Implement testRenderFrame() for the VTMetal renderer

This can be used to (hopefully) detect cases where importing the decoded frames onto the target GPU fails.

See #1885

app/streaming/video/ffmpeg-renderers/vt_metal.mm

@@ -398,6 +398,81 @@ public:
         return m_SwMappingTextures[planeIndex];
     }
 
+    bool createTexturesFromFrame(AVFrame* frame, std::array<CVMetalTextureRef, MAX_VIDEO_PLANES>& cvMetalTextures)
+    {
+        SDL_assert(frame->format == AV_PIX_FMT_VIDEOTOOLBOX);
+
+        CVPixelBufferRef pixBuf = reinterpret_cast<CVPixelBufferRef>(frame->data[3]);
+        size_t planes = getFramePlaneCount(frame);
+
+        // Create Metal textures for the planes of the CVPixelBuffer
+        for (size_t i = 0; i < planes; i++) {
+            MTLPixelFormat fmt;
+
+            switch (CVPixelBufferGetPixelFormatType(pixBuf)) {
+            case kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange:
+            case kCVPixelFormatType_444YpCbCr8BiPlanarVideoRange:
+            case kCVPixelFormatType_420YpCbCr8BiPlanarFullRange:
+            case kCVPixelFormatType_444YpCbCr8BiPlanarFullRange:
+                fmt = (i == 0) ? MTLPixelFormatR8Unorm : MTLPixelFormatRG8Unorm;
+                break;
+
+            case kCVPixelFormatType_420YpCbCr10BiPlanarFullRange:
+            case kCVPixelFormatType_444YpCbCr10BiPlanarFullRange:
+            case kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange:
+            case kCVPixelFormatType_444YpCbCr10BiPlanarVideoRange:
+                fmt = (i == 0) ? MTLPixelFormatR16Unorm : MTLPixelFormatRG16Unorm;
+                break;
+
+            default:
+                SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                             "Unknown pixel format: %x",
+                             CVPixelBufferGetPixelFormatType(pixBuf));
+                return false;
+            }
+
+            CVReturn err = CVMetalTextureCacheCreateTextureFromImage(kCFAllocatorDefault, m_TextureCache, pixBuf, nullptr, fmt,
+                                                                     CVPixelBufferGetWidthOfPlane(pixBuf, i),
+                                                                     CVPixelBufferGetHeightOfPlane(pixBuf, i),
+                                                                     i,
+                                                                     &cvMetalTextures[i]);
+            if (err != kCVReturnSuccess) {
+                for (size_t j = 0; j < i; j++) {
+                    CFRelease(cvMetalTextures[j]);
+                }
+                SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                             "CVMetalTextureCacheCreateTextureFromImage() failed: %d",
+                             err);
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    bool testRenderFrame(AVFrame *frame) override
+    { @autoreleasepool {
+        if (frame->format == AV_PIX_FMT_VIDEOTOOLBOX) {
+            std::array<CVMetalTextureRef, MAX_VIDEO_PLANES> cvMetalTextures;
+            size_t planes = getFramePlaneCount(frame);
+            SDL_assert(planes <= MAX_VIDEO_PLANES);
+
+            // Test that we can actually create Metal textures from the CVPixelBufferRef
+            if (!createTexturesFromFrame(frame, cvMetalTextures)) {
+                return false;
+            }
+
+            for (size_t i = 0; i < planes; i++) {
+                CFRelease(cvMetalTextures[i]);
+            }
+        }
+        else {
+            // Mapping software frames should always work
+        }
+
+        return true;
+    }}
+
     // Caller frees frame after we return
     virtual void renderFrameIntoDrawable(AVFrame* frame, id<CAMetalDrawable> drawable)
     { @autoreleasepool {
@@ -406,45 +481,8 @@ public:
         SDL_assert(planes <= MAX_VIDEO_PLANES);
 
         if (frame->format == AV_PIX_FMT_VIDEOTOOLBOX) {
-            CVPixelBufferRef pixBuf = reinterpret_cast<CVPixelBufferRef>(frame->data[3]);
+            if (!createTexturesFromFrame(frame, cvMetalTextures)) {
-
+                return;
-            // Create Metal textures for the planes of the CVPixelBuffer
-            for (size_t i = 0; i < planes; i++) {
-                MTLPixelFormat fmt;
-
-                switch (CVPixelBufferGetPixelFormatType(pixBuf)) {
-                case kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange:
-                case kCVPixelFormatType_444YpCbCr8BiPlanarVideoRange:
-                case kCVPixelFormatType_420YpCbCr8BiPlanarFullRange:
-                case kCVPixelFormatType_444YpCbCr8BiPlanarFullRange:
-                    fmt = (i == 0) ? MTLPixelFormatR8Unorm : MTLPixelFormatRG8Unorm;
-                    break;
-
-                case kCVPixelFormatType_420YpCbCr10BiPlanarFullRange:
-                case kCVPixelFormatType_444YpCbCr10BiPlanarFullRange:
-                case kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange:
-                case kCVPixelFormatType_444YpCbCr10BiPlanarVideoRange:
-                    fmt = (i == 0) ? MTLPixelFormatR16Unorm : MTLPixelFormatRG16Unorm;
-                    break;
-
-                default:
-                    SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
-                                 "Unknown pixel format: %x",
-                                 CVPixelBufferGetPixelFormatType(pixBuf));
-                    return;
-                }
-
-                CVReturn err = CVMetalTextureCacheCreateTextureFromImage(kCFAllocatorDefault, m_TextureCache, pixBuf, nullptr, fmt,
-                                                                         CVPixelBufferGetWidthOfPlane(pixBuf, i),
-                                                                         CVPixelBufferGetHeightOfPlane(pixBuf, i),
-                                                                         i,
-                                                                         &cvMetalTextures[i]);
-                if (err != kCVReturnSuccess) {
-                    SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
-                                 "CVMetalTextureCacheCreateTextureFromImage() failed: %d",
-                                 err);
-                    return;
-                }
             }
         }