_surface_capture_device_base_mac.h"
#include "media/base/video_util.h"
#include "media/capture/content/capture_resolution_chooser.h"
namespace content {
namespace {
float ComputeMinFrameRate(float requested_frame_rate) {
// Set a minimum frame rate of 5 fps, unless the requested frame rate is
// even lower.
constexpr float kMinFrameRate = 5.f;
// Don't send frames at more than 80% the requested rate, because doing so
// can stochastically toggle between repeated and new frames.
constexpr float kRequestedFrameRateFactor = 0.8f;
return std::min(requested_frame_rate * kRequestedFrameRateFactor,
kMinFrameRate);
}
} // namespace
IOSurfaceCaptureDeviceBase::IOSurfaceCaptureDeviceBase() = default;
IOSurfaceCaptureDeviceBase::~IOSurfaceCaptureDeviceBase() = default;
void IOSurfaceCaptureDeviceBase::AllocateAndStart(
const media::VideoCaptureParams& params,
std::unique_ptr<Client> client) {
DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
DCHECK(client && !client_);
client_ = std::move(client);
capture_params_ = params;
min_frame_rate_ =
ComputeMinFrameRate(capture_params_.requested_format.frame_rate);
OnStart();
}
void IOSurfaceCaptureDeviceBase::StopAndDeAllocate() {
DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
min_frame_rate_enforcement_timer_.reset();
weak_factory_base_.InvalidateWeakPtrs();
OnStop();
}
void IOSurfaceCaptureDeviceBase::OnReceivedIOSurfaceFromStream(
gfx::ScopedInUseIOSurface io_surface,
const media::VideoCaptureFormat& capture_format) {
DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
last_received_io_surface_ = std::move(io_surface);
last_received_capture_format_ = capture_format;
// Immediately send the new frame to the client.
SendLastReceivedIOSurfaceToClient();
}
void IOSurfaceCaptureDeviceBase::SendLastReceivedIOSurfaceToClient() {
DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
// Package `last_received_io_surface_` as a GpuMemoryBuffer.
gfx::GpuMemoryBufferHandle handle;
handle.id = gfx::GpuMemoryBufferHandle::kInvalidId;
handle.type = gfx::GpuMemoryBufferType::IO_SURFACE_BUFFER;
handle.io_surface.reset(last_received_io_surface_,
base::scoped_policy::RETAIN);
const auto now = base::TimeTicks::Now();
if (first_frame_time_.is_null())
first_frame_time_ = now;
client_->OnIncomingCapturedExternalBuffer(
media::CapturedExternalVideoBuffer(std::move(handle),
last_received_capture_format_,
gfx::ColorSpace::CreateREC709()),
{}, now, now - first_frame_time_);
// Reset `min_frame_rate_enforcement_timer_`.
if (!min_frame_rate_enforcement_timer_) {
min_frame_rate_enforcement_timer_ = std::make_unique<base::RepeatingTimer>(
FROM_HERE, base::Seconds(1 / min_frame_rate_),
base::BindRepeating(
&IOSurfaceCaptureDeviceBase::SendLastReceivedIOSurfaceToClient,
weak_factory_base_.GetWeakPtr()));
}
min_frame_rate_enforcement_timer_->Reset();
}
void IOSurfaceCaptureDeviceBase::ComputeFrameSizeAndDestRect(
const gfx::Size& source_size,
gfx::Size& frame_size,
gfx::RectF& dest_rect_in_frame) const {
DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
// Compute the destination frame size using CaptureResolutionChooser.
const auto constraints = capture_params_.SuggestConstraints();
{
media::CaptureResolutionChooser resolution_chooser;
resolution_chooser.SetConstraints(constraints.min_frame_size,
constraints.max_frame_size,
constraints.fixed_aspect_ratio);
resolution_chooser.SetSourceSize(source_size);
// Ensure that the resulting frame size has an even width and height. This
// matches the behavior of DesktopCaptureDevice.
frame_size = gfx::Size(resolution_chooser.capture_size().width() & ~1,
resolution_chooser.capture_size().height() & ~1);
if (frame_size.IsEmpty())
frame_size = gfx::Size(2, 2);
}
// Compute the rectangle to blit into.
if (constraints.fixed_aspect_ratio) {
dest_rect_in_frame = gfx::RectF(media::ComputeLetterboxRegionForI420(
gfx::Rect(frame_size), source_size));
// If the target rectangle is not exactly the full frame, then out-set
// the region by a tiny amount. This works around a bug wherein a green
// line appears on the left side of the content.
// https://crbug.com/1267655
if (dest_rect_in_frame != gfx::RectF(gfx::SizeF(frame_size)))
dest_rect_in_frame.Outset(1.f / 4096);
} else {
// If the aspect ratio is not fixed, then this is the full destination
// frame.
dest_rect_in_frame = gfx::RectF(gfx::SizeF(frame_size));
}
}
} // namespace content
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