我想在不使用提取器的情况下解码视频帧。因此，我只是尝试了一个小样本，我在其中使用媒体提取器，但没有执行extractor.readsample()将比特流数据复制到输入缓冲区，而是在JNI中使用FFmpeg解析器，将视频帧复制到输入字节中。缓冲区，然后将输入缓冲区排队。但是当我调用decoder.dequeueOutputBuffer(info, 10000)时，它将返回MediaCodec.INFO_TRY_AGAIN_LATER。如果我使用extractor.readsample()可以正常工作。
Java面：
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;
}
即使我通过FFmpeg复制每个帧的编码数据而没有调用提取器，我仍然遇到此outputbuffer超时问题-为什么？
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();
}