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// Copyright (c) 2012 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 "media/filters/skcanvas_video_renderer.h"
#include "base/logging.h"
#include "media/base/video_frame.h"
#include "media/base/yuv_convert.h"
#include "third_party/skia/include/core/SkCanvas.h"
#include "third_party/skia/include/core/SkDevice.h"
namespace media {
static bool IsEitherYV12OrYV16(media::VideoFrame::Format format) {
return format == media::VideoFrame::YV12 || format == media::VideoFrame::YV16;
}
static bool IsEitherYV12OrYV16OrNative(media::VideoFrame::Format format) {
return IsEitherYV12OrYV16(format) ||
format == media::VideoFrame::NATIVE_TEXTURE;
}
// CanFastPaint is a helper method to determine the conditions for fast
// painting. The conditions are:
// 1. No skew in canvas matrix.
// 2. No flipping nor mirroring.
// 3. Canvas has pixel format ARGB8888.
// 4. Canvas is opaque.
// 5. Frame format is YV12 or YV16.
//
// TODO(hclam): The fast paint method should support flipping and mirroring.
// Disable the flipping and mirroring checks once we have it.
static bool CanFastPaint(SkCanvas* canvas, uint8_t alpha,
media::VideoFrame::Format format) {
if (alpha != 0xFF || !IsEitherYV12OrYV16(format))
return false;
const SkMatrix& total_matrix = canvas->getTotalMatrix();
// Perform the following checks here:
// 1. Check for skewing factors of the transformation matrix. They should be
// zero.
// 2. Check for mirroring and flipping. Make sure they are greater than zero.
if (SkScalarNearlyZero(total_matrix.getSkewX()) &&
SkScalarNearlyZero(total_matrix.getSkewY()) &&
total_matrix.getScaleX() > 0 &&
total_matrix.getScaleY() > 0) {
SkDevice* device = canvas->getDevice();
const SkBitmap::Config config = device->config();
if (config == SkBitmap::kARGB_8888_Config && device->isOpaque()) {
return true;
}
}
return false;
}
// Fast paint does YUV => RGB, scaling, blitting all in one step into the
// canvas. It's not always safe and appropriate to perform fast paint.
// CanFastPaint() is used to determine the conditions.
static void FastPaint(
const scoped_refptr<media::VideoFrame>& video_frame,
SkCanvas* canvas,
const SkRect& dest_rect) {
DCHECK(IsEitherYV12OrYV16(video_frame->format())) << video_frame->format();
DCHECK_EQ(video_frame->stride(media::VideoFrame::kUPlane),
video_frame->stride(media::VideoFrame::kVPlane));
const SkBitmap& bitmap = canvas->getDevice()->accessBitmap(true);
media::YUVType yuv_type = media::YV16;
int y_shift = 0;
if (video_frame->format() == media::VideoFrame::YV12) {
yuv_type = media::YV12;
y_shift = 1;
}
// Transform the destination rectangle to local coordinates.
const SkMatrix& local_matrix = canvas->getTotalMatrix();
SkRect local_dest_rect;
local_matrix.mapRect(&local_dest_rect, dest_rect);
// After projecting the destination rectangle to local coordinates, round
// the projected rectangle to integer values, this will give us pixel values
// of the rectangle.
SkIRect local_dest_irect, local_dest_irect_saved;
local_dest_rect.round(&local_dest_irect);
local_dest_rect.round(&local_dest_irect_saved);
// No point painting if the destination rect doesn't intersect with the
// clip rect.
if (!local_dest_irect.intersect(canvas->getTotalClip().getBounds()))
return;
// At this point |local_dest_irect| contains the rect that we should draw
// to within the clipping rect.
// Calculate the address for the top left corner of destination rect in
// the canvas that we will draw to. The address is obtained by the base
// address of the canvas shifted by "left" and "top" of the rect.
uint8* dest_rect_pointer = static_cast<uint8*>(bitmap.getPixels()) +
local_dest_irect.fTop * bitmap.rowBytes() +
local_dest_irect.fLeft * 4;
// Project the clip rect to the original video frame, obtains the
// dimensions of the projected clip rect, "left" and "top" of the rect.
// The math here are all integer math so we won't have rounding error and
// write outside of the canvas.
// We have the assumptions of dest_rect.width() and dest_rect.height()
// being non-zero, these are valid assumptions since finding intersection
// above rejects empty rectangle so we just do a DCHECK here.
DCHECK_NE(0, dest_rect.width());
DCHECK_NE(0, dest_rect.height());
size_t frame_clip_width = local_dest_irect.width() *
video_frame->visible_rect().width() / local_dest_irect_saved.width();
size_t frame_clip_height = local_dest_irect.height() *
video_frame->visible_rect().height() / local_dest_irect_saved.height();
// Project the "left" and "top" of the final destination rect to local
// coordinates of the video frame, use these values to find the offsets
// in the video frame to start reading.
size_t frame_clip_left =
video_frame->visible_rect().x() +
(local_dest_irect.fLeft - local_dest_irect_saved.fLeft) *
video_frame->visible_rect().width() / local_dest_irect_saved.width();
size_t frame_clip_top =
video_frame->visible_rect().y() +
(local_dest_irect.fTop - local_dest_irect_saved.fTop) *
video_frame->visible_rect().height() / local_dest_irect_saved.height();
// Use the "left" and "top" of the destination rect to locate the offset
// in Y, U and V planes.
size_t y_offset = (video_frame->stride(media::VideoFrame::kYPlane) *
frame_clip_top) + frame_clip_left;
// For format YV12, there is one U, V value per 2x2 block.
// For format YV16, there is one U, V value per 2x1 block.
size_t uv_offset = (video_frame->stride(media::VideoFrame::kUPlane) *
(frame_clip_top >> y_shift)) + (frame_clip_left >> 1);
uint8* frame_clip_y =
video_frame->data(media::VideoFrame::kYPlane) + y_offset;
uint8* frame_clip_u =
video_frame->data(media::VideoFrame::kUPlane) + uv_offset;
uint8* frame_clip_v =
video_frame->data(media::VideoFrame::kVPlane) + uv_offset;
// TODO(hclam): do rotation and mirroring here.
// TODO(fbarchard): switch filtering based on performance.
bitmap.lockPixels();
media::ScaleYUVToRGB32(frame_clip_y,
frame_clip_u,
frame_clip_v,
dest_rect_pointer,
frame_clip_width,
frame_clip_height,
local_dest_irect.width(),
local_dest_irect.height(),
video_frame->stride(media::VideoFrame::kYPlane),
video_frame->stride(media::VideoFrame::kUPlane),
bitmap.rowBytes(),
yuv_type,
media::ROTATE_0,
media::FILTER_BILINEAR);
bitmap.unlockPixels();
}
// Converts a VideoFrame containing YUV data to a SkBitmap containing RGB data.
//
// |bitmap| will be (re)allocated to match the dimensions of |video_frame|.
static void ConvertVideoFrameToBitmap(
const scoped_refptr<media::VideoFrame>& video_frame,
SkBitmap* bitmap) {
DCHECK(IsEitherYV12OrYV16OrNative(video_frame->format()))
<< video_frame->format();
if (IsEitherYV12OrYV16(video_frame->format())) {
DCHECK_EQ(video_frame->stride(media::VideoFrame::kUPlane),
video_frame->stride(media::VideoFrame::kVPlane));
}
// Check if |bitmap| needs to be (re)allocated.
if (bitmap->isNull() ||
bitmap->width() != video_frame->visible_rect().width() ||
bitmap->height() != video_frame->visible_rect().height()) {
bitmap->setConfig(SkBitmap::kARGB_8888_Config,
video_frame->visible_rect().width(),
video_frame->visible_rect().height());
bitmap->allocPixels();
bitmap->setIsVolatile(true);
}
bitmap->lockPixels();
if (IsEitherYV12OrYV16(video_frame->format())) {
media::YUVType yuv_type = media::YV16;
int y_shift = 0;
if (video_frame->format() == media::VideoFrame::YV12) {
yuv_type = media::YV12;
y_shift = 1;
}
// Use the "left" and "top" of the destination rect to locate the offset
// in Y, U and V planes.
size_t y_offset = (video_frame->stride(media::VideoFrame::kYPlane) *
video_frame->visible_rect().y()) +
video_frame->visible_rect().x();
// For format YV12, there is one U, V value per 2x2 block.
// For format YV16, there is one U, V value per 2x1 block.
size_t uv_offset = (video_frame->stride(media::VideoFrame::kUPlane) *
(video_frame->visible_rect().y() >> y_shift)) +
(video_frame->visible_rect().x() >> 1);
uint8* frame_clip_y =
video_frame->data(media::VideoFrame::kYPlane) + y_offset;
uint8* frame_clip_u =
video_frame->data(media::VideoFrame::kUPlane) + uv_offset;
uint8* frame_clip_v =
video_frame->data(media::VideoFrame::kVPlane) + uv_offset;
media::ConvertYUVToRGB32(frame_clip_y,
frame_clip_u,
frame_clip_v,
static_cast<uint8*>(bitmap->getPixels()),
video_frame->visible_rect().width(),
video_frame->visible_rect().height(),
video_frame->stride(media::VideoFrame::kYPlane),
video_frame->stride(media::VideoFrame::kUPlane),
bitmap->rowBytes(),
yuv_type);
} else {
DCHECK_EQ(video_frame->format(), media::VideoFrame::NATIVE_TEXTURE);
video_frame->ReadPixelsFromNativeTexture(bitmap->getPixels());
}
bitmap->notifyPixelsChanged();
bitmap->unlockPixels();
}
SkCanvasVideoRenderer::SkCanvasVideoRenderer()
: last_frame_timestamp_(media::kNoTimestamp()) {
}
SkCanvasVideoRenderer::~SkCanvasVideoRenderer() {}
void SkCanvasVideoRenderer::Paint(media::VideoFrame* video_frame,
SkCanvas* canvas,
const gfx::RectF& dest_rect,
uint8_t alpha) {
if (alpha == 0) {
return;
}
SkRect dest;
dest.set(dest_rect.x(), dest_rect.y(), dest_rect.right(), dest_rect.bottom());
SkPaint paint;
paint.setAlpha(alpha);
// Paint black rectangle if there isn't a frame available or the
// frame has an unexpected format.
if (!video_frame || !IsEitherYV12OrYV16OrNative(video_frame->format())) {
canvas->drawRect(dest, paint);
return;
}
// Scale and convert to RGB in one step if we can.
if (CanFastPaint(canvas, alpha, video_frame->format())) {
FastPaint(video_frame, canvas, dest);
return;
}
// Check if we should convert and update |last_frame_|.
if (last_frame_.isNull() ||
video_frame->GetTimestamp() != last_frame_timestamp_) {
ConvertVideoFrameToBitmap(video_frame, &last_frame_);
last_frame_timestamp_ = video_frame->GetTimestamp();
}
// Do a slower paint using |last_frame_|.
paint.setFilterBitmap(true);
canvas->drawBitmapRect(last_frame_, NULL, dest, &paint);
}
} // namespace media
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