Unable to decode video using low-level Media Codec API.

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May 28, 2013 12:28:47 PM

Hi,
I wanted to decode video frames without using extractor.
So I just tried a small sample, where I use media extractor but I don't do "extractor.readsample()" to copy the bitstream data into the input buffer instead I use FFmpeg parser , inside JNI, where I memcopy the video frames into the input byte buffers and then queued the input buffer..
But when I call "decoder.dequeueOutputBuffer(info, 10000)" , it returns "MediaCodec.INFO_TRY_AGAIN_LATER".
While it works fine if I use extractor.readsample().

Please find the code snippet below :

Java Side :


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 = AVREADVIDEO(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;
}


Can anyone quickly help me on this,
though I am copying the encoded data of each frame through FFmpeg without calling extractor , then why I am getting this outputbuffer timeout issue.


Thanks

— modified on May 29, 2013 8:37:47 AM