无法使用媒体提取器无法在Android 4.2上对视频进行低级解码该怎么办?

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我想在不使用提取器的情况下解码视频帧。所以我只是尝试了一个小例子,在这里我使用了媒体提取器,但我不会 extractor.readsample()将比特流数据复制到输入缓冲区,而是使用JNI内部的FFmpeg分析器,其中我将视频帧memcopy复制到输入字节缓冲区,然后排队输入缓冲区..但是当我打电话时decoder.dequeueOutputBuffer(info, 10000),它会返回MediaCodec.INFO_TRY_AGAIN_LATER。虽然它可以正常使用,如果我使用extractor.readsample()

请在下面找到代码片段:

Java端:

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

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

public class VideoBrowser extends Activity implements SurfaceHolder.Callback {
    private static final String SAMPLE = Environment.getExternalStorageDirectory() + "/obama.mp4";
    private PlayerThread mPlayer = null;
    private static native <jintArray> int AVinitializecntxt(String strl, jintArray arr);
    private native int AVREADVIDEO(byte[] array);
    public int FLAG = 0;
    public int jk = 0;
    File f1;
    FileOutputStream f;


    static {
        Log.i("ABCD", "BEFORE");
        System.loadLibrary("ffmpeg");
        System.loadLibrary("ffmpeg-test-jni");
        Log.i("ABCD", "Success");
    }



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        SurfaceView sv = new SurfaceView(this);
        sv.getHolder().addCallback(this);
        setContentView(sv);
        int val;
        int[] array = new int[6];

        int END_OF_FILE = 0;
        int aud_stream = 0;
        int vid_stream = 0;
        String urlString = "/mnt/sdcard/obama.mp4";
        f1 = new File("/mnt/sdcard/t.h264");
        try {
            f = new FileOutputStream(f1);
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

             // This is where I call the function to initialize the ffmpeg inside JNI
        val = AVinitializecntxt(urlString, array);
        FLAG = val;
        Log.i("ABCD", "FLAG : "+ FLAG + val);
    }



    protected void onDestroy() {
        super.onDestroy();
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
        if (mPlayer == null) {
            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;
//      private VideoPlayer VideoPlayerAPIInterfaceClass = new VideoPlayer();

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

        @Override
        public void run() {

            if(FLAG == 1){
            extractor = new MediaExtractor();
            extractor.setDataSource(SAMPLE);

            for (int i = 0; i < extractor.getTrackCount(); i++) {
                MediaFormat format = extractor.getTrackFormat(i);
                String mime = format.getString(MediaFormat.KEY_MIME);
                if (mime.startsWith("video/")) {
                    extractor.selectTrack(i);
                    decoder = MediaCodec.createDecoderByType("video/avc");
                //  Log.i("ABCD", "MIME : " + mime);
                    decoder.configure(format, surface, null, 0);
                    break;
                }
            }

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

            decoder.start();

            ByteBuffer[] inputBuffers = decoder.getInputBuffers();
            ByteBuffer[] outputBuffers = decoder.getOutputBuffers();
            BufferInfo info = new BufferInfo();
            boolean isEOS = false;
            long startMs = System.currentTimeMillis();
            int  outIndex1 = -1 ;

            while(outIndex1 < 0){
                 outIndex1 = decoder.dequeueOutputBuffer(info, 10000);
                 Log.i("ABCD", "etgeuieoy");
            }

            while (!Thread.interrupted()) {
                if (!isEOS) {
                    int inIndex = decoder.dequeueInputBuffer(10000);
                    if (inIndex >= 0) {
                        ByteBuffer buffer = inputBuffers[inIndex];
                    //  int sampleSize = extractor.readSampleData(buffer, 0);

                         byte[] bytes = new byte[buffer.capacity()];

                                   // This is where we call JNI function to memcopy the encoded bitstream into the input buffer

                        int  sampleSize = [b]AVREADVIDEO[/b](bytes);


                            buffer.clear();
                            buffer.put(bytes, 0, sampleSize);



                        if (sampleSize < 0) {
                            // We shouldn't stop the playback at this point, just pass the EOS
                            // flag to decoder, we will get it again from the
                            // dequeueOutputBuffer
                        //  Log.d("DecodeActivity", "InputBuffer BUFFER_FLAG_END_OF_STREAM");
                            decoder.queueInputBuffer(inIndex, 0, 0, 0, MediaCodec.BUFFER_FLAG_END_OF_STREAM);

                            isEOS = true;
                        } else {
                            decoder.queueInputBuffer(inIndex, 0, sampleSize,0, 0);
                            extractor.advance();

                        }
                    }
                }

                int outIndex = decoder.dequeueOutputBuffer(info, 10000);
                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!");
                    break;
                default:
                    ByteBuffer buffer = outputBuffers[outIndex];
                    Log.v("DecodeActivity", "We can't use this buffer but render it due to the API limit, " + buffer);

                    // We use a very simple clock to keep the video FPS, or the video
                    // playback will be too fast
                    while (info.presentationTimeUs / 1000 > System.currentTimeMillis() - startMs) {
                        try {
                            sleep(10);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                            break;
                        }
                    }

                //  Log.i("ABCD", "RELEASING OUTPUT BUFFER");
                    decoder.releaseOutputBuffer(outIndex, true);
                    //decoder.releaseOutputBuffer(outIndex, false);
                    break;
                }


                // 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();
            extractor.release();
        }
        }
    }
}


JNI Side :

JNIEXPORT jint JNICALL
    Java_com_alldigital_videoplayer_VideoBrowser_AVREADVIDEO(JNIEnv *pEnv,
            jobject pObj, jbyteArray array ) {

    AV_ctxt *avctxt = &aud_vid_ctxt;

    jbyte *buf = (*pEnv)->GetByteArrayElements(pEnv,
            array, NULL);
    if (buf == NULL) {
        LOGERR(10, "AVVIDEOREAD", "Bytes null");
    }

    AVPacket *packet;
    packet = av_malloc(sizeof(AVPacket));

    av_init_packet(packet);


    int avread_res = av_read_frame(avctxt->gFormatCtx, packet);

    int size = packet->size;
    if (avread_res >= 0) {
        if (packet->stream_index == avctxt->gVideoStreamIndex) {
//          packet->size,packet->
            if (NULL
                    == memcpy(buf,
                            (char *) packet->data,
                            packet->size
                            ))
                LOGERR(10, "AV_AUDIO_DECODE",
                        "memcpy for audio buffer failed");
        }


}
(*pEnv)->ReleaseByteArrayElements(pEnv, array, buf,
        0);
av_free_packet(packet);
packet = NULL;
    return size;

}

提问于
用户回答回答于
你可以试试这段代码:
                try {

                    ByteArrayOutputStream baos = new ByteArrayOutputStream();
                    FileInputStream fis = new FileInputStream(new File(
                            "ur file path"));

                    byte[] buf = new byte[1024];
                    int n;
                    while (-1 != (n = fis.read(buf))) {
                        baos.write(buf, 0, n);
                    }

                    byte[] videoBytes = baos.toByteArray();

                    // use this videoBytes which is low level of original video 

                } catch (Exception e) {

                    e.printStackTrace();
                }

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