android - 无法播放 mp4 视频

Question

我正在尝试在 android 中制作视频播放器。它播放 3GP 格式的视频。但它不支持 mp4 视频。下面是我在 android 中的代码。为什么它不支持设备和模拟器上的 mp4 格式？

package com.example.videoplayer;


import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import org.json.JSONObject;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.StrictMode;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.webkit.URLUtil;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.Toast;
import android.widget.VideoView;

public class VideoViewDemo extends Activity {
    private static final String TAG = "VideoViewDemo";

    private VideoView mVideoView;
    private EditText mPath;
    private ImageButton mPlay;
    private ImageButton mPause;
    private ImageButton mReset;
    private ImageButton mStop;
    private String current;

    @SuppressLint({ "NewApi", "NewApi", "NewApi" })
    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.activity_main);
        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();

        StrictMode.setThreadPolicy(policy); 
        mVideoView = (VideoView) findViewById(R.id.surface_view);

        mPath = (EditText) findViewById(R.id.path);
        mPath.setText("ooklnet.com/files/368/368007/video.mp4");

        mPlay = (ImageButton) findViewById(R.id.play);
        mPause = (ImageButton) findViewById(R.id.pause);
        mReset = (ImageButton) findViewById(R.id.reset);
        mStop = (ImageButton) findViewById(R.id.stop);

        mPlay.setOnClickListener(new OnClickListener() {
            public void onClick(View view) {
                playVideo();
            }
        });
        mPause.setOnClickListener(new OnClickListener() {
            public void onClick(View view) {
                if (mVideoView != null) {
                    mVideoView.pause();
                }
            }
        });
        mReset.setOnClickListener(new OnClickListener() {
            public void onClick(View view) {
                if (mVideoView != null) {
                    mVideoView.seekTo(0);
                }
            }
        });
        mStop.setOnClickListener(new OnClickListener() {
            public void onClick(View view) {
                if (mVideoView != null) {
                    current = null;
                    mVideoView.stopPlayback();
                }
            }
        });
        /*runOnUiThread(new Runnable(){
            public void run() {
                sleep(2000);
                playVideo();

            }

        });*/
        Thread _trd1 = new Thread() {
            public void run() {
                try {
                    sleep(2000);
                    runOnUiThread(new Runnable() {


                    public void run() {
                        playVideo();
                    }
                });

                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        };
        _trd1.start();
    //  new DoBackgroundTask().execute();
    }

    public class DoBackgroundTask extends AsyncTask
    <String, Void, String> {
        @Override
        protected void onPreExecute() {
            // TODO Auto-generated method stub

        }
        protected String doInBackground(String... locationNames) {
            playVideo();
            return null;    
        }

        protected void onPostExecute(String addresses){


            }
        }
    private void playVideo() {
        try {
            final String path = mPath.getText().toString();
            Log.v(TAG, "path: " + path);
            if (path == null || path.length() == 0) {
                Toast.makeText(VideoViewDemo.this, "File URL/path is empty",
                        Toast.LENGTH_LONG).show();

            } else {
                // If the path has not changed, just start the media player
                if (path.equals(current) && mVideoView != null) {
                    mVideoView.start();
                    mVideoView.requestFocus();
                    return;
                }
                current = path;
                mVideoView.setVideoPath(getDataSource("ooklnet.com/files/368/368007/video.mp4"));
                mVideoView.start();
                mVideoView.requestFocus();

            }
        } catch (Exception e) {
            Log.e(TAG, "error: " + e.getMessage(), e);
            if (mVideoView != null) {
                mVideoView.stopPlayback();
            }
        }
    }

    private String getDataSource(String path) throws IOException {
        if (!URLUtil.isNetworkUrl(path)) {
            return path;
        } else {
            URL url = new URL(path);
            URLConnection cn = url.openConnection();
            cn.connect();
            InputStream stream = cn.getInputStream();
            if (stream == null)
                throw new RuntimeException("stream is null");
            File temp = File.createTempFile("mediaplayertmp", "dat");
            temp.deleteOnExit();
            String tempPath = temp.getAbsolutePath(); 
            FileOutputStream out = new FileOutputStream(temp);
            byte buf[] = new byte[128];
            do {
                int numread = stream.read(buf);
                if (numread <= 0)
                    break;
                out.write(buf, 0, numread);
            } while (true);
            try {
                stream.close();
            } catch (IOException ex) {
                Log.e(TAG, "error: " + ex.getMessage(), ex);
            }
            return tempPath;
        }
    }

}


Please advise as soon as possible.
Thanks.

Answer 1

问题可能出在视频编码上。 Android Froyo 和 Gingerbread 不支持“Baseline”H264 以外的 H264 格式。因此，如果您的视频采用 Mp4 和 H264 编码，请确保其“AVC 基线” 已编码。在 windows/Linux 中使用“媒体信息”等工具并检查您的视频编码。如果可能，将视频转换为基线。

另一种解决方法是跳过视频 View 并使用视频播放 Intent 并将播放重​​定向到应用程序。系统将提示用户选择一个播放器来处理播放。显然，如果视频 View 无法播放该文件，则默认播放器也无法处理该文件。您可以选择其他一些已安装的播放器，例如 Mx-Player，它可以完美地传输文件。希望这能解决您的问题。