impement android.media.MediaCodec using libavcodec

The current implementation requires a VA-API driver and a Wayland
compositor with YUV-buffer support. GNOME supports YUV-buffers
since the recent version 45 release

src/api-impl/android/media/MediaCodec.java

@@ -1,9 +1,150 @@
 package android.media;
 
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.util.ArrayDeque;
+import java.util.Queue;
+import android.view.Surface;
+
 public class MediaCodec {
 
+	private String codecName;
+	private ByteBuffer[] inputBuffers;
+	private ByteBuffer[] outputBuffers;
+	private long[] inputBufferTimestamps;
+	private long native_codec;
+	private boolean outputFormatSet = false;
+	private MediaFormat mediaFormat;
+
+	private Queue<Integer> freeOutputBuffers;
+	private Queue<Integer> queuedInputBuffers;
+	private Queue<Integer> freeInputBuffers;
+
+	private MediaCodec(String codecName) {
+		this.codecName = codecName;
+		native_codec = native_constructor(codecName);
+		inputBuffers = new ByteBuffer[1];
+		inputBufferTimestamps = new long[inputBuffers.length];
+		freeInputBuffers = new ArrayDeque<>(inputBuffers.length);
+		queuedInputBuffers = new ArrayDeque<>(inputBuffers.length);
+		for (int i = 0; i < inputBuffers.length; i++) {
+			inputBuffers[i] = ByteBuffer.allocate(262144).order(ByteOrder.LITTLE_ENDIAN);
+			freeInputBuffers.add(i);
+		}
+		outputBuffers = new ByteBuffer[2];
+		freeOutputBuffers = new ArrayDeque<>(outputBuffers.length);
+		for (int i = 0; i < outputBuffers.length; i++) {
+			outputBuffers[i] = ByteBuffer.allocate(4096).order(ByteOrder.LITTLE_ENDIAN);
+			freeOutputBuffers.add(i);
+		}
+	}
+
+	public static MediaCodec createByCodecName(String codecName) {
+		return new MediaCodec(codecName);
+	}
+
+	public void configure(MediaFormat format, Surface surface, MediaCrypto crypto, int flags) {
+		System.out.println("MediaCodec.configure(" + format + ", " + surface + ", " + crypto +	", " + flags + "): codecName=" + codecName);
+		this.mediaFormat = format;
+		if ("aac".equals(codecName)) {
+			native_configure_audio(native_codec, format.getByteBuffer("csd-0"), format.getInteger("sample-rate"), format.getInteger("channel-count"));
+		} else if ("h264".equals(codecName)) {
+			native_configure_video(native_codec, format.getByteBuffer("csd-0"), format.getByteBuffer("csd-1"), surface);
+		}
+	}
+
+	public void start() {
+		System.out.println("MediaCodec.start(): codecName=" + codecName);
+		native_start(native_codec);
+	}
+
+	public ByteBuffer[] getInputBuffers() {
+		return inputBuffers;
+	}
+
+	public ByteBuffer[] getOutputBuffers() {
+		return outputBuffers;
+	}
+
+	public int dequeueOutputBuffer(BufferInfo info, long timeoutUs) {
+		if (!outputFormatSet) {
+			outputFormatSet = true;
+			return /*INFO_OUTPUT_FORMAT_CHANGED*/ -2;
+		}
+		Integer index = freeOutputBuffers.poll();
+		if (index == null) {
+			return /*INFO_TRY_AGAIN_LATER*/ -1;
+		}
+		outputBuffers[index].clear();
+		int ret = native_dequeueOutputBuffer(native_codec, outputBuffers[index], info);
+		if (ret == 0) {
+			ret = index;
+		} else {
+			freeOutputBuffers.add(index);
+			ret = /*INFO_TRY_AGAIN_LATER*/ -1;
+		}
+		return ret;
+	}
+
+	public void releaseOutputBuffer(int index, boolean render) {
+		native_releaseOutputBuffer(native_codec, outputBuffers[index], render);
+		freeOutputBuffers.add(index);
+	}
+
+	public MediaFormat getOutputFormat() {
+		return mediaFormat;
+	}
+
+	public void flush() {}
+
+	private void tryProcessInputBuffer() {
+		Integer index = queuedInputBuffers.peek();
+		if (index != null) {
+			int ret = native_queueInputBuffer(native_codec, inputBuffers[index], inputBufferTimestamps[index]);
+			if (ret == 0) {
+				queuedInputBuffers.remove(index);
+				freeInputBuffers.add(index);
+			}
+		}
+	}
+
+	public int dequeueInputBuffer(long timeoutUs) {
+		tryProcessInputBuffer();
+		Integer index = freeInputBuffers.poll();
+		if (index == null) {
+			return /*INFO_TRY_AGAIN_LATER*/ -1;
+		} else {
+			return index;
+		}
+	}
+
+	public void queueInputBuffer(int index, int offset, int size, long presentationTimeUs, int flags) {
+		inputBufferTimestamps[index] = presentationTimeUs;
+		queuedInputBuffers.add(index);
+		tryProcessInputBuffer();
+	}
+
+	public void setVideoScalingMode(int mode) {
+		System.out.println("MediaCodec.setVideoScalingMode(" + mode + "): codecName=" + codecName);
+	}
+
+	private native long native_constructor(String codecName);
+	private native void native_configure_audio(long codec, ByteBuffer extradata, int sampleRate, int channelCount);
+	private native void native_configure_video(long codec, ByteBuffer csd0, ByteBuffer csd1, Surface surface);
+	private native void native_start(long codec);
+	private native int native_queueInputBuffer(long codec, ByteBuffer buffer, long presentationTimeUs);
+	private native int native_dequeueOutputBuffer(long codec, ByteBuffer buffer, BufferInfo info);
+	private native void native_releaseOutputBuffer(long codec, ByteBuffer buffer, boolean render);
+
 	public static final class CryptoInfo {}
 
-	public static final class BufferInfo {}
+	public static final class BufferInfo {
+		public int size;
+		public int flags;
+		public int offset;
+		public long presentationTimeUs;
+	}
+
+	public static interface OnFrameRenderedListener {}
 	
 }

src/api-impl/android/media/MediaCodecInfo.java

@@ -0,0 +1,32 @@
+package android.media;
+
+public class MediaCodecInfo {
+
+	private String name;
+	private String mime;
+
+	public MediaCodecInfo(String name, String mime) {
+		this.name = name;
+		this.mime = mime;		
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	public boolean isEncoder() {
+		return false;
+	}
+
+	public String[] getSupportedTypes() {
+		return new String[] { mime };
+	}
+
+	public CodecCapabilities getCapabilitiesForType(String type) {
+		return null;
+	}
+
+	public static class CodecCapabilities {}
+
+	public static class CodecProfileLevel {}
+}

src/api-impl/android/media/MediaCodecList.java

@@ -3,7 +3,18 @@ package android.media;
 public class MediaCodecList {
 
 	public static int getCodecCount() {
-		return 0;
+		return 2;
+	}
+
+	public static MediaCodecInfo getCodecInfoAt(int index) {
+		switch (index) {
+		case 0:
+			return new MediaCodecInfo("aac", "audio/mp4a-latm");
+		case 1:
+			return new MediaCodecInfo("h264", "video/avc");
+		default:
+			return null;
+		}
 	}
 
 }

src/api-impl/android/media/MediaCrypto.java

@@ -0,0 +1,4 @@
+package android.media;
+
+public class MediaCrypto {
+}

src/api-impl/android/media/MediaFormat.java

@@ -0,0 +1,42 @@
+package android.media;
+
+import java.nio.ByteBuffer;
+import java.util.HashMap;
+import java.util.Map;
+
+public class MediaFormat {
+
+	private Map<String, Object> map = new HashMap<>();
+
+	public void setString(String key, String value) {
+		map.put(key, value);
+	}
+
+	public void setInteger(String key, int value) {
+		map.put(key, value);
+	}
+
+	public void setByteBuffer(String key, ByteBuffer value) {
+		map.put(key, value);
+	}
+
+	public void setFloat(String key, float value) {
+		map.put(key, value);
+	}
+
+	public ByteBuffer getByteBuffer(String name) {
+		return (ByteBuffer) map.get(name);
+	}
+
+	public int getInteger(String name) {
+		return (int) map.get(name);
+	}
+
+	public boolean containsKey(String name) {
+		return map.containsKey(name);
+	}
+
+	public String toString() {
+		return map.toString();
+	}
+}