The H.264 avc video encoded by MediaCodec in Android cannot be played

Question

BACKGROUND:

I have been working on implementing a Vine like video recorder for two days. First, I tried the MediaRecorder. But the video I need may be composed by small video clips. This class cannot be used to record a short-time video clip. Then I found the MediaCodec, FFmpeg and JavaCV. FFmpeg and JavaCV could solve this problem. But I have to compile my project with many library files. It will generate a very large APK file. So I prefer implementing it by MediaCodec, although this class only can be used after Android 4.1. 90% percent users will be satisfied.

RESULT:

I finally got the encoded file, but it cannot be played. I checked the information by FFprobe, the result is like:

Input #0, h264, from 'test.mp4': Duration: N/A, bitrate: N/A Stream #0:0: Video: h264 (Baseline), yuv420p, 640x480, 25 fps, 25 tbr, 1200k tbn, 50 tbc

I do not know much about the mechanism of H.264 coding.

CODE:

Modified from this link

public class AvcEncoder {

private static String TAG = AvcEncoder.class.getSimpleName();

private MediaCodec mediaCodec;
private BufferedOutputStream outputStream;
private int mWidth, mHeight;
private byte[] mDestData;

public AvcEncoder(int w, int h) {

    mWidth = w;
    mHeight = h;
    Log.d(TAG, "Thread Id: " + Thread.currentThread().getId());

    File f = new File("/sdcard/videos/test.mp4");

    try {
        outputStream = new BufferedOutputStream(new FileOutputStream(f));
        Log.i("AvcEncoder", "outputStream initialized");
    } catch (Exception e) {
        e.printStackTrace();
    }

    try {
        mediaCodec = MediaCodec.createEncoderByType("video/avc");
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    MediaFormat mediaFormat = MediaFormat.createVideoFormat("video/avc", w,
            h);
    mediaFormat.setInteger(MediaFormat.KEY_BIT_RATE, 2000000);
    mediaFormat.setInteger(MediaFormat.KEY_FRAME_RATE, 15);
    // mediaFormat.setInteger(MediaFormat.KEY_COLOR_FORMAT,
    // MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420Planar);
    mediaFormat.setInteger(MediaFormat.KEY_COLOR_FORMAT,
            MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420Planar);

    mDestData = new byte[w * h
            * ImageFormat.getBitsPerPixel(ImageFormat.YV12) / 8];
    mediaFormat.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, 5);
    mediaCodec.configure(mediaFormat, null, null,
            MediaCodec.CONFIGURE_FLAG_ENCODE);
    mediaCodec.start();
}

public void close() {
    try {
        mediaCodec.stop();
        mediaCodec.release();
        mediaCodec = null;

        // outputStream.flush();
        outputStream.close();
    } catch (IOException e) {

    }
}

public void offerEncoder(byte[] input) {
    try {
        CameraUtils.transYV12toYUV420Planar(input, mDestData, mWidth,
                mHeight);
        ByteBuffer[] inputBuffers = mediaCodec.getInputBuffers();
        ByteBuffer[] outputBuffers = mediaCodec.getOutputBuffers();
        int inputBufferIndex = mediaCodec.dequeueInputBuffer(-1);

        if (inputBufferIndex >= 0) {
            ByteBuffer inputBuffer = inputBuffers[inputBufferIndex];
            inputBuffer.clear();
            inputBuffer.put(mDestData);
            mediaCodec.queueInputBuffer(inputBufferIndex, 0,
                    mDestData.length, 0, 0);
        }

        MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo();
        int outputBufferIndex = mediaCodec.dequeueOutputBuffer(bufferInfo,
                0);

        while (outputBufferIndex >= 0) {
            ByteBuffer outputBuffer = outputBuffers[outputBufferIndex];
            byte[] outData = new byte[bufferInfo.size];
            outputBuffer.get(outData);
            try {
                outputStream.write(outData, 0, outData.length);

            } catch (Exception e) {
                Log.d("AvcEncoder", "Outputstream write failed");
                e.printStackTrace();
            }
            // Log.i("AvcEncoder", outData.length + " bytes written");

            mediaCodec.releaseOutputBuffer(outputBufferIndex, false);
            outputBufferIndex = mediaCodec.dequeueOutputBuffer(bufferInfo,
                    0);

        }
    } catch (Throwable t) {
        t.printStackTrace();
    }
}
}

Invoke this class by Camera's startPreview:

private void startPreview() {
    if (mCamera == null) {
        return;
    }
    try {
        mCamera.setPreviewDisplay(mSurfaceView.getHolder());
        Parameters p = mCamera.getParameters();
        Size s = p.getPreviewSize();
        int len = s.width * s.height
                * ImageFormat.getBitsPerPixel(p.getPreviewFormat()) / 8;
        mAvcEncoder = new AvcEncoder(s.width, s.height);
        mCamera.addCallbackBuffer(new byte[len]);
        mCamera.setPreviewCallbackWithBuffer(new PreviewCallback() {

            @Override
            public void onPreviewFrame(byte[] data, Camera camera) {
                mAvcEncoder.offerEncoder(data);
                mCamera.addCallbackBuffer(data);
            }
        });
        mCamera.startPreview();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

Close it when release Camera:

private void releaseCamera() {
    if (mCamera != null) {
        mCamera.stopPreview();
        mCamera.release();
        mCamera = null;
    }
    if (mAvcEncoder != null) {
        mAvcEncoder.close();
    }
}

fadden fadden · Accepted Answer · 2015-06-07T15:54:06

You're saving a raw H.264 stream. You should convert it to .mp4 format. The easiest way to do this is with the MediaMuxer class (API 18+).

You can find a simple example on bigflake and more complete examples in Grafika.

You will need to provide presentation time stamps for each frame. You can either generate them according to your desired frame rate (like the bigflake example) or acquire them from the source (like the camera-input examples in Grafika).

Edit: For pre-API-18 devices (Android 4.1/4.2), MediaCodec is much more difficult to work with. You can't use Surface input or MediaMuxer, and the lack of platform tests led to some unfortunate incompatibilities. This answer has an overview.

In your specific case, I will note that your sample code is attempting to specify the input format, but that has no effect -- the AVC codec defines what input formats it accepts, and your app must query for it. You will likely find that the colors in your encoded video are currently wrong, as the Camera and MediaCodec don't have any color formats in common (see that answer for color-swap code).

The H.264 avc video encoded by MediaCodec in Android cannot be played

2 Answers