xref: /cts/tests/tests/media/src/android/media/cts/Vp8CodecTestBase.java

/*
 * Copyright (C) 2013 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.media.cts;

import android.content.Context;
import android.content.res.Resources;
import android.media.MediaCodec;
import android.media.MediaCodec.CodecException;
import android.media.MediaCodecInfo.CodecCapabilities;
import android.media.MediaCodecList;
import android.media.MediaCodecInfo;
import android.media.MediaFormat;
import android.os.Bundle;
import android.os.Environment;
import android.os.Looper;
import android.os.Handler;
import android.test.AndroidTestCase;
import android.util.Log;
import com.android.cts.media.R;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.util.Locale;
import java.util.ArrayList;
import java.util.concurrent.Callable;
import java.util.concurrent.CountDownLatch;

/**
 * Verification test for vp8 encoder and decoder.
 *
 * A raw yv12 stream is encoded at various settings and written to an IVF
 * file. Encoded stream bitrate and key frame interval are checked against target values.
 * The stream is later decoded by vp8 decoder to verify frames are decodable and to
 * calculate PSNR values for various bitrates.
 */
public class Vp8CodecTestBase extends AndroidTestCase {

    protected static final String TAG = "VP8CodecTestBase";
    protected static final String VP8_MIME = MediaFormat.MIMETYPE_VIDEO_VP8;
    private static final String GOOGLE_CODEC_PREFIX = "omx.google.";
    protected static final String SDCARD_DIR =
            Environment.getExternalStorageDirectory().getAbsolutePath();

    // Default timeout for MediaCodec buffer dequeue - 200 ms.
    protected static final long DEFAULT_DEQUEUE_TIMEOUT_US = 200000;
    // Default timeout for MediaEncoderAsync - 30 sec.
    protected static final long DEFAULT_ENCODE_TIMEOUT_MS = 30000;
    // Default sync frame interval in frames (zero means allow the encoder to auto-select
    // key frame interval).
    private static final int SYNC_FRAME_INTERVAL = 0;
    // Video bitrate type - should be set to OMX_Video_ControlRateConstant from OMX_Video.h
    protected static final int VIDEO_ControlRateVariable = 1;
    protected 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[] mSupportedColorList = {
            CodecCapabilities.COLOR_FormatYUV420Planar,
            CodecCapabilities.COLOR_FormatYUV420SemiPlanar,
            CodecCapabilities.COLOR_QCOM_FormatYUV420SemiPlanar,
            COLOR_QCOM_FORMATYUV420PackedSemiPlanar32m
    };
    // Scaled image cache list - contains scale factors, for which up-scaled frames
    // were calculated and were written to yuv file.
    ArrayList<Integer> mScaledImages = new ArrayList<Integer>();

    private Resources mResources;

    @Override
    public void setContext(Context context) {
        super.setContext(context);
        mResources = mContext.getResources();
    }

    /**
     *  VP8 codec properties generated by getVp8CodecProperties() function.
     */
    private class CodecProperties {
        CodecProperties(String codecName, int colorFormat) {
            this.codecName = codecName;
            this.colorFormat = colorFormat;
        }
        public boolean  isGoogleCodec() {
            return codecName.toLowerCase().startsWith(GOOGLE_CODEC_PREFIX);
        }

        public final String codecName; // OpenMax component name for VP8 codec.
        public final int colorFormat;  // Color format supported by codec.
    }

    /**
     * Function to find VP8 codec.
     *
     * Iterates through the list of available codecs and tries to find
     * VPX codec, which can support either YUV420 planar or NV12 color formats.
     * If forceGoogleCodec parameter set to true the function always returns
     * Google VPX codec.
     * If forceGoogleCodec parameter set to false the functions looks for platform
     * specific VPX codec first. If no platform specific codec exist, falls back to
     * Google VPX codec.
     *
     * @param isEncoder     Flag if encoder is requested.
     * @param forceGoogleCodec  Forces to use Google codec.
     */
    private CodecProperties getVpxCodecProperties(
            boolean isEncoder,
            MediaFormat format,
            boolean forceGoogleCodec) throws Exception {
        CodecProperties codecProperties = null;
        String mime = format.getString(MediaFormat.KEY_MIME);

        // Loop through the list of omx components in case platform specific codec
        // is requested.
        MediaCodecList mcl = new MediaCodecList(MediaCodecList.REGULAR_CODECS);
        for (MediaCodecInfo codecInfo : mcl.getCodecInfos()) {
            if (isEncoder != codecInfo.isEncoder()) {
                continue;
            }
            Log.v(TAG, codecInfo.getName());
            // TODO: remove dependence of Google from the test
            // Check if this is Google codec - we should ignore it.
            boolean isGoogleCodec =
                codecInfo.getName().toLowerCase().startsWith(GOOGLE_CODEC_PREFIX);
            if (!isGoogleCodec && forceGoogleCodec) {
                continue;
            }

            for (String type : codecInfo.getSupportedTypes()) {
                if (!type.equalsIgnoreCase(mime)) {
                    continue;
                }
                CodecCapabilities capabilities = codecInfo.getCapabilitiesForType(type);
                if (!capabilities.isFormatSupported(format)) {
                    continue;
                }

                // Get candidate codec properties.
                Log.v(TAG, "Found candidate codec " + codecInfo.getName());
                for (int colorFormat: capabilities.colorFormats) {
                    Log.v(TAG, "   Color: 0x" + Integer.toHexString(colorFormat));
                }

                // Check supported color formats.
                for (int supportedColorFormat : mSupportedColorList) {
                    for (int codecColorFormat : capabilities.colorFormats) {
                        if (codecColorFormat == supportedColorFormat) {
                            codecProperties = new CodecProperties(codecInfo.getName(),
                                    codecColorFormat);
                            Log.v(TAG, "Found target codec " + codecProperties.codecName +
                                    ". Color: 0x" + Integer.toHexString(codecColorFormat));
                            // return first HW codec found
                            if (!isGoogleCodec) {
                                return codecProperties;
                            }
                        }
                    }
                }
            }
        }
        if (codecProperties == null) {
            Log.i(TAG, "no suitable " + (forceGoogleCodec ? "google " : "")
                    + (isEncoder ? "encoder " : "decoder ") + "found for " + format);
        }
        return codecProperties;
    }

    /**
     * Parameters for encoded video stream.
     */
    protected class EncoderOutputStreamParameters {
        // Name of raw YUV420 input file. When the value of this parameter
        // is set to null input file descriptor from inputResourceId parameter
        // is used instead.
        public String inputYuvFilename;
        // Name of scaled YUV420 input file.
        public String scaledYuvFilename;
        // File descriptor for the raw input file (YUV420). Used only if
        // inputYuvFilename parameter is null.
        int inputResourceId;
        // Name of the IVF file to write encoded bitsream
        public String outputIvfFilename;
        // Force to use Google VP8 encoder.
        boolean forceGoogleEncoder;
        // Number of frames to encode.
        int frameCount;
        // Frame rate of input file in frames per second.
        int frameRate;
        // Encoded frame width.
        public int frameWidth;
        // Encoded frame height.
        public int frameHeight;
        // Encoding bitrate array in bits/second for every frame. If array length
        // is shorter than the total number of frames, the last value is re-used for
        // all remaining frames. For constant bitrate encoding single element
        // array can be used with first element set to target bitrate value.
        public int[] bitrateSet;
        // Encoding bitrate type - VBR or CBR
        public int bitrateType;
        // Number of temporal layers
        public int temporalLayers;
        // Desired key frame interval - codec is asked to generate key frames
        // at a period defined by this parameter.
        public int syncFrameInterval;
        // Optional parameter - forced key frame interval. Used to
        // explicitly request the codec to generate key frames using
        // MediaCodec.PARAMETER_KEY_REQUEST_SYNC_FRAME parameter.
        public int syncForceFrameInterval;
        // Buffer timeout
        long timeoutDequeue;
        // Flag if encoder should run in Looper thread.
        boolean runInLooperThread;
    }

    /**
     * Generates an array of default parameters for encoder output stream based on
     * upscaling value.
     */
    protected ArrayList<EncoderOutputStreamParameters> getDefaultEncodingParameterList(
            String inputYuvName,
            String outputIvfBaseName,
            int encodeSeconds,
            int[] resolutionScales,
            int frameWidth,
            int frameHeight,
            int frameRate,
            int bitrateMode,
            int[] bitrates,
            boolean syncEncoding) {
        assertTrue(resolutionScales.length == bitrates.length);
        int numCodecs = resolutionScales.length;
        ArrayList<EncoderOutputStreamParameters> outputParameters =
                new ArrayList<EncoderOutputStreamParameters>(numCodecs);
        for (int i = 0; i < numCodecs; i++) {
            EncoderOutputStreamParameters params = new EncoderOutputStreamParameters();
            if (inputYuvName != null) {
                params.inputYuvFilename = SDCARD_DIR + File.separator + inputYuvName;
            } else {
                params.inputYuvFilename = null;
            }
            params.scaledYuvFilename = SDCARD_DIR + File.separator +
                    outputIvfBaseName + resolutionScales[i]+ ".yuv";
            params.inputResourceId = R.raw.football_qvga;
            params.outputIvfFilename = SDCARD_DIR + File.separator +
                    outputIvfBaseName + resolutionScales[i] + ".ivf";
            params.forceGoogleEncoder = false;
            params.frameCount = encodeSeconds * frameRate;
            params.frameRate = frameRate;
            params.frameWidth = Math.min(frameWidth * resolutionScales[i], 1280);
            params.frameHeight = Math.min(frameHeight * resolutionScales[i], 720);
            params.bitrateSet = new int[1];
            params.bitrateSet[0] = bitrates[i];
            params.bitrateType = bitrateMode;
            params.temporalLayers = 0;
            params.syncFrameInterval = SYNC_FRAME_INTERVAL;
            params.syncForceFrameInterval = 0;
            if (syncEncoding) {
                params.timeoutDequeue = DEFAULT_DEQUEUE_TIMEOUT_US;
                params.runInLooperThread = false;
            } else {
                params.timeoutDequeue = 0;
                params.runInLooperThread = true;
            }
            outputParameters.add(params);
        }
        return outputParameters;
    }

    protected EncoderOutputStreamParameters getDefaultEncodingParameters(
            String inputYuvName,
            String outputIvfBaseName,
            int encodeSeconds,
            int frameWidth,
            int frameHeight,
            int frameRate,
            int bitrateMode,
            int bitrate,
            boolean syncEncoding) {
        int[] scaleValues = { 1 };
        int[] bitrates = { bitrate };
        return getDefaultEncodingParameterList(
                inputYuvName,
                outputIvfBaseName,
                encodeSeconds,
                scaleValues,
                frameWidth,
                frameHeight,
                frameRate,
                bitrateMode,
                bitrates,
                syncEncoding).get(0);
    }

    /**
     * Converts (interleaves) YUV420 planar to NV12.
     * Assumes packed, macroblock-aligned frame with no cropping
     * (visible/coded row length == stride).
     */
    private static byte[] YUV420ToNV(int width, int height, byte[] yuv) {
        byte[] nv = new byte[yuv.length];
        // Y plane we just copy.
        System.arraycopy(yuv, 0, nv, 0, width * height);

        // U & V plane we interleave.
        int u_offset = width * height;
        int v_offset = u_offset + u_offset / 4;
        int nv_offset = width * height;
        for (int i = 0; i < width * height / 4; i++) {
            nv[nv_offset++] = yuv[u_offset++];
            nv[nv_offset++] = yuv[v_offset++];
        }
        return nv;
    }

    /**
     * Converts (de-interleaves) NV12 to YUV420 planar.
     * Stride may be greater than width, slice height may be greater than height.
     */
    private static byte[] NV12ToYUV420(int width, int height,
            int stride, int sliceHeight, byte[] nv12) {
        byte[] yuv = new byte[width * height * 3 / 2];

        // Y plane we just copy.
        for (int i = 0; i < height; i++) {
            System.arraycopy(nv12, i * stride, yuv, i * width, width);
        }

        // U & V plane - de-interleave.
        int u_offset = width * height;
        int v_offset = u_offset + u_offset / 4;
        int nv_offset;
        for (int i = 0; i < height / 2; i++) {
            nv_offset = stride * (sliceHeight + i);
            for (int j = 0; j < width / 2; j++) {
                yuv[u_offset++] = nv12[nv_offset++];
                yuv[v_offset++] = nv12[nv_offset++];
            }
        }
        return yuv;
    }

    /**
     * Packs YUV420 frame by moving it to a smaller size buffer with stride and slice
     * height equal to the original frame width and height.
     */
    private static byte[] PackYUV420(int width, int height,
            int stride, int sliceHeight, byte[] src) {
        byte[] dst = new byte[width * height * 3 / 2];
        // Y copy.
        for (int i = 0; i < height; i++) {
            System.arraycopy(src, i * stride, dst, i * width, width);
        }
        // U and V copy.
        int u_src_offset = stride * sliceHeight;
        int v_src_offset = u_src_offset + u_src_offset / 4;
        int u_dst_offset = width * height;
        int v_dst_offset = u_dst_offset + u_dst_offset / 4;
        for (int i = 0; i < height / 2; i++) {
            System.arraycopy(src, u_src_offset + i * (stride / 2),
                    dst, u_dst_offset + i * (width / 2), width / 2);
            System.arraycopy(src, v_src_offset + i * (stride / 2),
                    dst, v_dst_offset + i * (width / 2), width / 2);
        }
        return dst;
    }


    private static void imageUpscale1To2(byte[] src, int srcByteOffset, int srcStride,
            byte[] dst, int dstByteOffset, int dstWidth, int dstHeight) {
        for (int i = 0; i < dstHeight/2 - 1; i++) {
            int dstOffset0 = 2 * i * dstWidth + dstByteOffset;
            int dstOffset1 = dstOffset0 + dstWidth;
            int srcOffset0 = i * srcStride + srcByteOffset;
            int srcOffset1 = srcOffset0 + srcStride;
            int pixel00 = (int)src[srcOffset0++] & 0xff;
            int pixel10 = (int)src[srcOffset1++] & 0xff;
            for (int j = 0; j < dstWidth/2 - 1; j++) {
                int pixel01 = (int)src[srcOffset0++] & 0xff;
                int pixel11 = (int)src[srcOffset1++] & 0xff;
                dst[dstOffset0++] = (byte)pixel00;
                dst[dstOffset0++] = (byte)((pixel00 + pixel01 + 1) / 2);
                dst[dstOffset1++] = (byte)((pixel00 + pixel10 + 1) / 2);
                dst[dstOffset1++] = (byte)((pixel00 + pixel01 + pixel10 + pixel11 + 2) / 4);
                pixel00 = pixel01;
                pixel10 = pixel11;
            }
            // last column
            dst[dstOffset0++] = (byte)pixel00;
            dst[dstOffset0++] = (byte)pixel00;
            dst[dstOffset1++] = (byte)((pixel00 + pixel10 + 1) / 2);
            dst[dstOffset1++] = (byte)((pixel00 + pixel10 + 1) / 2);
        }

        // last row
        int dstOffset0 = (dstHeight - 2) * dstWidth + dstByteOffset;
        int dstOffset1 = dstOffset0 + dstWidth;
        int srcOffset0 = (dstHeight/2 - 1) * srcStride + srcByteOffset;
        int pixel00 = (int)src[srcOffset0++] & 0xff;
        for (int j = 0; j < dstWidth/2 - 1; j++) {
            int pixel01 = (int)src[srcOffset0++] & 0xff;
            dst[dstOffset0++] = (byte)pixel00;
            dst[dstOffset0++] = (byte)((pixel00 + pixel01 + 1) / 2);
            dst[dstOffset1++] = (byte)pixel00;
            dst[dstOffset1++] = (byte)((pixel00 + pixel01 + 1) / 2);
            pixel00 = pixel01;
        }
        // the very last pixel - bottom right
        dst[dstOffset0++] = (byte)pixel00;
        dst[dstOffset0++] = (byte)pixel00;
        dst[dstOffset1++] = (byte)pixel00;
        dst[dstOffset1++] = (byte)pixel00;
    }

    /**
    * Up-scale image.
    * Scale factor is defined by source and destination width ratio.
    * Only 1:2 and 1:4 up-scaling is supported for now.
    * For 640x480 -> 1280x720 conversion only top 640x360 part of the original
    * image is scaled.
    */
    private static byte[] imageScale(byte[] src, int srcWidth, int srcHeight,
            int dstWidth, int dstHeight) throws Exception {
        int srcYSize = srcWidth * srcHeight;
        int dstYSize = dstWidth * dstHeight;
        byte[] dst = null;
        if (dstWidth == 2 * srcWidth && dstHeight <= 2 * srcHeight) {
            // 1:2 upscale
            dst = new byte[dstWidth * dstHeight * 3 / 2];
            imageUpscale1To2(src, 0, srcWidth,
                    dst, 0, dstWidth, dstHeight);                                 // Y
            imageUpscale1To2(src, srcYSize, srcWidth / 2,
                    dst, dstYSize, dstWidth / 2, dstHeight / 2);                  // U
            imageUpscale1To2(src, srcYSize * 5 / 4, srcWidth / 2,
                    dst, dstYSize * 5 / 4, dstWidth / 2, dstHeight / 2);          // V
        } else if (dstWidth == 4 * srcWidth && dstHeight <= 4 * srcHeight) {
            // 1:4 upscale - in two steps
            int midWidth = 2 * srcWidth;
            int midHeight = 2 * srcHeight;
            byte[] midBuffer = imageScale(src, srcWidth, srcHeight, midWidth, midHeight);
            dst = imageScale(midBuffer, midWidth, midHeight, dstWidth, dstHeight);

        } else {
            throw new RuntimeException("Can not find proper scaling function");
        }

        return dst;
    }

    private void cacheScaledImage(
            String srcYuvFilename, int srcResourceId, int srcFrameWidth, int srcFrameHeight,
            String dstYuvFilename, int dstFrameWidth, int dstFrameHeight) throws Exception {
        InputStream srcStream = OpenFileOrResourceId(srcYuvFilename, srcResourceId);
        FileOutputStream dstFile = new FileOutputStream(dstYuvFilename, false);
        int srcFrameSize = srcFrameWidth * srcFrameHeight * 3 / 2;
        byte[] srcFrame = new byte[srcFrameSize];
        byte[] dstFrame = null;
        Log.d(TAG, "Scale to " + dstFrameWidth + " x " + dstFrameHeight + ". -> " + dstYuvFilename);
        while (true) {
            int bytesRead = srcStream.read(srcFrame);
            if (bytesRead != srcFrame.length) {
                break;
            }
            if (dstFrameWidth == srcFrameWidth && dstFrameHeight == srcFrameHeight) {
                dstFrame = srcFrame;
            } else {
                dstFrame = imageScale(srcFrame, srcFrameWidth, srcFrameHeight,
                        dstFrameWidth, dstFrameHeight);
            }
            dstFile.write(dstFrame);
        }
        srcStream.close();
        dstFile.close();
    }


    /**
     * A basic check if an encoded stream is decodable.
     *
     * The most basic confirmation we can get about a frame
     * being properly encoded is trying to decode it.
     * (Especially in realtime mode encode output is non-
     * deterministic, therefore a more thorough check like
     * md5 sum comparison wouldn't work.)
     *
     * Indeed, MediaCodec will raise an IllegalStateException
     * whenever vp8 decoder fails to decode a frame, and
     * this test uses that fact to verify the bitstream.
     *
     * @param inputIvfFilename  The name of the IVF file containing encoded bitsream.
     * @param outputYuvFilename The name of the output YUV file (optional).
     * @param frameRate         Frame rate of input file in frames per second
     * @param forceGoogleDecoder    Force to use Google VP8 decoder.
     */
    protected ArrayList<MediaCodec.BufferInfo> decode(
            String inputIvfFilename,
            String outputYuvFilename,
            int frameRate,
            boolean forceGoogleDecoder) throws Exception {
        ArrayList<MediaCodec.BufferInfo> bufferInfos = new ArrayList<MediaCodec.BufferInfo>();

        // Open input/output.
        IvfReader ivf = new IvfReader(inputIvfFilename);
        int frameWidth = ivf.getWidth();
        int frameHeight = ivf.getHeight();
        int frameCount = ivf.getFrameCount();
        int frameStride = frameWidth;
        int frameSliceHeight = frameHeight;
        assertTrue(frameWidth > 0);
        assertTrue(frameHeight > 0);
        assertTrue(frameCount > 0);

        // Create decoder.
        MediaFormat format = MediaFormat.createVideoFormat(
                VP8_MIME, ivf.getWidth(), ivf.getHeight());
        CodecProperties properties = getVpxCodecProperties(
                false /* encoder */, format, forceGoogleDecoder);
        if (properties == null) {
            ivf.close();
            return null;
        }
        int frameColorFormat = properties.colorFormat;
        format.setInteger(MediaFormat.KEY_COLOR_FORMAT, properties.colorFormat);

        FileOutputStream yuv = null;
        if (outputYuvFilename != null) {
            yuv = new FileOutputStream(outputYuvFilename, false);
        }

        Log.d(TAG, "Creating decoder " + properties.codecName +
                ". Color format: 0x" + Integer.toHexString(frameColorFormat) +
                ". " + frameWidth + " x " + frameHeight);
        Log.d(TAG, "  Format: " + format);
        Log.d(TAG, "  In: " + inputIvfFilename + ". Out:" + outputYuvFilename);
        MediaCodec decoder = MediaCodec.createByCodecName(properties.codecName);
        decoder.configure(format,
                          null,  // surface
                          null,  // crypto
                          0);    // flags
        decoder.start();

        ByteBuffer[] inputBuffers = decoder.getInputBuffers();
        ByteBuffer[] outputBuffers = decoder.getOutputBuffers();
        MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo();

        // decode loop
        int inputFrameIndex = 0;
        int outputFrameIndex = 0;
        long inPresentationTimeUs = 0;
        long outPresentationTimeUs = 0;
        boolean sawOutputEOS = false;
        boolean sawInputEOS = false;

        while (!sawOutputEOS) {
            if (!sawInputEOS) {
                int inputBufIndex = decoder.dequeueInputBuffer(DEFAULT_DEQUEUE_TIMEOUT_US);
                if (inputBufIndex >= 0) {
                    byte[] frame = ivf.readFrame(inputFrameIndex);

                    if (inputFrameIndex == frameCount - 1) {
                        Log.d(TAG, "  Input EOS for frame # " + inputFrameIndex);
                        sawInputEOS = true;
                    }

                    inputBuffers[inputBufIndex].clear();
                    inputBuffers[inputBufIndex].put(frame);
                    inputBuffers[inputBufIndex].rewind();
                    inPresentationTimeUs = (inputFrameIndex * 1000000) / frameRate;

                    decoder.queueInputBuffer(
                            inputBufIndex,
                            0,  // offset
                            frame.length,
                            inPresentationTimeUs,
                            sawInputEOS ? MediaCodec.BUFFER_FLAG_END_OF_STREAM : 0);

                    inputFrameIndex++;
                }
            }

            int result = decoder.dequeueOutputBuffer(bufferInfo, DEFAULT_DEQUEUE_TIMEOUT_US);
            while (result == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED ||
                    result == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
                if (result == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
                    outputBuffers = decoder.getOutputBuffers();
                } else  if (result == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
                    // Process format change
                    format = decoder.getOutputFormat();
                    frameWidth = format.getInteger(MediaFormat.KEY_WIDTH);
                    frameHeight = format.getInteger(MediaFormat.KEY_HEIGHT);
                    frameColorFormat = format.getInteger(MediaFormat.KEY_COLOR_FORMAT);
                    Log.d(TAG, "Decoder output format change. Color: 0x" +
                            Integer.toHexString(frameColorFormat));
                    Log.d(TAG, "Format: " + format.toString());

                    // Parse frame and slice height from undocumented values
                    if (format.containsKey("stride")) {
                        frameStride = format.getInteger("stride");
                    } else {
                        frameStride = frameWidth;
                    }
                    if (format.containsKey("slice-height")) {
                        frameSliceHeight = format.getInteger("slice-height");
                    } else {
                        frameSliceHeight = frameHeight;
                    }
                    Log.d(TAG, "Frame stride and slice height: " + frameStride +
                            " x " + frameSliceHeight);
                    frameStride = Math.max(frameWidth, frameStride);
                    frameSliceHeight = Math.max(frameHeight, frameSliceHeight);
                }
                result = decoder.dequeueOutputBuffer(bufferInfo, DEFAULT_DEQUEUE_TIMEOUT_US);
            }
            if (result >= 0) {
                int outputBufIndex = result;
                outPresentationTimeUs = bufferInfo.presentationTimeUs;
                Log.v(TAG, "Writing buffer # " + outputFrameIndex +
                        ". Size: " + bufferInfo.size +
                        ". InTime: " + (inPresentationTimeUs + 500)/1000 +
                        ". OutTime: " + (outPresentationTimeUs + 500)/1000);
                if ((bufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
                    sawOutputEOS = true;
                    Log.d(TAG, "   Output EOS for frame # " + outputFrameIndex);
                }

                if (bufferInfo.size > 0) {
                    // Save decoder output to yuv file.
                    if (yuv != null) {
                        byte[] frame = new byte[bufferInfo.size];
                        outputBuffers[outputBufIndex].position(bufferInfo.offset);
                        outputBuffers[outputBufIndex].get(frame, 0, bufferInfo.size);
                        // Convert NV12 to YUV420 if necessary.
                        if (frameColorFormat != CodecCapabilities.COLOR_FormatYUV420Planar) {
                            frame = NV12ToYUV420(frameWidth, frameHeight,
                                    frameStride, frameSliceHeight, frame);
                        }
                        int writeLength = Math.min(frameWidth * frameHeight * 3 / 2, frame.length);
                        // Pack frame if necessary.
                        if (writeLength < frame.length &&
                                (frameStride > frameWidth || frameSliceHeight > frameHeight)) {
                            frame = PackYUV420(frameWidth, frameHeight,
                                    frameStride, frameSliceHeight, frame);
                        }
                        yuv.write(frame, 0, writeLength);
                    }
                    outputFrameIndex++;

                    // Update statistics - store presentation time delay in offset
                    long presentationTimeUsDelta = inPresentationTimeUs - outPresentationTimeUs;
                    MediaCodec.BufferInfo bufferInfoCopy = new MediaCodec.BufferInfo();
                    bufferInfoCopy.set((int)presentationTimeUsDelta, bufferInfo.size,
                            outPresentationTimeUs, bufferInfo.flags);
                    bufferInfos.add(bufferInfoCopy);
                }
                decoder.releaseOutputBuffer(outputBufIndex, false);
            }
        }
        decoder.stop();
        decoder.release();
        ivf.close();
        if (yuv != null) {
            yuv.close();
        }

        return bufferInfos;
    }


    /**
     * Helper function to return InputStream from either filename (if set)
     * or resource id (if filename is not set).
     */
    private InputStream OpenFileOrResourceId(String filename, int resourceId) throws Exception {
        if (filename != null) {
            return new FileInputStream(filename);
        }
        return mResources.openRawResource(resourceId);
    }

    /**
     * Results of frame encoding.
     */
    protected class MediaEncoderOutput {
        public long inPresentationTimeUs;
        public long outPresentationTimeUs;
        public boolean outputGenerated;
        public int flags;
        public byte[] buffer;
    }

    protected class MediaEncoderAsyncHelper {
        private final EncoderOutputStreamParameters mStreamParams;
        private final CodecProperties mProperties;
        private final ArrayList<MediaCodec.BufferInfo> mBufferInfos;
        private final IvfWriter mIvf;
        private final byte[] mSrcFrame;

        private InputStream mYuvStream;
        private int mInputFrameIndex;

        MediaEncoderAsyncHelper(
                EncoderOutputStreamParameters streamParams,
                CodecProperties properties,
                ArrayList<MediaCodec.BufferInfo> bufferInfos,
                IvfWriter ivf)
                throws Exception {
            mStreamParams = streamParams;
            mProperties = properties;
            mBufferInfos = bufferInfos;
            mIvf = ivf;

            int srcFrameSize = streamParams.frameWidth * streamParams.frameHeight * 3 / 2;
            mSrcFrame = new byte[srcFrameSize];

            mYuvStream = OpenFileOrResourceId(
                    streamParams.inputYuvFilename, streamParams.inputResourceId);
        }

        public byte[] getInputFrame() {
            // Check EOS
            if (mStreamParams.frameCount == 0
                    || (mStreamParams.frameCount > 0
                            && mInputFrameIndex >= mStreamParams.frameCount)) {
                Log.d(TAG, "---Sending EOS empty frame for frame # " + mInputFrameIndex);
                return null;
            }

            try {
                int bytesRead = mYuvStream.read(mSrcFrame);

                if (bytesRead == -1) {
                    // rewind to beginning of file
                    mYuvStream.close();
                    mYuvStream = OpenFileOrResourceId(
                            mStreamParams.inputYuvFilename, mStreamParams.inputResourceId);
                    bytesRead = mYuvStream.read(mSrcFrame);
                }
            } catch (Exception e) {
                Log.e(TAG, "Failed to read YUV file.");
                return null;
            }
            mInputFrameIndex++;

            // Convert YUV420 to NV12 if necessary
            if (mProperties.colorFormat != CodecCapabilities.COLOR_FormatYUV420Planar) {
                return YUV420ToNV(mStreamParams.frameWidth, mStreamParams.frameHeight,
                        mSrcFrame);
            } else {
                return mSrcFrame;
            }
        }

        public boolean saveOutputFrame(MediaEncoderOutput out) {
            if (out.outputGenerated) {
                if (out.buffer.length > 0) {
                    // Save frame
                    try {
                        mIvf.writeFrame(out.buffer, out.outPresentationTimeUs);
                    } catch (Exception e) {
                        Log.d(TAG, "Failed to write frame");
                        return true;
                    }

                    // Update statistics - store presentation time delay in offset
                    long presentationTimeUsDelta = out.inPresentationTimeUs -
                            out.outPresentationTimeUs;
                    MediaCodec.BufferInfo bufferInfoCopy = new MediaCodec.BufferInfo();
                    bufferInfoCopy.set((int)presentationTimeUsDelta, out.buffer.length,
                            out.outPresentationTimeUs, out.flags);
                    mBufferInfos.add(bufferInfoCopy);
                }
                // Detect output EOS
                if ((out.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
                    Log.d(TAG, "----Output EOS ");
                    return true;
                }
            }
            return false;
        }
    }

    /**
     * Video encoder wrapper class.
     * Allows to run the encoder either in a callee's thread or in a looper thread
     * using buffer dequeue ready notification callbacks.
     *
     * Function feedInput() is used to send raw video frame to the encoder input. When encoder
     * is configured to run in async mode the function will run in a looper thread.
     * Encoded frame can be retrieved by calling getOutput() function.
     */
    protected class MediaEncoderAsync extends Thread {
        private int mId;
        private MediaCodec mCodec;
        private MediaFormat mFormat;
        private ByteBuffer[] mInputBuffers;
        private ByteBuffer[] mOutputBuffers;
        private int mInputFrameIndex;
        private int mOutputFrameIndex;
        private int mInputBufIndex;
        private int mFrameRate;
        private long mTimeout;
        private MediaCodec.BufferInfo mBufferInfo;
        private long mInPresentationTimeUs;
        private long mOutPresentationTimeUs;
        private boolean mAsync;
        // Flag indicating if input frame was consumed by the encoder in feedInput() call.
        private boolean mConsumedInput;
        // Result of frame encoding returned by getOutput() call.
        private MediaEncoderOutput mOutput;
        // Object used to signal that looper thread has started and Handler instance associated
        // with looper thread has been allocated.
        private final Object mThreadEvent = new Object();
        // Object used to signal that MediaCodec buffer dequeue notification callback
        // was received.
        private final Object mCallbackEvent = new Object();
        private Handler mHandler;
        private boolean mCallbackReceived;
        private MediaEncoderAsyncHelper mHelper;
        private final Object mCompletionEvent = new Object();
        private boolean mCompleted;

        private MediaCodec.Callback mCallback = new MediaCodec.Callback() {
            @Override
            public void onInputBufferAvailable(MediaCodec codec, int index) {
                if (mHelper == null) {
                    Log.e(TAG, "async helper not available");
                    return;
                }

                byte[] encFrame = mHelper.getInputFrame();
                boolean inputEOS = (encFrame == null);

                int encFrameLength = 0;
                int flags = 0;
                if (inputEOS) {
                    flags = MediaCodec.BUFFER_FLAG_END_OF_STREAM;
                } else {
                    encFrameLength = encFrame.length;

                    ByteBuffer byteBuffer = mCodec.getInputBuffer(index);
                    byteBuffer.put(encFrame);
                    byteBuffer.rewind();

                    mInPresentationTimeUs = (mInputFrameIndex * 1000000) / mFrameRate;

                    Log.v(TAG, "Enc" + mId + ". Frame in # " + mInputFrameIndex +
                            ". InTime: " + (mInPresentationTimeUs + 500)/1000);

                    mInputFrameIndex++;
                }

                mCodec.queueInputBuffer(
                        index,
                        0,  // offset
                        encFrameLength,  // size
                        mInPresentationTimeUs,
                        flags);
            }

            @Override
            public void onOutputBufferAvailable(MediaCodec codec,
                    int index, MediaCodec.BufferInfo info) {
                if (mHelper == null) {
                    Log.e(TAG, "async helper not available");
                    return;
                }

                MediaEncoderOutput out = new MediaEncoderOutput();

                out.buffer = new byte[info.size];
                ByteBuffer outputBuffer = mCodec.getOutputBuffer(index);
                outputBuffer.get(out.buffer, 0, info.size);
                mOutPresentationTimeUs = info.presentationTimeUs;

                String logStr = "Enc" + mId + ". Frame # " + mOutputFrameIndex;
                if ((info.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0) {
                    logStr += " CONFIG. ";
                }
                if ((info.flags & MediaCodec.BUFFER_FLAG_SYNC_FRAME) != 0) {
                    logStr += " KEY. ";
                }
                if ((info.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
                    logStr += " EOS. ";
                }
                logStr += " Size: " + info.size;
                logStr += ". InTime: " + (mInPresentationTimeUs + 500)/1000 +
                        ". OutTime: " + (mOutPresentationTimeUs + 500)/1000;
                Log.v(TAG, logStr);

                if (mOutputFrameIndex == 0 &&
                        ((info.flags & MediaCodec.BUFFER_FLAG_SYNC_FRAME) == 0) ) {
                    throw new RuntimeException("First frame is not a sync frame.");
                }

                if (info.size > 0) {
                    mOutputFrameIndex++;
                    out.inPresentationTimeUs = mInPresentationTimeUs;
                    out.outPresentationTimeUs = mOutPresentationTimeUs;
                }
                mCodec.releaseOutputBuffer(index, false);

                out.flags = info.flags;
                out.outputGenerated = true;

                if (mHelper.saveOutputFrame(out)) {
                    // output EOS
                    signalCompletion();
                }
            }

            @Override
            public void onError(MediaCodec codec, CodecException e) {
                Log.e(TAG, "onError: " + e
                        + ", transient " + e.isTransient()
                        + ", recoverable " + e.isRecoverable()
                        + ", error " + e.getErrorCode());
            }

            @Override
            public void onOutputFormatChanged(MediaCodec codec, MediaFormat format) {
                Log.i(TAG, "onOutputFormatChanged: " + format.toString());
            }
        };

        private synchronized void requestStart() throws Exception {
            mHandler = null;
            start();
            // Wait for Hander allocation
            synchronized (mThreadEvent) {
                while (mHandler == null) {
                    mThreadEvent.wait();
                }
            }
        }

        public void setAsyncHelper(MediaEncoderAsyncHelper helper) {
            mHelper = helper;
        }

        @Override
        public void run() {
            Looper.prepare();
            synchronized (mThreadEvent) {
                mHandler = new Handler();
                mThreadEvent.notify();
            }
            Looper.loop();
        }

        private void runCallable(final Callable<?> callable) throws Exception {
            if (mAsync) {
                final Exception[] exception = new Exception[1];
                final CountDownLatch countDownLatch = new CountDownLatch(1);
                mHandler.post( new Runnable() {
                    @Override
                    public void run() {
                        try {
                            callable.call();
                        } catch (Exception e) {
                            exception[0] = e;
                        } finally {
                            countDownLatch.countDown();
                        }
                    }
                } );

                // Wait for task completion
                countDownLatch.await();
                if (exception[0] != null) {
                    throw exception[0];
                }
            } else {
                callable.call();
            }
        }

        private synchronized void requestStop() throws Exception {
            mHandler.post( new Runnable() {
                @Override
                public void run() {
                    // This will run on the Looper thread
                    Log.v(TAG, "MediaEncoder looper quitting");
                    Looper.myLooper().quitSafely();
                }
            } );
            // Wait for completion
            join();
            mHandler = null;
        }

        private void createCodecInternal(final String name,
                final MediaFormat format, final long timeout) throws Exception {
            mBufferInfo = new MediaCodec.BufferInfo();
            mFormat = format;
            mFrameRate = format.getInteger(MediaFormat.KEY_FRAME_RATE);
            mTimeout = timeout;
            mInputFrameIndex = 0;
            mOutputFrameIndex = 0;
            mInPresentationTimeUs = 0;
            mOutPresentationTimeUs = 0;

            mCodec = MediaCodec.createByCodecName(name);
            if (mAsync) {
                mCodec.setCallback(mCallback);
            }
            mCodec.configure(mFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
            mCodec.start();

            // get the cached input/output only in sync mode
            if (!mAsync) {
                mInputBuffers = mCodec.getInputBuffers();
                mOutputBuffers = mCodec.getOutputBuffers();
            }
        }

        public void createCodec(int id, final String name, final MediaFormat format,
                final long timeout, boolean async)  throws Exception {
            mId = id;
            mAsync = async;
            if (mAsync) {
                requestStart(); // start looper thread
            }
            runCallable( new Callable<Void>() {
                @Override
                public Void call() throws Exception {
                    createCodecInternal(name, format, timeout);
                    return null;
                }
            } );
        }

        private void feedInputInternal(final byte[] encFrame, final boolean inputEOS) {
            mConsumedInput = false;
            // Feed input
            mInputBufIndex = mCodec.dequeueInputBuffer(mTimeout);

            if (mInputBufIndex >= 0) {
                mInputBuffers[mInputBufIndex].clear();
                mInputBuffers[mInputBufIndex].put(encFrame);
                mInputBuffers[mInputBufIndex].rewind();
                int encFrameLength = encFrame.length;
                int flags = 0;
                if (inputEOS) {
                    encFrameLength = 0;
                    flags = MediaCodec.BUFFER_FLAG_END_OF_STREAM;
                }
                if (!inputEOS) {
                    Log.v(TAG, "Enc" + mId + ". Frame in # " + mInputFrameIndex +
                            ". InTime: " + (mInPresentationTimeUs + 500)/1000);
                    mInPresentationTimeUs = (mInputFrameIndex * 1000000) / mFrameRate;
                    mInputFrameIndex++;
                }

                mCodec.queueInputBuffer(
                        mInputBufIndex,
                        0,  // offset
                        encFrameLength,  // size
                        mInPresentationTimeUs,
                        flags);

                mConsumedInput = true;
            } else {
                Log.v(TAG, "In " + mId + " - TRY_AGAIN_LATER");
            }
            mCallbackReceived = false;
        }

        public boolean feedInput(final byte[] encFrame, final boolean inputEOS) throws Exception {
            runCallable( new Callable<Void>() {
                @Override
                public Void call() throws Exception {
                    feedInputInternal(encFrame, inputEOS);
                    return null;
                }
            } );
            return mConsumedInput;
        }

        private void getOutputInternal() {
            mOutput = new MediaEncoderOutput();
            mOutput.inPresentationTimeUs = mInPresentationTimeUs;
            mOutput.outPresentationTimeUs = mOutPresentationTimeUs;
            mOutput.outputGenerated = false;

            // Get output from the encoder
            int result = mCodec.dequeueOutputBuffer(mBufferInfo, mTimeout);
            while (result == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED ||
                    result == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
                if (result == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
                    mOutputBuffers = mCodec.getOutputBuffers();
                } else if (result == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
                    mFormat = mCodec.getOutputFormat();
                    Log.d(TAG, "Format changed: " + mFormat.toString());
                }
                result = mCodec.dequeueOutputBuffer(mBufferInfo, mTimeout);
            }
            if (result == MediaCodec.INFO_TRY_AGAIN_LATER) {
                Log.v(TAG, "Out " + mId + " - TRY_AGAIN_LATER");
            }

            if (result >= 0) {
                int outputBufIndex = result;
                mOutput.buffer = new byte[mBufferInfo.size];
                mOutputBuffers[outputBufIndex].position(mBufferInfo.offset);
                mOutputBuffers[outputBufIndex].get(mOutput.buffer, 0, mBufferInfo.size);
                mOutPresentationTimeUs = mBufferInfo.presentationTimeUs;

                String logStr = "Enc" + mId + ". Frame # " + mOutputFrameIndex;
                if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0) {
                    logStr += " CONFIG. ";
                }
                if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_SYNC_FRAME) != 0) {
                    logStr += " KEY. ";
                }
                if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
                    logStr += " EOS. ";
                }
                logStr += " Size: " + mBufferInfo.size;
                logStr += ". InTime: " + (mInPresentationTimeUs + 500)/1000 +
                        ". OutTime: " + (mOutPresentationTimeUs + 500)/1000;
                Log.v(TAG, logStr);
                if (mOutputFrameIndex == 0 &&
                        ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_SYNC_FRAME) == 0) ) {
                    throw new RuntimeException("First frame is not a sync frame.");
                }

                if (mBufferInfo.size > 0) {
                    mOutputFrameIndex++;
                    mOutput.outPresentationTimeUs = mOutPresentationTimeUs;
                }
                mCodec.releaseOutputBuffer(outputBufIndex, false);

                mOutput.flags = mBufferInfo.flags;
                mOutput.outputGenerated = true;
            }
            mCallbackReceived = false;
        }

        public MediaEncoderOutput getOutput() throws Exception {
            runCallable( new Callable<Void>() {
                @Override
                public Void call() throws Exception {
                    getOutputInternal();
                    return null;
                }
            } );
            return mOutput;
        }

        public void forceSyncFrame() throws Exception {
            final Bundle syncFrame = new Bundle();
            syncFrame.putInt(MediaCodec.PARAMETER_KEY_REQUEST_SYNC_FRAME, 0);
            runCallable( new Callable<Void>() {
                @Override
                public Void call() throws Exception {
                    mCodec.setParameters(syncFrame);
                    return null;
                }
            } );
        }

        public void updateBitrate(int bitrate) throws Exception {
            final Bundle bitrateUpdate = new Bundle();
            bitrateUpdate.putInt(MediaCodec.PARAMETER_KEY_VIDEO_BITRATE, bitrate);
            runCallable( new Callable<Void>() {
                @Override
                public Void call() throws Exception {
                    mCodec.setParameters(bitrateUpdate);
                    return null;
                }
            } );
        }


        public void waitForBufferEvent() throws Exception {
            Log.v(TAG, "----Enc" + mId + " waiting for bufferEvent");
            if (mAsync) {
                synchronized (mCallbackEvent) {
                    if (!mCallbackReceived) {
                        mCallbackEvent.wait(1000); // wait 1 sec for a callback
                        // throw an exception if callback was not received
                        if (!mCallbackReceived) {
                            throw new RuntimeException("MediaCodec callback was not received");
                        }
                    }
                }
            } else {
                Thread.sleep(5);
            }
            Log.v(TAG, "----Waiting for bufferEvent done");
        }


        public void waitForCompletion(long timeoutMs) throws Exception {
            synchronized (mCompletionEvent) {
                long timeoutExpiredMs = System.currentTimeMillis() + timeoutMs;

                while (!mCompleted) {
                    mCompletionEvent.wait(timeoutExpiredMs - System.currentTimeMillis());
                    if (System.currentTimeMillis() >= timeoutExpiredMs) {
                        throw new RuntimeException("encoding has timed out!");
                    }
                }
            }
        }

        public void signalCompletion() {
            synchronized (mCompletionEvent) {
                mCompleted = true;
                mCompletionEvent.notify();
            }
        }

        public void deleteCodec() throws Exception {
            runCallable( new Callable<Void>() {
                @Override
                public Void call() throws Exception {
                    mCodec.stop();
                    mCodec.release();
                    return null;
                }
            } );
            if (mAsync) {
                requestStop(); // Stop looper thread
            }
        }
    }

    /**
     * Vp8 encoding loop supporting encoding single streams with an option
     * to run in a looper thread and use buffer ready notification callbacks.
     *
     * Output stream is described by encodingParams parameters.
     *
     * MediaCodec will raise an IllegalStateException
     * whenever vp8 encoder fails to encode a frame.
     *
     * Color format of input file should be YUV420, and frameWidth,
     * frameHeight should be supplied correctly as raw input file doesn't
     * include any header data.
     *
     * @param streamParams  Structure with encoder parameters
     * @return              Returns array of encoded frames information for each frame.
     */
    protected ArrayList<MediaCodec.BufferInfo> encode(
            EncoderOutputStreamParameters streamParams) throws Exception {

        ArrayList<MediaCodec.BufferInfo> bufferInfos = new ArrayList<MediaCodec.BufferInfo>();
        Log.d(TAG, "Source resolution: "+streamParams.frameWidth + " x " +
                streamParams.frameHeight);
        int bitrate = streamParams.bitrateSet[0];

        // Create minimal media format signifying desired output.
        MediaFormat format = MediaFormat.createVideoFormat(
                VP8_MIME, streamParams.frameWidth, streamParams.frameHeight);
        format.setInteger(MediaFormat.KEY_BIT_RATE, bitrate);
        CodecProperties properties = getVpxCodecProperties(
                true, format, streamParams.forceGoogleEncoder);
        if (properties == null) {
            return null;
        }

        // Open input/output
        InputStream yuvStream = OpenFileOrResourceId(
                streamParams.inputYuvFilename, streamParams.inputResourceId);
        IvfWriter ivf = new IvfWriter(
                streamParams.outputIvfFilename, streamParams.frameWidth, streamParams.frameHeight);

        // Create a media format signifying desired output.
        if (streamParams.bitrateType == VIDEO_ControlRateConstant) {
            format.setInteger("bitrate-mode", VIDEO_ControlRateConstant); // set CBR
        }
        if (streamParams.temporalLayers > 0) {
            format.setInteger("ts-layers", streamParams.temporalLayers); // 1 temporal layer
        }
        format.setInteger(MediaFormat.KEY_COLOR_FORMAT, properties.colorFormat);
        format.setInteger(MediaFormat.KEY_FRAME_RATE, streamParams.frameRate);
        int syncFrameInterval = (streamParams.syncFrameInterval + streamParams.frameRate/2) /
                streamParams.frameRate;
        format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, syncFrameInterval);

        // Create encoder
        Log.d(TAG, "Creating encoder " + properties.codecName +
                ". Color format: 0x" + Integer.toHexString(properties.colorFormat)+ " : " +
                streamParams.frameWidth + " x " + streamParams.frameHeight +
                ". Bitrate: " + bitrate + " Bitrate type: " + streamParams.bitrateType +
                ". Fps:" + streamParams.frameRate + ". TS Layers: " + streamParams.temporalLayers +
                ". Key frame:" + syncFrameInterval * streamParams.frameRate +
                ". Force keyFrame: " + streamParams.syncForceFrameInterval);
        Log.d(TAG, "  Format: " + format);
        Log.d(TAG, "  Output ivf:" + streamParams.outputIvfFilename);
        MediaEncoderAsync codec = new MediaEncoderAsync();
        codec.createCodec(0, properties.codecName, format,
                streamParams.timeoutDequeue, streamParams.runInLooperThread);

        // encode loop
        boolean sawInputEOS = false;  // no more data
        boolean consumedInputEOS = false; // EOS flag is consumed dy encoder
        boolean sawOutputEOS = false;
        boolean inputConsumed = true;
        int inputFrameIndex = 0;
        int lastBitrate = bitrate;
        int srcFrameSize = streamParams.frameWidth * streamParams.frameHeight * 3 / 2;
        byte[] srcFrame = new byte[srcFrameSize];

        while (!sawOutputEOS) {

            // Read and feed input frame
            if (!consumedInputEOS) {

                // Read new input buffers - if previous input was consumed and no EOS
                if (inputConsumed && !sawInputEOS) {
                    int bytesRead = yuvStream.read(srcFrame);

                    // Check EOS
                    if (streamParams.frameCount > 0 && inputFrameIndex >= streamParams.frameCount) {
                        sawInputEOS = true;
                        Log.d(TAG, "---Sending EOS empty frame for frame # " + inputFrameIndex);
                    }

                    if (!sawInputEOS && bytesRead == -1) {
                        if (streamParams.frameCount == 0) {
                            sawInputEOS = true;
                            Log.d(TAG, "---Sending EOS empty frame for frame # " + inputFrameIndex);
                        } else {
                            yuvStream.close();
                            yuvStream = OpenFileOrResourceId(
                                    streamParams.inputYuvFilename, streamParams.inputResourceId);
                            bytesRead = yuvStream.read(srcFrame);
                        }
                    }

                    // Force sync frame if syncForceFrameinterval is set.
                    if (!sawInputEOS && inputFrameIndex > 0 &&
                            streamParams.syncForceFrameInterval > 0 &&
                            (inputFrameIndex % streamParams.syncForceFrameInterval) == 0) {
                        Log.d(TAG, "---Requesting sync frame # " + inputFrameIndex);
                        codec.forceSyncFrame();
                    }

                    // Dynamic bitrate change.
                    if (!sawInputEOS && streamParams.bitrateSet.length > inputFrameIndex) {
                        int newBitrate = streamParams.bitrateSet[inputFrameIndex];
                        if (newBitrate != lastBitrate) {
                            Log.d(TAG, "--- Requesting new bitrate " + newBitrate +
                                    " for frame " + inputFrameIndex);
                            codec.updateBitrate(newBitrate);
                            lastBitrate = newBitrate;
                        }
                    }

                    // Convert YUV420 to NV12 if necessary
                    if (properties.colorFormat != CodecCapabilities.COLOR_FormatYUV420Planar) {
                        srcFrame = YUV420ToNV(streamParams.frameWidth, streamParams.frameHeight,
                                srcFrame);
                    }
                }

                inputConsumed = codec.feedInput(srcFrame, sawInputEOS);
                if (inputConsumed) {
                    inputFrameIndex++;
                    consumedInputEOS = sawInputEOS;
                }
            }

            // Get output from the encoder
            MediaEncoderOutput out = codec.getOutput();
            if (out.outputGenerated) {
                // Detect output EOS
                if ((out.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
                    Log.d(TAG, "----Output EOS ");
                    sawOutputEOS = true;
                }

                if (out.buffer.length > 0) {
                    // Save frame
                    ivf.writeFrame(out.buffer, out.outPresentationTimeUs);

                    // Update statistics - store presentation time delay in offset
                    long presentationTimeUsDelta = out.inPresentationTimeUs -
                            out.outPresentationTimeUs;
                    MediaCodec.BufferInfo bufferInfoCopy = new MediaCodec.BufferInfo();
                    bufferInfoCopy.set((int)presentationTimeUsDelta, out.buffer.length,
                            out.outPresentationTimeUs, out.flags);
                    bufferInfos.add(bufferInfoCopy);
                }
            }

            // If codec is not ready to accept input/poutput - wait for buffer ready callback
            if ((!inputConsumed || consumedInputEOS) && !out.outputGenerated) {
                codec.waitForBufferEvent();
            }
        }

        codec.deleteCodec();
        ivf.close();
        yuvStream.close();

        return bufferInfos;
    }

    /**
     * Vp8 encoding run in a looper thread and use buffer ready callbacks.
     *
     * Output stream is described by encodingParams parameters.
     *
     * MediaCodec will raise an IllegalStateException
     * whenever vp8 encoder fails to encode a frame.
     *
     * Color format of input file should be YUV420, and frameWidth,
     * frameHeight should be supplied correctly as raw input file doesn't
     * include any header data.
     *
     * @param streamParams  Structure with encoder parameters
     * @return              Returns array of encoded frames information for each frame.
     */
    protected ArrayList<MediaCodec.BufferInfo> encodeAsync(
            EncoderOutputStreamParameters streamParams) throws Exception {
        if (!streamParams.runInLooperThread) {
            throw new RuntimeException("encodeAsync should run with a looper thread!");
        }

        ArrayList<MediaCodec.BufferInfo> bufferInfos = new ArrayList<MediaCodec.BufferInfo>();
        Log.d(TAG, "Source resolution: "+streamParams.frameWidth + " x " +
                streamParams.frameHeight);
        int bitrate = streamParams.bitrateSet[0];

        // Create minimal media format signifying desired output.
        MediaFormat format = MediaFormat.createVideoFormat(
                VP8_MIME, streamParams.frameWidth, streamParams.frameHeight);
        format.setInteger(MediaFormat.KEY_BIT_RATE, bitrate);
        CodecProperties properties = getVpxCodecProperties(
                true, format, streamParams.forceGoogleEncoder);
        if (properties == null) {
            return null;
        }

        // Open input/output
        IvfWriter ivf = new IvfWriter(
                streamParams.outputIvfFilename, streamParams.frameWidth, streamParams.frameHeight);

        // Create a media format signifying desired output.
        if (streamParams.bitrateType == VIDEO_ControlRateConstant) {
            format.setInteger("bitrate-mode", VIDEO_ControlRateConstant); // set CBR
        }
        if (streamParams.temporalLayers > 0) {
            format.setInteger("ts-layers", streamParams.temporalLayers); // 1 temporal layer
        }
        format.setInteger(MediaFormat.KEY_COLOR_FORMAT, properties.colorFormat);
        format.setInteger(MediaFormat.KEY_FRAME_RATE, streamParams.frameRate);
        int syncFrameInterval = (streamParams.syncFrameInterval + streamParams.frameRate/2) /
                streamParams.frameRate;
        format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, syncFrameInterval);

        // Create encoder
        Log.d(TAG, "Creating encoder " + properties.codecName +
                ". Color format: 0x" + Integer.toHexString(properties.colorFormat)+ " : " +
                streamParams.frameWidth + " x " + streamParams.frameHeight +
                ". Bitrate: " + bitrate + " Bitrate type: " + streamParams.bitrateType +
                ". Fps:" + streamParams.frameRate + ". TS Layers: " + streamParams.temporalLayers +
                ". Key frame:" + syncFrameInterval * streamParams.frameRate +
                ". Force keyFrame: " + streamParams.syncForceFrameInterval);
        Log.d(TAG, "  Format: " + format);
        Log.d(TAG, "  Output ivf:" + streamParams.outputIvfFilename);

        MediaEncoderAsync codec = new MediaEncoderAsync();
        MediaEncoderAsyncHelper helper = new MediaEncoderAsyncHelper(
                streamParams, properties, bufferInfos, ivf);

        codec.setAsyncHelper(helper);
        codec.createCodec(0, properties.codecName, format,
                streamParams.timeoutDequeue, streamParams.runInLooperThread);
        codec.waitForCompletion(DEFAULT_ENCODE_TIMEOUT_MS);

        codec.deleteCodec();
        ivf.close();

        return bufferInfos;
    }

    /**
     * Vp8 encoding loop supporting encoding multiple streams at a time.
     * Each output stream is described by encodingParams parameters allowing
     * simultaneous encoding of various resolutions, bitrates with an option to
     * control key frame and dynamic bitrate for each output stream indepandently.
     *
     * MediaCodec will raise an IllegalStateException
     * whenever vp8 encoder fails to encode a frame.
     *
     * Color format of input file should be YUV420, and frameWidth,
     * frameHeight should be supplied correctly as raw input file doesn't
     * include any header data.
     *
     * @param srcFrameWidth     Frame width of input yuv file
     * @param srcFrameHeight    Frame height of input yuv file
     * @param encodingParams    Encoder parameters
     * @return                  Returns 2D array of encoded frames information for each stream and
     *                          for each frame.
     */
    protected ArrayList<ArrayList<MediaCodec.BufferInfo>> encodeSimulcast(
            int srcFrameWidth,
            int srcFrameHeight,
            ArrayList<EncoderOutputStreamParameters> encodingParams)  throws Exception {
        int numEncoders = encodingParams.size();

        // Create arrays of input/output, formats, bitrates etc
        ArrayList<ArrayList<MediaCodec.BufferInfo>> bufferInfos =
                new ArrayList<ArrayList<MediaCodec.BufferInfo>>(numEncoders);
        InputStream yuvStream[] = new InputStream[numEncoders];
        IvfWriter[] ivf = new IvfWriter[numEncoders];
        FileOutputStream[] yuvScaled = new FileOutputStream[numEncoders];
        MediaFormat[] format = new MediaFormat[numEncoders];
        MediaEncoderAsync[] codec = new MediaEncoderAsync[numEncoders];
        int[] inputFrameIndex = new int[numEncoders];
        boolean[] sawInputEOS = new boolean[numEncoders];
        boolean[] consumedInputEOS = new boolean[numEncoders];
        boolean[] inputConsumed = new boolean[numEncoders];
        boolean[] bufferConsumed = new boolean[numEncoders];
        boolean[] sawOutputEOS = new boolean[numEncoders];
        byte[][] srcFrame = new byte[numEncoders][];
        boolean sawOutputEOSTotal = false;
        boolean bufferConsumedTotal = false;
        CodecProperties[] codecProperties = new CodecProperties[numEncoders];

        numEncoders = 0;
        for (EncoderOutputStreamParameters params : encodingParams) {
            int i = numEncoders;
            Log.d(TAG, "Source resolution: " + params.frameWidth + " x " +
                    params.frameHeight);
            int bitrate = params.bitrateSet[0];

            // Create minimal media format signifying desired output.
            format[i] = MediaFormat.createVideoFormat(VP8_MIME,
                    params.frameWidth, params.frameHeight);
            format[i].setInteger(MediaFormat.KEY_BIT_RATE, bitrate);
            CodecProperties properties = getVpxCodecProperties(
                    true, format[i], params.forceGoogleEncoder);
            if (properties == null) {
                continue;
            }

            // Check if scaled image was created
            int scale = params.frameWidth / srcFrameWidth;
            if (!mScaledImages.contains(scale)) {
                // resize image
                cacheScaledImage(params.inputYuvFilename, params.inputResourceId,
                        srcFrameWidth, srcFrameHeight,
                        params.scaledYuvFilename, params.frameWidth, params.frameHeight);
                mScaledImages.add(scale);
            }

            // Create buffer info storage
            bufferInfos.add(new ArrayList<MediaCodec.BufferInfo>());

            // Create YUV reader
            yuvStream[i] = new FileInputStream(params.scaledYuvFilename);

            // Create IVF writer
            ivf[i] = new IvfWriter(params.outputIvfFilename, params.frameWidth, params.frameHeight);

            // Frame buffer
            int frameSize = params.frameWidth * params.frameHeight * 3 / 2;
            srcFrame[i] = new byte[frameSize];

            // Create a media format signifying desired output.
            if (params.bitrateType == VIDEO_ControlRateConstant) {
                format[i].setInteger("bitrate-mode", VIDEO_ControlRateConstant); // set CBR
            }
            if (params.temporalLayers > 0) {
                format[i].setInteger("ts-layers", params.temporalLayers); // 1 temporal layer
            }
            format[i].setInteger(MediaFormat.KEY_COLOR_FORMAT, properties.colorFormat);
            format[i].setInteger(MediaFormat.KEY_FRAME_RATE, params.frameRate);
            int syncFrameInterval = (params.syncFrameInterval + params.frameRate/2) /
                    params.frameRate; // in sec
            format[i].setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, syncFrameInterval);
            // Create encoder
            Log.d(TAG, "Creating encoder #" + i +" : " + properties.codecName +
                    ". Color format: 0x" + Integer.toHexString(properties.colorFormat)+ " : " +
                    params.frameWidth + " x " + params.frameHeight +
                    ". Bitrate: " + bitrate + " Bitrate type: " + params.bitrateType +
                    ". Fps:" + params.frameRate + ". TS Layers: " + params.temporalLayers +
                    ". Key frame:" + syncFrameInterval * params.frameRate +
                    ". Force keyFrame: " + params.syncForceFrameInterval);
            Log.d(TAG, "  Format: " + format[i]);
            Log.d(TAG, "  Output ivf:" + params.outputIvfFilename);

            // Create encoder
            codec[i] = new MediaEncoderAsync();
            codec[i].createCodec(i, properties.codecName, format[i],
                    params.timeoutDequeue, params.runInLooperThread);
            codecProperties[i] = new CodecProperties(properties.codecName, properties.colorFormat);

            inputConsumed[i] = true;
            ++numEncoders;
        }
        if (numEncoders == 0) {
            Log.i(TAG, "no suitable encoders found for any of the streams");
            return null;
        }

        while (!sawOutputEOSTotal) {
            // Feed input buffer to all encoders
            for (int i = 0; i < numEncoders; i++) {
                bufferConsumed[i] = false;
                if (consumedInputEOS[i]) {
                    continue;
                }

                EncoderOutputStreamParameters params = encodingParams.get(i);
                // Read new input buffers - if previous input was consumed and no EOS
                if (inputConsumed[i] && !sawInputEOS[i]) {
                    int bytesRead = yuvStream[i].read(srcFrame[i]);

                    // Check EOS
                    if (params.frameCount > 0 && inputFrameIndex[i] >= params.frameCount) {
                        sawInputEOS[i] = true;
                        Log.d(TAG, "---Enc" + i +
                                ". Sending EOS empty frame for frame # " + inputFrameIndex[i]);
                    }

                    if (!sawInputEOS[i] && bytesRead == -1) {
                        if (params.frameCount == 0) {
                            sawInputEOS[i] = true;
                            Log.d(TAG, "---Enc" + i +
                                    ". Sending EOS empty frame for frame # " + inputFrameIndex[i]);
                        } else {
                            yuvStream[i].close();
                            yuvStream[i] = new FileInputStream(params.scaledYuvFilename);
                            bytesRead = yuvStream[i].read(srcFrame[i]);
                        }
                    }

                    // Convert YUV420 to NV12 if necessary
                    if (codecProperties[i].colorFormat !=
                            CodecCapabilities.COLOR_FormatYUV420Planar) {
                        srcFrame[i] =
                            YUV420ToNV(params.frameWidth, params.frameHeight, srcFrame[i]);
                    }
                }

                inputConsumed[i] = codec[i].feedInput(srcFrame[i], sawInputEOS[i]);
                if (inputConsumed[i]) {
                    inputFrameIndex[i]++;
                    consumedInputEOS[i] = sawInputEOS[i];
                    bufferConsumed[i] = true;
                }

            }

            // Get output from all encoders
            for (int i = 0; i < numEncoders; i++) {
                if (sawOutputEOS[i]) {
                    continue;
                }

                MediaEncoderOutput out = codec[i].getOutput();
                if (out.outputGenerated) {
                    bufferConsumed[i] = true;
                    // Detect output EOS
                    if ((out.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
                        Log.d(TAG, "----Enc" + i + ". Output EOS ");
                        sawOutputEOS[i] = true;
                    }

                    if (out.buffer.length > 0) {
                        // Save frame
                        ivf[i].writeFrame(out.buffer, out.outPresentationTimeUs);

                        // Update statistics - store presentation time delay in offset
                        long presentationTimeUsDelta = out.inPresentationTimeUs -
                                out.outPresentationTimeUs;
                        MediaCodec.BufferInfo bufferInfoCopy = new MediaCodec.BufferInfo();
                        bufferInfoCopy.set((int)presentationTimeUsDelta, out.buffer.length,
                                out.outPresentationTimeUs, out.flags);
                        bufferInfos.get(i).add(bufferInfoCopy);
                    }
                }
            }

            // If codec is not ready to accept input/output - wait for buffer ready callback
            bufferConsumedTotal = false;
            for (boolean bufferConsumedCurrent : bufferConsumed) {
                bufferConsumedTotal |= bufferConsumedCurrent;
            }
            if (!bufferConsumedTotal) {
                // Pick the encoder to wait for
                for (int i = 0; i < numEncoders; i++) {
                    if (!bufferConsumed[i] && !sawOutputEOS[i]) {
                        codec[i].waitForBufferEvent();
                        break;
                    }
                }
            }

            // Check if EOS happened for all encoders
            sawOutputEOSTotal = true;
            for (boolean sawOutputEOSStream : sawOutputEOS) {
                sawOutputEOSTotal &= sawOutputEOSStream;
            }
        }

        for (int i = 0; i < numEncoders; i++) {
            codec[i].deleteCodec();
            ivf[i].close();
            yuvStream[i].close();
            if (yuvScaled[i] != null) {
                yuvScaled[i].close();
            }
        }

        return bufferInfos;
    }

    /**
     * Some encoding statistics.
     */
    protected class Vp8EncodingStatistics {
        Vp8EncodingStatistics() {
            mBitrates = new ArrayList<Integer>();
            mFrames = new ArrayList<Integer>();
            mKeyFrames = new ArrayList<Integer>();
            mMinimumKeyFrameInterval = Integer.MAX_VALUE;
        }

        public ArrayList<Integer> mBitrates;// Bitrate values for each second of the encoded stream.
        public ArrayList<Integer> mFrames; // Number of frames in each second of the encoded stream.
        public int mAverageBitrate;         // Average stream bitrate.
        public ArrayList<Integer> mKeyFrames;// Stores the position of key frames in a stream.
        public int mAverageKeyFrameInterval; // Average key frame interval.
        public int mMaximumKeyFrameInterval; // Maximum key frame interval.
        public int mMinimumKeyFrameInterval; // Minimum key frame interval.
    }

    /**
     * Calculates average bitrate and key frame interval for the encoded streams.
     * Output mBitrates field will contain bitrate values for every second
     * of the encoded stream.
     * Average stream bitrate will be stored in mAverageBitrate field.
     * mKeyFrames array will contain the position of key frames in the encoded stream and
     * mKeyFrameInterval - average key frame interval.
     */
    protected Vp8EncodingStatistics computeEncodingStatistics(int encoderId,
            ArrayList<MediaCodec.BufferInfo> bufferInfos ) {
        Vp8EncodingStatistics statistics = new Vp8EncodingStatistics();

        int totalSize = 0;
        int frames = 0;
        int framesPerSecond = 0;
        int totalFrameSizePerSecond = 0;
        int maxFrameSize = 0;
        int currentSecond;
        int nextSecond = 0;
        String keyFrameList = "  IFrame List: ";
        String bitrateList = "  Bitrate list: ";
        String framesList = "  FPS list: ";


        for (int j = 0; j < bufferInfos.size(); j++) {
            MediaCodec.BufferInfo info = bufferInfos.get(j);
            currentSecond = (int)(info.presentationTimeUs / 1000000);
            boolean lastFrame = (j == bufferInfos.size() - 1);
            if (!lastFrame) {
                nextSecond = (int)(bufferInfos.get(j+1).presentationTimeUs / 1000000);
            }

            totalSize += info.size;
            totalFrameSizePerSecond += info.size;
            maxFrameSize = Math.max(maxFrameSize, info.size);
            framesPerSecond++;
            frames++;

            // Update the bitrate statistics if the next frame will
            // be for the next second
            if (lastFrame || nextSecond > currentSecond) {
                int currentBitrate = totalFrameSizePerSecond * 8;
                bitrateList += (currentBitrate + " ");
                framesList += (framesPerSecond + " ");
                statistics.mBitrates.add(currentBitrate);
                statistics.mFrames.add(framesPerSecond);
                totalFrameSizePerSecond = 0;
                framesPerSecond = 0;
            }

            // Update key frame statistics.
            if ((info.flags & MediaCodec.BUFFER_FLAG_SYNC_FRAME) != 0) {
                statistics.mKeyFrames.add(j);
                keyFrameList += (j + "  ");
            }
        }
        int duration = (int)(bufferInfos.get(bufferInfos.size() - 1).presentationTimeUs / 1000);
        duration = (duration + 500) / 1000;
        statistics.mAverageBitrate = (int)(((long)totalSize * 8) / duration);
        Log.d(TAG, "Statistics for encoder # " + encoderId);
        // Calculate average key frame interval in frames.
        int keyFrames = statistics.mKeyFrames.size();
        if (keyFrames > 1) {
            statistics.mAverageKeyFrameInterval =
                    statistics.mKeyFrames.get(keyFrames - 1) - statistics.mKeyFrames.get(0);
            statistics.mAverageKeyFrameInterval =
                    Math.round((float)statistics.mAverageKeyFrameInterval / (keyFrames - 1));
            for (int j = 1; j < keyFrames; j++) {
                int keyFrameInterval =
                        statistics.mKeyFrames.get(j) - statistics.mKeyFrames.get(j - 1);
                statistics.mMaximumKeyFrameInterval =
                        Math.max(statistics.mMaximumKeyFrameInterval, keyFrameInterval);
                statistics.mMinimumKeyFrameInterval =
                        Math.min(statistics.mMinimumKeyFrameInterval, keyFrameInterval);
            }
            Log.d(TAG, "  Key frame intervals: Max: " + statistics.mMaximumKeyFrameInterval +
                    ". Min: " + statistics.mMinimumKeyFrameInterval +
                    ". Avg: " + statistics.mAverageKeyFrameInterval);
        }
        Log.d(TAG, "  Frames: " + frames + ". Duration: " + duration +
                ". Total size: " + totalSize + ". Key frames: " + keyFrames);
        Log.d(TAG, keyFrameList);
        Log.d(TAG, bitrateList);
        Log.d(TAG, framesList);
        Log.d(TAG, "  Bitrate average: " + statistics.mAverageBitrate);
        Log.d(TAG, "  Maximum frame size: " + maxFrameSize);

        return statistics;
    }

    protected Vp8EncodingStatistics computeEncodingStatistics(
            ArrayList<MediaCodec.BufferInfo> bufferInfos ) {
        return computeEncodingStatistics(0, bufferInfos);
    }

    protected ArrayList<Vp8EncodingStatistics> computeSimulcastEncodingStatistics(
            ArrayList<ArrayList<MediaCodec.BufferInfo>> bufferInfos) {
        int numCodecs = bufferInfos.size();
        ArrayList<Vp8EncodingStatistics> statistics = new ArrayList<Vp8EncodingStatistics>();

        for (int i = 0; i < numCodecs; i++) {
            Vp8EncodingStatistics currentStatistics =
                    computeEncodingStatistics(i, bufferInfos.get(i));
            statistics.add(currentStatistics);
        }
        return statistics;
    }

    /**
     * Calculates maximum latency for encoder/decoder based on buffer info array
     * generated either by encoder or decoder.
     */
    protected int maxPresentationTimeDifference(ArrayList<MediaCodec.BufferInfo> bufferInfos) {
        int maxValue = 0;
        for (MediaCodec.BufferInfo bufferInfo : bufferInfos) {
            maxValue = Math.max(maxValue,  bufferInfo.offset);
        }
        maxValue = (maxValue + 500) / 1000; // mcs -> ms
        return maxValue;
    }

    /**
     * Decoding PSNR statistics.
     */
    protected class Vp8DecodingStatistics {
        Vp8DecodingStatistics() {
            mMinimumPSNR = Integer.MAX_VALUE;
        }
        public double mAveragePSNR;
        public double mMinimumPSNR;
    }

    /**
     * Calculates PSNR value between two video frames.
     */
    private double computePSNR(byte[] data0, byte[] data1) {
        long squareError = 0;
        assertTrue(data0.length == data1.length);
        int length = data0.length;
        for (int i = 0 ; i < length; i++) {
            int diff = ((int)data0[i] & 0xff) - ((int)data1[i] & 0xff);
            squareError += diff * diff;
        }
        double meanSquareError = (double)squareError / length;
        double psnr = 10 * Math.log10((double)255 * 255 / meanSquareError);
        return psnr;
    }

    /**
     * Calculates average and minimum PSNR values between
     * set of reference and decoded video frames.
     * Runs PSNR calculation for the full duration of the decoded data.
     */
    protected Vp8DecodingStatistics computeDecodingStatistics(
            String referenceYuvFilename,
            int referenceYuvRawId,
            String decodedYuvFilename,
            int width,
            int height) throws Exception {
        Vp8DecodingStatistics statistics = new Vp8DecodingStatistics();
        InputStream referenceStream =
                OpenFileOrResourceId(referenceYuvFilename, referenceYuvRawId);
        InputStream decodedStream = new FileInputStream(decodedYuvFilename);

        int ySize = width * height;
        int uvSize = width * height / 4;
        byte[] yRef = new byte[ySize];
        byte[] yDec = new byte[ySize];
        byte[] uvRef = new byte[uvSize];
        byte[] uvDec = new byte[uvSize];

        int frames = 0;
        double averageYPSNR = 0;
        double averageUPSNR = 0;
        double averageVPSNR = 0;
        double minimumYPSNR = Integer.MAX_VALUE;
        double minimumUPSNR = Integer.MAX_VALUE;
        double minimumVPSNR = Integer.MAX_VALUE;
        int minimumPSNRFrameIndex = 0;

        while (true) {
            // Calculate Y PSNR.
            int bytesReadRef = referenceStream.read(yRef);
            int bytesReadDec = decodedStream.read(yDec);
            if (bytesReadDec == -1) {
                break;
            }
            if (bytesReadRef == -1) {
                // Reference file wrapping up
                referenceStream.close();
                referenceStream =
                        OpenFileOrResourceId(referenceYuvFilename, referenceYuvRawId);
                bytesReadRef = referenceStream.read(yRef);
            }
            double curYPSNR = computePSNR(yRef, yDec);
            averageYPSNR += curYPSNR;
            minimumYPSNR = Math.min(minimumYPSNR, curYPSNR);
            double curMinimumPSNR = curYPSNR;

            // Calculate U PSNR.
            bytesReadRef = referenceStream.read(uvRef);
            bytesReadDec = decodedStream.read(uvDec);
            double curUPSNR = computePSNR(uvRef, uvDec);
            averageUPSNR += curUPSNR;
            minimumUPSNR = Math.min(minimumUPSNR, curUPSNR);
            curMinimumPSNR = Math.min(curMinimumPSNR, curUPSNR);

            // Calculate V PSNR.
            bytesReadRef = referenceStream.read(uvRef);
            bytesReadDec = decodedStream.read(uvDec);
            double curVPSNR = computePSNR(uvRef, uvDec);
            averageVPSNR += curVPSNR;
            minimumVPSNR = Math.min(minimumVPSNR, curVPSNR);
            curMinimumPSNR = Math.min(curMinimumPSNR, curVPSNR);

            // Frame index for minimum PSNR value - help to detect possible distortions
            if (curMinimumPSNR < statistics.mMinimumPSNR) {
                statistics.mMinimumPSNR = curMinimumPSNR;
                minimumPSNRFrameIndex = frames;
            }

            String logStr = String.format(Locale.US, "PSNR #%d: Y: %.2f. U: %.2f. V: %.2f",
                    frames, curYPSNR, curUPSNR, curVPSNR);
            Log.v(TAG, logStr);

            frames++;
        }

        averageYPSNR /= frames;
        averageUPSNR /= frames;
        averageVPSNR /= frames;
        statistics.mAveragePSNR = (4 * averageYPSNR + averageUPSNR + averageVPSNR) / 6;

        Log.d(TAG, "PSNR statistics for " + frames + " frames.");
        String logStr = String.format(Locale.US,
                "Average PSNR: Y: %.1f. U: %.1f. V: %.1f. Average: %.1f",
                averageYPSNR, averageUPSNR, averageVPSNR, statistics.mAveragePSNR);
        Log.d(TAG, logStr);
        logStr = String.format(Locale.US,
                "Minimum PSNR: Y: %.1f. U: %.1f. V: %.1f. Overall: %.1f at frame %d",
                minimumYPSNR, minimumUPSNR, minimumVPSNR,
                statistics.mMinimumPSNR, minimumPSNRFrameIndex);
        Log.d(TAG, logStr);

        referenceStream.close();
        decodedStream.close();
        return statistics;
    }
}