#hbVPRemap

• The underlying gdc only supports bilinear interpolation, and does not need to configure borderType padValue parameter;

• Since the implementation principle of gdc is different from that of dsp, the accuracy of the image output by gdc and dsp from the same map will be different;

• GDC has the following requirements for map:

  • Map coordinates must be positive numbers;
  • Try to keep the sampling points in the same row with a smooth transition. If the transition between two points changes sharply, the accuracy of the spline will not be enough to handle it;
  • Four sampling points cannot form a triangle;
  • If the sampling accuracy is insufficient, it may cause aliasing, distortion, etc. In this case, it is recommended to use subpixel coordinates.

• GDC supports 10-bit and 12-bit image processing. Note that 10-bit and 12-bit are only the pixel widths of the Y channel; the UV channel remains 8 bits. Furthermore, 10-bit and 12-bit Y data must be stored as 16 bits with the MSB being the most significant bit, meaning one pixel occupies two bytes. :::

• Member

  Member Name	Description
  mapPhyAddr	Physical address of map data, data type double.
  mapVirAddr	The map data virtual address.
  srcWidth	Input width.
  srcHeight	Input height.
  mapWidth	map width (i.e., target width).
  mapHeight	map height (i.e., target height).
  interpoType	Interpolation type in Remap, supports NEAREST and LINEAR types in hbVPInterpolationType.
  borderType	Reserved parameter.
  padValue	Reserved parameter.
  dataType	Data types in map that supports the type HB_VP_IMAGE_TYPE_F64C2 in hbVPImageType.

::: info Note

Note that the data layout in map (i.e. the memory data under the physical address of phyAddr) is x_0, y_0, x_1, y_1, ..., and the memory length should be 2 * mapWidth * mapHeight * sizeof(dataType), please refer to the sample for detailed usage.

1. When the task is deployed on a GDC, srcWidth and mapWidth are in the range [96, 3840], and srcHeight and mapHeight are in the range [96, 2160] and satisfy: mapWidth <= srcWidth, mapHeight <= srcHeight. Since GDC has data alignment restrictions, mapWidth needs to be 16 aligned, which means that when srcWidth does not meet 16 alignment, the mapWidth will be less than srcWidth. The stride of the input and output is aligned to 16 in the width direction. When processing 8-bit images, the input and output stride range is [96, 3840]. When processing 10-bit and 12-bit images, the input and output stride range is [192, 7680]. When allocating memory, please use the height and stride size as the criteria.
2. When the task is deployed on a DSP, srcWidth and dstWidth range [32, 4096] and srcHeight and dstHeight range [16, 2160].

1. hbVPCreateMapWrap is used to create map resources for remap. Since different backends require different hardware resources to be prepared, it is necessary to specify the backend here to determine which resource the map applies to.
2. Interface support hardware resources for GDC, DSP. When specifying DSP deployment resources, backend needs to be set according to the hardware configuration of the development board. For example, on a single-core DSP development board, backend can be: HB_UCP_DSP_CORE_ANY, HB_UCP_DSP_CORE_0.
3. Supports specifying both dsp and gdc backends at the same time, creating two hardware map resources respectively, such as: backend=HB_UCP_GDC_CORE_0|HB_UCP_DSP_CORE_ANY (specifies the hardware resources to create two kinds of backends, GDC and DSP, and the parameter needs to satisfy the constraints on the sizes of GDC and DSP at the same time, HB_UCP_CORE_ANY cannot be ORed with other backends).