我用图书馆对话框创建了一个视频录制应用程序。这个库对话框显示录制视频列表，其中每个项目包括图标、视频标题、标签和位置信息，如下所示：
请问是否可以将图标替换为视频缩略图（单帧预览）？
谢谢！
安卓：是否可以显示视频缩略图？
101
- Niko Gamulin
1
有人回答了这个问题吗？[http://stackoverflow.com/questions/16190374/how-to-display-the-videos-url-in-thumbnails] - Make it Simple
12个回答
98
如果你不能或不想使用游标，并且只有路径或文件对象，你可以使用自API级别8（2.2）开始提供的以下方法:
public static Bitmap createVideoThumbnail(String filePath, int kind)
以下代码运行正常:
Bitmap bMap = ThumbnailUtils.createVideoThumbnail(file.getAbsolutePath(), MediaStore.Video.Thumbnails.MICRO_KIND);
- Damien Praca
7
7当我试图创建缩略图时，出现 null 的情况。我认为我的路径可能有问题？我的路径是 "/external/video/media/14180"。 - haythem souissi
它就像魔法一样。即使我没有视频ID，它也能正常工作。为了获得更好的质量，请使用“MediaStore.Video.Thumbnails.FULL_SCREEN_KIND”。 - Sami Eltamawy
haythem souussi因为这不是路径，而是Uri，您需要将其转换为路径。 - Nadir Novruzov
这个代码可以运行，但是返回的视频图像不正确。我需要获取第一帧，但是却获得了5-6秒钟之后的图像。有什么建议吗？ - speedynomads
1"'createVideoThumbnail(java.lang.String, int)'"已被弃用。 - mufazmi
显示剩余2条评论
76
如果您正在使用API 2.0或更高版本，则这将起作用。
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);
- Greg Zimmers
8
10
id是什么？ - phunehehe1您可以查询手机上的视频媒体库。 "id" 只是您查询的信息之一。有关 MediaStore 的更多信息，请参见 http://developer.android.com/reference/android/provider/MediaStore.Video.html。 - Greg Zimmers
6似乎所有人都能让这个工作，令人惊讶。我也尝试过，但是 curThumb 最终为空值。 - BlueVoodoo
8如果视频来自一个URL，怎么办？ - jayellos
2使用Glide，它非常容易。 - Dhruvam Sharma
显示剩余3条评论
43
使用这个类：
import android.provider.MediaStore.Video.Thumbnails;
我们可以从视频中获取两种预览缩略图大小：
Thumbnails.MICRO_KIND 为 96 x 96
Thumbnails.MINI_KIND 为 512 x 384 px
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);
- Jorgesys
5
如果我有一个文件路径的链接，像这样，这样设置到ImageView上不会起作用，因为它没有显示任何内容...这是文件路径"http:/ /unknown.com/v3-1aox9d1 .mp4"，显然是一个真实的域名，但是这个路径不能生成缩略图吗？ - Lion789
要使用ThumbnailUtils类，您必须先将文件保存到磁盘上，然后使用方法ThumbnailUtils.createVideoThumbnail()。 - Jorgesys
谢谢，请问我该如何获取创建缩略图的新文件路径？ - Lion789
为什么在 Android 4 及以上版本不能正常工作？ - Criss
1嗨，Cris，我有三个设备4.1、4.2.2和5.0，它们都可以正常工作。发一个带有你的问题和一些代码的问题，我可以帮助你。 - Jorgesys
28
我强烈建议您使用Glide库。它是生成和显示本地视频文件缩略图最有效的方法之一。
只需将以下代码添加到您的gradle文件中：
compile 'com.github.bumptech.glide:glide:3.7.0'
并且它将变得像这样简单：
String filePath = "/storage/emulated/0/Pictures/example_video.mp4";
Glide
.with( context )
.load( Uri.fromFile( new File( filePath ) ) )
.into( imageViewGifAsBitmap );
在这里您可以找到更多信息：https://futurestud.io/blog/glide-displaying-gifs-and-videos
干杯！
- Edouard Brèthes
2
4滑动（Glide）只适用于本地视频，而不是URL视频，难道没有简单的方法可以解决这个问题吗？ - Lutaaya Huzaifah Idris
有些设备无法显示本地视频的缩略图。 - Sathish Gadde
22
目前我使用以下代码：
Bitmap bMap = ThumbnailUtils.createVideoThumbnail(file.getAbsolutePath(), MediaStore.Video.Thumbnails.MICRO_KIND);
但我发现使用Glide库并采用以下代码可以获得更好的解决方案（它会缓存您的图像，并且比之前的方法表现更佳）
Glide.with(context)
.load(uri)
.placeholder(R.drawable.ic_video_place_holder)
.into(imageView);
- Amir
10
试试这个，它对我有效
RequestOptions requestOptions = new RequestOptions();
Glide.with(getContext())
.load("video_url")
.apply(requestOptions)
.thumbnail(Glide.with(getContext()).load("video_url"))
.into("yourimageview");
- karan brahmaxatriya
6
这个解决方案适用于任何版本的Android系统。它已经被证明可以在1.5和2.2版本上使用，而不仅仅是“适用于Android 2.0+”的解决方案。我是从一封电子邮件留言板收集页面中发现了这个解决方案，但无法找到原始链接。所有的功劳都归原作者。
在您的应用程序中，您可以通过调用以下方法来使用它：
Bitmap bm = getVideoFrame(VideoStringUri);
在其自己的函数中（在OnCreate之外等），您需要：
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;
}
在您的src文件夹中，需要一个名为android/media的新子目录，其中包含了允许您使用此功能的类（从android源代码本身复制而来）。此部分不应更改、重命名或放置在其他任何位置。为使所有内容正常工作，MediaMetadataRetriever.java需要位于您源文件夹中的android.media下。
/*
* 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...
}
- Abandoned Cart
9
1我可以确认这个不起作用。我也需要这个功能。它不会起作用，因为它使用了常规应用程序没有权限使用的本地系统调用。 - Andy
MediaMetadataRetriever 支持 API 级别 10 及以上。 - Asahi@LoungeKatt，它是否可以在多个时间点从同一视频中捕获多个图像？ - android developer
@androiddeveloper 这只是用来获取通用单帧的。它不会在本地执行捕获。系统会选择帧。 - Abandoned Cart
@LoungeKatt 系统是如何实现的？是否可以覆盖它或使用您自定义的方式来获取特定时间的缩略图？ - android developer
显示剩余4条评论
5
Android 1.5和1.6没有提供这样的缩略图功能，但2.0提供了，如官方发布说明所示：
媒体
- MediaScanner现在在将所有图片插入到MediaStore时生成缩略图。
- 新的缩略图API可以按需检索图像和视频缩略图。
- Marc Climent
4
我虽然回答这个问题有些晚了，但我希望能够帮助到其他遇到同样问题的候选人。
我使用了两种方法来为视频列表加载缩略图，第一种方法是：
我推荐使用后一种方法来显示视频列表中的缩略图。谢谢。
我使用了两种方法来为视频列表加载缩略图，第一种方法是：
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");
}
这个方案看起来不错，但存在一个问题，当我滚动视频列表时，由于处理量太大，它会有时候会冻结。
因此，在此之后，我找到了另一个完美的解决方案，使用了Glide库。
Glide
.with( mContext )
.load( Uri.fromFile( new File( FILE_PATH+videoList.get(position) ) ) )
.into( holder.imgVideo );
我推荐使用后一种方法来显示视频列表中的缩略图。谢谢。
- Mudassir Khan
1
嗨@AllanRibas，很高兴听到这个解决方案对你有用。 - Mudassir Khan
1
我知道这是一个旧问题，并且已经有了一个被接受的答案，但是我想发表我的答案以便于某些人搜索到:
当我只想使用Uri时，我这样做:
val mmr = MediaMetadataRetriever()
mmr.setDataSource(videoUri)
val thummbnailBitmap = mmr.frameAtTime
imageView.setImageBitmap(thummbnailBitmap)
- Pouya Danesh
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