Merge pull request #23469 from gottagofaster236:use_nv12_for_obs_camera

modules/videoio/src/cap_dshow.cpp

@@ -186,6 +186,7 @@ DEFINE_GUID(MEDIASUBTYPE_YV12,0x32315659,0x0000,0x0010,0x80,0x00,0x00,0xaa,0x00,
 DEFINE_GUID(MEDIASUBTYPE_YVU9,0x39555659,0x0000,0x0010,0x80,0x00,0x00,0xaa,0x00,0x38,0x9b,0x71);
 DEFINE_GUID(MEDIASUBTYPE_YVYU,0x55595659,0x0000,0x0010,0x80,0x00,0x00,0xaa,0x00,0x38,0x9b,0x71);
 DEFINE_GUID(MEDIASUBTYPE_MJPG,0x47504A4D, 0x0000, 0x0010, 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71); // MGB
+DEFINE_GUID(MEDIASUBTYPE_NV12,0x3231564e,0x0000,0x0010,0x80,0x00,0x00,0xaa,0x00,0x38,0x9b,0x71);
 DEFINE_GUID(MEDIATYPE_Interleaved,0x73766169,0x0000,0x0010,0x80,0x00,0x00,0xaa,0x00,0x38,0x9b,0x71);
 DEFINE_GUID(MEDIATYPE_Video,0x73646976,0x0000,0x0010,0x80,0x00,0x00,0xaa,0x00,0x38,0x9b,0x71);
 DEFINE_GUID(PIN_CATEGORY_CAPTURE,0xfb6c4281,0x0353,0x11d1,0x90,0x5f,0x00,0x00,0xc0,0xcc,0x16,0xba);
@@ -338,7 +339,7 @@ static void DebugPrintOut(const char *format, ...)
 //videoInput defines
 #define VI_VERSION      0.1995
 #define VI_MAX_CAMERAS  20
-#define VI_NUM_TYPES    22 //MGB
+#define VI_NUM_TYPES    23 //MGB
 #define VI_NUM_FORMATS  18 //DON'T TOUCH
 
 //defines for setPhyCon - tuner is not as well supported as composite and s-video
@@ -826,11 +827,14 @@ void videoDevice::setSize(int w, int h){
         {
             videoSize      = w * h;
         }
-        else if (pAmMediaType->subtype == MEDIASUBTYPE_Y16 ||
-            pAmMediaType->subtype == MEDIASUBTYPE_YUY2)
+        else if (pAmMediaType->subtype == MEDIASUBTYPE_Y16)
         {
             videoSize      = w * h * 2;
         }
+        else if (pAmMediaType->subtype == MEDIASUBTYPE_NV12)
+        {
+            videoSize = w * h * 3 / 2;
+        }
         else
         {
             videoSize      = w * h * 3;
@@ -1109,6 +1113,7 @@ videoInput::videoInput(){
     mediaSubtypes[19]    = MEDIASUBTYPE_I420;
     mediaSubtypes[20] = MEDIASUBTYPE_BY8;
     mediaSubtypes[21] = MEDIASUBTYPE_Y16;
+    mediaSubtypes[22] = MEDIASUBTYPE_NV12;
 
     //The video formats we support
     formatTypes[VI_NTSC_M]      = AnalogVideo_NTSC_M;
@@ -1575,11 +1580,11 @@ bool videoInput::getPixels(int id, unsigned char * dstBuffer, bool flipRedAndBlu
                         processPixels(src, dst, width, height, flipRedAndBlue, flipImage, 2);
                     }
                 }
-                else if (VDList[id]->pAmMediaType->subtype == MEDIASUBTYPE_YUY2)
+                else if (VDList[id]->pAmMediaType->subtype == MEDIASUBTYPE_NV12)
                 {
-                    cv::Mat srcMat(height, width, CV_8UC2, src);
+                    cv::Mat srcMat(height * 3 / 2, width, CV_8UC1, src);
                     cv::Mat dstMat(height, width, CV_8UC3, dst);
-                    cv::cvtColor(srcMat, dstMat, cv::COLOR_YUV2BGR_YUY2);
+                    cv::cvtColor(srcMat, dstMat, cv::COLOR_YUV2BGR_NV12);
                 }
                 else
                 {
@@ -2331,6 +2336,7 @@ void videoInput::getMediaSubtypeAsString(GUID type, char * typeAsString){
     else if(type == MEDIASUBTYPE_I420)  snprintf(tmpStr, sizeof(tmpStr), "I420");
     else if (type == MEDIASUBTYPE_BY8)  snprintf(tmpStr, sizeof(tmpStr), "BY8");
     else if (type == MEDIASUBTYPE_Y16)  snprintf(tmpStr, sizeof(tmpStr), "Y16");
+    else if (type == MEDIASUBTYPE_NV12) snprintf(tmpStr, sizeof(tmpStr), "NV12");
     else snprintf(tmpStr, sizeof(tmpStr), "OTHER");
 
     memcpy(typeAsString, tmpStr, sizeof(char)*8);
@@ -2768,9 +2774,9 @@ int videoInput::start(int deviceID, videoDevice *VD){
         if (strcmp("OBS Virtual Camera", VD->nDeviceName) == 0)
         {
             // OBS Virtual Camera always returns S_OK on SetFormat(), even if it doesn't support
-            // the actual format. So we have to choose a format that it supports manually, e.g. YUY2.
+            // the actual format. So we have to choose a format that it supports manually, e.g. NV12.
             // https://github.com/opencv/opencv/issues/19746#issuecomment-1383056787
-            VD->tryVideoType = MEDIASUBTYPE_YUY2;
+            VD->tryVideoType = MEDIASUBTYPE_NV12;
         }
 
         char guidStr[8];
@@ -2885,7 +2891,7 @@ int videoInput::start(int deviceID, videoDevice *VD){
 
     // Disable format conversion if using 8/16-bit data (e-Con systems)
     if (checkSingleByteFormat(VD->pAmMediaType->subtype) ||
-        (VD->pAmMediaType->subtype == MEDIASUBTYPE_Y16 || VD->pAmMediaType->subtype == MEDIASUBTYPE_YUY2))
+        (VD->pAmMediaType->subtype == MEDIASUBTYPE_Y16 || VD->pAmMediaType->subtype == MEDIASUBTYPE_NV12))
     {
         DebugPrintOut("SETUP: Not converting frames to RGB.\n");
         mt.subtype = VD->pAmMediaType->subtype;