Write a better native library loader so DLLs are no longer extracted to the current directory on Windows.

src/com/limelight/Limelight.java

@@ -1,14 +1,12 @@
 package com.limelight;
 
-import java.io.File;
-import java.io.FileNotFoundException;
-import java.io.FileOutputStream;
 import java.io.IOException;
-import java.io.InputStream;
+
 import javax.swing.JFrame;
 import javax.swing.JOptionPane;
 import javax.swing.UIManager;
 
+import com.limelight.binding.LibraryHelper;
 import com.limelight.binding.PlatformBinding;
 import com.limelight.gui.MainFrame;
 import com.limelight.gui.StreamFrame;
@@ -34,53 +32,6 @@ public class Limelight implements NvConnectionListener {
 		this.host = host;
 	}
 
-	private static void extractNativeLibrary(String libraryName, String targetDirectory) throws IOException {
-		InputStream resource = new Object().getClass().getResourceAsStream("/binlib/"+libraryName);
-		if (resource == null) {
-			throw new FileNotFoundException("Unable to find native library in JAR: "+libraryName);
-		}
-		File destination = new File(targetDirectory+File.separatorChar+libraryName);
-		
-		// this will only delete it if it exists, and then create a new file
-		destination.delete();
-		destination.createNewFile();
-		
-		//this is the janky java 6 way to copy a file
-		FileOutputStream fos = null;
-		try {
-			fos = new FileOutputStream(destination);
-			int read;
-			byte[] readBuffer = new byte[16384];
-			while ((read = resource.read(readBuffer)) != -1) {
-				fos.write(readBuffer, 0, read);
-			}
-		} finally {
-			if (fos != null) {
-				fos.close();
-			}
-		}
-	}
-
-	private static void prepareNativeLibraries() throws IOException {
-		if (!System.getProperty("os.name").contains("Windows")) {
-			// Nothing to do for platforms other than Windows
-			return;
-		}
-
-		// We need to extract nv_avc_dec's runtime dependencies manually
-		// because the current JRE extracts them with different file names
-		// so they don't load properly.
-		String nativeLibDir = ".";
-		extractNativeLibrary("avfilter-3.dll", nativeLibDir);
-		extractNativeLibrary("avformat-55.dll", nativeLibDir);
-		extractNativeLibrary("avutil-52.dll", nativeLibDir);
-		extractNativeLibrary("postproc-52.dll", nativeLibDir);
-		extractNativeLibrary("pthreadVC2.dll", nativeLibDir);
-		extractNativeLibrary("swresample-0.dll", nativeLibDir);
-		extractNativeLibrary("swscale-2.dll", nativeLibDir);
-		extractNativeLibrary("avcodec-55.dll", nativeLibDir);
-	}
-
 	private void startUp() {
 		streamFrame = new StreamFrame();
 		
@@ -150,7 +101,7 @@ public class Limelight implements NvConnectionListener {
 		}
 
 		try {
-			prepareNativeLibraries();
+			LibraryHelper.prepareNativeLibraries();
 		} catch (IOException e) {
 			// This is expected to fail when not in a JAR
 		}

src/com/limelight/binding/LibraryHelper.java

@@ -0,0 +1,85 @@
+package com.limelight.binding;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.HashSet;
+
+public class LibraryHelper {
+	private static final HashSet<String> avcDependencies = new HashSet<String>();
+	private static final boolean needsDependencyExtraction;
+	private static final String libraryExtractionFolder;
+	
+	static {
+		needsDependencyExtraction = System.getProperty("os.name", "").contains("Windows");
+		libraryExtractionFolder = System.getProperty("java.io.tmpdir", ".");
+		
+		// FFMPEG libraries
+		avcDependencies.add("avutil-52");
+		avcDependencies.add("swresample-0");
+		avcDependencies.add("swscale-2");
+		avcDependencies.add("avcodec-55");
+		avcDependencies.add("avformat-55");
+		avcDependencies.add("avfilter-3");
+		
+		// The AVC JNI library itself
+		avcDependencies.add("nv_avc_dec");
+		
+		// Additional Windows dependencies
+		if (System.getProperty("os.name").contains("Windows")) {
+			avcDependencies.add("postproc-52");
+			avcDependencies.add("pthreadVC2");
+		}
+	}
+	
+	public static void loadNativeLibrary(String libraryName) {
+		if (needsDependencyExtraction && avcDependencies.contains(libraryName)) {
+			System.load(libraryExtractionFolder + File.separatorChar + System.mapLibraryName(libraryName));
+		}
+		else {
+			System.loadLibrary(libraryName);
+		}
+	}
+
+	public static void prepareNativeLibraries() throws IOException {
+		if (!needsDependencyExtraction) {
+			return;
+		}
+		
+		for (String dependency : avcDependencies) {
+			extractNativeLibrary(dependency);
+		}
+	}
+	
+	private static void extractNativeLibrary(String libraryName) throws IOException {
+		// convert general library name to platform-specific name
+		libraryName = System.mapLibraryName(libraryName);
+		
+		InputStream resource = new Object().getClass().getResourceAsStream("/binlib/"+libraryName);
+		if (resource == null) {
+			throw new FileNotFoundException("Unable to find native library in JAR: "+libraryName);
+		}
+		File destination = new File(libraryExtractionFolder+File.separatorChar+libraryName);
+		
+		// this will only delete it if it exists, and then create a new file
+		destination.delete();
+		destination.createNewFile();
+		
+		//this is the janky java 6 way to copy a file
+		FileOutputStream fos = null;
+		try {
+			fos = new FileOutputStream(destination);
+			int read;
+			byte[] readBuffer = new byte[16384];
+			while ((read = resource.read(readBuffer)) != -1) {
+				fos.write(readBuffer, 0, read);
+			}
+		} finally {
+			if (fos != null) {
+				fos.close();
+			}
+		}
+	}
+}

src/com/limelight/binding/video/SwingCpuDecoderRenderer.java

@@ -38,14 +38,6 @@ public class SwingCpuDecoderRenderer implements VideoDecoderRenderer {
 		int avcFlags = AvcDecoder.LOW_LATENCY_DECODE;
 		int threadCount = 1;
 
-		// Hack to work around the bad Java native library loader
-		// which can't resolve native library dependencies
-		if (System.getProperty("os.name").contains("Windows")) {
-			System.loadLibrary("avutil-52");
-			System.loadLibrary("postproc-52");
-			System.loadLibrary("pthreadVC2");
-		}
-		
 		int err = AvcDecoder.init(width, height, avcFlags, threadCount);
 		if (err != 0) {
 			throw new IllegalStateException("AVC decoder initialization failure: "+err);

src/com/limelight/nvstream/av/video/cpu/AvcDecoder.java

@@ -0,0 +1,50 @@
+package com.limelight.nvstream.av.video.cpu;
+
+import com.limelight.binding.LibraryHelper;
+
+public class AvcDecoder {
+	static {
+		LibraryHelper.loadNativeLibrary("avutil-52");
+		if (System.getProperty("os.name").contains("Windows")) {
+			LibraryHelper.loadNativeLibrary("postproc-52");
+			LibraryHelper.loadNativeLibrary("pthreadVC2");
+		}
+		LibraryHelper.loadNativeLibrary("swresample-0");
+		LibraryHelper.loadNativeLibrary("swscale-2");
+		LibraryHelper.loadNativeLibrary("avcodec-55");
+		LibraryHelper.loadNativeLibrary("avformat-55");
+		LibraryHelper.loadNativeLibrary("avfilter-3");
+		
+		LibraryHelper.loadNativeLibrary("nv_avc_dec");
+	}
+	
+	/** Disables the deblocking filter at the cost of image quality */
+	public static final int DISABLE_LOOP_FILTER = 0x1;
+	/** Uses the low latency decode flag (disables multithreading) */
+	public static final int LOW_LATENCY_DECODE = 0x2;
+	/** Threads process each slice, rather than each frame */
+	public static final int SLICE_THREADING = 0x4;
+	/** Uses nonstandard speedup tricks */
+	public static final int FAST_DECODE = 0x8;
+	/** Uses bilinear filtering instead of bicubic */
+	public static final int BILINEAR_FILTERING = 0x10;
+	/** Uses a faster bilinear filtering with lower image quality */
+	public static final int FAST_BILINEAR_FILTERING = 0x20;
+	/** Disables color conversion (output is NV21) */
+	public static final int NO_COLOR_CONVERSION = 0x40;
+	
+	public static native int init(int width, int height, int perflvl, int threadcount);
+	public static native void destroy();
+	
+	// Rendering API when NO_COLOR_CONVERSION == 0
+	public static native boolean setRenderTarget(Object androidSurface);
+	public static native boolean getRgbFrameInt(int[] rgbFrame, int bufferSize);
+	public static native boolean getRgbFrame(byte[] rgbFrame, int bufferSize);
+	public static native boolean redraw();
+
+	// Rendering API when NO_COLOR_CONVERSION == 1
+	public static native boolean getRawFrame(byte[] yuvFrame, int bufferSize);
+	
+	public static native int getInputPaddingSize();
+	public static native int decode(byte[] indata, int inoff, int inlen);
+}