Added asynchronous LoadImageAtPathAsync and GetVideoThumbnailAsync functions (requires 2018.4 or later)

Author: yasirkula

.github/README.md

@@ -99,11 +99,15 @@ Beginning with *6.0 Marshmallow*, Android apps must request runtime permissions
 - **generateMipmaps** determines whether texture should have mipmaps or not
 - **linearColorSpace** determines whether texture should be in linear color space or sRGB color space
 
-`Texture2D NativeCamera.GetVideoThumbnail( string videoPath, int maxSize = -1, double captureTimeInSeconds = -1.0, bool markTextureNonReadable = true )`: creates a Texture2D thumbnail from a video file and returns it. Returns *null*, if something goes wrong.
+`async Task<Texture2D> NativeCamera.LoadImageAtPathAsync( string imagePath, int maxSize = -1, bool markTextureNonReadable = true, bool generateMipmaps = true, bool linearColorSpace = false )`: asynchronous variant of *LoadImageAtPath* (requires Unity 2018.4 or later). Works best when *linearColorSpace* is *false*. It's also slightly faster when *generateMipmaps* is *false*. Note that it isn't possible to load multiple images simultaneously using this function.
+
+`Texture2D NativeCamera.GetVideoThumbnail( string videoPath, int maxSize = -1, double captureTimeInSeconds = -1.0, bool markTextureNonReadable = true, bool generateMipmaps = true, bool linearColorSpace = false )`: creates a Texture2D thumbnail from a video file and returns it. Returns *null*, if something goes wrong.
 - **maxSize** determines the maximum size of the returned Texture2D in pixels. Larger thumbnails will be down-scaled. If untouched, its value will be set to *SystemInfo.maxTextureSize*. It is recommended to set a proper maxSize for better performance
 - **captureTimeInSeconds** determines the frame of the video that the thumbnail is captured from. If untouched, OS will decide this value
 - **markTextureNonReadable** (see *LoadImageAtPath*)
 
+`async Task<Texture2D> NativeCamera.GetVideoThumbnailAsync( string videoPath, int maxSize = -1, double captureTimeInSeconds = -1.0, bool markTextureNonReadable = true, bool generateMipmaps = true, bool linearColorSpace = false )`: asynchronous variant of *GetVideoThumbnail* (requires Unity 2018.4 or later). Works best when *linearColorSpace* is *false*. It's also slightly faster when *generateMipmaps* is *false*. Note that it isn't possible to generate multiple video thumbnails simultaneously using this function.
+
 ## EXAMPLE CODE
 
 The following code has two functions:

Plugins/NativeCamera/NativeCamera.cs

@@ -2,10 +2,15 @@
 using System.Globalization;
 using System.IO;
 using UnityEngine;
-using Object = UnityEngine.Object;
+#if UNITY_2018_4_OR_NEWER && !NATIVE_CAMERA_DISABLE_ASYNC_FUNCTIONS
+using System.Threading.Tasks;
+using Unity.Collections;
+using UnityEngine.Networking;
+#endif
 #if UNITY_ANDROID || UNITY_IOS
 using NativeCameraNamespace;
 #endif
+using Object = UnityEngine.Object;
 
 public static class NativeCamera
 {
@@ -287,8 +292,7 @@ public static bool IsCameraBusy()
 	#endregion
 
 	#region Utility Functions
-	public static Texture2D LoadImageAtPath( string imagePath, int maxSize = -1, bool markTextureNonReadable = true,
-		bool generateMipmaps = true, bool linearColorSpace = false )
+	public static Texture2D LoadImageAtPath( string imagePath, int maxSize = -1, bool markTextureNonReadable = true, bool generateMipmaps = true, bool linearColorSpace = false )
 	{
 		if( string.IsNullOrEmpty( imagePath ) )
 			throw new ArgumentException( "Parameter 'imagePath' is null or empty!" );
@@ -316,6 +320,8 @@ public static Texture2D LoadImageAtPath( string imagePath, int maxSize = -1, boo
 		{
 			if( !result.LoadImage( File.ReadAllBytes( loadPath ), markTextureNonReadable ) )
 			{
+				Debug.LogWarning( "Couldn't load image at path: " + loadPath );
+
 				Object.DestroyImmediate( result );
 				return null;
 			}
@@ -342,7 +348,129 @@ public static Texture2D LoadImageAtPath( string imagePath, int maxSize = -1, boo
 		return result;
 	}
 
-	public static Texture2D GetVideoThumbnail( string videoPath, int maxSize = -1, double captureTimeInSeconds = -1.0, bool markTextureNonReadable = true )
+#if UNITY_2018_4_OR_NEWER && !NATIVE_CAMERA_DISABLE_ASYNC_FUNCTIONS
+	public static async Task<Texture2D> LoadImageAtPathAsync( string imagePath, int maxSize = -1, bool markTextureNonReadable = true, bool generateMipmaps = true, bool linearColorSpace = false )
+	{
+		if( string.IsNullOrEmpty( imagePath ) )
+			throw new ArgumentException( "Parameter 'imagePath' is null or empty!" );
+
+		if( !File.Exists( imagePath ) )
+			throw new FileNotFoundException( "File not found at " + imagePath );
+
+		if( maxSize <= 0 )
+			maxSize = SystemInfo.maxTextureSize;
+
+#if !UNITY_EDITOR && UNITY_ANDROID
+		string loadPath = await TryCallNativeAndroidFunctionOnSeparateThread( () => AJC.CallStatic<string>( "LoadImageAtPath", Context, imagePath, TemporaryImagePath, maxSize ) );
+#elif !UNITY_EDITOR && UNITY_IOS
+		string loadPath = await Task.Run( () => _NativeCamera_LoadImageAtPath( imagePath, TemporaryImagePath, maxSize ) );
+#else
+		string loadPath = imagePath;
+#endif
+
+		Texture2D result = null;
+
+		if( !linearColorSpace )
+		{
+			using( UnityWebRequest www = UnityWebRequestTexture.GetTexture( "file://" + loadPath, markTextureNonReadable && !generateMipmaps ) )
+			{
+				UnityWebRequestAsyncOperation asyncOperation = www.SendWebRequest();
+				while( !asyncOperation.isDone )
+					await Task.Yield();
+
+#if UNITY_2020_1_OR_NEWER
+				if( www.result != UnityWebRequest.Result.Success )
+#else
+				if( www.isNetworkError || www.isHttpError )
+#endif
+				{
+					Debug.LogWarning( "Couldn't use UnityWebRequest to load image, falling back to LoadImage: " + www.error );
+				}
+				else
+				{
+					Texture2D texture = DownloadHandlerTexture.GetContent( www );
+
+					if( !generateMipmaps )
+						result = texture;
+					else
+					{
+						Texture2D mipmapTexture = null;
+						try
+						{
+							// Generate a Texture with mipmaps enabled
+							// Credits: https://forum.unity.com/threads/generate-mipmaps-at-runtime-for-a-texture-loaded-with-unitywebrequest.644842/#post-7571809
+							NativeArray<byte> textureData = texture.GetRawTextureData<byte>();
+
+							mipmapTexture = new Texture2D( texture.width, texture.height, texture.format, true );
+#if UNITY_2019_3_OR_NEWER
+							mipmapTexture.SetPixelData( textureData, 0 );
+#else
+							NativeArray<byte> mipmapTextureData = mipmapTexture.GetRawTextureData<byte>();
+							NativeArray<byte>.Copy( textureData, mipmapTextureData, textureData.Length );
+							mipmapTexture.LoadRawTextureData( mipmapTextureData );
+#endif
+							mipmapTexture.Apply( true, markTextureNonReadable );
+
+							result = mipmapTexture;
+						}
+						catch( Exception e )
+						{
+							Debug.LogException( e );
+
+							if( mipmapTexture )
+								Object.DestroyImmediate( mipmapTexture );
+						}
+						finally
+						{
+							Object.DestroyImmediate( texture );
+						}
+					}
+				}
+			}
+		}
+
+		if( !result ) // Fallback to Texture2D.LoadImage if something goes wrong
+		{
+			string extension = Path.GetExtension( imagePath ).ToLowerInvariant();
+			TextureFormat format = ( extension == ".jpg" || extension == ".jpeg" ) ? TextureFormat.RGB24 : TextureFormat.RGBA32;
+
+			result = new Texture2D( 2, 2, format, generateMipmaps, linearColorSpace );
+
+			try
+			{
+				if( !result.LoadImage( File.ReadAllBytes( loadPath ), markTextureNonReadable ) )
+				{
+					Debug.LogWarning( "Couldn't load image at path: " + loadPath );
+
+					Object.DestroyImmediate( result );
+					return null;
+				}
+			}
+			catch( Exception e )
+			{
+				Debug.LogException( e );
+
+				Object.DestroyImmediate( result );
+				return null;
+			}
+			finally
+			{
+				if( loadPath != imagePath )
+				{
+					try
+					{
+						File.Delete( loadPath );
+					}
+					catch { }
+				}
+			}
+		}
+
+		return result;
+	}
+#endif
+
+	public static Texture2D GetVideoThumbnail( string videoPath, int maxSize = -1, double captureTimeInSeconds = -1.0, bool markTextureNonReadable = true, bool generateMipmaps = true, bool linearColorSpace = false )
 	{
 		if( maxSize <= 0 )
 			maxSize = SystemInfo.maxTextureSize;
@@ -356,11 +484,58 @@ public static Texture2D GetVideoThumbnail( string videoPath, int maxSize = -1, d
 #endif
 
 		if( !string.IsNullOrEmpty( thumbnailPath ) )
-			return LoadImageAtPath( thumbnailPath, maxSize, markTextureNonReadable );
+			return LoadImageAtPath( thumbnailPath, maxSize, markTextureNonReadable, generateMipmaps, linearColorSpace );
+		else
+			return null;
+	}
+
+#if UNITY_2018_4_OR_NEWER && !NATIVE_CAMERA_DISABLE_ASYNC_FUNCTIONS
+	public static async Task<Texture2D> GetVideoThumbnailAsync( string videoPath, int maxSize = -1, double captureTimeInSeconds = -1.0, bool markTextureNonReadable = true, bool generateMipmaps = true, bool linearColorSpace = false )
+	{
+		if( maxSize <= 0 )
+			maxSize = SystemInfo.maxTextureSize;
+
+#if !UNITY_EDITOR && UNITY_ANDROID
+		string thumbnailPath = await TryCallNativeAndroidFunctionOnSeparateThread( () => AJC.CallStatic<string>( "GetVideoThumbnail", Context, videoPath, TemporaryImagePath + ".png", false, maxSize, captureTimeInSeconds ) );
+#elif !UNITY_EDITOR && UNITY_IOS
+		string thumbnailPath = await Task.Run( () => _NativeCamera_GetVideoThumbnail( videoPath, TemporaryImagePath + ".png", maxSize, captureTimeInSeconds ) );
+#else
+		string thumbnailPath = null;
+#endif
+
+		if( !string.IsNullOrEmpty( thumbnailPath ) )
+			return await LoadImageAtPathAsync( thumbnailPath, maxSize, markTextureNonReadable, generateMipmaps, linearColorSpace );
 		else
 			return null;
 	}
 
+	private static async Task<T> TryCallNativeAndroidFunctionOnSeparateThread<T>( Func<T> function )
+	{
+		T result = default( T );
+		bool hasResult = false;
+
+		await Task.Run( () =>
+		{
+			if( AndroidJNI.AttachCurrentThread() != 0 )
+				Debug.LogWarning( "Couldn't attach JNI thread, calling native function on the main thread" );
+			else
+			{
+				try
+				{
+					result = function();
+					hasResult = true;
+				}
+				finally
+				{
+					AndroidJNI.DetachCurrentThread();
+				}
+			}
+		} );
+
+		return hasResult ? result : function();
+	}
+#endif
+
 	public static ImageProperties GetImageProperties( string imagePath )
 	{
 		if( !File.Exists( imagePath ) )

Plugins/NativeCamera/README.txt

@@ -1,4 +1,4 @@
-= Native Camera for Android & iOS =
+= Native Camera for Android & iOS (v1.3.5) =
 
 Online documentation & example code available at: https://github.com/yasirkula/UnityNativeCamera
 E-mail: yasirkula@gmail.com
@@ -78,12 +78,16 @@ bool NativeCamera.CanOpenSettings();
 // generateMipmaps: determines whether texture should have mipmaps or not
 // linearColorSpace: determines whether texture should be in linear color space or sRGB color space
 Texture2D NativeCamera.LoadImageAtPath( string imagePath, int maxSize = -1, bool markTextureNonReadable = true, bool generateMipmaps = true, bool linearColorSpace = false );
+async Task<Texture2D> NativeCamera.LoadImageAtPathAsync( string imagePath, int maxSize = -1, bool markTextureNonReadable = true, bool generateMipmaps = true, bool linearColorSpace = false );
 
 // Creates a Texture2D thumbnail from a video file and returns it. Returns null, if something goes wrong
 // maxSize: determines the maximum size of the returned Texture2D in pixels. Larger thumbnails will be down-scaled. If untouched, its value will be set to SystemInfo.maxTextureSize. It is recommended to set a proper maxSize for better performance
 // captureTimeInSeconds: determines the frame of the video that the thumbnail is captured from. If untouched, OS will decide this value
 // markTextureNonReadable: see LoadImageAtPath
-Texture2D NativeCamera.GetVideoThumbnail( string videoPath, int maxSize = -1, double captureTimeInSeconds = -1.0, bool markTextureNonReadable = true );
+// generateMipmaps: see LoadImageAtPath
+// linearColorSpace: see LoadImageAtPath
+Texture2D NativeCamera.GetVideoThumbnail( string videoPath, int maxSize = -1, double captureTimeInSeconds = -1.0, bool markTextureNonReadable = true, bool generateMipmaps = true, bool linearColorSpace = false );
+async Task<Texture2D> NativeCamera.GetVideoThumbnailAsync( string videoPath, int maxSize = -1, double captureTimeInSeconds = -1.0, bool markTextureNonReadable = true, bool generateMipmaps = true, bool linearColorSpace = false );
 
 // Returns an ImageProperties instance that holds the width, height and mime type information of an image file without creating a Texture2D object. Mime type will be null, if it can't be determined
 NativeCamera.ImageProperties NativeCamera.GetImageProperties( string imagePath );

package.json

@@ -1,7 +1,7 @@
 {
   "name": "com.yasirkula.nativecamera",
   "displayName": "Native Camera",
-  "version": "1.3.3",
+  "version": "1.3.5",
   "documentationUrl": "https://github.com/yasirkula/UnityNativeCamera",
   "changelogUrl": "https://github.com/yasirkula/UnityNativeCamera/releases",
   "licensesUrl": "https://github.com/yasirkula/UnityNativeCamera/blob/master/LICENSE.txt",