diff options
| -rw-r--r-- | remoting/codec/video_encoder_vpx.cc | 49 |
1 files changed, 23 insertions, 26 deletions
diff --git a/remoting/codec/video_encoder_vpx.cc b/remoting/codec/video_encoder_vpx.cc index 0977564..cee7994 100644 --- a/remoting/codec/video_encoder_vpx.cc +++ b/remoting/codec/video_encoder_vpx.cc @@ -257,39 +257,36 @@ bool VideoEncoderVpx::Initialize(const webrtc::DesktopSize& size) { active_map_height_ = (image_->h + kMacroBlockSize - 1) / kMacroBlockSize; active_map_.reset(new uint8[active_map_width_ * active_map_height_]); - // YUV image size is 1.5 times of a plane. Multiplication is performed first - // to avoid rounding error. - const int y_plane_size = image_->w * image_->h; - const int uv_width = (image_->w + 1) / 2; - const int uv_height = (image_->h + 1) / 2; - const int uv_plane_size = uv_width * uv_height; - const int yuv_image_size = y_plane_size + uv_plane_size * 2; - - // libvpx may try to access memory after the buffer (it still - // doesn't use it) - it copies the data in 16x16 blocks: - // crbug.com/119633 . Here we workaround that problem by adding - // padding at the end of the buffer. Overreading to U and V buffers - // is safe so the padding is necessary only at the end. - // - // TODO(sergeyu): Remove this padding when the bug is fixed in libvpx. - const int active_map_area = active_map_width_ * kMacroBlockSize * - active_map_height_ * kMacroBlockSize; - const int padding_size = active_map_area - y_plane_size; - const int buffer_size = yuv_image_size + padding_size; - + // libyuv's fast-path requires 16-byte aligned pointers and strides, so pad + // the Y, U and V planes' strides to multiples of 16 bytes. + const int y_stride = ((image_->w - 1) & ~15) + 16; + const int uv_unaligned_stride = y_stride / 2; + const int uv_stride = ((uv_unaligned_stride - 1) & ~15) + 16; + + // libvpx accesses the source image in macro blocks, and will over-read + // if the image is not padded out to the next macroblock: crbug.com/119633. + // Pad the Y, U and V planes' height out to compensate. + // Assuming macroblocks are 16x16, aligning the planes' strides above also + // macroblock aligned them. + DCHECK_EQ(16, kMacroBlockSize); + const int y_rows = active_map_height_ * kMacroBlockSize; + const int uv_rows = y_rows / 2; + + // Allocate a YUV buffer large enough for the aligned data & padding. + const int buffer_size = y_stride * y_rows + 2 * uv_stride * uv_rows; yuv_image_.reset(new uint8[buffer_size]); // Reset image value to 128 so we just need to fill in the y plane. - memset(yuv_image_.get(), 128, yuv_image_size); + memset(yuv_image_.get(), 128, buffer_size); // Fill in the information for |image_|. unsigned char* image = reinterpret_cast<unsigned char*>(yuv_image_.get()); image_->planes[0] = image; - image_->planes[1] = image + y_plane_size; - image_->planes[2] = image + y_plane_size + uv_plane_size; - image_->stride[0] = image_->w; - image_->stride[1] = uv_width; - image_->stride[2] = uv_width; + image_->planes[1] = image_->planes[0] + y_stride * y_rows; + image_->planes[2] = image_->planes[1] + uv_stride * uv_rows; + image_->stride[0] = y_stride; + image_->stride[1] = uv_stride; + image_->stride[2] = uv_stride; // Initialize the codec. codec_ = init_codec_.Run(size); |