The nv122rgba function converts NV12 image format to a 4-channel
RGBA image. The inputs to the function are separate Y and UV planes.
NV12 holds sub sampled data, Y plane is sampled at unit rate and 1 U and
1 V value each for every 2x2 Y values. To generate the RGBA data, each U
and V value is duplicated (2x2) times.
API Syntax
template<int SRC_T, int UV_T, int DST_T, int ROWS, int COLS, int NPC=1, int XFCVDEPTH_IN_0 = _XFCVDEPTH_DEFAULT, int XFCVDEPTH_IN_1 = _XFCVDEPTH_DEFAULT, int XFCVDEPTH_OUT = _XFCVDEPTH_DEFAULT>
void nv122rgba(xf::cv::Mat<SRC_T, ROWS, COLS, NPC, XFCVDEPTH_IN_0> & src_y,xf::cv::Mat<UV_T, ROWS/2, COLS/2, NP, XFCVDEPTH_IN_1C> & src_uv,xf::cv::Mat<DST_T, ROWS, COLS, NPC, XFCVDEPTH_OUT> & _dst0)
Parameter Descriptions
The following table describes the template and the function parameters.
| 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,4channel is supported (XF_8UC4). |
| ROWS | Maximum height of input and output image. |
| COLS | Maximum width of input and output image. Must be a multiple of 8, for 8 pixel mode. |
| 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. |
| XFCVDEPTH_IN_0 | Depth of input image |
| XFCVDEPTH_IN_1 | Depth of input image |
| XFCVDEPTH_OUT | Depth of output image |
| 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 NV12 to RGBA for different configurations, as generated in the Vivado HLS 2019.1 version tool for the Xczu9eg-ffvb1156-1-i-es1 FPGA, to process a HD (1080x1920) image.
| Operating Mode | Operating Frequency (MHz) | Utilization Estimate | ||||
|---|---|---|---|---|---|---|
| BRAM_18K | DSP_48Es | FF | LUT | CLB | ||
| 1 Pixel | 300 | 2 | 5 | 1191 | 708 | 195 |
Performance Estimate
The following table summarizes the performance of NV12 to RGBA for different configurations, as generated using the Vivado HLS 2019.1 version tool for the Xczu9eg-ffvb1156-1-i-es1, to process a grayscale HD (1080x1920) image.
| Operating Mode | Latency Estimate |
|---|---|
| Max Latency (ms) | |
| 1 pixel operation (300 MHz) | 6.9 |