MediaPlayer播放聲音但不播放視頻

Question

我正在嘗試使用SurfaceView從Android播放視頻。

我可以加載視頻，聲音可以正確播放，但是看不到視頻。

這是我的活動：

public class VideoTest extends Activity implements OnBufferingUpdateListener, OnCompletionListener, OnPreparedListener, OnVideoSizeChangedListener, SurfaceHolder.Callback, OnErrorListener {

    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;
    public static final String MEDIA = "media";
    private static final int LOCAL_AUDIO = 1;
    public static final int STREAM_AUDIO = 2;
    private static final int RESOURCES_AUDIO = 3;
    private static final int LOCAL_VIDEO = 4;
    public static final int STREAM_VIDEO = 5;
    private boolean mIsVideoSizeKnown = false;
    private boolean mIsVideoReadyToBePlayed = false;
    private RelativeLayout layout;

    /**
     *
     * Called when the activity is first created.
     */
    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);

        mPreview = new SurfaceView(this);
        holder = mPreview.getHolder();
        holder.addCallback(this);
        holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        extras = getIntent().getExtras();

        mPreview.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));

        layout = new RelativeLayout(this);
        layout.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));
        layout.addView(mPreview, 0);

        setContentView(layout);

    }

    private void playVideo(Integer Media) {
        doCleanUp();
        try {
            mMediaPlayer = MediaPlayer.create(this, R.raw.video);
            mMediaPlayer.setDisplay(holder);

            mMediaPlayer.setOnBufferingUpdateListener(this);
            mMediaPlayer.setOnCompletionListener(this);
            mMediaPlayer.setOnPreparedListener(this);
            mMediaPlayer.setOnVideoSizeChangedListener(this);
            mMediaPlayer.setOnErrorListener(this);

            mMediaPlayer.setAudioStreamType(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 + " pos : " + mMediaPlayer.getCurrentPosition() + " / " + mMediaPlayer.getDuration());
        if (mMediaPlayer.isPlaying()) {
            Log.d(TAG, "Playing");
        } else {
            mMediaPlayer.start();
        }
    }

    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. Width : " + j + ", height : " + k);
        holder = surfaceholder;
        mMediaPlayer.setDisplay(holder);
        mIsVideoSizeKnown = true;
        mVideoWidth = j;
        mVideoHeight = k;
        if (mIsVideoReadyToBePlayed && mIsVideoSizeKnown) {
            startVideoPlayback();
        }
    }

    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 " + mVideoWidth + "x" + mVideoHeight);

        int width = mPreview.getWidth();
        int height = mPreview.getHeight();
        float boxWidth = width;
        float boxHeight = height;

        float videoWidth = mMediaPlayer.getVideoWidth();
        float videoHeight = mMediaPlayer.getVideoHeight();

        Log.i(TAG, String.format("startVideoPlayback @ video %dx%d - box %dx%d", (int) videoWidth, (int) videoHeight, width, height));

        float wr = boxWidth / videoWidth;
        float hr = boxHeight / videoHeight;
        float ar = videoWidth / videoHeight;

        if (wr > hr) {
            width = (int) (boxHeight * ar);
        } else {
            height = (int) (boxWidth / ar);
        }

        Log.i(TAG, String.format("Scaled to %dx%d", width, height));

        holder.setFixedSize(width, height);
        mMediaPlayer.start();
    }

    public boolean onError(MediaPlayer arg0, int arg1, int arg2) {
        Log.e(TAG, "ERROR called : " + arg1 + ", " + arg2);
        return false;
    }
}

永遠不會調用onVideoSizeChanged函數，但會調用onPrepared和surfaceChanged 。 因此將startVideoPlayback函數，但視頻的寬度和高度為0。

我可以聽見聲音，但正在播放視頻，但屏幕上沒有任何顯示。 我還嘗試為SurfaceHolder對象的setFixedSize函數提供原始寬度和高度，但仍然沒有顯示任何內容。

你能幫助我嗎？ 我正在使用Android 8

編輯

這是我從資源播放視頻時的日志：

WARN    info/warning (1, 35)
WARN    info/warning (1, 44)
DEBUG   Duration : 101248
DEBUG   surfaceChanged called. Width : 480, height : 270
INFO    Info (1,35)
INFO    Info (1,44)
DEBUG   onPrepared called
VERBOSE startVideoPlayback 480x270
INFO    startVideoPlayback @ video 0x0 - box 480x270
INFO    Scaled to 480x0
DEBUG   surfaceDestroyed called

編輯2

我嘗試了另一個視頻，它正在工作。

以下是“無效”視頻的規格：

• 容器 ：MP4-QuickTime
• 速率 ：2340 Kbps
• 格式 ：H.264 / MPEG-4-AVC
• 尺寸 ：1280 * 640
• 寬高比像素 ：未定義
• 圖像比例 ：2.000
• 編碼配置文件 ：Baseline@L3.1

以下是工作視頻的規格：

• 容器 ：MP4-QuickTime
• 速率 ：537 Kbps
• 格式 ：H.264 / MPEG-4-AVC
• 尺寸 ：640 * 360
• 寬高比像素 ：未定義
• 圖像比例 16：9
• 編碼配置文件 ：Baseline@L3.0

您知道第一個視頻出了什么問題嗎？

Answer 1

可以嘗試的一些事情：

1）您是否應該在playVideo方法中調用mMediaPlayer.prepareAsync（）？

2）嘗試刪除onPrepared中的if語句

3）我會打電話給holder.setSizeFromLayout（）; 然后從onPrepared回調（而不是onBufferingUpdate）中選擇mMediaPlayer.start（）。