G-API (Fluid) core support for I420

- Extended NV12 support in Fluid Core engine to cover I420

modules/gapi/include/opencv2/gapi/fluid/gfluidkernel.hpp

@@ -50,7 +50,7 @@ public:
     {
         Filter,
         Resize,
-        NV12toRGB
+        YUV420toRGB //Color conversion of 4:2:0 chroma sub-sampling formats (NV12, I420 ..etc) to RGB
     };
 
     // This function is a generic "doWork" callback

modules/gapi/src/backends/fluid/gfluidbackend.cpp

@@ -198,7 +198,7 @@ public:
     using FluidAgent::FluidAgent;
 };
 
-struct FluidNV12toRGBAgent : public FluidAgent
+struct Fluid420toRGBAgent : public FluidAgent
 {
 private:
     virtual int firstWindow(std::size_t inPort) const override;
@@ -313,7 +313,7 @@ static int maxLineConsumption(const cv::GFluidKernel::Kind kind, int window, int
             return (inH == 1) ? 1 : 2 + lpi - 1;
         }
     } break;
-    case cv::GFluidKernel::Kind::NV12toRGB: return inPort == 0 ? 2 : 1; break;
+    case cv::GFluidKernel::Kind::YUV420toRGB: return inPort == 0 ? 2 : 1; break;
     default: GAPI_Assert(false); return 0;
     }
 }
@@ -325,7 +325,7 @@ static int borderSize(const cv::GFluidKernel::Kind kind, int window)
     case cv::GFluidKernel::Kind::Filter: return (window - 1) / 2; break;
     // Resize never reads from border pixels
     case cv::GFluidKernel::Kind::Resize: return 0; break;
-    case cv::GFluidKernel::Kind::NV12toRGB: return 0; break;
+    case cv::GFluidKernel::Kind::YUV420toRGB: return 0; break;
     default: GAPI_Assert(false); return 0;
     }
 }
@@ -435,13 +435,13 @@ std::pair<int,int> cv::gimpl::FluidResizeAgent::linesReadAndnextWindow(std::size
     return m_mapper->linesReadAndNextWindow(outIdx, lpi);
 }
 
-int cv::gimpl::FluidNV12toRGBAgent::firstWindow(std::size_t inPort) const
+int cv::gimpl::Fluid420toRGBAgent::firstWindow(std::size_t inPort) const
 {
     // 2 lines for Y, 1 for UV
     return inPort == 0 ? 2 : 1;
 }
 
-std::pair<int,int> cv::gimpl::FluidNV12toRGBAgent::linesReadAndnextWindow(std::size_t inPort) const
+std::pair<int,int> cv::gimpl::Fluid420toRGBAgent::linesReadAndnextWindow(std::size_t inPort) const
 {
     // 2 lines for Y, 1 for UV
     return inPort == 0 ? std::make_pair(2, 2) : std::make_pair(1, 1);
@@ -675,7 +675,7 @@ void cv::gimpl::GFluidExecutable::initBufferRois(std::vector<int>& readStarts,
                         return roi;
                     };
 
-                    auto adjNV12Roi = [&](cv::gapi::own::Rect produced, std::size_t port) {
+                    auto adj420Roi = [&](cv::gapi::own::Rect produced, std::size_t port) {
                         GAPI_Assert(produced.x % 2 == 0);
                         GAPI_Assert(produced.y % 2 == 0);
                         GAPI_Assert(produced.width % 2 == 0);
@@ -684,7 +684,8 @@ void cv::gimpl::GFluidExecutable::initBufferRois(std::vector<int>& readStarts,
                         cv::gapi::own::Rect roi;
                         switch (port) {
                         case 0: roi = produced; break;
-                        case 1: roi = cv::gapi::own::Rect{ produced.x/2, produced.y/2, produced.width/2, produced.height/2 }; break;
+                        case 1:
+                        case 2: roi = cv::gapi::own::Rect{ produced.x/2, produced.y/2, produced.width/2, produced.height/2 }; break;
                         default: GAPI_Assert(false);
                         }
                         return roi;
@@ -696,19 +697,19 @@ void cv::gimpl::GFluidExecutable::initBufferRois(std::vector<int>& readStarts,
                     cv::gapi::own::Rect resized;
                     switch (fg.metadata(oh).get<FluidUnit>().k.m_kind)
                     {
-                    case GFluidKernel::Kind::Filter:    resized = produced; break;
-                    case GFluidKernel::Kind::Resize:    resized = adjResizeRoi(produced, in_meta.size, meta.size); break;
-                    case GFluidKernel::Kind::NV12toRGB: resized = adjNV12Roi(produced, m_gm.metadata(in_edge).get<Input>().port); break;
+                    case GFluidKernel::Kind::Filter:      resized = produced; break;
+                    case GFluidKernel::Kind::Resize:      resized = adjResizeRoi(produced, in_meta.size, meta.size); break;
+                    case GFluidKernel::Kind::YUV420toRGB: resized = adj420Roi(produced, m_gm.metadata(in_edge).get<Input>().port); break;
                     default: GAPI_Assert(false);
                     }
 
                     // All below transformations affect roi of the writer, preserve read start position here
                     int readStart = resized.y;
 
-                    // Extend required input roi (both y and height) to be even if it's produced by NV12toRGB
+                    // Extend required input roi (both y and height) to be even if it's produced by CS420toRGB
                     if (!in_node->inNodes().empty()) {
                         auto in_data_producer = in_node->inNodes().front();
-                        if (fg.metadata(in_data_producer).get<FluidUnit>().k.m_kind == GFluidKernel::Kind::NV12toRGB) {
+                        if (fg.metadata(in_data_producer).get<FluidUnit>().k.m_kind == GFluidKernel::Kind::YUV420toRGB) {
                             if (resized.y % 2 != 0) {
                                 resized.y--;
                                 resized.height++;
@@ -840,9 +841,9 @@ cv::gimpl::GFluidExecutable::GFluidExecutable(const ade::Graph
         std::unique_ptr<FluidAgent> agent_ptr;
         switch (agent_data.kind)
         {
-            case GFluidKernel::Kind::Filter:    agent_ptr.reset(new FluidFilterAgent(g, agent_data.nh));      break;
-            case GFluidKernel::Kind::Resize:    agent_ptr.reset(new FluidResizeAgent(g, agent_data.nh));      break;
-            case GFluidKernel::Kind::NV12toRGB: agent_ptr.reset(new FluidNV12toRGBAgent(g, agent_data.nh));   break;
+            case GFluidKernel::Kind::Filter:      agent_ptr.reset(new FluidFilterAgent(g, agent_data.nh));      break;
+            case GFluidKernel::Kind::Resize:      agent_ptr.reset(new FluidResizeAgent(g, agent_data.nh));      break;
+            case GFluidKernel::Kind::YUV420toRGB: agent_ptr.reset(new Fluid420toRGBAgent(g, agent_data.nh));    break;
             default: GAPI_Assert(false);
         }
         std::tie(agent_ptr->in_buffer_ids, agent_ptr->out_buffer_ids) = std::tie(agent_data.in_buffer_ids, agent_data.out_buffer_ids);
@@ -1005,7 +1006,7 @@ namespace
 
                 GAPI_Assert((out_ws.size() == 1 && out_hs.size() == 1) &&
                             ((in_hs.size() == 1) ||
-                            ((in_hs.size() == 2) && fu.k.m_kind == cv::GFluidKernel::Kind::NV12toRGB)));
+                            ((in_hs.size() == 2) && fu.k.m_kind == cv::GFluidKernel::Kind::YUV420toRGB)));
 
                 const auto &op = g.metadata(node).get<Op>();
                 fu.line_consumption.resize(op.args.size(), 0);

modules/gapi/test/gapi_fluid_test_kernels.cpp

@@ -530,7 +530,7 @@ GAPI_FLUID_KERNEL(FNV12toRGB, cv::gapi::imgproc::GNV12toRGB, false)
 {
     static const int Window = 1;
     static const int LPI    = 2;
-    static const auto Kind = GFluidKernel::Kind::NV12toRGB;
+    static const auto Kind = GFluidKernel::Kind::YUV420toRGB;
 
     static void run(const cv::gapi::fluid::View   &in1,
                     const cv::gapi::fluid::View   &in2,