EncodeAndMuxTest.java (requires 4.3, API 18) Generates a movie using OpenGL ES. Uses MediaCodec to encode the movie in an H.264 elementary stream, and MediaMuxer to convert the stream to a .MP4 file. This was written as if it were a CTS test, but is not part of CTS. It should be straightforward to adapt the code to other environments.

EncodeAndMuxTest.java

/*
 * Copyright 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.media.MediaCodec;
import android.media.MediaCodecInfo;
import android.media.MediaFormat;
import android.media.MediaMuxer;
import android.opengl.EGL14;
import android.opengl.EGLConfig;
import android.opengl.EGLContext;
import android.opengl.EGLDisplay;
import android.opengl.EGLExt;
import android.opengl.EGLSurface;
import android.opengl.GLES20;
import android.os.Environment;
import android.test.AndroidTestCase;
import android.util.Log;
import android.view.Surface;

import java.io.File;
import java.io.IOException;
import java.nio.ByteBuffer;

//20131106: removed hard-coded "/sdcard"

/**
 * Generate an MP4 file using OpenGL ES drawing commands.  Demonstrates the use of MediaMuxer
 * and MediaCodec with Surface input.
 * <p>
 * This uses various features first available in Android "Jellybean" 4.3 (API 18).  There is
 * no equivalent functionality in previous releases.
 * <p>
 * (This was derived from bits and pieces of CTS tests, and is packaged as such, but is not
 * currently part of CTS.)
 */
public class EncodeAndMuxTest extends AndroidTestCase {
    private static final String TAG = "EncodeAndMuxTest";
    private static final boolean VERBOSE = false;           // lots of logging

    // where to put the output file (note: /sdcard requires WRITE_EXTERNAL_STORAGE permission)
    private static final File OUTPUT_DIR = Environment.getExternalStorageDirectory();

    // parameters for the encoder
    private static final String MIME_TYPE = "video/avc";    // H.264 Advanced Video Coding
    private static final int FRAME_RATE = 15;               // 15fps
    private static final int IFRAME_INTERVAL = 10;          // 10 seconds between I-frames
    private static final int NUM_FRAMES = 30;               // two seconds of video

    // RGB color values for generated frames
    private static final int TEST_R0 = 0;
    private static final int TEST_G0 = 136;
    private static final int TEST_B0 = 0;
    private static final int TEST_R1 = 236;
    private static final int TEST_G1 = 50;
    private static final int TEST_B1 = 186;

    // size of a frame, in pixels
    private int mWidth = -1;
    private int mHeight = -1;
    // bit rate, in bits per second
    private int mBitRate = -1;

    // encoder / muxer state
    private MediaCodec mEncoder;
    private CodecInputSurface mInputSurface;
    private MediaMuxer mMuxer;
    private int mTrackIndex;
    private boolean mMuxerStarted;

    // allocate one of these up front so we don't need to do it every time
    private MediaCodec.BufferInfo mBufferInfo;


    /**
     * Tests encoding of AVC video from a Surface.  The output is saved as an MP4 file.
     */
    public void testEncodeVideoToMp4() {
        // QVGA at 2Mbps
        mWidth = 320;
        mHeight = 240;
        mBitRate = 2000000;

        try {
            prepareEncoder();
            mInputSurface.makeCurrent();

            for (int i = 0; i < NUM_FRAMES; i++) {
                // Feed any pending encoder output into the muxer.
                drainEncoder(false);

                // Generate a new frame of input.
                generateSurfaceFrame(i);
                mInputSurface.setPresentationTime(computePresentationTimeNsec(i));

                // Submit it to the encoder.  The eglSwapBuffers call will block if the input
                // is full, which would be bad if it stayed full until we dequeued an output
                // buffer (which we can't do, since we're stuck here).  So long as we fully drain
                // the encoder before supplying additional input, the system guarantees that we
                // can supply another frame without blocking.
                if (VERBOSE) Log.d(TAG, "sending frame " + i + " to encoder");
                mInputSurface.swapBuffers();
            }

            // send end-of-stream to encoder, and drain remaining output
            drainEncoder(true);
        } finally {
            // release encoder, muxer, and input Surface
            releaseEncoder();
        }

        // To test the result, open the file with MediaExtractor, and get the format.  Pass
        // that into the MediaCodec decoder configuration, along with a SurfaceTexture surface,
        // and examine the output with glReadPixels.
    }

    /**
     * Configures encoder and muxer state, and prepares the input Surface.
     */
    private void prepareEncoder() {
        mBufferInfo = new MediaCodec.BufferInfo();

        MediaFormat format = MediaFormat.createVideoFormat(MIME_TYPE, mWidth, mHeight);

        // Set some properties.  Failing to specify some of these can cause the MediaCodec
        // configure() call to throw an unhelpful exception.
        format.setInteger(MediaFormat.KEY_COLOR_FORMAT,
                MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface);
        format.setInteger(MediaFormat.KEY_BIT_RATE, mBitRate);
        format.setInteger(MediaFormat.KEY_FRAME_RATE, FRAME_RATE);
        format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, IFRAME_INTERVAL);
        if (VERBOSE) Log.d(TAG, "format: " + format);

        // Create a MediaCodec encoder, and configure it with our format.  Get a Surface
        // we can use for input and wrap it with a class that handles the EGL work.
        //
        // If you want to have two EGL contexts -- one for display, one for recording --
        // you will likely want to defer instantiation of CodecInputSurface until after the
        // "display" EGL context is created, then modify the eglCreateContext call to
        // take eglGetCurrentContext() as the share_context argument.
        mEncoder = MediaCodec.createEncoderByType(MIME_TYPE);
        mEncoder.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
        mInputSurface = new CodecInputSurface(mEncoder.createInputSurface());
        mEncoder.start();

        // Output filename.  Ideally this would use Context.getFilesDir() rather than a
        // hard-coded output directory.
        String outputPath = new File(OUTPUT_DIR,
                "test." + mWidth + "x" + mHeight + ".mp4").toString();
        Log.d(TAG, "output file is " + outputPath);


        // Create a MediaMuxer.  We can't add the video track and start() the muxer here,
        // because our MediaFormat doesn't have the Magic Goodies.  These can only be
        // obtained from the encoder after it has started processing data.
        //
        // We're not actually interested in multiplexing audio.  We just want to convert
        // the raw H.264 elementary stream we get from MediaCodec into a .mp4 file.
        try {
            mMuxer = new MediaMuxer(outputPath, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
        } catch (IOException ioe) {
            throw new RuntimeException("MediaMuxer creation failed", ioe);
        }

        mTrackIndex = -1;
        mMuxerStarted = false;
    }

    /**
     * Releases encoder resources.  May be called after partial / failed initialization.
     */
    private void releaseEncoder() {
        if (VERBOSE) Log.d(TAG, "releasing encoder objects");
        if (mEncoder != null) {
            mEncoder.stop();
            mEncoder.release();
            mEncoder = null;
        }
        if (mInputSurface != null) {
            mInputSurface.release();
            mInputSurface = null;
        }
        if (mMuxer != null) {
            mMuxer.stop();
            mMuxer.release();
            mMuxer = null;
        }
    }

    /**
     * Extracts all pending data from the encoder.
     * <p>
     * If endOfStream is not set, this returns when there is no more data to drain.  If it
     * is set, we send EOS to the encoder, and then iterate until we see EOS on the output.
     * Calling this with endOfStream set should be done once, right before stopping the muxer.
     */
    private void drainEncoder(boolean endOfStream) {
        final int TIMEOUT_USEC = 10000;
        if (VERBOSE) Log.d(TAG, "drainEncoder(" + endOfStream + ")");

        if (endOfStream) {
            if (VERBOSE) Log.d(TAG, "sending EOS to encoder");
            mEncoder.signalEndOfInputStream();
        }

        ByteBuffer[] encoderOutputBuffers = mEncoder.getOutputBuffers();
        while (true) {
            int encoderStatus = mEncoder.dequeueOutputBuffer(mBufferInfo, TIMEOUT_USEC);
            if (encoderStatus == MediaCodec.INFO_TRY_AGAIN_LATER) {
                // no output available yet
                if (!endOfStream) {
                    break;      // out of while
                } else {
                    if (VERBOSE) Log.d(TAG, "no output available, spinning to await EOS");
                }
            } else if (encoderStatus == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
                // not expected for an encoder
                encoderOutputBuffers = mEncoder.getOutputBuffers();
            } else if (encoderStatus == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
                // should happen before receiving buffers, and should only happen once
                if (mMuxerStarted) {
                    throw new RuntimeException("format changed twice");
                }
                MediaFormat newFormat = mEncoder.getOutputFormat();
                Log.d(TAG, "encoder output format changed: " + newFormat);

                // now that we have the Magic Goodies, start the muxer
                mTrackIndex = mMuxer.addTrack(newFormat);
                mMuxer.start();
                mMuxerStarted = true;
            } else if (encoderStatus < 0) {
                Log.w(TAG, "unexpected result from encoder.dequeueOutputBuffer: " +
                        encoderStatus);
                // let's ignore it
            } else {
                ByteBuffer encodedData = encoderOutputBuffers[encoderStatus];
                if (encodedData == null) {
                    throw new RuntimeException("encoderOutputBuffer " + encoderStatus +
                            " was null");
                }

                if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0) {
                    // The codec config data was pulled out and fed to the muxer when we got
                    // the INFO_OUTPUT_FORMAT_CHANGED status.  Ignore it.
                    if (VERBOSE) Log.d(TAG, "ignoring BUFFER_FLAG_CODEC_CONFIG");
                    mBufferInfo.size = 0;
                }

                if (mBufferInfo.size != 0) {
                    if (!mMuxerStarted) {
                        throw new RuntimeException("muxer hasn't started");
                    }

                    // adjust the ByteBuffer values to match BufferInfo (not needed?)
                    encodedData.position(mBufferInfo.offset);
                    encodedData.limit(mBufferInfo.offset + mBufferInfo.size);

                    mMuxer.writeSampleData(mTrackIndex, encodedData, mBufferInfo);
                    if (VERBOSE) Log.d(TAG, "sent " + mBufferInfo.size + " bytes to muxer");
                }

                mEncoder.releaseOutputBuffer(encoderStatus, false);

                if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
                    if (!endOfStream) {
                        Log.w(TAG, "reached end of stream unexpectedly");
                    } else {
                        if (VERBOSE) Log.d(TAG, "end of stream reached");
                    }
                    break;      // out of while
                }
            }
        }
    }

    /**
     * Generates a frame of data using GL commands.  We have an 8-frame animation
     * sequence that wraps around.  It looks like this:
     * <pre>
     *   0 1 2 3
     *   7 6 5 4
     * </pre>
     * We draw one of the eight rectangles and leave the rest set to the clear color.
     */
    private void generateSurfaceFrame(int frameIndex) {
        frameIndex %= 8;

        int startX, startY;
        if (frameIndex < 4) {
            // (0,0) is bottom-left in GL
            startX = frameIndex * (mWidth / 4);
            startY = mHeight / 2;
        } else {
            startX = (7 - frameIndex) * (mWidth / 4);
            startY = 0;
        }

        GLES20.glClearColor(TEST_R0 / 255.0f, TEST_G0 / 255.0f, TEST_B0 / 255.0f, 1.0f);
        GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);

        GLES20.glEnable(GLES20.GL_SCISSOR_TEST);
        GLES20.glScissor(startX, startY, mWidth / 4, mHeight / 2);
        GLES20.glClearColor(TEST_R1 / 255.0f, TEST_G1 / 255.0f, TEST_B1 / 255.0f, 1.0f);
        GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
        GLES20.glDisable(GLES20.GL_SCISSOR_TEST);
    }

    /**
     * Generates the presentation time for frame N, in nanoseconds.
     */
    private static long computePresentationTimeNsec(int frameIndex) {
        final long ONE_BILLION = 1000000000;
        return frameIndex * ONE_BILLION / FRAME_RATE;
    }


    /**
     * Holds state associated with a Surface used for MediaCodec encoder input.
     * <p>
     * The constructor takes a Surface obtained from MediaCodec.createInputSurface(), and uses that
     * to create an EGL window surface.  Calls to eglSwapBuffers() cause a frame of data to be sent
     * to the video encoder.
     * <p>
     * This object owns the Surface -- releasing this will release the Surface too.
     */
    private static class CodecInputSurface {
        private static final int EGL_RECORDABLE_ANDROID = 0x3142;

        private EGLDisplay mEGLDisplay = EGL14.EGL_NO_DISPLAY;
        private EGLContext mEGLContext = EGL14.EGL_NO_CONTEXT;
        private EGLSurface mEGLSurface = EGL14.EGL_NO_SURFACE;

        private Surface mSurface;

        /**
         * Creates a CodecInputSurface from a Surface.
         */
        public CodecInputSurface(Surface surface) {
            if (surface == null) {
                throw new NullPointerException();
            }
            mSurface = surface;

            eglSetup();
        }

        /**
         * Prepares EGL.  We want a GLES 2.0 context and a surface that supports recording.
         */
        private void eglSetup() {
            mEGLDisplay = EGL14.eglGetDisplay(EGL14.EGL_DEFAULT_DISPLAY);
            if (mEGLDisplay == EGL14.EGL_NO_DISPLAY) {
                throw new RuntimeException("unable to get EGL14 display");
            }
            int[] version = new int[2];
            if (!EGL14.eglInitialize(mEGLDisplay, version, 0, version, 1)) {
                throw new RuntimeException("unable to initialize EGL14");
            }

            // Configure EGL for recording and OpenGL ES 2.0.
            int[] attribList = {
                    EGL14.EGL_RED_SIZE, 8,
                    EGL14.EGL_GREEN_SIZE, 8,
                    EGL14.EGL_BLUE_SIZE, 8,
                    EGL14.EGL_RENDERABLE_TYPE, EGL14.EGL_OPENGL_ES2_BIT,
                    EGL_RECORDABLE_ANDROID, 1,
                    EGL14.EGL_NONE
            };
            EGLConfig[] configs = new EGLConfig[1];
            int[] numConfigs = new int[1];
            EGL14.eglChooseConfig(mEGLDisplay, attribList, 0, configs, 0, configs.length,
                    numConfigs, 0);
            checkEglError("eglCreateContext RGB888+recordable ES2");

            // Configure context for OpenGL ES 2.0.
            int[] attrib_list = {
                    EGL14.EGL_CONTEXT_CLIENT_VERSION, 2,
                    EGL14.EGL_NONE
            };
            mEGLContext = EGL14.eglCreateContext(mEGLDisplay, configs[0], EGL14.EGL_NO_CONTEXT,
                    attrib_list, 0);
            checkEglError("eglCreateContext");

            // Create a window surface, and attach it to the Surface we received.
            int[] surfaceAttribs = {
                    EGL14.EGL_NONE
            };
            mEGLSurface = EGL14.eglCreateWindowSurface(mEGLDisplay, configs[0], mSurface,
                    surfaceAttribs, 0);
            checkEglError("eglCreateWindowSurface");
        }

        /**
         * Discards all resources held by this class, notably the EGL context.  Also releases the
         * Surface that was passed to our constructor.
         */
        public void release() {
            if (mEGLDisplay != EGL14.EGL_NO_DISPLAY) {
                EGL14.eglMakeCurrent(mEGLDisplay, EGL14.EGL_NO_SURFACE, EGL14.EGL_NO_SURFACE,
                        EGL14.EGL_NO_CONTEXT);
                EGL14.eglDestroySurface(mEGLDisplay, mEGLSurface);
                EGL14.eglDestroyContext(mEGLDisplay, mEGLContext);
                EGL14.eglReleaseThread();
                EGL14.eglTerminate(mEGLDisplay);
            }

            mSurface.release();

            mEGLDisplay = EGL14.EGL_NO_DISPLAY;
            mEGLContext = EGL14.EGL_NO_CONTEXT;
            mEGLSurface = EGL14.EGL_NO_SURFACE;

            mSurface = null;
        }

        /**
         * Makes our EGL context and surface current.
         */
        public void makeCurrent() {
            EGL14.eglMakeCurrent(mEGLDisplay, mEGLSurface, mEGLSurface, mEGLContext);
            checkEglError("eglMakeCurrent");
        }

        /**
         * Calls eglSwapBuffers.  Use this to "publish" the current frame.
         */
        public boolean swapBuffers() {
            boolean result = EGL14.eglSwapBuffers(mEGLDisplay, mEGLSurface);
            checkEglError("eglSwapBuffers");
            return result;
        }

        /**
         * Sends the presentation time stamp to EGL.  Time is expressed in nanoseconds.
         */
        public void setPresentationTime(long nsecs) {
            EGLExt.eglPresentationTimeANDROID(mEGLDisplay, mEGLSurface, nsecs);
            checkEglError("eglPresentationTimeANDROID");
        }

        /**
         * Checks for EGL errors.  Throws an exception if one is found.
         */
        private void checkEglError(String msg) {
            int error;
            if ((error = EGL14.eglGetError()) != EGL14.EGL_SUCCESS) {
                throw new RuntimeException(msg + ": EGL error: 0x" + Integer.toHexString(error));
            }
        }
    }
}