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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 "content/renderer/image_capture/image_capture_frame_grabber.h"
#include "cc/paint/paint_canvas.h"
#include "media/base/bind_to_current_loop.h"
#include "media/base/video_frame.h"
#include "media/base/video_util.h"
#include "skia/ext/platform_canvas.h"
#include "third_party/blink/public/platform/web_callbacks.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/libyuv/include/libyuv.h"
#include "third_party/skia/include/core/SkImage.h"
#include "third_party/skia/include/core/SkSurface.h"
namespace content {
using blink::WebImageCaptureGrabFrameCallbacks;
namespace {
void OnError(std::unique_ptr<WebImageCaptureGrabFrameCallbacks> 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 base::RefCountedThreadSafe<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.
void OnVideoFrameOnIOThread(SkImageDeliverCB callback,
const scoped_refptr<media::VideoFrame>& frame,
base::TimeTicks current_time);
private:
friend class base::RefCountedThreadSafe<SingleShotFrameHandler>;
virtual ~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,
const scoped_refptr<media::VideoFrame>& frame,
base::TimeTicks /* current_time */) {
DCHECK(frame->format() == media::PIXEL_FORMAT_I420 ||
frame->format() == media::PIXEL_FORMAT_I420A);
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);
SkPixmap pixmap;
if (!skia::GetWritablePixels(surface->getCanvas(), &pixmap)) {
DLOG(ERROR) << "Error trying to map SkSurface's pixels";
std::move(callback).Run(sk_sp<SkImage>());
return;
}
const uint32 destination_pixel_format =
(kN32_SkColorType == kRGBA_8888_SkColorType) ? libyuv::FOURCC_ABGR
: libyuv::FOURCC_ARGB;
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),
static_cast<uint8*>(pixmap.writable_addr()),
pixmap.width() * 4, pixmap.width(), pixmap.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),
static_cast<uint8*>(pixmap.writable_addr()),
pixmap.width() * 4, pixmap.width(),
pixmap.height());
}
std::move(callback).Run(surface->makeImageSnapshot());
}
ImageCaptureFrameGrabber::ImageCaptureFrameGrabber()
: frame_grab_in_progress_(false), weak_factory_(this) {}
ImageCaptureFrameGrabber::~ImageCaptureFrameGrabber() {
DCHECK(thread_checker_.CalledOnValidThread());
}
void ImageCaptureFrameGrabber::GrabFrame(
blink::WebMediaStreamTrack* track,
WebImageCaptureGrabFrameCallbacks* callbacks) {
DCHECK(thread_checker_.CalledOnValidThread());
DCHECK(!!callbacks);
DCHECK(track && !track->IsNull() && track->GetTrackData());
DCHECK_EQ(blink::WebMediaStreamSource::kTypeVideo, track->Source().GetType());
if (frame_grab_in_progress_) {
// Reject grabFrame()s too close back to back.
callbacks->OnError();
return;
}
ScopedWebCallbacks<WebImageCaptureGrabFrameCallbacks> scoped_callbacks =
make_scoped_web_callbacks(callbacks, base::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,
base::Bind(
&SingleShotFrameHandler::OnVideoFrameOnIOThread,
base::MakeRefCounted<SingleShotFrameHandler>(),
media::BindToCurrentLoop(base::Bind(
&ImageCaptureFrameGrabber::OnSkImage, weak_factory_.GetWeakPtr(),
base::Passed(&scoped_callbacks)))),
false);
}
void ImageCaptureFrameGrabber::OnSkImage(
ScopedWebCallbacks<blink::WebImageCaptureGrabFrameCallbacks> callbacks,
sk_sp<SkImage> image) {
DCHECK(thread_checker_.CalledOnValidThread());
MediaStreamVideoSink::DisconnectFromTrack();
frame_grab_in_progress_ = false;
if (image)
callbacks.PassCallbacks()->OnSuccess(image);
else
callbacks.PassCallbacks()->OnError();
}
} // namespace content
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