Implement libplacebo on MoltenVK

app/streaming/video/ffmpeg-renderers/plvk.h

@@ -10,6 +10,21 @@
 #include <libplacebo/renderer.h>
 #include <libplacebo/vulkan.h>
 
+#ifdef Q_OS_DARWIN
+class MetalVulkanTextureFactory {
+public:
+    MetalVulkanTextureFactory(pl_vulkan vulkan);
+    ~MetalVulkanTextureFactory();
+
+    bool mapVideoToolboxToPlacebo(const AVFrame *frame, pl_frame* mappedFrame);
+    void unmapVideoToolboxFromPlacebo(pl_frame* mappedFrame);
+
+private:
+    pl_vulkan m_Vulkan;
+    /* CVMetalTextureCacheRef */ void* m_TextureCache = nullptr;
+};
+#endif
+
 class PlVkRenderer : public IFFmpegRenderer {
 public:
     PlVkRenderer(AVHWDeviceType hwDeviceType = AV_HWDEVICE_TYPE_NONE, IFFmpegRenderer *backendRenderer = nullptr);
@@ -35,6 +50,7 @@ private:
     static void overlayUploadComplete(void* opaque);
 
     bool mapAvFrameToPlacebo(const AVFrame *frame, pl_frame* mappedFrame);
+    void unmapAvFrameFromPlacebo(const AVFrame *frame, pl_frame* mappedFrame);
     bool populateQueues(int videoFormat);
     bool chooseVulkanDevice(PDECODER_PARAMETERS params, bool hdrOutputRequired);
     bool tryInitializeDevice(VkPhysicalDevice device, VkPhysicalDeviceProperties* deviceProps,
@@ -48,6 +64,10 @@ private:
     IFFmpegRenderer* m_Backend;
     AVHWDeviceType m_HwDeviceType;
 
+#ifdef Q_OS_DARWIN
+    std::unique_ptr<MetalVulkanTextureFactory> m_MetalTextureFactory;
+#endif
+
     // SDL state
     SDL_Window* m_Window = nullptr;