media/filters/skcanvas_video_renderer.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "media/filters/skcanvas_video_renderer.h"
   6
   7 #include "base/logging.h"
   8 #include "media/base/video_frame.h"
   9 #include "media/base/yuv_convert.h"
  10 #include "third_party/skia/include/core/SkCanvas.h"
  11 #include "third_party/skia/include/core/SkDevice.h"
  12
  13 namespace media {
  14
  15 static bool IsEitherYV12OrYV16(media::VideoFrame::Format format) {
  16   return format == media::VideoFrame::YV12 || format == media::VideoFrame::YV16;
  17 }
  18
  19 static bool IsEitherYV12OrYV16OrNative(media::VideoFrame::Format format) {
  20   return IsEitherYV12OrYV16(format) ||
  21       format == media::VideoFrame::NATIVE_TEXTURE;
  22 }
  23
  24 static bool IsEitherYV12OrYV12AOrYV16(media::VideoFrame::Format format) {
  25   return IsEitherYV12OrYV16(format) ||
  26       format == media::VideoFrame::YV12A;
  27 }
  28
  29 static bool IsEitherYV12OrYV12AOrYV16OrNative(
  30     media::VideoFrame::Format format) {
  31   return IsEitherYV12OrYV16OrNative(format) ||
  32       format == media::VideoFrame::YV12A;
  33 }
  34
  35 // CanFastPaint is a helper method to determine the conditions for fast
  36 // painting. The conditions are:
  37 // 1. No skew in canvas matrix.
  38 // 2. No flipping nor mirroring.
  39 // 3. Canvas has pixel format ARGB8888.
  40 // 4. Canvas is opaque.
  41 // 5. Frame format is YV12 or YV16.
  42 //
  43 // TODO(hclam): The fast paint method should support flipping and mirroring.
  44 // Disable the flipping and mirroring checks once we have it.
  45 static bool CanFastPaint(SkCanvas* canvas, uint8 alpha,
  46                          media::VideoFrame::Format format) {
  47   if (alpha != 0xFF || !IsEitherYV12OrYV16(format))
  48     return false;
  49
  50   const SkMatrix& total_matrix = canvas->getTotalMatrix();
  51   // Perform the following checks here:
  52   // 1. Check for skewing factors of the transformation matrix. They should be
  53   //    zero.
  54   // 2. Check for mirroring and flipping. Make sure they are greater than zero.
  55   if (SkScalarNearlyZero(total_matrix.getSkewX()) &&
  56       SkScalarNearlyZero(total_matrix.getSkewY()) &&
  57       total_matrix.getScaleX() > 0 &&
  58       total_matrix.getScaleY() > 0) {
  59     SkDevice* device = canvas->getDevice();
  60     const SkBitmap::Config config = device->config();
  61
  62     if (config == SkBitmap::kARGB_8888_Config && device->isOpaque()) {
  63       return true;
  64     }
  65   }
  66
  67   return false;
  68 }
  69
  70 // Fast paint does YUV => RGB, scaling, blitting all in one step into the
  71 // canvas. It's not always safe and appropriate to perform fast paint.
  72 // CanFastPaint() is used to determine the conditions.
  73 static void FastPaint(
  74     const scoped_refptr<media::VideoFrame>& video_frame,
  75     SkCanvas* canvas,
  76     const SkRect& dest_rect) {
  77   DCHECK(IsEitherYV12OrYV16(video_frame->format())) << video_frame->format();
  78   DCHECK_EQ(video_frame->stride(media::VideoFrame::kUPlane),
  79             video_frame->stride(media::VideoFrame::kVPlane));
  80
  81   const SkBitmap& bitmap = canvas->getDevice()->accessBitmap(true);
  82   media::YUVType yuv_type = media::YV16;
  83   int y_shift = 0;
  84   if (video_frame->format() == media::VideoFrame::YV12 ||
  85       video_frame->format() == media::VideoFrame::YV12A) {
  86     yuv_type = media::YV12;
  87     y_shift = 1;
  88   }
  89
  90   // Transform the destination rectangle to local coordinates.
  91   const SkMatrix& local_matrix = canvas->getTotalMatrix();
  92   SkRect local_dest_rect;
  93   local_matrix.mapRect(&local_dest_rect, dest_rect);
  94
  95   // After projecting the destination rectangle to local coordinates, round
  96   // the projected rectangle to integer values, this will give us pixel values
  97   // of the rectangle.
  98   SkIRect local_dest_irect, local_dest_irect_saved;
  99   local_dest_rect.round(&local_dest_irect);
 100   local_dest_rect.round(&local_dest_irect_saved);
 101
 102   // No point painting if the destination rect doesn't intersect with the
 103   // clip rect.
 104   if (!local_dest_irect.intersect(canvas->getTotalClip().getBounds()))
 105     return;
 106
 107   // At this point |local_dest_irect| contains the rect that we should draw
 108   // to within the clipping rect.
 109
 110   // Calculate the address for the top left corner of destination rect in
 111   // the canvas that we will draw to. The address is obtained by the base
 112   // address of the canvas shifted by "left" and "top" of the rect.
 113   uint8* dest_rect_pointer = static_cast<uint8*>(bitmap.getPixels()) +
 114       local_dest_irect.fTop * bitmap.rowBytes() +
 115       local_dest_irect.fLeft * 4;
 116
 117   // Project the clip rect to the original video frame, obtains the
 118   // dimensions of the projected clip rect, "left" and "top" of the rect.
 119   // The math here are all integer math so we won't have rounding error and
 120   // write outside of the canvas.
 121   // We have the assumptions of dest_rect.width() and dest_rect.height()
 122   // being non-zero, these are valid assumptions since finding intersection
 123   // above rejects empty rectangle so we just do a DCHECK here.
 124   DCHECK_NE(0, dest_rect.width());
 125   DCHECK_NE(0, dest_rect.height());
 126   size_t frame_clip_width = local_dest_irect.width() *
 127       video_frame->visible_rect().width() / local_dest_irect_saved.width();
 128   size_t frame_clip_height = local_dest_irect.height() *
 129       video_frame->visible_rect().height() / local_dest_irect_saved.height();
 130
 131   // Project the "left" and "top" of the final destination rect to local
 132   // coordinates of the video frame, use these values to find the offsets
 133   // in the video frame to start reading.
 134   size_t frame_clip_left =
 135       video_frame->visible_rect().x() +
 136       (local_dest_irect.fLeft - local_dest_irect_saved.fLeft) *
 137       video_frame->visible_rect().width() / local_dest_irect_saved.width();
 138   size_t frame_clip_top =
 139       video_frame->visible_rect().y() +
 140       (local_dest_irect.fTop - local_dest_irect_saved.fTop) *
 141       video_frame->visible_rect().height() / local_dest_irect_saved.height();
 142
 143   // Use the "left" and "top" of the destination rect to locate the offset
 144   // in Y, U and V planes.
 145   size_t y_offset = (video_frame->stride(media::VideoFrame::kYPlane) *
 146                      frame_clip_top) + frame_clip_left;
 147
 148   // For format YV12, there is one U, V value per 2x2 block.
 149   // For format YV16, there is one U, V value per 2x1 block.
 150   size_t uv_offset = (video_frame->stride(media::VideoFrame::kUPlane) *
 151                       (frame_clip_top >> y_shift)) + (frame_clip_left >> 1);
 152   uint8* frame_clip_y =
 153       video_frame->data(media::VideoFrame::kYPlane) + y_offset;
 154   uint8* frame_clip_u =
 155       video_frame->data(media::VideoFrame::kUPlane) + uv_offset;
 156   uint8* frame_clip_v =
 157       video_frame->data(media::VideoFrame::kVPlane) + uv_offset;
 158
 159   // TODO(hclam): do rotation and mirroring here.
 160   // TODO(fbarchard): switch filtering based on performance.
 161   bitmap.lockPixels();
 162   media::ScaleYUVToRGB32(frame_clip_y,
 163                          frame_clip_u,
 164                          frame_clip_v,
 165                          dest_rect_pointer,
 166                          frame_clip_width,
 167                          frame_clip_height,
 168                          local_dest_irect.width(),
 169                          local_dest_irect.height(),
 170                          video_frame->stride(media::VideoFrame::kYPlane),
 171                          video_frame->stride(media::VideoFrame::kUPlane),
 172                          bitmap.rowBytes(),
 173                          yuv_type,
 174                          media::ROTATE_0,
 175                          media::FILTER_BILINEAR);
 176   bitmap.unlockPixels();
 177 }
 178
 179 // Converts a VideoFrame containing YUV data to a SkBitmap containing RGB data.
 180 //
 181 // |bitmap| will be (re)allocated to match the dimensions of |video_frame|.
 182 static void ConvertVideoFrameToBitmap(
 183     const scoped_refptr<media::VideoFrame>& video_frame,
 184     SkBitmap* bitmap) {
 185   DCHECK(IsEitherYV12OrYV12AOrYV16OrNative(video_frame->format()))
 186       << video_frame->format();
 187   if (IsEitherYV12OrYV12AOrYV16(video_frame->format())) {
 188     DCHECK_EQ(video_frame->stride(media::VideoFrame::kUPlane),
 189               video_frame->stride(media::VideoFrame::kVPlane));
 190   }
 191
 192   // Check if |bitmap| needs to be (re)allocated.
 193   if (bitmap->isNull() ||
 194       bitmap->width() != video_frame->visible_rect().width() ||
 195       bitmap->height() != video_frame->visible_rect().height()) {
 196     bitmap->setConfig(SkBitmap::kARGB_8888_Config,
 197                       video_frame->visible_rect().width(),
 198                       video_frame->visible_rect().height());
 199     bitmap->allocPixels();
 200     bitmap->setIsVolatile(true);
 201   }
 202
 203   bitmap->lockPixels();
 204
 205   size_t y_offset = 0;
 206   size_t uv_offset = 0;
 207   if (IsEitherYV12OrYV12AOrYV16(video_frame->format())) {
 208     int y_shift = (video_frame->format() == media::VideoFrame::YV16) ? 0 : 1;
 209     // Use the "left" and "top" of the destination rect to locate the offset
 210     // in Y, U and V planes.
 211     y_offset = (video_frame->stride(media::VideoFrame::kYPlane) *
 212                 video_frame->visible_rect().y()) +
 213                 video_frame->visible_rect().x();
 214     // For format YV12, there is one U, V value per 2x2 block.
 215     // For format YV16, there is one U, V value per 2x1 block.
 216     uv_offset = (video_frame->stride(media::VideoFrame::kUPlane) *
 217                 (video_frame->visible_rect().y() >> y_shift)) +
 218                 (video_frame->visible_rect().x() >> 1);
 219   }
 220   switch (video_frame->format()) {
 221     case media::VideoFrame::YV12:
 222       media::ConvertYUVToRGB32(
 223           video_frame->data(media::VideoFrame::kYPlane) + y_offset,
 224           video_frame->data(media::VideoFrame::kUPlane) + uv_offset,
 225           video_frame->data(media::VideoFrame::kVPlane) + uv_offset,
 226           static_cast<uint8*>(bitmap->getPixels()),
 227           video_frame->visible_rect().width(),
 228           video_frame->visible_rect().height(),
 229           video_frame->stride(media::VideoFrame::kYPlane),
 230           video_frame->stride(media::VideoFrame::kUPlane),
 231           bitmap->rowBytes(),
 232           media::YV12);
 233       break;
 234
 235     case media::VideoFrame::YV16:
 236       media::ConvertYUVToRGB32(
 237           video_frame->data(media::VideoFrame::kYPlane) + y_offset,
 238           video_frame->data(media::VideoFrame::kUPlane) + uv_offset,
 239           video_frame->data(media::VideoFrame::kVPlane) + uv_offset,
 240           static_cast<uint8*>(bitmap->getPixels()),
 241           video_frame->visible_rect().width(),
 242           video_frame->visible_rect().height(),
 243           video_frame->stride(media::VideoFrame::kYPlane),
 244           video_frame->stride(media::VideoFrame::kUPlane),
 245           bitmap->rowBytes(),
 246           media::YV16);
 247       break;
 248
 249     case media::VideoFrame::YV12A:
 250       media::ConvertYUVAToARGB(
 251           video_frame->data(media::VideoFrame::kYPlane) + y_offset,
 252           video_frame->data(media::VideoFrame::kUPlane) + uv_offset,
 253           video_frame->data(media::VideoFrame::kVPlane) + uv_offset,
 254           video_frame->data(media::VideoFrame::kAPlane),
 255           static_cast<uint8*>(bitmap->getPixels()),
 256           video_frame->visible_rect().width(),
 257           video_frame->visible_rect().height(),
 258           video_frame->stride(media::VideoFrame::kYPlane),
 259           video_frame->stride(media::VideoFrame::kUPlane),
 260           video_frame->stride(media::VideoFrame::kAPlane),
 261           bitmap->rowBytes(),
 262           media::YV12);
 263       break;
 264
 265     case media::VideoFrame::NATIVE_TEXTURE:
 266       DCHECK_EQ(video_frame->format(), media::VideoFrame::NATIVE_TEXTURE);
 267       video_frame->ReadPixelsFromNativeTexture(*bitmap);
 268       break;
 269
 270     default:
 271       NOTREACHED();
 272       break;
 273   }
 274   bitmap->notifyPixelsChanged();
 275   bitmap->unlockPixels();
 276 }
 277
 278 SkCanvasVideoRenderer::SkCanvasVideoRenderer()
 279     : last_frame_timestamp_(media::kNoTimestamp()) {
 280 }
 281
 282 SkCanvasVideoRenderer::~SkCanvasVideoRenderer() {}
 283
 284 void SkCanvasVideoRenderer::Paint(media::VideoFrame* video_frame,
 285                                   SkCanvas* canvas,
 286                                   const gfx::RectF& dest_rect,
 287                                   uint8 alpha) {
 288   if (alpha == 0) {
 289     return;
 290   }
 291
 292   SkRect dest;
 293   dest.set(dest_rect.x(), dest_rect.y(), dest_rect.right(), dest_rect.bottom());
 294
 295   SkPaint paint;
 296   paint.setAlpha(alpha);
 297
 298   // Paint black rectangle if there isn't a frame available or the
 299   // frame has an unexpected format.
 300   if (!video_frame ||
 301       !IsEitherYV12OrYV12AOrYV16OrNative(video_frame->format())) {
 302     canvas->drawRect(dest, paint);
 303     return;
 304   }
 305
 306   // Scale and convert to RGB in one step if we can.
 307   if (CanFastPaint(canvas, alpha, video_frame->format())) {
 308     FastPaint(video_frame, canvas, dest);
 309     return;
 310   }
 311
 312   // Check if we should convert and update |last_frame_|.
 313   if (last_frame_.isNull() ||
 314       video_frame->GetTimestamp() != last_frame_timestamp_) {
 315     ConvertVideoFrameToBitmap(video_frame, &last_frame_);
 316     last_frame_timestamp_ = video_frame->GetTimestamp();
 317   }
 318
 319   // Do a slower paint using |last_frame_|.
 320   paint.setFilterBitmap(true);
 321   canvas->drawBitmapRect(last_frame_, NULL, dest, &paint);
 322 }
 323
 324 }  // namespace media