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// Copyright 2016 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 "third_party/blink/renderer/modules/imagecapture/image_capture_frame_grabber.h"
#include "media/base/bind_to_current_loop.h"
#include "media/base/video_frame.h"
#include "media/base/video_types.h"
#include "media/base/video_util.h"
#include "skia/ext/platform_canvas.h"
#include "third_party/blink/public/platform/web_media_stream_source.h"
#include "third_party/blink/public/platform/web_media_stream_track.h"
#include "third_party/blink/renderer/core/imagebitmap/image_bitmap.h"
#include "third_party/blink/renderer/platform/wtf/cross_thread_functional.h"
#include "third_party/blink/renderer/platform/wtf/functional.h"
#include "third_party/blink/renderer/platform/wtf/thread_safe_ref_counted.h"
#include "third_party/libyuv/include/libyuv.h"
#include "third_party/skia/include/core/SkImage.h"
#include "third_party/skia/include/core/SkSurface.h"
#include "ui/gfx/gpu_memory_buffer.h"
namespace WTF {
// Template specialization of [1], needed to be able to pass callbacks
// that have ScopedWebCallbacks paramaters across threads.
//
// [1] third_party/blink/renderer/platform/wtf/cross_thread_copier.h.
template <typename T>
struct CrossThreadCopier<blink::ScopedWebCallbacks<T>>
: public CrossThreadCopierPassThrough<blink::ScopedWebCallbacks<T>> {
STATIC_ONLY(CrossThreadCopier);
using Type = blink::ScopedWebCallbacks<T>;
static blink::ScopedWebCallbacks<T> Copy(
blink::ScopedWebCallbacks<T> pointer) {
return pointer;
}
};
} // namespace WTF
namespace blink {
namespace {
void OnError(std::unique_ptr<ImageCaptureGrabFrameCallbacks> callbacks) {
callbacks->OnError();
}
} // anonymous namespace
// Ref-counted class to receive a single VideoFrame on IO thread, convert it and
// send it to |main_task_runner_|, where this class is created and destroyed.
class ImageCaptureFrameGrabber::SingleShotFrameHandler
: public WTF::ThreadSafeRefCounted<SingleShotFrameHandler> {
public:
SingleShotFrameHandler() : first_frame_received_(false) {}
// Receives a |frame| and converts its pixels into a SkImage via an internal
// PaintSurface and SkPixmap. Alpha channel, if any, is copied.
using SkImageDeliverCB = WTF::CrossThreadFunction<void(sk_sp<SkImage>)>;
void OnVideoFrameOnIOThread(
SkImageDeliverCB callback,
scoped_refptr<base::SingleThreadTaskRunner> task_runner,
scoped_refptr<media::VideoFrame> frame,
base::TimeTicks current_time);
private:
friend class WTF::ThreadSafeRefCounted<SingleShotFrameHandler>;
// Flag to indicate that the first frames has been processed, and subsequent
// ones can be safely discarded.
bool first_frame_received_;
DISALLOW_COPY_AND_ASSIGN(SingleShotFrameHandler);
};
void ImageCaptureFrameGrabber::SingleShotFrameHandler::OnVideoFrameOnIOThread(
SkImageDeliverCB callback,
scoped_refptr<base::SingleThreadTaskRunner> task_runner,
scoped_refptr<media::VideoFrame> frame,
base::TimeTicks /* current_time */) {
DCHECK(frame->format() == media::PIXEL_FORMAT_I420 ||
frame->format() == media::PIXEL_FORMAT_I420A ||
frame->format() == media::PIXEL_FORMAT_NV12);
if (first_frame_received_)
return;
first_frame_received_ = true;
const SkAlphaType alpha = media::IsOpaque(frame->format())
? kOpaque_SkAlphaType
: kPremul_SkAlphaType;
const SkImageInfo info = SkImageInfo::MakeN32(
frame->visible_rect().width(), frame->visible_rect().height(), alpha);
sk_sp<SkSurface> surface = SkSurface::MakeRaster(info);
DCHECK(surface);
auto wrapper_callback =
media::BindToLoop(std::move(task_runner),
ConvertToBaseRepeatingCallback(std::move(callback)));
SkPixmap pixmap;
if (!skia::GetWritablePixels(surface->getCanvas(), &pixmap)) {
DLOG(ERROR) << "Error trying to map SkSurface's pixels";
std::move(wrapper_callback).Run(sk_sp<SkImage>());
return;
}
#if SK_PMCOLOR_BYTE_ORDER(R, G, B, A)
const uint32_t destination_pixel_format = libyuv::FOURCC_ABGR;
#else
const uint32_t destination_pixel_format = libyuv::FOURCC_ARGB;
#endif
uint8_t* destination_plane = static_cast<uint8_t*>(pixmap.writable_addr());
int destination_stride = pixmap.width() * 4;
int destination_width = pixmap.width();
int destination_height = pixmap.height();
if (frame->storage_type() == media::VideoFrame::STORAGE_GPU_MEMORY_BUFFER) {
auto* gmb = frame->GetGpuMemoryBuffer();
if (!gmb->Map()) {
DLOG(ERROR) << "Error mapping GpuMemoryBuffer video frame";
std::move(wrapper_callback).Run(sk_sp<SkImage>());
return;
}
// NV12 is the only supported pixel format at the moment.
DCHECK_EQ(frame->format(), media::PIXEL_FORMAT_NV12);
int y_stride = gmb->stride(0);
int uv_stride = gmb->stride(1);
const uint8_t* y_plane =
(static_cast<uint8_t*>(gmb->memory(0)) + frame->visible_rect().x() +
(frame->visible_rect().y() * y_stride));
// UV plane of NV12 has 2-byte pixel width, with half chroma subsampling
// both horizontally and vertically.
const uint8_t* uv_plane = (static_cast<uint8_t*>(gmb->memory(1)) +
((frame->visible_rect().x() * 2) / 2) +
((frame->visible_rect().y() / 2) * uv_stride));
switch (destination_pixel_format) {
case libyuv::FOURCC_ABGR:
libyuv::NV12ToABGR(y_plane, y_stride, uv_plane, uv_stride,
destination_plane, destination_stride,
destination_width, destination_height);
break;
case libyuv::FOURCC_ARGB:
libyuv::NV12ToARGB(y_plane, y_stride, uv_plane, uv_stride,
destination_plane, destination_stride,
destination_width, destination_height);
break;
default:
NOTREACHED();
}
gmb->Unmap();
} else {
DCHECK(frame->format() == media::PIXEL_FORMAT_I420 ||
frame->format() == media::PIXEL_FORMAT_I420A);
libyuv::ConvertFromI420(frame->visible_data(media::VideoFrame::kYPlane),
frame->stride(media::VideoFrame::kYPlane),
frame->visible_data(media::VideoFrame::kUPlane),
frame->stride(media::VideoFrame::kUPlane),
frame->visible_data(media::VideoFrame::kVPlane),
frame->stride(media::VideoFrame::kVPlane),
destination_plane, destination_stride,
destination_width, destination_height,
destination_pixel_format);
if (frame->format() == media::PIXEL_FORMAT_I420A) {
DCHECK(!info.isOpaque());
// This function copies any plane into the alpha channel of an ARGB image.
libyuv::ARGBCopyYToAlpha(frame->visible_data(media::VideoFrame::kAPlane),
frame->stride(media::VideoFrame::kAPlane),
destination_plane, destination_stride,
destination_width, destination_height);
}
}
std::move(wrapper_callback).Run(surface->makeImageSnapshot());
}
ImageCaptureFrameGrabber::ImageCaptureFrameGrabber()
: frame_grab_in_progress_(false) {}
ImageCaptureFrameGrabber::~ImageCaptureFrameGrabber() {
DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
}
void ImageCaptureFrameGrabber::GrabFrame(
WebMediaStreamTrack* track,
std::unique_ptr<ImageCaptureGrabFrameCallbacks> callbacks,
scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
DCHECK(!!callbacks);
DCHECK(track && !track->IsNull() && track->GetPlatformTrack());
DCHECK_EQ(WebMediaStreamSource::kTypeVideo, track->Source().GetType());
if (frame_grab_in_progress_) {
// Reject grabFrame()s too close back to back.
callbacks->OnError();
return;
}
auto scoped_callbacks =
MakeScopedWebCallbacks(std::move(callbacks), WTF::Bind(&OnError));
// A SingleShotFrameHandler is bound and given to the Track to guarantee that
// only one VideoFrame is converted and delivered to OnSkImage(), otherwise
// SKImages might be sent to resolved |callbacks| while DisconnectFromTrack()
// is being processed, which might be further held up if UI is busy, see
// https://crbug.com/623042.
frame_grab_in_progress_ = true;
MediaStreamVideoSink::ConnectToTrack(
*track,
ConvertToBaseRepeatingCallback(CrossThreadBindRepeating(
&SingleShotFrameHandler::OnVideoFrameOnIOThread,
base::MakeRefCounted<SingleShotFrameHandler>(),
WTF::Passed(CrossThreadBindRepeating(
&ImageCaptureFrameGrabber::OnSkImage, weak_factory_.GetWeakPtr(),
WTF::Passed(std::move(scoped_callbacks)))),
WTF::Passed(std::move(task_runner)))),
false);
}
void ImageCaptureFrameGrabber::OnSkImage(
ScopedWebCallbacks<ImageCaptureGrabFrameCallbacks> callbacks,
sk_sp<SkImage> image) {
DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
MediaStreamVideoSink::DisconnectFromTrack();
frame_grab_in_progress_ = false;
if (image)
callbacks.PassCallbacks()->OnSuccess(image);
else
callbacks.PassCallbacks()->OnError();
}
} // namespace blink
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