在Android 4.2.2上播放视频时,Android MediaPlayer会闪烁

Question

我正面临Android MediaPlayer类的一个奇怪问题.我正在使用MediaPlayer在VideoView中播放视频.这适用于所有设备,除了搭载Android 4.2.2的Samsung GT-I8200N.好吧,我实际上已经听说过这些视频无法在某些三星4.1.X设备上播放的报道,但是我无法将这些视频放到其中一个设备上.我在Google Android模拟器中没有任何错误.

更详细一点:带有Android 4.2.2的三星GT-I8200N能够以一个片段播放视频,但不能在另一个片段中播放,即使使用相同的代码播放视频.当视频开始时,除了视频应该在的空间外,整个屏幕都会闪烁黑色.

这是代码:

public abstract class AbstractSignVideoFragment extends Fragment {

private static final double MAXMIMUM_VIDEO_HEIGHT_ON_LANDSCAPE = 0.4;
private static final double MAXIMUM_VIDEO_WIDTH_ON_PORTRAIT = 0.8;
private final static String TAG = AbstractSignVideoFragment.class.getSimpleName();
private static final String ANDROID_RESOURCE = "android.resource://";
private static final String SLASH = "/";
private static final String RAW = "raw";
protected VideoView videoView;
protected ProgressBar progressBar;

@SuppressWarnings("BooleanMethodIsAlwaysInverted")
protected boolean isSetupVideoViewSuccessful(final Sign sign, final SOUND sound, final CONTROLS controls) {
    initializeMediaController();
    final String mainActivityPackageName = getActivity().getPackageName();
    final int signIdentifier = getActivity().getResources().getIdentifier(sign.getName(), RAW, mainActivityPackageName);
    if (0 == signIdentifier) {
        return false;
    }
    final Uri uri = Uri.parse(ANDROID_RESOURCE + mainActivityPackageName + SLASH + signIdentifier);
    if (!isVideoViewDimensionSetToMatchVideoMetadata(this.videoView, uri)) {
        return false;
    }
    this.videoView.setVideoURI(uri);
    this.videoView.requestFocus();
    this.videoView.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
        public void onPrepared(MediaPlayer mp) {
            AbstractSignVideoFragment.this.progressBar.setVisibility(View.GONE);
            if (sound.equals(SOUND.OFF)) {
                mp.setVolume(0f, 0f);
            }
            AbstractSignVideoFragment.this.videoView.start();
            AbstractSignVideoFragment.this.videoView.setContentDescription(getActivity()
                    .getString(R.string.videoIsPlaying) + ": " + sign.getName());
            Log.d(TAG, String.format("Actual width: %s, Actual height: %s",
                    AbstractSignVideoFragment.this.videoView.getWidth(),
                    AbstractSignVideoFragment.this.videoView.getHeight()));
            // Set the MediaController to null so the controls are not 'popping up'
            // when the video plays for the first time.
            AbstractSignVideoFragment.this.videoView.setMediaController(null);
        }
    });
    this.videoView.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mp) {
            if (controls.equals(CONTROLS.SHOW)) {
                initializeMediaController();
            }
        }
    });
    return true;
}

private void initializeMediaController() {
    final MediaController mediaController = new MediaController(getActivity(), false);
    mediaController.setAnchorView(this.videoView);
    this.videoView.setMediaController(mediaController);
}

private boolean isVideoViewDimensionSetToMatchVideoMetadata(VideoView videoView, Uri uri) {
    String metadataVideoWidth;
    String metadataVideoHeight;
    try {
        final MediaMetadataRetriever metaRetriever = new MediaMetadataRetriever();
        metaRetriever.setDataSource(getActivity(), uri);
        metadataVideoWidth = metaRetriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_WIDTH);
        metadataVideoHeight = metaRetriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_HEIGHT);
        metaRetriever.release();
        Validate.notEmpty(metadataVideoWidth);
        Validate.notEmpty(metadataVideoHeight);
    } catch (NullPointerException | IllegalArgumentException ex) {
        return false;
    }
    final double videoWidth = Double.valueOf(metadataVideoWidth);
    final double videoHeight = Double.valueOf(metadataVideoHeight);
    final double videoRatio = videoWidth / videoHeight;
    Log.d(TAG, String.format("videoWidth: %s, videoHeight: %s, videoRatio: %s", videoWidth, videoHeight, videoRatio));
    boolean isOrientationPortrait = Configuration.ORIENTATION_PORTRAIT == getResources().getConfiguration().orientation;
    int displayHeight = getResources().getDisplayMetrics().heightPixels;
    int displayWidth = getResources().getDisplayMetrics().widthPixels;
    Log.d(TAG, String.format("displayHeight: %s, displayWidth: %s", displayHeight, displayWidth));
    final double desiredVideoWidth, desiredVideoHeight;
    if (isOrientationPortrait) {
        desiredVideoWidth = displayWidth * MAXIMUM_VIDEO_WIDTH_ON_PORTRAIT;
        desiredVideoHeight = 1 / (videoRatio / desiredVideoWidth);
        Log.d(TAG, String.format("OrientationPortrait: desiredVideoWidth: %s, desiredVideoHeight: %s", desiredVideoWidth, desiredVideoHeight));
    } else { // orientation is Landscape
        desiredVideoHeight = displayHeight * MAXMIMUM_VIDEO_HEIGHT_ON_LANDSCAPE;
        desiredVideoWidth = desiredVideoHeight * videoRatio;
        Log.d(TAG, String.format("OrientationLandscape: desiredVideoWidth: %s, desiredVideoHeight: %s", desiredVideoWidth, desiredVideoHeight));
    }
    final ViewGroup.LayoutParams layoutParams = videoView.getLayoutParams();
    layoutParams.width = (int) desiredVideoWidth;
    layoutParams.height = (int) desiredVideoHeight;
    return true;
}

public enum SOUND {ON, OFF}

public enum CONTROLS {SHOW, HIDE}
}

这是logcat输出,当屏幕闪烁时循环:

D/v_gal(115):[tid = 275] gcmVERIFY_ARGUMENT失败:

D/v_gal(115):[tid = 275] gcmONERROR:status = -1(gcvSTATUS_INVALID_ARGUMENT)@ _Blit(2208)

E/v_hwc(115):_Blit:status = -1失败

D/v_gal(115):[tid = 275] gcmONERROR:status = -1(gcvSTATUS_INVALID_ARGUMENT)@ hwcComposeG2D(615)

E/v_hwc(115):hwcComposeG2D失败:status = -1

E/v_hwc(115):_ Set(1007):撰写失败

完整的logcat输出可以在这里找到:Github问题(完整的logcat)

视频查看代码:

< VideoView
android:id="@+id/signTrainerVideoView"
android:layout_width="0dip"
android:layout_height="0dip"
android:layout_below="@+id/signTrainerQuestionText"
android:layout_centerHorizontal="true" />

片段的完整布局xml可以在这里找到:layout xml(完整片段)

Answer 1

我不确定这是否能解决问题，但我只会报告其中似乎可以改进的内容。

为了实现您的 VideoView 大小：

final ViewGroup.LayoutParams layoutParams = videoView.getLayoutParams();
layoutParams.width = (int) desiredVideoWidth;
layoutParams.height = (int) desiredVideoHeight;
videoView.setLayoutParams(layoutParams); // Input Changes
videoView.getHolder().setSizeFromLayout(); // Apply Changes

另外，根据我的实验，“0dip”大小意味着使用权重参数进行计算，而您似乎没有提供该参数。可能是错的，但值得一提。

// Add android:weightSum="1" to the sup. Layout
// And set a weight there
<VideoView
            android:id="@+id/signTrainerVideoView"
            android:layout_width="0dip"
            android:layout_height="0dip"
            android:layout_weight="1"
            android:layout_below="@+id/signTrainerQuestionText"
            android:layout_centerHorizontal="true" />