Mediacodec decoder always times out while decoding

2019-03-31 21:38发布

问题:

I have been trying to decode a video file which is encoded via H264 encoding with Android's MediaCodec and tried to put the output of the decoder to a surface, but when I run the app it shows a black surface and in DDMS logcat I see that decoder timed out.

I have parsed the file into valid frames first [reading 4 bytes first which indicates the length of the upcoming frame and then read length amount bytes which indicates the frame, then again reading 4 bytes for the length of the next frame and so on.] then passed the frames to the decoder in a loop. When configuring the decoder, I passed sps & pps in the mediaFormat by hardcoding values directly from the encoded file [I got those values by opening that file with hexedit]. I did not set any presentationTimeUS and used 0 for it. Now the decoder's dequeInputBuffer() method returns >=0 value but dequeOutputBuffer() only returns MediaCodec.INFO_TRY_AGAIN_LATER which eventually means the decoder is being timed out.

Please have a look at my code and please help.

Thanks in advance.

Here is the file url - https://drive.google.com/file/d/0B39qOyEnXlR8Z3FSb2lzTWlORUU/edit?usp=sharing

Here is my code -

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.util.ArrayList;

import android.app.Activity;
import android.media.MediaCodec;
import android.media.MediaCodec.BufferInfo;
import android.media.MediaFormat;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.util.Log;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.widget.Toast;

public class MainActivity extends Activity implements SurfaceHolder.Callback 
{

    private static final String filePath = Environment.getExternalStorageDirectory()+ "/H264Data1.264"; // + "/video_encoded.263";//"/video_encoded.264";
    private PlayerThread mPlayer = null;
    Handler handler = null;
    public static byte[] SPS = null;
    public static byte[] PPS = null;
    public static ArrayList<Frame> frames = null;
    public static int frameID = 0;
    public static boolean incompleteLastFrame = false;
    File encodedFile = new File(filePath);
    InputStream is;

    private static class Frame
    {
        public int id;
        public byte[] frameData;

        public Frame(int id)
        {
            this.id = id;
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        try 
        {
            is = new FileInputStream(encodedFile);
            byte[] data = new byte[(int)encodedFile.length()];

            System.out.println("Total file size : " + encodedFile.length());
            frameID = 0;
            frames = new ArrayList<Frame>();

            try {
                if ((is.read(data, 0, (int)encodedFile.length())) != -1) 
                {
                    getFramesFromData(data);
                    Toast.makeText(getApplicationContext(), "frames processing finished. number of frames : " + frames.size(), Toast.LENGTH_SHORT).show();

                    SurfaceView sv = new SurfaceView(this);
                    handler = new Handler();
                    sv.getHolder().addCallback(this);
                    setContentView(sv);
                }

            } catch (IOException e) {
                e.printStackTrace();
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }


    }
    public static void getFramesFromData(byte[] data) 
    {
        int dataLength = data.length;
        int frameLength = 0;
        frameID = 0;

        if(data.length <= 0) return;

        // each iteration in this loop indicates generation of a new frame
        for(int i = 0; ; )
        {
            if(i+3 >= dataLength) return;

            frameLength = ((data[i] & 0xff) << 24)
                    + ((data[i + 1] & 0xff) << 16)
                    + ((data[i + 2] & 0xff) << 8)
                    + (data[i + 3] & 0xff);

            i += 4;

            if(frameLength > 0)
            {
                if(i+frameLength-1 >= dataLength) return;
                Frame frame = new Frame(frameID);
                frame.frameData = new byte[frameLength];
                System.arraycopy(data, i, frame.frameData, 0, frameLength);
                frames.add(frame);
                frameID++;
                i += frameLength;
            }

        }
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) 
    {
        Log.d("DecodeActivity", "in surfaceCreated");
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) 
    {
        Log.d("DecodeActivity", "in surfaceChanged");
        if (mPlayer == null) 
        {
            Toast.makeText(getApplicationContext(), "in surfaceChanged. creating playerthread", Toast.LENGTH_SHORT).show();
            mPlayer = new PlayerThread(holder.getSurface());
            mPlayer.start();
        }
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) 
    {
        if (mPlayer != null) 
        {
            mPlayer.interrupt();    
        }
    }

    private class PlayerThread extends Thread 
    {
        //private MediaExtractor extractor;
        private MediaCodec decoder;
        private Surface surface;

        public PlayerThread(Surface surface) 
        {
            this.surface = surface;
        }

        @Override
        public void run() 
        {
            handler.post(new Runnable()
            {

                @Override
                public void run() 
                {

                    decoder = MediaCodec.createDecoderByType("video/avc");
                    MediaFormat mediaFormat = MediaFormat.createVideoFormat("video/avc", 320, 240);

                    byte[] header_sps  = { 0x00, 0x00, 0x00, 0x01, 0x67, 0x42, (byte)0x80, 0x0C, (byte)0xE4, 0x40, (byte)0xA0, (byte)0xFD, 0x00, (byte)0xDA, 0x14, 0x26, (byte)0xA0 };
                    byte[] header_pps = {0x00, 0x00, 0x00, 0x01, 0x68, (byte)0xCE, 0x38, (byte)0x80 };
                    mediaFormat.setByteBuffer("csd-0", ByteBuffer.wrap(header_sps));
                    mediaFormat.setByteBuffer("csd-1", ByteBuffer.wrap(header_pps));

                    decoder.configure(mediaFormat, surface /* surface */, null /* crypto */, 0 /* flags */);

                    if (decoder == null) 
                    {
                        Log.e("DecodeActivity", "Can't find video info!");
                        return;
                    }

                    decoder.start();
                    Log.d("DecodeActivity", "decoder.start() called");

                    ByteBuffer[] inputBuffers = decoder.getInputBuffers();
                    ByteBuffer[] outputBuffers = decoder.getOutputBuffers();


                    long startMs = System.currentTimeMillis();
                    int i = 0;
                    while(!Thread.interrupted())
                    {
                        if(i >= frames.size()) 
                            break;
                        byte[] data = new byte[frames.get(i).frameData.length];
                        System.arraycopy(frames.get(i).frameData, 0, data, 0, frames.get(i).frameData.length);
                        Log.d("DecodeActivity", "i = " + i + " dataLength = " + frames.get(i).frameData.length);

                        int inIndex = 0; 
                        while ((inIndex = decoder.dequeueInputBuffer(1)) < 0)
                            ;

                        if (inIndex >= 0) 
                        {
                            ByteBuffer buffer = inputBuffers[inIndex];
                            buffer.clear();
                            int sampleSize = data.length;
                            if (sampleSize < 0) 
                            {
                                Log.d("DecodeActivity", "InputBuffer BUFFER_FLAG_END_OF_STREAM");
                                decoder.queueInputBuffer(inIndex, 0, 0, 0, MediaCodec.BUFFER_FLAG_END_OF_STREAM);
                                break;
                            } 
                            else 
                            {
                                Log.d("DecodeActivity", "sample size: " + sampleSize);

                                buffer = ByteBuffer.allocate(data.length);
                                buffer.put(data);
                                decoder.queueInputBuffer(inIndex, 0, sampleSize, 0, 0);
                            }


                            BufferInfo info = new BufferInfo();
                            int outIndex = decoder.dequeueOutputBuffer(info, 100000);

                            switch (outIndex) 
                            {
                            case MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED:
                                Log.d("DecodeActivity", "INFO_OUTPUT_BUFFERS_CHANGED");
                                outputBuffers = decoder.getOutputBuffers();
                                break;
                            case MediaCodec.INFO_OUTPUT_FORMAT_CHANGED:
                                Log.d("DecodeActivity", "New format " + decoder.getOutputFormat());

                                break;
                            case MediaCodec.INFO_TRY_AGAIN_LATER:
                                Log.d("DecodeActivity", "dequeueOutputBuffer timed out!");
                                try {
                                    sleep(100);
                                } catch (InterruptedException e) {
                                    // TODO Auto-generated catch block
                                    e.printStackTrace();
                                }
                                break;
                            default:
                                ByteBuffer outbuffer = outputBuffers[outIndex];

                                Log.d("DecodeActivity", "We can't use this buffer but render it due to the API limit, " + outbuffer);

                                /*while (info.presentationTimeUs / 1000 > System.currentTimeMillis() - startMs) 
                                {
                                    try 
                                    {
                                        sleep(10);
                                    } catch (InterruptedException e) {
                                        e.printStackTrace();
                                        break;
                                    }
                                }*/

                                decoder.releaseOutputBuffer(outIndex, true);
                                break;
                            }
                            i++;
                            // All decoded frames have been rendered, we can stop playing now
                            /*if ((info.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) 
                            {
                                Log.d("DecodeActivity", "OutputBuffer BUFFER_FLAG_END_OF_STREAM");
                                break;
                            }*/

                        }
                    }

                    decoder.stop();
                    decoder.release();
                }
            });         
        }
    }
}

回答1:

This part looks wrong:

ByteBuffer buffer = inputBuffers[inIndex];
[...]
buffer = ByteBuffer.allocate(data.length);
buffer.put(data);
decoder.queueInputBuffer(inIndex, 0, sampleSize, 0, 0);

You're getting the input buffer, and then ignoring it in favor of a buffer you're allocating yourself. Replace the ByteBuffer.allocate() call with buffer.clear().

What you're doing is pretty similar to the check pass in DecodeEditEncodeTest, except that the latter is just holding the whole thing in memory instead of serializing it to disk. Take a look at checkVideoData().

You may want to adopt the test's approach of serializing the chunk flags out with the data. If you did that, you wouldn't need to treat the SPS/PPS header specially -- just write it to the stream like any other chunk (it just happens to have the CODEC_CONFIG flag set). It would also be a good idea to serialize the time stamp unless the input video is guaranteed to have a known, non-varying frame rate.