talk/app/webrtc/java/src/org/webrtc/MediaCodecVideoEncoder.java - platform/external/webrtc - Git at Google

 /*
  * libjingle
  * Copyright 2013 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
  *     this list of conditions and the following disclaimer in the documentation
  *     and/or other materials provided with the distribution.
  *  3. The name of the author may not be used to endorse or promote products
  *     derived from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 package org.webrtc;

 import android.media.MediaCodec;
 import android.media.MediaCodecInfo.CodecCapabilities;
 import android.media.MediaCodecInfo;
 import android.media.MediaCodecList;
 import android.media.MediaFormat;
 import android.os.Build;
 import android.os.Bundle;

 import org.webrtc.Logging;

 import java.nio.ByteBuffer;
 import java.util.Arrays;
 import java.util.List;
 import java.util.concurrent.CountDownLatch;

 // Java-side of peerconnection_jni.cc:MediaCodecVideoEncoder.
 // This class is an implementation detail of the Java PeerConnection API.
 public class MediaCodecVideoEncoder {
   // This class is constructed, operated, and destroyed by its C++ incarnation,
   // so the class and its methods have non-public visibility.  The API this
   // class exposes aims to mimic the webrtc::VideoEncoder API as closely as
   // possibly to minimize the amount of translation work necessary.

   private static final String TAG = "MediaCodecVideoEncoder";

   // Tracks webrtc::VideoCodecType.
   public enum VideoCodecType {
     VIDEO_CODEC_VP8,
     VIDEO_CODEC_VP9,
     VIDEO_CODEC_H264
   }

   private static final int MEDIA_CODEC_RELEASE_TIMEOUT_MS = 5000; // Timeout for codec releasing.
   private static final int DEQUEUE_TIMEOUT = 0;  // Non-blocking, no wait.
   // Active running encoder instance. Set in initEncode() (called from native code)
   // and reset to null in release() call.
   private static MediaCodecVideoEncoder runningInstance = null;
   private static MediaCodecVideoEncoderErrorCallback errorCallback = null;
   private static int codecErrors = 0;

   private Thread mediaCodecThread;
   private MediaCodec mediaCodec;
   private ByteBuffer[] outputBuffers;
   private static final String VP8_MIME_TYPE = "video/x-vnd.on2.vp8";
   private static final String H264_MIME_TYPE = "video/avc";
   // List of supported HW VP8 codecs.
   private static final String[] supportedVp8HwCodecPrefixes =
     {"OMX.qcom.", "OMX.Intel." };
   // List of supported HW H.264 codecs.
   private static final String[] supportedH264HwCodecPrefixes =
     {"OMX.qcom." };
   // List of devices with poor H.264 encoder quality.
   private static final String[] H264_HW_EXCEPTION_MODELS = new String[] {
     // HW H.264 encoder on below devices has poor bitrate control - actual
     // bitrates deviates a lot from the target value.
     "SAMSUNG-SGH-I337",
     "Nexus 7",
     "Nexus 4"
   };

   // Bitrate modes - should be in sync with OMX_VIDEO_CONTROLRATETYPE defined
   // in OMX_Video.h
   private static final int VIDEO_ControlRateVariable = 1;
   private static final int VIDEO_ControlRateConstant = 2;
   // NV12 color format supported by QCOM codec, but not declared in MediaCodec -
   // see /hardware/qcom/media/mm-core/inc/OMX_QCOMExtns.h
   private static final int
     COLOR_QCOM_FORMATYUV420PackedSemiPlanar32m = 0x7FA30C04;
   // Allowable color formats supported by codec - in order of preference.
   private static final int[] supportedColorList = {
     CodecCapabilities.COLOR_FormatYUV420Planar,
     CodecCapabilities.COLOR_FormatYUV420SemiPlanar,
     CodecCapabilities.COLOR_QCOM_FormatYUV420SemiPlanar,
     COLOR_QCOM_FORMATYUV420PackedSemiPlanar32m
   };
   private VideoCodecType type;
   private int colorFormat;  // Used by native code.

   // SPS and PPS NALs (Config frame) for H.264.
   private ByteBuffer configData = null;

   // MediaCodec error handler - invoked when critical error happens which may prevent
   // further use of media codec API. Now it means that one of media codec instances
   // is hanging and can no longer be used in the next call.
   public static interface MediaCodecVideoEncoderErrorCallback {
     void onMediaCodecVideoEncoderCriticalError(int codecErrors);
   }

   public static void setErrorCallback(MediaCodecVideoEncoderErrorCallback errorCallback) {
     Logging.d(TAG, "Set error callback");
     MediaCodecVideoEncoder.errorCallback = errorCallback;
   }

   // Helper struct for findHwEncoder() below.
   private static class EncoderProperties {
     public EncoderProperties(String codecName, int colorFormat) {
       this.codecName = codecName;
       this.colorFormat = colorFormat;
     }
     public final String codecName; // OpenMax component name for HW codec.
     public final int colorFormat;  // Color format supported by codec.
   }

   private static EncoderProperties findHwEncoder(
       String mime, String[] supportedHwCodecPrefixes) {
     // MediaCodec.setParameters is missing for JB and below, so bitrate
     // can not be adjusted dynamically.
     if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
       return null;
     }

     // Check if device is in H.264 exception list.
     if (mime.equals(H264_MIME_TYPE)) {
       List<String> exceptionModels = Arrays.asList(H264_HW_EXCEPTION_MODELS);
       if (exceptionModels.contains(Build.MODEL)) {
         Logging.w(TAG, "Model: " + Build.MODEL + " has black listed H.264 encoder.");
         return null;
       }
     }

     for (int i = 0; i < MediaCodecList.getCodecCount(); ++i) {
       MediaCodecInfo info = MediaCodecList.getCodecInfoAt(i);
       if (!info.isEncoder()) {
         continue;
       }
       String name = null;
       for (String mimeType : info.getSupportedTypes()) {
         if (mimeType.equals(mime)) {
           name = info.getName();
           break;
         }
       }
       if (name == null) {
         continue;  // No HW support in this codec; try the next one.
       }
       Logging.v(TAG, "Found candidate encoder " + name);

       // Check if this is supported HW encoder.
       boolean supportedCodec = false;
       for (String hwCodecPrefix : supportedHwCodecPrefixes) {
         if (name.startsWith(hwCodecPrefix)) {
           supportedCodec = true;
           break;
         }
       }
       if (!supportedCodec) {
         continue;
       }

       CodecCapabilities capabilities = info.getCapabilitiesForType(mime);
       for (int colorFormat : capabilities.colorFormats) {
         Logging.v(TAG, "   Color: 0x" + Integer.toHexString(colorFormat));
       }

       // Check if codec supports either yuv420 or nv12.
       for (int supportedColorFormat : supportedColorList) {
         for (int codecColorFormat : capabilities.colorFormats) {
           if (codecColorFormat == supportedColorFormat) {
             // Found supported HW encoder.
             Logging.d(TAG, "Found target encoder for mime " + mime + " : " + name +
                 ". Color: 0x" + Integer.toHexString(codecColorFormat));
             return new EncoderProperties(name, codecColorFormat);
           }
         }
       }
     }
     return null;  // No HW VP8 encoder.
   }

   public static boolean isVp8HwSupported() {
     return findHwEncoder(VP8_MIME_TYPE, supportedVp8HwCodecPrefixes) != null;
   }

   public static boolean isH264HwSupported() {
     return findHwEncoder(H264_MIME_TYPE, supportedH264HwCodecPrefixes) != null;
   }

   private void checkOnMediaCodecThread() {
     if (mediaCodecThread.getId() != Thread.currentThread().getId()) {
       throw new RuntimeException(
           "MediaCodecVideoEncoder previously operated on " + mediaCodecThread +
           " but is now called on " + Thread.currentThread());
     }
   }

   public static void printStackTrace() {
     if (runningInstance != null && runningInstance.mediaCodecThread != null) {
       StackTraceElement[] mediaCodecStackTraces = runningInstance.mediaCodecThread.getStackTrace();
       if (mediaCodecStackTraces.length > 0) {
         Logging.d(TAG, "MediaCodecVideoEncoder stacks trace:");
         for (StackTraceElement stackTrace : mediaCodecStackTraces) {
           Logging.d(TAG, stackTrace.toString());
         }
       }
     }
   }

   static MediaCodec createByCodecName(String codecName) {
     try {
       // In the L-SDK this call can throw IOException so in order to work in
       // both cases catch an exception.
       return MediaCodec.createByCodecName(codecName);
     } catch (Exception e) {
       return null;
     }
   }

   // Returns false if the hardware encoder currently can't be used.
   boolean initEncode(VideoCodecType type, int width, int height, int kbps, int fps) {
     Logging.d(TAG, "Java initEncode: " + type + " : " + width + " x " + height +
         ". @ " + kbps + " kbps. Fps: " + fps + ".");

     if (mediaCodecThread != null) {
       throw new RuntimeException("Forgot to release()?");
     }
     EncoderProperties properties = null;
     String mime = null;
     int keyFrameIntervalSec = 0;
     if (type == VideoCodecType.VIDEO_CODEC_VP8) {
       mime = VP8_MIME_TYPE;
       properties = findHwEncoder(VP8_MIME_TYPE, supportedVp8HwCodecPrefixes);
       keyFrameIntervalSec = 100;
     } else if (type == VideoCodecType.VIDEO_CODEC_H264) {
       mime = H264_MIME_TYPE;
       properties = findHwEncoder(H264_MIME_TYPE, supportedH264HwCodecPrefixes);
       keyFrameIntervalSec = 20;
     }
     if (properties == null) {
       throw new RuntimeException("Can not find HW encoder for " + type);
     }
     runningInstance = this; // Encoder is now running and can be queried for stack traces.
     colorFormat = properties.colorFormat;
     Logging.d(TAG, "Color format: " + colorFormat);

     mediaCodecThread = Thread.currentThread();
     try {
       MediaFormat format = MediaFormat.createVideoFormat(mime, width, height);
       format.setInteger(MediaFormat.KEY_BIT_RATE, 1000 * kbps);
       format.setInteger("bitrate-mode", VIDEO_ControlRateConstant);
       format.setInteger(MediaFormat.KEY_COLOR_FORMAT, properties.colorFormat);
       format.setInteger(MediaFormat.KEY_FRAME_RATE, fps);
       format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, keyFrameIntervalSec);
       Logging.d(TAG, "  Format: " + format);
       mediaCodec = createByCodecName(properties.codecName);
       this.type = type;
       if (mediaCodec == null) {
         Logging.e(TAG, "Can not create media encoder");
         return false;
       }
       mediaCodec.configure(
           format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);

       mediaCodec.start();
       outputBuffers = mediaCodec.getOutputBuffers();
       Logging.d(TAG, "Output buffers: " + outputBuffers.length);

     } catch (IllegalStateException e) {
       Logging.e(TAG, "initEncode failed", e);
       return false;
     }
     return true;
   }

   ByteBuffer[]  getInputBuffers() {
     ByteBuffer[] inputBuffers = mediaCodec.getInputBuffers();
     Logging.d(TAG, "Input buffers: " + inputBuffers.length);
     return inputBuffers;
   }

   boolean encodeBuffer(
       boolean isKeyframe, int inputBuffer, int size,
       long presentationTimestampUs) {
     checkOnMediaCodecThread();
     try {
       if (isKeyframe) {
         // Ideally MediaCodec would honor BUFFER_FLAG_SYNC_FRAME so we could
         // indicate this in queueInputBuffer() below and guarantee _this_ frame
         // be encoded as a key frame, but sadly that flag is ignored.  Instead,
         // we request a key frame "soon".
         Logging.d(TAG, "Sync frame request");
         Bundle b = new Bundle();
         b.putInt(MediaCodec.PARAMETER_KEY_REQUEST_SYNC_FRAME, 0);
         mediaCodec.setParameters(b);
       }
       mediaCodec.queueInputBuffer(
           inputBuffer, 0, size, presentationTimestampUs, 0);
       return true;
     }
     catch (IllegalStateException e) {
       Logging.e(TAG, "encodeBuffer failed", e);
       return false;
     }
   }

   void release() {
     Logging.d(TAG, "Java releaseEncoder");
     checkOnMediaCodecThread();

     // Run Mediacodec stop() and release() on separate thread since sometime
     // Mediacodec.stop() may hang.
     final CountDownLatch releaseDone = new CountDownLatch(1);

     Runnable runMediaCodecRelease = new Runnable() {
       @Override
       public void run() {
         try {
           Logging.d(TAG, "Java releaseEncoder on release thread");
           mediaCodec.stop();
           mediaCodec.release();
           Logging.d(TAG, "Java releaseEncoder on release thread done");
         } catch (Exception e) {
           Logging.e(TAG, "Media encoder release failed", e);
         }
         releaseDone.countDown();
       }
     };
     new Thread(runMediaCodecRelease).start();

     if (!ThreadUtils.awaitUninterruptibly(releaseDone, MEDIA_CODEC_RELEASE_TIMEOUT_MS)) {
       Logging.e(TAG, "Media encoder release timeout");
       codecErrors++;
       if (errorCallback != null) {
         Logging.e(TAG, "Invoke codec error callback. Errors: " + codecErrors);
         errorCallback.onMediaCodecVideoEncoderCriticalError(codecErrors);
       }
     }

     mediaCodec = null;
     mediaCodecThread = null;
     runningInstance = null;
     Logging.d(TAG, "Java releaseEncoder done");
   }

   private boolean setRates(int kbps, int frameRateIgnored) {
     // frameRate argument is ignored - HW encoder is supposed to use
     // video frame timestamps for bit allocation.
     checkOnMediaCodecThread();
     Logging.v(TAG, "setRates: " + kbps + " kbps. Fps: " + frameRateIgnored);
     try {
       Bundle params = new Bundle();
       params.putInt(MediaCodec.PARAMETER_KEY_VIDEO_BITRATE, 1000 * kbps);
       mediaCodec.setParameters(params);
       return true;
     } catch (IllegalStateException e) {
       Logging.e(TAG, "setRates failed", e);
       return false;
     }
   }

   // Dequeue an input buffer and return its index, -1 if no input buffer is
   // available, or -2 if the codec is no longer operative.
   int dequeueInputBuffer() {
     checkOnMediaCodecThread();
     try {
       return mediaCodec.dequeueInputBuffer(DEQUEUE_TIMEOUT);
     } catch (IllegalStateException e) {
       Logging.e(TAG, "dequeueIntputBuffer failed", e);
       return -2;
     }
   }

   // Helper struct for dequeueOutputBuffer() below.
   static class OutputBufferInfo {
     public OutputBufferInfo(
         int index, ByteBuffer buffer,
         boolean isKeyFrame, long presentationTimestampUs) {
       this.index = index;
       this.buffer = buffer;
       this.isKeyFrame = isKeyFrame;
       this.presentationTimestampUs = presentationTimestampUs;
     }

     public final int index;
     public final ByteBuffer buffer;
     public final boolean isKeyFrame;
     public final long presentationTimestampUs;
   }

   // Dequeue and return an output buffer, or null if no output is ready.  Return
   // a fake OutputBufferInfo with index -1 if the codec is no longer operable.
   OutputBufferInfo dequeueOutputBuffer() {
     checkOnMediaCodecThread();
     try {
       MediaCodec.BufferInfo info = new MediaCodec.BufferInfo();
       int result = mediaCodec.dequeueOutputBuffer(info, DEQUEUE_TIMEOUT);
       // Check if this is config frame and save configuration data.
       if (result >= 0) {
         boolean isConfigFrame =
             (info.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0;
         if (isConfigFrame) {
           Logging.d(TAG, "Config frame generated. Offset: " + info.offset +
               ". Size: " + info.size);
           configData = ByteBuffer.allocateDirect(info.size);
           outputBuffers[result].position(info.offset);
           outputBuffers[result].limit(info.offset + info.size);
           configData.put(outputBuffers[result]);
           // Release buffer back.
           mediaCodec.releaseOutputBuffer(result, false);
           // Query next output.
           result = mediaCodec.dequeueOutputBuffer(info, DEQUEUE_TIMEOUT);
         }
       }
       if (result >= 0) {
         // MediaCodec doesn't care about Buffer position/remaining/etc so we can
         // mess with them to get a slice and avoid having to pass extra
         // (BufferInfo-related) parameters back to C++.
         ByteBuffer outputBuffer = outputBuffers[result].duplicate();
         outputBuffer.position(info.offset);
         outputBuffer.limit(info.offset + info.size);
         // Check key frame flag.
         boolean isKeyFrame =
             (info.flags & MediaCodec.BUFFER_FLAG_SYNC_FRAME) != 0;
         if (isKeyFrame) {
           Logging.d(TAG, "Sync frame generated");
         }
         if (isKeyFrame && type == VideoCodecType.VIDEO_CODEC_H264) {
           Logging.d(TAG, "Appending config frame of size " + configData.capacity() +
               " to output buffer with offset " + info.offset + ", size " +
               info.size);
           // For H.264 key frame append SPS and PPS NALs at the start
           ByteBuffer keyFrameBuffer = ByteBuffer.allocateDirect(
               configData.capacity() + info.size);
           configData.rewind();
           keyFrameBuffer.put(configData);
           keyFrameBuffer.put(outputBuffer);
           keyFrameBuffer.position(0);
           return new OutputBufferInfo(result, keyFrameBuffer,
               isKeyFrame, info.presentationTimeUs);
         } else {
           return new OutputBufferInfo(result, outputBuffer.slice(),
               isKeyFrame, info.presentationTimeUs);
         }
       } else if (result == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
         outputBuffers = mediaCodec.getOutputBuffers();
         return dequeueOutputBuffer();
       } else if (result == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
         return dequeueOutputBuffer();
       } else if (result == MediaCodec.INFO_TRY_AGAIN_LATER) {
         return null;
       }
       throw new RuntimeException("dequeueOutputBuffer: " + result);
     } catch (IllegalStateException e) {
       Logging.e(TAG, "dequeueOutputBuffer failed", e);
       return new OutputBufferInfo(-1, null, false, -1);
     }
   }

   // Release a dequeued output buffer back to the codec for re-use.  Return
   // false if the codec is no longer operable.
   boolean releaseOutputBuffer(int index) {
     checkOnMediaCodecThread();
     try {
       mediaCodec.releaseOutputBuffer(index, false);
       return true;
     } catch (IllegalStateException e) {
       Logging.e(TAG, "releaseOutputBuffer failed", e);
       return false;
     }
   }
 }
	/*
	* libjingle
	* Copyright 2013 Google Inc.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are met:
	*
	* 1. Redistributions of source code must retain the above copyright notice,
	* this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright notice,
	* this list of conditions and the following disclaimer in the documentation
	* and/or other materials provided with the distribution.
	* 3. The name of the author may not be used to endorse or promote products
	* derived from this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
	* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
	* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
	* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
	* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
	* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	package org.webrtc;

	import android.media.MediaCodec;
	import android.media.MediaCodecInfo.CodecCapabilities;
	import android.media.MediaCodecInfo;
	import android.media.MediaCodecList;
	import android.media.MediaFormat;
	import android.os.Build;
	import android.os.Bundle;

	import org.webrtc.Logging;

	import java.nio.ByteBuffer;
	import java.util.Arrays;
	import java.util.List;
	import java.util.concurrent.CountDownLatch;

	// Java-side of peerconnection_jni.cc:MediaCodecVideoEncoder.
	// This class is an implementation detail of the Java PeerConnection API.
	public class MediaCodecVideoEncoder {
	// This class is constructed, operated, and destroyed by its C++ incarnation,
	// so the class and its methods have non-public visibility. The API this
	// class exposes aims to mimic the webrtc::VideoEncoder API as closely as
	// possibly to minimize the amount of translation work necessary.

	private static final String TAG = "MediaCodecVideoEncoder";

	// Tracks webrtc::VideoCodecType.
	public enum VideoCodecType {
	VIDEO_CODEC_VP8,
	VIDEO_CODEC_VP9,
	VIDEO_CODEC_H264
	}

	private static final int MEDIA_CODEC_RELEASE_TIMEOUT_MS = 5000; // Timeout for codec releasing.
	private static final int DEQUEUE_TIMEOUT = 0; // Non-blocking, no wait.
	// Active running encoder instance. Set in initEncode() (called from native code)
	// and reset to null in release() call.
	private static MediaCodecVideoEncoder runningInstance = null;
	private static MediaCodecVideoEncoderErrorCallback errorCallback = null;
	private static int codecErrors = 0;

	private Thread mediaCodecThread;
	private MediaCodec mediaCodec;
	private ByteBuffer[] outputBuffers;
	private static final String VP8_MIME_TYPE = "video/x-vnd.on2.vp8";
	private static final String H264_MIME_TYPE = "video/avc";
	// List of supported HW VP8 codecs.
	private static final String[] supportedVp8HwCodecPrefixes =
	{"OMX.qcom.", "OMX.Intel." };
	// List of supported HW H.264 codecs.
	private static final String[] supportedH264HwCodecPrefixes =
	{"OMX.qcom." };
	// List of devices with poor H.264 encoder quality.
	private static final String[] H264_HW_EXCEPTION_MODELS = new String[] {
	// HW H.264 encoder on below devices has poor bitrate control - actual
	// bitrates deviates a lot from the target value.
	"SAMSUNG-SGH-I337",
	"Nexus 7",
	"Nexus 4"
	};

	// Bitrate modes - should be in sync with OMX_VIDEO_CONTROLRATETYPE defined
	// in OMX_Video.h
	private static final int VIDEO_ControlRateVariable = 1;
	private static final int VIDEO_ControlRateConstant = 2;
	// NV12 color format supported by QCOM codec, but not declared in MediaCodec -
	// see /hardware/qcom/media/mm-core/inc/OMX_QCOMExtns.h
	private static final int
	COLOR_QCOM_FORMATYUV420PackedSemiPlanar32m = 0x7FA30C04;
	// Allowable color formats supported by codec - in order of preference.
	private static final int[] supportedColorList = {
	CodecCapabilities.COLOR_FormatYUV420Planar,
	CodecCapabilities.COLOR_FormatYUV420SemiPlanar,
	CodecCapabilities.COLOR_QCOM_FormatYUV420SemiPlanar,
	COLOR_QCOM_FORMATYUV420PackedSemiPlanar32m
	};
	private VideoCodecType type;
	private int colorFormat; // Used by native code.

	// SPS and PPS NALs (Config frame) for H.264.
	private ByteBuffer configData = null;

	// MediaCodec error handler - invoked when critical error happens which may prevent
	// further use of media codec API. Now it means that one of media codec instances
	// is hanging and can no longer be used in the next call.
	public static interface MediaCodecVideoEncoderErrorCallback {
	void onMediaCodecVideoEncoderCriticalError(int codecErrors);
	}

	public static void setErrorCallback(MediaCodecVideoEncoderErrorCallback errorCallback) {
	Logging.d(TAG, "Set error callback");
	MediaCodecVideoEncoder.errorCallback = errorCallback;
	}

	// Helper struct for findHwEncoder() below.
	private static class EncoderProperties {
	public EncoderProperties(String codecName, int colorFormat) {
	this.codecName = codecName;
	this.colorFormat = colorFormat;
	}
	public final String codecName; // OpenMax component name for HW codec.
	public final int colorFormat; // Color format supported by codec.
	}

	private static EncoderProperties findHwEncoder(
	String mime, String[] supportedHwCodecPrefixes) {
	// MediaCodec.setParameters is missing for JB and below, so bitrate
	// can not be adjusted dynamically.
	if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
	return null;
	}

	// Check if device is in H.264 exception list.
	if (mime.equals(H264_MIME_TYPE)) {
	List<String> exceptionModels = Arrays.asList(H264_HW_EXCEPTION_MODELS);
	if (exceptionModels.contains(Build.MODEL)) {
	Logging.w(TAG, "Model: " + Build.MODEL + " has black listed H.264 encoder.");
	return null;
	}
	}

	for (int i = 0; i < MediaCodecList.getCodecCount(); ++i) {
	MediaCodecInfo info = MediaCodecList.getCodecInfoAt(i);
	if (!info.isEncoder()) {
	continue;
	}
	String name = null;
	for (String mimeType : info.getSupportedTypes()) {
	if (mimeType.equals(mime)) {
	name = info.getName();
	break;
	}
	}
	if (name == null) {
	continue; // No HW support in this codec; try the next one.
	}
	Logging.v(TAG, "Found candidate encoder " + name);

	// Check if this is supported HW encoder.
	boolean supportedCodec = false;
	for (String hwCodecPrefix : supportedHwCodecPrefixes) {
	if (name.startsWith(hwCodecPrefix)) {
	supportedCodec = true;
	break;
	}
	}
	if (!supportedCodec) {
	continue;
	}

	CodecCapabilities capabilities = info.getCapabilitiesForType(mime);
	for (int colorFormat : capabilities.colorFormats) {
	Logging.v(TAG, " Color: 0x" + Integer.toHexString(colorFormat));
	}

	// Check if codec supports either yuv420 or nv12.
	for (int supportedColorFormat : supportedColorList) {
	for (int codecColorFormat : capabilities.colorFormats) {
	if (codecColorFormat == supportedColorFormat) {
	// Found supported HW encoder.
	Logging.d(TAG, "Found target encoder for mime " + mime + " : " + name +
	". Color: 0x" + Integer.toHexString(codecColorFormat));
	return new EncoderProperties(name, codecColorFormat);
	}
	}
	}
	}
	return null; // No HW VP8 encoder.
	}

	public static boolean isVp8HwSupported() {
	return findHwEncoder(VP8_MIME_TYPE, supportedVp8HwCodecPrefixes) != null;
	}

	public static boolean isH264HwSupported() {
	return findHwEncoder(H264_MIME_TYPE, supportedH264HwCodecPrefixes) != null;
	}

	private void checkOnMediaCodecThread() {
	if (mediaCodecThread.getId() != Thread.currentThread().getId()) {
	throw new RuntimeException(
	"MediaCodecVideoEncoder previously operated on " + mediaCodecThread +
	" but is now called on " + Thread.currentThread());
	}
	}

	public static void printStackTrace() {
	if (runningInstance != null && runningInstance.mediaCodecThread != null) {
	StackTraceElement[] mediaCodecStackTraces = runningInstance.mediaCodecThread.getStackTrace();
	if (mediaCodecStackTraces.length > 0) {
	Logging.d(TAG, "MediaCodecVideoEncoder stacks trace:");
	for (StackTraceElement stackTrace : mediaCodecStackTraces) {
	Logging.d(TAG, stackTrace.toString());
	}
	}
	}
	}

	static MediaCodec createByCodecName(String codecName) {
	try {
	// In the L-SDK this call can throw IOException so in order to work in
	// both cases catch an exception.
	return MediaCodec.createByCodecName(codecName);
	} catch (Exception e) {
	return null;
	}
	}

	// Returns false if the hardware encoder currently can't be used.
	boolean initEncode(VideoCodecType type, int width, int height, int kbps, int fps) {
	Logging.d(TAG, "Java initEncode: " + type + " : " + width + " x " + height +
	". @ " + kbps + " kbps. Fps: " + fps + ".");

	if (mediaCodecThread != null) {
	throw new RuntimeException("Forgot to release()?");
	}
	EncoderProperties properties = null;
	String mime = null;
	int keyFrameIntervalSec = 0;
	if (type == VideoCodecType.VIDEO_CODEC_VP8) {
	mime = VP8_MIME_TYPE;
	properties = findHwEncoder(VP8_MIME_TYPE, supportedVp8HwCodecPrefixes);
	keyFrameIntervalSec = 100;
	} else if (type == VideoCodecType.VIDEO_CODEC_H264) {
	mime = H264_MIME_TYPE;
	properties = findHwEncoder(H264_MIME_TYPE, supportedH264HwCodecPrefixes);
	keyFrameIntervalSec = 20;
	}
	if (properties == null) {
	throw new RuntimeException("Can not find HW encoder for " + type);
	}
	runningInstance = this; // Encoder is now running and can be queried for stack traces.
	colorFormat = properties.colorFormat;
	Logging.d(TAG, "Color format: " + colorFormat);

	mediaCodecThread = Thread.currentThread();
	try {
	MediaFormat format = MediaFormat.createVideoFormat(mime, width, height);
	format.setInteger(MediaFormat.KEY_BIT_RATE, 1000 * kbps);
	format.setInteger("bitrate-mode", VIDEO_ControlRateConstant);
	format.setInteger(MediaFormat.KEY_COLOR_FORMAT, properties.colorFormat);
	format.setInteger(MediaFormat.KEY_FRAME_RATE, fps);
	format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, keyFrameIntervalSec);
	Logging.d(TAG, " Format: " + format);
	mediaCodec = createByCodecName(properties.codecName);
	this.type = type;
	if (mediaCodec == null) {
	Logging.e(TAG, "Can not create media encoder");
	return false;
	}
	mediaCodec.configure(
	format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);

	mediaCodec.start();
	outputBuffers = mediaCodec.getOutputBuffers();
	Logging.d(TAG, "Output buffers: " + outputBuffers.length);

	} catch (IllegalStateException e) {
	Logging.e(TAG, "initEncode failed", e);
	return false;
	}
	return true;
	}

	ByteBuffer[] getInputBuffers() {
	ByteBuffer[] inputBuffers = mediaCodec.getInputBuffers();
	Logging.d(TAG, "Input buffers: " + inputBuffers.length);
	return inputBuffers;
	}

	boolean encodeBuffer(
	boolean isKeyframe, int inputBuffer, int size,
	long presentationTimestampUs) {
	checkOnMediaCodecThread();
	try {
	if (isKeyframe) {
	// Ideally MediaCodec would honor BUFFER_FLAG_SYNC_FRAME so we could
	// indicate this in queueInputBuffer() below and guarantee _this_ frame
	// be encoded as a key frame, but sadly that flag is ignored. Instead,
	// we request a key frame "soon".
	Logging.d(TAG, "Sync frame request");
	Bundle b = new Bundle();
	b.putInt(MediaCodec.PARAMETER_KEY_REQUEST_SYNC_FRAME, 0);
	mediaCodec.setParameters(b);
	}
	mediaCodec.queueInputBuffer(
	inputBuffer, 0, size, presentationTimestampUs, 0);
	return true;
	}
	catch (IllegalStateException e) {
	Logging.e(TAG, "encodeBuffer failed", e);
	return false;
	}
	}

	void release() {
	Logging.d(TAG, "Java releaseEncoder");
	checkOnMediaCodecThread();

	// Run Mediacodec stop() and release() on separate thread since sometime
	// Mediacodec.stop() may hang.
	final CountDownLatch releaseDone = new CountDownLatch(1);

	Runnable runMediaCodecRelease = new Runnable() {
	@Override
	public void run() {
	try {
	Logging.d(TAG, "Java releaseEncoder on release thread");
	mediaCodec.stop();
	mediaCodec.release();
	Logging.d(TAG, "Java releaseEncoder on release thread done");
	} catch (Exception e) {
	Logging.e(TAG, "Media encoder release failed", e);
	}
	releaseDone.countDown();
	}
	};
	new Thread(runMediaCodecRelease).start();

	if (!ThreadUtils.awaitUninterruptibly(releaseDone, MEDIA_CODEC_RELEASE_TIMEOUT_MS)) {
	Logging.e(TAG, "Media encoder release timeout");
	codecErrors++;
	if (errorCallback != null) {
	Logging.e(TAG, "Invoke codec error callback. Errors: " + codecErrors);
	errorCallback.onMediaCodecVideoEncoderCriticalError(codecErrors);
	}
	}

	mediaCodec = null;
	mediaCodecThread = null;
	runningInstance = null;
	Logging.d(TAG, "Java releaseEncoder done");
	}

	private boolean setRates(int kbps, int frameRateIgnored) {
	// frameRate argument is ignored - HW encoder is supposed to use
	// video frame timestamps for bit allocation.
	checkOnMediaCodecThread();
	Logging.v(TAG, "setRates: " + kbps + " kbps. Fps: " + frameRateIgnored);
	try {
	Bundle params = new Bundle();
	params.putInt(MediaCodec.PARAMETER_KEY_VIDEO_BITRATE, 1000 * kbps);
	mediaCodec.setParameters(params);
	return true;
	} catch (IllegalStateException e) {
	Logging.e(TAG, "setRates failed", e);
	return false;
	}
	}

	// Dequeue an input buffer and return its index, -1 if no input buffer is
	// available, or -2 if the codec is no longer operative.
	int dequeueInputBuffer() {
	checkOnMediaCodecThread();
	try {
	return mediaCodec.dequeueInputBuffer(DEQUEUE_TIMEOUT);
	} catch (IllegalStateException e) {
	Logging.e(TAG, "dequeueIntputBuffer failed", e);
	return -2;
	}
	}

	// Helper struct for dequeueOutputBuffer() below.
	static class OutputBufferInfo {
	public OutputBufferInfo(
	int index, ByteBuffer buffer,
	boolean isKeyFrame, long presentationTimestampUs) {
	this.index = index;
	this.buffer = buffer;
	this.isKeyFrame = isKeyFrame;
	this.presentationTimestampUs = presentationTimestampUs;
	}

	public final int index;
	public final ByteBuffer buffer;
	public final boolean isKeyFrame;
	public final long presentationTimestampUs;
	}

	// Dequeue and return an output buffer, or null if no output is ready. Return
	// a fake OutputBufferInfo with index -1 if the codec is no longer operable.
	OutputBufferInfo dequeueOutputBuffer() {
	checkOnMediaCodecThread();
	try {
	MediaCodec.BufferInfo info = new MediaCodec.BufferInfo();
	int result = mediaCodec.dequeueOutputBuffer(info, DEQUEUE_TIMEOUT);
	// Check if this is config frame and save configuration data.
	if (result >= 0) {
	boolean isConfigFrame =
	(info.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0;
	if (isConfigFrame) {
	Logging.d(TAG, "Config frame generated. Offset: " + info.offset +
	". Size: " + info.size);
	configData = ByteBuffer.allocateDirect(info.size);
	outputBuffers[result].position(info.offset);
	outputBuffers[result].limit(info.offset + info.size);
	configData.put(outputBuffers[result]);
	// Release buffer back.
	mediaCodec.releaseOutputBuffer(result, false);
	// Query next output.
	result = mediaCodec.dequeueOutputBuffer(info, DEQUEUE_TIMEOUT);
	}
	}
	if (result >= 0) {
	// MediaCodec doesn't care about Buffer position/remaining/etc so we can
	// mess with them to get a slice and avoid having to pass extra
	// (BufferInfo-related) parameters back to C++.
	ByteBuffer outputBuffer = outputBuffers[result].duplicate();
	outputBuffer.position(info.offset);
	outputBuffer.limit(info.offset + info.size);
	// Check key frame flag.
	boolean isKeyFrame =
	(info.flags & MediaCodec.BUFFER_FLAG_SYNC_FRAME) != 0;
	if (isKeyFrame) {
	Logging.d(TAG, "Sync frame generated");
	}
	if (isKeyFrame && type == VideoCodecType.VIDEO_CODEC_H264) {
	Logging.d(TAG, "Appending config frame of size " + configData.capacity() +
	" to output buffer with offset " + info.offset + ", size " +
	info.size);
	// For H.264 key frame append SPS and PPS NALs at the start
	ByteBuffer keyFrameBuffer = ByteBuffer.allocateDirect(
	configData.capacity() + info.size);
	configData.rewind();
	keyFrameBuffer.put(configData);
	keyFrameBuffer.put(outputBuffer);
	keyFrameBuffer.position(0);
	return new OutputBufferInfo(result, keyFrameBuffer,
	isKeyFrame, info.presentationTimeUs);
	} else {
	return new OutputBufferInfo(result, outputBuffer.slice(),
	isKeyFrame, info.presentationTimeUs);
	}
	} else if (result == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
	outputBuffers = mediaCodec.getOutputBuffers();
	return dequeueOutputBuffer();
	} else if (result == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
	return dequeueOutputBuffer();
	} else if (result == MediaCodec.INFO_TRY_AGAIN_LATER) {
	return null;
	}
	throw new RuntimeException("dequeueOutputBuffer: " + result);
	} catch (IllegalStateException e) {
	Logging.e(TAG, "dequeueOutputBuffer failed", e);
	return new OutputBufferInfo(-1, null, false, -1);
	}
	}

	// Release a dequeued output buffer back to the codec for re-use. Return
	// false if the codec is no longer operable.
	boolean releaseOutputBuffer(int index) {
	checkOnMediaCodecThread();
	try {
	mediaCodec.releaseOutputBuffer(index, false);
	return true;
	} catch (IllegalStateException e) {
	Logging.e(TAG, "releaseOutputBuffer failed", e);
	return false;
	}
	}
	}