[android] Android : 비디오 섬네일을 표시 할 수 있습니까?

이 솔루션은 모든 버전의 Android에서 작동합니다. 1.5 및 2.2에서 작동하는 것으로 입증되었습니다. 이것은 또 다른 “This is for Android 2.0+”솔루션이 아닙니다. 이메일 게시판 컬렉션 페이지를 통해 찾았는데 원본 링크를 찾을 수 없습니다. 모든 크레딧은 원래 포스터에 있습니다.

앱에서 다음을 호출하여이를 사용합니다.

Bitmap bm = getVideoFrame(VideoStringUri);

자체 기능 (OnCreate 외) 어딘가에 다음이 필요합니다.

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;
    }

src 폴더에이 함수를 사용할 수있는 클래스 (안드로이드 소스 자체에서 복사)를 저장할 새 하위 디렉토리 android / media가 필요합니다. 이 부분은 변경하거나 이름을 바꾸거나 다른 곳에 배치해서는 안됩니다. 이 모든 것이 작동하려면 MediaMetadataRetriever.java가 소스 폴더의 android.media 아래에 있어야합니다.

/*
 * 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...
}