feat: Add streaming handlers for live TV proxying and VOD HLS transcoding using FFmpeg.

windows/flutter/ephemeral/flutter_texture_registrar.h

@@ -0,0 +1,187 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef FLUTTER_SHELL_PLATFORM_COMMON_PUBLIC_FLUTTER_TEXTURE_REGISTRAR_H_
+#define FLUTTER_SHELL_PLATFORM_COMMON_PUBLIC_FLUTTER_TEXTURE_REGISTRAR_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "flutter_export.h"
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+struct FlutterDesktopTextureRegistrar;
+// Opaque reference to a texture registrar.
+typedef struct FlutterDesktopTextureRegistrar*
+    FlutterDesktopTextureRegistrarRef;
+
+// Possible values for the type specified in FlutterDesktopTextureInfo.
+// Additional types may be added in the future.
+typedef enum {
+  // A Pixel buffer-based texture.
+  kFlutterDesktopPixelBufferTexture,
+  // A platform-specific GPU surface-backed texture.
+  kFlutterDesktopGpuSurfaceTexture
+} FlutterDesktopTextureType;
+
+// Supported GPU surface types.
+typedef enum {
+  // Uninitialized.
+  kFlutterDesktopGpuSurfaceTypeNone,
+  // A DXGI shared texture handle (Windows only).
+  // See
+  // https://docs.microsoft.com/en-us/windows/win32/api/dxgi/nf-dxgi-idxgiresource-getsharedhandle
+  kFlutterDesktopGpuSurfaceTypeDxgiSharedHandle,
+  // A |ID3D11Texture2D| (Windows only).
+  kFlutterDesktopGpuSurfaceTypeD3d11Texture2D
+} FlutterDesktopGpuSurfaceType;
+
+// Supported pixel formats.
+typedef enum {
+  // Uninitialized.
+  kFlutterDesktopPixelFormatNone,
+  // Represents a 32-bit RGBA color format with 8 bits each for red, green, blue
+  // and alpha.
+  kFlutterDesktopPixelFormatRGBA8888,
+  // Represents a 32-bit BGRA color format with 8 bits each for blue, green, red
+  // and alpha.
+  kFlutterDesktopPixelFormatBGRA8888
+} FlutterDesktopPixelFormat;
+
+// An image buffer object.
+typedef struct {
+  // The pixel data buffer.
+  const uint8_t* buffer;
+  // Width of the pixel buffer.
+  size_t width;
+  // Height of the pixel buffer.
+  size_t height;
+  // An optional callback that gets invoked when the |buffer| can be released.
+  void (*release_callback)(void* release_context);
+  // Opaque data passed to |release_callback|.
+  void* release_context;
+} FlutterDesktopPixelBuffer;
+
+// A GPU surface descriptor.
+typedef struct {
+  // The size of this struct. Must be
+  // sizeof(FlutterDesktopGpuSurfaceDescriptor).
+  size_t struct_size;
+  // The surface handle. The expected type depends on the
+  // |FlutterDesktopGpuSurfaceType|.
+  //
+  // Provide a |ID3D11Texture2D*| when using
+  // |kFlutterDesktopGpuSurfaceTypeD3d11Texture2D| or a |HANDLE| when using
+  // |kFlutterDesktopGpuSurfaceTypeDxgiSharedHandle|.
+  //
+  // The referenced resource needs to stay valid until it has been opened by
+  // Flutter. Consider incrementing the resource's reference count in the
+  // |FlutterDesktopGpuSurfaceTextureCallback| and registering a
+  // |release_callback| for decrementing the reference count once it has been
+  // opened.
+  void* handle;
+  // The physical width.
+  size_t width;
+  // The physical height.
+  size_t height;
+  // The visible width.
+  // It might be less or equal to the physical |width|.
+  size_t visible_width;
+  // The visible height.
+  // It might be less or equal to the physical |height|.
+  size_t visible_height;
+  // The pixel format which might be optional depending on the surface type.
+  FlutterDesktopPixelFormat format;
+  // An optional callback that gets invoked when the |handle| has been opened.
+  void (*release_callback)(void* release_context);
+  // Opaque data passed to |release_callback|.
+  void* release_context;
+} FlutterDesktopGpuSurfaceDescriptor;
+
+// The pixel buffer copy callback definition provided to
+// the Flutter engine to copy the texture.
+// It is invoked with the intended surface size specified by |width| and
+// |height| and the |user_data| held by
+// |FlutterDesktopPixelBufferTextureConfig|.
+//
+// As this is usually called from the render thread, the callee must take
+// care of proper synchronization. It also needs to be ensured that the
+// returned |FlutterDesktopPixelBuffer| isn't released prior to unregistering
+// the corresponding texture.
+typedef const FlutterDesktopPixelBuffer* (
+    *FlutterDesktopPixelBufferTextureCallback)(size_t width,
+                                               size_t height,
+                                               void* user_data);
+
+// The GPU surface callback definition provided to the Flutter engine to obtain
+// the surface. It is invoked with the intended surface size specified by
+// |width| and |height| and the |user_data| held by
+// |FlutterDesktopGpuSurfaceTextureConfig|.
+typedef const FlutterDesktopGpuSurfaceDescriptor* (
+    *FlutterDesktopGpuSurfaceTextureCallback)(size_t width,
+                                              size_t height,
+                                              void* user_data);
+
+// An object used to configure pixel buffer textures.
+typedef struct {
+  // The callback used by the engine to copy the pixel buffer object.
+  FlutterDesktopPixelBufferTextureCallback callback;
+  // Opaque data that will get passed to the provided |callback|.
+  void* user_data;
+} FlutterDesktopPixelBufferTextureConfig;
+
+// An object used to configure GPU-surface textures.
+typedef struct {
+  // The size of this struct. Must be
+  // sizeof(FlutterDesktopGpuSurfaceTextureConfig).
+  size_t struct_size;
+  // The concrete surface type (e.g.
+  // |kFlutterDesktopGpuSurfaceTypeDxgiSharedHandle|)
+  FlutterDesktopGpuSurfaceType type;
+  // The callback used by the engine to obtain the surface descriptor.
+  FlutterDesktopGpuSurfaceTextureCallback callback;
+  // Opaque data that will get passed to the provided |callback|.
+  void* user_data;
+} FlutterDesktopGpuSurfaceTextureConfig;
+
+typedef struct {
+  FlutterDesktopTextureType type;
+  union {
+    FlutterDesktopPixelBufferTextureConfig pixel_buffer_config;
+    FlutterDesktopGpuSurfaceTextureConfig gpu_surface_config;
+  };
+} FlutterDesktopTextureInfo;
+
+// Registers a new texture with the Flutter engine and returns the texture ID.
+// This function can be called from any thread.
+FLUTTER_EXPORT int64_t FlutterDesktopTextureRegistrarRegisterExternalTexture(
+    FlutterDesktopTextureRegistrarRef texture_registrar,
+    const FlutterDesktopTextureInfo* info);
+
+// Asynchronously unregisters the texture identified by |texture_id| from the
+// Flutter engine.
+// An optional |callback| gets invoked upon completion.
+// This function can be called from any thread.
+FLUTTER_EXPORT void FlutterDesktopTextureRegistrarUnregisterExternalTexture(
+    FlutterDesktopTextureRegistrarRef texture_registrar,
+    int64_t texture_id,
+    void (*callback)(void* user_data),
+    void* user_data);
+
+// Marks that a new texture frame is available for a given |texture_id|.
+// Returns true on success or false if the specified texture doesn't exist.
+// This function can be called from any thread.
+FLUTTER_EXPORT bool
+FlutterDesktopTextureRegistrarMarkExternalTextureFrameAvailable(
+    FlutterDesktopTextureRegistrarRef texture_registrar,
+    int64_t texture_id);
+
+#if defined(__cplusplus)
+}  // extern "C"
+#endif
+
+#endif  // FLUTTER_SHELL_PLATFORM_COMMON_PUBLIC_FLUTTER_TEXTURE_REGISTRAR_H_