我使用“库”对话框创建了一个视频录制应用程序。“库”对话框显示已录制视频的列表，其中每个项目均通过以下方式由图标，视频标题，标签和位置信息组成：
有谁知道是否可以用视频缩略图替换图标（单帧预览）？
谢谢！
Answers:
如果您使用的是API 2.0或更高版本，则可以使用。
int id = **"The Video's ID"**
ImageView iv = (ImageView ) convertView.findViewById(R.id.imagePreview);
ContentResolver crThumb = getContentResolver();
BitmapFactory.Options options=new BitmapFactory.Options();
options.inSampleSize = 1;
Bitmap curThumb = MediaStore.Video.Thumbnails.getThumbnail(crThumb, id, MediaStore.Video.Thumbnails.MICRO_KIND, options);
iv.setImageBitmap(curThumb);id什么呢？
如果您没有通过光标或无法通过光标，并且只有路径或File对象，则可以使用自API级别8（2.2）以来的公共静态位图createVideoThumbnail（字符串filePath，int类型）
以下代码可以完美运行：
Bitmap bMap = ThumbnailUtils.createVideoThumbnail(file.getAbsolutePath(), MediaStore.Video.Thumbnails.MICRO_KIND);t have my video ID. For better quality use MediaStore.Video.Thumbnails.FULL_SCREEN_KIND`
使用类：
import android.provider.MediaStore.Video.Thumbnails;我们可以从视频中获得两个预览缩略图大小：
Thumbnails.MICRO_KIND 为96 x 96Thumbnails.MINI_KIND 为512 x 384像素这是一个代码示例：
String filePath = "/sdcard/DCIM/Camera/my_video.mp4"; //change the location of your file!
ImageView imageview_mini = (ImageView)findViewById(R.id.thumbnail_mini);
ImageView imageview_micro = (ImageView)findViewById(R.id.thumbnail_micro);
Bitmap bmThumbnail;
//MICRO_KIND, size: 96 x 96 thumbnail
bmThumbnail = ThumbnailUtils.createVideoThumbnail(filePath, Thumbnails.MICRO_KIND);
imageview_micro.setImageBitmap(bmThumbnail);
// MINI_KIND, size: 512 x 384 thumbnail
bmThumbnail = ThumbnailUtils.createVideoThumbnail(filePath, Thumbnails.MINI_KIND);
imageview_mini.setImageBitmap(bmThumbnail);我真的建议您使用滑翔机库。这是为本地视频文件生成和显示视频缩略图的最有效方法之一。
只需将此行添加到您的gradle文件中：
compile 'com.github.bumptech.glide:glide:3.7.0'它将变得非常简单：
String filePath = "/storage/emulated/0/Pictures/example_video.mp4";
Glide
.with( context )
.load( Uri.fromFile( new File( filePath ) ) )
.into( imageViewGifAsBitmap );您可以在这里找到更多信息：https : //futurestud.io/blog/glide-displaying-gifs-and-videos
干杯！
该解决方案适用于任何版本的Android。它已被证明可以在1.5和2.2中工作。这不是另一个“这是针对Android 2.0+”的解决方案。我是通过电子邮件留言板收集页面找到的，但是找不到原始链接。一切归功于原始海报。
在您的应用中，您可以通过以下方式使用此功能：
Bitmap bm = getVideoFrame(VideoStringUri);在其自身功能的某个位置（在OnCreate等区域之外），您将需要：
private Bitmap getVideoFrame(String uri) {
MediaMetadataRetriever retriever = new MediaMetadataRetriever();
try {
retriever.setMode(MediaMetadataRetriever.MODE_CAPTURE_FRAME_ONLY);
retriever.setDataSource(uri);
return retriever.captureFrame();
} catch (IllegalArgumentException ex) {
ex.printStackTrace();
} catch (RuntimeException ex) {
ex.printStackTrace();
} finally {
try {
retriever.release();
} catch (RuntimeException ex) {
}
}
return null;
}在src文件夹中，您需要一个新的子目录android / media，该子目录将容纳该类（从android源本身复制），该类可让您使用此功能。此部分不应更改，重命名或放置在其他任何地方。MediaMetadataRetriever.java必须在您的源文件夹中的android.media下才能正常工作。
/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.media;
import java.io.FileDescriptor;
import java.io.FileNotFoundException;
import java.io.IOException;
import android.content.ContentResolver;
import android.content.Context;
import android.content.res.AssetFileDescriptor;
import android.graphics.Bitmap;
import android.net.Uri;
/**
* MediaMetadataRetriever class provides a unified interface for retrieving
* frame and meta data from an input media file. {@hide}
*/
public class MediaMetadataRetriever {
static {
System.loadLibrary("media_jni");
native_init();
}
// The field below is accessed by native methods
private int mNativeContext;
public MediaMetadataRetriever() {
native_setup();
}
/**
* Call this method before setDataSource() so that the mode becomes
* effective for subsequent operations. This method can be called only once
* at the beginning if the intended mode of operation for a
* MediaMetadataRetriever object remains the same for its whole lifetime,
* and thus it is unnecessary to call this method each time setDataSource()
* is called. If this is not never called (which is allowed), by default the
* intended mode of operation is to both capture frame and retrieve meta
* data (i.e., MODE_GET_METADATA_ONLY | MODE_CAPTURE_FRAME_ONLY). Often,
* this may not be what one wants, since doing this has negative performance
* impact on execution time of a call to setDataSource(), since both types
* of operations may be time consuming.
*
* @param mode
* The intended mode of operation. Can be any combination of
* MODE_GET_METADATA_ONLY and MODE_CAPTURE_FRAME_ONLY: 1.
* MODE_GET_METADATA_ONLY & MODE_CAPTURE_FRAME_ONLY: For neither
* frame capture nor meta data retrieval 2.
* MODE_GET_METADATA_ONLY: For meta data retrieval only 3.
* MODE_CAPTURE_FRAME_ONLY: For frame capture only 4.
* MODE_GET_METADATA_ONLY | MODE_CAPTURE_FRAME_ONLY: For both
* frame capture and meta data retrieval
*/
public native void setMode(int mode);
/**
* @return the current mode of operation. A negative return value indicates
* some runtime error has occurred.
*/
public native int getMode();
/**
* Sets the data source (file pathname) to use. Call this method before the
* rest of the methods in this class. This method may be time-consuming.
*
* @param path
* The path of the input media file.
* @throws IllegalArgumentException
* If the path is invalid.
*/
public native void setDataSource(String path)
throws IllegalArgumentException;
/**
* Sets the data source (FileDescriptor) to use. It is the caller's
* responsibility to close the file descriptor. It is safe to do so as soon
* as this call returns. Call this method before the rest of the methods in
* this class. This method may be time-consuming.
*
* @param fd
* the FileDescriptor for the file you want to play
* @param offset
* the offset into the file where the data to be played starts,
* in bytes. It must be non-negative
* @param length
* the length in bytes of the data to be played. It must be
* non-negative.
* @throws IllegalArgumentException
* if the arguments are invalid
*/
public native void setDataSource(FileDescriptor fd, long offset, long length)
throws IllegalArgumentException;
/**
* Sets the data source (FileDescriptor) to use. It is the caller's
* responsibility to close the file descriptor. It is safe to do so as soon
* as this call returns. Call this method before the rest of the methods in
* this class. This method may be time-consuming.
*
* @param fd
* the FileDescriptor for the file you want to play
* @throws IllegalArgumentException
* if the FileDescriptor is invalid
*/
public void setDataSource(FileDescriptor fd)
throws IllegalArgumentException {
// intentionally less than LONG_MAX
setDataSource(fd, 0, 0x7ffffffffffffffL);
}
/**
* Sets the data source as a content Uri. Call this method before the rest
* of the methods in this class. This method may be time-consuming.
*
* @param context
* the Context to use when resolving the Uri
* @param uri
* the Content URI of the data you want to play
* @throws IllegalArgumentException
* if the Uri is invalid
* @throws SecurityException
* if the Uri cannot be used due to lack of permission.
*/
public void setDataSource(Context context, Uri uri)
throws IllegalArgumentException, SecurityException {
if (uri == null) {
throw new IllegalArgumentException();
}
String scheme = uri.getScheme();
if (scheme == null || scheme.equals("file")) {
setDataSource(uri.getPath());
return;
}
AssetFileDescriptor fd = null;
try {
ContentResolver resolver = context.getContentResolver();
try {
fd = resolver.openAssetFileDescriptor(uri, "r");
} catch (FileNotFoundException e) {
throw new IllegalArgumentException();
}
if (fd == null) {
throw new IllegalArgumentException();
}
FileDescriptor descriptor = fd.getFileDescriptor();
if (!descriptor.valid()) {
throw new IllegalArgumentException();
}
// Note: using getDeclaredLength so that our behavior is the same
// as previous versions when the content provider is returning
// a full file.
if (fd.getDeclaredLength() < 0) {
setDataSource(descriptor);
} else {
setDataSource(descriptor, fd.getStartOffset(),
fd.getDeclaredLength());
}
return;
} catch (SecurityException ex) {
} finally {
try {
if (fd != null) {
fd.close();
}
} catch (IOException ioEx) {
}
}
setDataSource(uri.toString());
}
/**
* Call this method after setDataSource(). This method retrieves the meta
* data value associated with the keyCode.
*
* The keyCode currently supported is listed below as METADATA_XXX
* constants. With any other value, it returns a null pointer.
*
* @param keyCode
* One of the constants listed below at the end of the class.
* @return The meta data value associate with the given keyCode on success;
* null on failure.
*/
public native String extractMetadata(int keyCode);
/**
* Call this method after setDataSource(). This method finds a
* representative frame if successful and returns it as a bitmap. This is
* useful for generating a thumbnail for an input media source.
*
* @return A Bitmap containing a representative video frame, which can be
* null, if such a frame cannot be retrieved.
*/
public native Bitmap captureFrame();
/**
* Call this method after setDataSource(). This method finds the optional
* graphic or album art associated (embedded or external url linked) the
* related data source.
*
* @return null if no such graphic is found.
*/
public native byte[] extractAlbumArt();
/**
* Call it when one is done with the object. This method releases the memory
* allocated internally.
*/
public native void release();
private native void native_setup();
private static native void native_init();
private native final void native_finalize();
@Override
protected void finalize() throws Throwable {
try {
native_finalize();
} finally {
super.finalize();
}
}
public static final int MODE_GET_METADATA_ONLY = 0x01;
public static final int MODE_CAPTURE_FRAME_ONLY = 0x02;
/*
* Do not change these values without updating their counterparts in
* include/media/mediametadataretriever.h!
*/
public static final int METADATA_KEY_CD_TRACK_NUMBER = 0;
public static final int METADATA_KEY_ALBUM = 1;
public static final int METADATA_KEY_ARTIST = 2;
public static final int METADATA_KEY_AUTHOR = 3;
public static final int METADATA_KEY_COMPOSER = 4;
public static final int METADATA_KEY_DATE = 5;
public static final int METADATA_KEY_GENRE = 6;
public static final int METADATA_KEY_TITLE = 7;
public static final int METADATA_KEY_YEAR = 8;
public static final int METADATA_KEY_DURATION = 9;
public static final int METADATA_KEY_NUM_TRACKS = 10;
public static final int METADATA_KEY_IS_DRM_CRIPPLED = 11;
public static final int METADATA_KEY_CODEC = 12;
public static final int METADATA_KEY_RATING = 13;
public static final int METADATA_KEY_COMMENT = 14;
public static final int METADATA_KEY_COPYRIGHT = 15;
public static final int METADATA_KEY_BIT_RATE = 16;
public static final int METADATA_KEY_FRAME_RATE = 17;
public static final int METADATA_KEY_VIDEO_FORMAT = 18;
public static final int METADATA_KEY_VIDEO_HEIGHT = 19;
public static final int METADATA_KEY_VIDEO_WIDTH = 20;
public static final int METADATA_KEY_WRITER = 21;
public static final int METADATA_KEY_MIMETYPE = 22;
public static final int METADATA_KEY_DISCNUMBER = 23;
public static final int METADATA_KEY_ALBUMARTIST = 24;
// Add more here...
}MediaMetadataRetrieverAPI级别10
试试这个对我有用
RequestOptions requestOptions = new RequestOptions();
Glide.with(getContext())
.load("video_url")
.apply(requestOptions)
.thumbnail(Glide.with(getContext()).load("video_url"))
.into("yourimageview");我很晚才回答这个问题，但希望它能帮助其他面临相同问题的候选人。
我使用两种方法为视频列表加载缩略图，第一种是
Bitmap bmThumbnail;
bmThumbnail = ThumbnailUtils.createVideoThumbnail(FILE_PATH
+ videoList.get(position),
MediaStore.Video.Thumbnails.MINI_KIND);
if (bmThumbnail != null) {
Log.d("VideoAdapter","video thumbnail found");
holder.imgVideo.setImageBitmap(bmThumbnail);
} else {
Log.d("VideoAdapter","video thumbnail not found");
}它看起来不错，但是此解决方案存在问题，因为当我滚动视频列表时，由于处理量大，它会冻结一些时间。
因此，在此之后，我找到了另一个使用Glide Library完美工作的解决方案。
Glide
.with( mContext )
.load( Uri.fromFile( new File( FILE_PATH+videoList.get(position) ) ) )
.into( holder.imgVideo );我建议使用稍后的解决方案来显示带有视频列表的缩略图。谢谢
这是实时视频缩略图的代码。
public class LoadVideoThumbnail extends AsyncTask<Object, Object, Bitmap>{
@Override
protected Bitmap doInBackground(Object... params) {try {
String mMediaPath = "http://commonsware.com/misc/test2.3gp";
Log.e("TEST Chirag","<< thumbnail doInBackground"+ mMediaPath);
FileOutputStream out;
File land=new File(Environment.getExternalStorageDirectory().getAbsoluteFile()
+"/portland.jpg");
Bitmap bitmap = ThumbnailUtils.createVideoThumbnail(mMediaPath, MediaStore.Video.Thumbnails.MICRO_KIND);
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
byte[] byteArray = stream.toByteArray();
out=new FileOutputStream(land.getPath());
out.write(byteArray);
out.close();
return bitmap;
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Bitmap result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
if(result != null){
((ImageView)findViewById(R.id.imageView1)).setImageBitmap(result);
}
Log.e("TEST Chirag","====> End");
}
}Bitmap bitmap = ThumbnailUtils.createVideoThumbnail(mMediaPath, MediaStore.Video.Thumbnails.MICRO_KIND);注意到所有参数