Attach EDR metadata to Metal layer

This improves the accuracy of HDR streaming and enables HDR->SDR tonemapping.

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

@@ -6,8 +6,15 @@
 #import <Metal/Metal.h>
 class VTBaseRenderer : public IFFmpegRenderer {
 public:
-    VTBaseRenderer(IFFmpegRenderer::RendererType type) : IFFmpegRenderer(type) {}
+    VTBaseRenderer(IFFmpegRenderer::RendererType type);
+    virtual ~VTBaseRenderer();
     bool checkDecoderCapabilities(id<MTLDevice> device, PDECODER_PARAMETERS params);
+    void setHdrMode(bool enabled) override;
+
+protected:
+    bool m_HdrMetadataChanged; // Manual reset
+    CFDataRef m_MasteringDisplayColorVolume;
+    CFDataRef m_ContentLightLevelInfo;
 };
 #endif
 

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

@@ -39,8 +39,6 @@ public:
           m_HwContext(nullptr),
           m_DisplayLayer(nullptr),
           m_FormatDesc(nullptr),
-          m_ContentLightLevelInfo(nullptr),
-          m_MasteringDisplayColorVolume(nullptr),
           m_StreamView(nullptr),
           m_DisplayLink(nullptr),
           m_LastColorSpace(-1),
@@ -90,14 +88,6 @@ public:
             CGColorSpaceRelease(m_ColorSpace);
         }
 
-        if (m_MasteringDisplayColorVolume != nullptr) {
-            CFRelease(m_MasteringDisplayColorVolume);
-        }
-
-        if (m_ContentLightLevelInfo != nullptr) {
-            CFRelease(m_ContentLightLevelInfo);
-        }
-
         for (int i = 0; i < Overlay::OverlayMax; i++) {
             if (m_OverlayTextFields[i] != nullptr) {
                 [m_OverlayTextFields[i] removeFromSuperview];
@@ -204,63 +194,6 @@ public:
         }
     }
 
-    virtual void setHdrMode(bool enabled) override
-    {
-        // Free existing HDR metadata
-        if (m_MasteringDisplayColorVolume != nullptr) {
-            CFRelease(m_MasteringDisplayColorVolume);
-            m_MasteringDisplayColorVolume = nullptr;
-        }
-        if (m_ContentLightLevelInfo != nullptr) {
-            CFRelease(m_ContentLightLevelInfo);
-            m_ContentLightLevelInfo = nullptr;
-        }
-
-        // Store new HDR metadata if available
-        SS_HDR_METADATA hdrMetadata;
-        if (enabled && LiGetHdrMetadata(&hdrMetadata)) {
-            if (hdrMetadata.displayPrimaries[0].x != 0 && hdrMetadata.maxDisplayLuminance != 0) {
-                // This data is all in big-endian
-                struct {
-                  vector_ushort2 primaries[3];
-                  vector_ushort2 white_point;
-                  uint32_t luminance_max;
-                  uint32_t luminance_min;
-                } __attribute__((packed, aligned(4))) mdcv;
-
-                // mdcv is in GBR order while SS_HDR_METADATA is in RGB order
-                mdcv.primaries[0].x = __builtin_bswap16(hdrMetadata.displayPrimaries[1].x);
-                mdcv.primaries[0].y = __builtin_bswap16(hdrMetadata.displayPrimaries[1].y);
-                mdcv.primaries[1].x = __builtin_bswap16(hdrMetadata.displayPrimaries[2].x);
-                mdcv.primaries[1].y = __builtin_bswap16(hdrMetadata.displayPrimaries[2].y);
-                mdcv.primaries[2].x = __builtin_bswap16(hdrMetadata.displayPrimaries[0].x);
-                mdcv.primaries[2].y = __builtin_bswap16(hdrMetadata.displayPrimaries[0].y);
-
-                mdcv.white_point.x = __builtin_bswap16(hdrMetadata.whitePoint.x);
-                mdcv.white_point.y = __builtin_bswap16(hdrMetadata.whitePoint.y);
-
-                // These luminance values are in 10000ths of a nit
-                mdcv.luminance_max = __builtin_bswap32((uint32_t)hdrMetadata.maxDisplayLuminance * 10000);
-                mdcv.luminance_min = __builtin_bswap32(hdrMetadata.minDisplayLuminance);
-
-                m_MasteringDisplayColorVolume = CFDataCreate(nullptr, (const UInt8*)&mdcv, sizeof(mdcv));
-            }
-
-            if (hdrMetadata.maxContentLightLevel != 0 && hdrMetadata.maxFrameAverageLightLevel != 0) {
-                // This data is all in big-endian
-                struct {
-                    uint16_t max_content_light_level;
-                    uint16_t max_frame_average_light_level;
-                } __attribute__((packed, aligned(2))) cll;
-
-                cll.max_content_light_level = __builtin_bswap16(hdrMetadata.maxContentLightLevel);
-                cll.max_frame_average_light_level = __builtin_bswap16(hdrMetadata.maxFrameAverageLightLevel);
-
-                m_ContentLightLevelInfo = CFDataCreate(nullptr, (const UInt8*)&cll, sizeof(cll));
-            }
-        }
-    }
-
     // Caller frees frame after we return
     virtual void renderFrame(AVFrame* frame) override
     { @autoreleasepool {
@@ -573,8 +506,6 @@ private:
     AVBufferRef* m_HwContext;
     AVSampleBufferDisplayLayer* m_DisplayLayer;
     CMVideoFormatDescriptionRef m_FormatDesc;
-    CFDataRef m_ContentLightLevelInfo;
-    CFDataRef m_MasteringDisplayColorVolume;
     NSView* m_StreamView;
     dispatch_block_t m_OverlayUpdateBlocks[Overlay::OverlayMax];
     NSTextField* m_OverlayTextFields[Overlay::OverlayMax];

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

@@ -9,6 +9,24 @@
 #import <AVFoundation/AVFoundation.h>
 #import <Metal/Metal.h>
 
+VTBaseRenderer::VTBaseRenderer(IFFmpegRenderer::RendererType type) :
+    IFFmpegRenderer(type),
+    m_HdrMetadataChanged(false),
+    m_MasteringDisplayColorVolume(nullptr),
+    m_ContentLightLevelInfo(nullptr) {
+
+}
+
+VTBaseRenderer::~VTBaseRenderer() {
+    if (m_MasteringDisplayColorVolume != nullptr) {
+        CFRelease(m_MasteringDisplayColorVolume);
+    }
+
+    if (m_ContentLightLevelInfo != nullptr) {
+        CFRelease(m_ContentLightLevelInfo);
+    }
+}
+
 bool VTBaseRenderer::checkDecoderCapabilities(id<MTLDevice> device, PDECODER_PARAMETERS params) {
     if (params->videoFormat & VIDEO_FORMAT_MASK_H264) {
         if (!VTIsHardwareDecodeSupported(kCMVideoCodecType_H264)) {
@@ -76,3 +94,61 @@ bool VTBaseRenderer::checkDecoderCapabilities(id<MTLDevice> device, PDECODER_PAR
 
     return true;
 }
+
+void VTBaseRenderer::setHdrMode(bool enabled) {
+    // Free existing HDR metadata
+    if (m_MasteringDisplayColorVolume != nullptr) {
+        CFRelease(m_MasteringDisplayColorVolume);
+        m_MasteringDisplayColorVolume = nullptr;
+    }
+    if (m_ContentLightLevelInfo != nullptr) {
+        CFRelease(m_ContentLightLevelInfo);
+        m_ContentLightLevelInfo = nullptr;
+    }
+
+    // Store new HDR metadata if available
+    SS_HDR_METADATA hdrMetadata;
+    if (enabled && LiGetHdrMetadata(&hdrMetadata)) {
+        if (hdrMetadata.displayPrimaries[0].x != 0 && hdrMetadata.maxDisplayLuminance != 0) {
+            // This data is all in big-endian
+            struct {
+              vector_ushort2 primaries[3];
+              vector_ushort2 white_point;
+              uint32_t luminance_max;
+              uint32_t luminance_min;
+            } __attribute__((packed, aligned(4))) mdcv;
+
+            // mdcv is in GBR order while SS_HDR_METADATA is in RGB order
+            mdcv.primaries[0].x = __builtin_bswap16(hdrMetadata.displayPrimaries[1].x);
+            mdcv.primaries[0].y = __builtin_bswap16(hdrMetadata.displayPrimaries[1].y);
+            mdcv.primaries[1].x = __builtin_bswap16(hdrMetadata.displayPrimaries[2].x);
+            mdcv.primaries[1].y = __builtin_bswap16(hdrMetadata.displayPrimaries[2].y);
+            mdcv.primaries[2].x = __builtin_bswap16(hdrMetadata.displayPrimaries[0].x);
+            mdcv.primaries[2].y = __builtin_bswap16(hdrMetadata.displayPrimaries[0].y);
+
+            mdcv.white_point.x = __builtin_bswap16(hdrMetadata.whitePoint.x);
+            mdcv.white_point.y = __builtin_bswap16(hdrMetadata.whitePoint.y);
+
+            // These luminance values are in 10000ths of a nit
+            mdcv.luminance_max = __builtin_bswap32((uint32_t)hdrMetadata.maxDisplayLuminance * 10000);
+            mdcv.luminance_min = __builtin_bswap32(hdrMetadata.minDisplayLuminance);
+
+            m_MasteringDisplayColorVolume = CFDataCreate(nullptr, (const UInt8*)&mdcv, sizeof(mdcv));
+        }
+
+        if (hdrMetadata.maxContentLightLevel != 0 && hdrMetadata.maxFrameAverageLightLevel != 0) {
+            // This data is all in big-endian
+            struct {
+                uint16_t max_content_light_level;
+                uint16_t max_frame_average_light_level;
+            } __attribute__((packed, aligned(2))) cll;
+
+            cll.max_content_light_level = __builtin_bswap16(hdrMetadata.maxContentLightLevel);
+            cll.max_frame_average_light_level = __builtin_bswap16(hdrMetadata.maxFrameAverageLightLevel);
+
+            m_ContentLightLevelInfo = CFDataCreate(nullptr, (const UInt8*)&cll, sizeof(cll));
+        }
+    }
+
+    m_HdrMetadataChanged = true;
+}

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

@@ -326,7 +326,7 @@ public:
     {
         int colorspace = getFrameColorspace(frame);
         bool fullRange = isFrameFullRange(frame);
-        if (colorspace != m_LastColorSpace || fullRange != m_LastFullRange) {
+        if (colorspace != m_LastColorSpace || fullRange != m_LastFullRange || m_HdrMetadataChanged) {
             CGColorSpaceRef newColorSpace;
             ParamBuffer paramBuffer;
 
@@ -340,14 +340,13 @@ public:
                 paramBuffer.cscParams = (fullRange ? k_CscParams_Bt709Full : k_CscParams_Bt709Lim);
                 break;
             case COLORSPACE_REC_2020:
-                // https://developer.apple.com/documentation/metal/hdr_content/using_color_spaces_to_display_hdr_content
+                m_MetalLayer.pixelFormat = MTLPixelFormatBGR10A2Unorm;
                 if (frame->color_trc == AVCOL_TRC_SMPTE2084) {
+                    // https://developer.apple.com/documentation/metal/hdr_content/using_color_spaces_to_display_hdr_content
                     m_MetalLayer.colorspace = newColorSpace = CGColorSpaceCreateWithName(kCGColorSpaceITUR_2100_PQ);
-                    m_MetalLayer.pixelFormat = MTLPixelFormatBGR10A2Unorm;
                 }
                 else {
                     m_MetalLayer.colorspace = newColorSpace = CGColorSpaceCreateWithName(kCGColorSpaceITUR_2020);
-                    m_MetalLayer.pixelFormat = MTLPixelFormatBGRA8Unorm;
                 }
                 paramBuffer.cscParams = (fullRange ? k_CscParams_Bt2020Full : k_CscParams_Bt2020Lim);
                 break;
@@ -359,6 +358,16 @@ public:
                 break;
             }
 
+            // Set the EDR metadata for HDR10 to enable OS tonemapping
+            if (frame->color_trc == AVCOL_TRC_SMPTE2084 && m_MasteringDisplayColorVolume != nullptr) {
+                m_MetalLayer.EDRMetadata = [CAEDRMetadata HDR10MetadataWithDisplayInfo:(__bridge NSData*)m_MasteringDisplayColorVolume
+                                                                           contentInfo:(__bridge NSData*)m_ContentLightLevelInfo
+                                                                    opticalOutputScale:203.0];
+            }
+            else {
+                m_MetalLayer.EDRMetadata = nullptr;
+            }
+
             paramBuffer.bitnessScaleFactor = getBitnessScaleFactor(frame);
 
             // The CAMetalLayer retains the CGColorSpace
@@ -410,6 +419,7 @@ public:
 
             m_LastColorSpace = colorspace;
             m_LastFullRange = fullRange;
+            m_HdrMetadataChanged = false;
         }
 
         return true;