NV21 to RGBA

ThexFnv212rgbafunction converts a NV21 image format to a 4-channel RGBA image. The inputs to the function are separate Y and VU planes. NV21 holds sub sampled data, Yplane is sampled at unit rate and 1 U and 1V value each for every 2x2 Yvalues. To generate the RGBA data, each U and V value is duplicated (2x2) times.

API Syntax

template void xFnv212rgba(xF::Mat & src_y, xF::Mat & src_uv,xF::Mat & _dst0)

Parameter Descriptions

The following table describes the template and the function parameters.

Table 1.xFnv212rgba Function Parameter Descriptions
Parameter Description
SRC_T Input pixel type. Only 8-bit, unsigned, 1-channel is supported (XF_8UC1).
UV_T Input pixel type. Only 8-bit, unsigned, 2-channel is supported (XF_8UC2).
DST_T Output pixel type. Only 8-bit, unsigned, 4-channel is supported (XF_8UC4).
ROWS Maximum height of input and output image (must be a multiple of 8).
COLS Maximum width of input and output image (must be a multiple of 8).
NPC Number of pixels to be processed per cycle; possible options are XF_NPPC1 and XF_NPPC8 for 1 pixel and 8 pixel operations respectively.
src_y Input Y plane of size (ROWS, COLS).
src_uv Input UV plane of size (ROWS/2, COLS/2).
_dst0 Output RGBA image of size (ROWS, COLS).

Resource Utilization

The following table summarizes the resource utilization of NV21 to RGBA for different configurations, as generated in theVivado HLS 2017.1version tool for theXilinx Xczu9eg-ffvb1156-1-i-es1FPGA, to process a HD (1080x1920) image.

Table 2.xFnv212rgba Function Resource Utilization Summary
Operating Mode

Operating Frequency

(MHz)

 Utilization Estimate
BRAM_18K DSP_48Es FF LUT CLB
1pixel 300 2 5 1170 673 183

Performance Estimate

The following table summarizes the performance of NV12 to IYUV for different configurations, as generated using theVivado HLS 2017.1version tool for theXilinx Xczu9eg-ffvb1156-1-i-es1, to process a grayscale HD (1080x1920) image.

Table 3.xFnv212rgba Function Performance Estimate Summary
Operating Mode Latency Estimate
Max Latency (ms)
1 pixel operation(300Mhz) 6.9