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社区首页 >问答首页 >android项目中视频特定帧集的慢速

android项目中视频特定帧集的慢速
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Stack Overflow用户
提问于 2016-04-04 05:56:02
回答 1查看 1.9K关注 0票数 1

我需要实现一个应用程序,其中视频显示在视频视图。用户从视频中选择特定的帧范围,这样帧的速度就会减慢。基本上,我已经完成了显示帧的视频和用户也可以选择一组帧。其次,不知道如何减缓音频和视频速度选定的一组帧。

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回答 1

Stack Overflow用户

回答已采纳

发布于 2016-04-11 12:55:02

使用维塔米奥阿皮视频减速(以改变播放速度播放视频)可以执行。出于测试目的,用户可以使用GitHub Vitamio android示例上可用的维生素样本。或者可以在维生素样本中添加类MediaPlayerDemo_Video avaialbe来减缓视频。

以下是MediaPlayerDemo_Video的代码

代码语言:javascript
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    public class MediaPlayerDemo_Video extends Activity implements OnBufferingUpdateListener, OnCompletionListener, OnPreparedListener, OnVideoSizeChangedListener, SurfaceHolder.Callback {

    private static final String TAG = "MediaPlayerDemo";
    private int mVideoWidth;
    private int mVideoHeight;
    private MediaPlayer mMediaPlayer;
    private SurfaceView mPreview;
    private SurfaceHolder holder;
    private String path;
    private Bundle extras;
    private static final String MEDIA = "media";
    private static final int LOCAL_AUDIO = 1;
    private static final int STREAM_AUDIO = 2;
    private static final int RESOURCES_AUDIO = 3;
    private static final int LOCAL_VIDEO = 4;
    private static final int STREAM_VIDEO = 5;
    private boolean mIsVideoSizeKnown = false;
    private boolean mIsVideoReadyToBePlayed = false;

    /**
     * 
     * Called when the activity is first created.
     */
    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        if (!LibsChecker.checkVitamioLibs(this))
            return;
        setContentView(R.layout.mediaplayer_2);
        mPreview = (SurfaceView) findViewById(R.id.surface);
        holder = mPreview.getHolder();
        holder.addCallback(this);
        holder.setFormat(PixelFormat.RGBA_8888); 
        extras = getIntent().getExtras();

    }

    private void playVideo(Integer Media) {
        doCleanUp();
        try {

            switch (Media) {
            case LOCAL_VIDEO:
                /*
                 * TODO: Set the path variable to a local media file path.
                 */
                path = "";
                if (path == "") {
                    // Tell the user to provide a media file URL.
                    Toast.makeText(MediaPlayerDemo_Video.this, "Please edit MediaPlayerDemo_Video Activity, " + "and set the path variable to your media file path." + " Your media file must be stored on sdcard.", Toast.LENGTH_LONG).show();
                    return;
                }
                break;
            case STREAM_VIDEO:
                /*
                 * TODO: Set path variable to progressive streamable mp4 or
                 * 3gpp format URL. Http protocol should be used.
                 * Mediaplayer can only play "progressive streamable
                 * contents" which basically means: 1. the movie atom has to
                 * precede all the media data atoms. 2. The clip has to be
                 * reasonably interleaved.
                 * 
                 */
                path = "";
                if (path == "") {
                    // Tell the user to provide a media file URL.
                    Toast.makeText(MediaPlayerDemo_Video.this, "Please edit MediaPlayerDemo_Video Activity," + " and set the path variable to your media file URL.", Toast.LENGTH_LONG).show();
                    return;
                }

                break;

            }

            // Create a new media player and set the listeners
            mMediaPlayer = new MediaPlayer(this);
            mMediaPlayer.setDataSource(path);
            mMediaPlayer.setDisplay(holder);
            mMediaPlayer.prepareAsync();
            mMediaPlayer.setOnBufferingUpdateListener(this);
            mMediaPlayer.setOnCompletionListener(this);
            mMediaPlayer.setOnPreparedListener(this);
            mMediaPlayer.setOnVideoSizeChangedListener(this);
            setVolumeControlStream(AudioManager.STREAM_MUSIC);

        } catch (Exception e) {
            Log.e(TAG, "error: " + e.getMessage(), e);
        }
    }

    public void onBufferingUpdate(MediaPlayer arg0, int percent) {
        // Log.d(TAG, "onBufferingUpdate percent:" + percent);

    }

    public void onCompletion(MediaPlayer arg0) {
        Log.d(TAG, "onCompletion called");
    }

    public void onVideoSizeChanged(MediaPlayer mp, int width, int height) {
        Log.v(TAG, "onVideoSizeChanged called");
        if (width == 0 || height == 0) {
            Log.e(TAG, "invalid video width(" + width + ") or height(" + height + ")");
            return;
        }
        mIsVideoSizeKnown = true;
        mVideoWidth = width;
        mVideoHeight = height;
        if (mIsVideoReadyToBePlayed && mIsVideoSizeKnown) {
            startVideoPlayback();
        }
    }

    public void onPrepared(MediaPlayer mediaplayer) {
        Log.d(TAG, "onPrepared called");
        mIsVideoReadyToBePlayed = true;
        if (mIsVideoReadyToBePlayed && mIsVideoSizeKnown) {
            startVideoPlayback();
        }
    }

    public void surfaceChanged(SurfaceHolder surfaceholder, int i, int j, int k) {
        Log.d(TAG, "surfaceChanged called");

    }

    public void surfaceDestroyed(SurfaceHolder surfaceholder) {
        Log.d(TAG, "surfaceDestroyed called");
    }

    public void surfaceCreated(SurfaceHolder holder) {
        Log.d(TAG, "surfaceCreated called");
        playVideo(extras.getInt(MEDIA));

    }

    @Override
    protected void onPause() {
        super.onPause();
        releaseMediaPlayer();
        doCleanUp();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        releaseMediaPlayer();
        doCleanUp();
    }

    private void releaseMediaPlayer() {
        if (mMediaPlayer != null) {
            mMediaPlayer.release();
            mMediaPlayer = null;
        }
    }

    private void doCleanUp() {
        mVideoWidth = 0;
        mVideoHeight = 0;
        mIsVideoReadyToBePlayed = false;
        mIsVideoSizeKnown = false;
    }

    private void startVideoPlayback() {
        Log.v(TAG, "startVideoPlayback");
        holder.setFixedSize(mVideoWidth, mVideoHeight);
        mMediaPlayer.start();
    }
}

布局代码

代码语言:javascript
运行
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 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <io.vov.vitamio.widget.CenterLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical" >

        <SurfaceView
            android:id="@+id/surface"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center" >
        </SurfaceView>
    </io.vov.vitamio.widget.CenterLayout>

</LinearLayout>
票数 0
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页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接:

https://stackoverflow.com/questions/36395418

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