如何用示例在安卓系统中使用 FFmpeg？
原文:https://www . geesforgeks . org/how-用法-ffmpeg-in-Android-with-example/
FFmpeg，Fast-forward MPEG 的简称，是一个自由开源的多媒体框架，能够对迄今为止已经创建的各种多媒体文件进行解码、编码、转码、mux、demux、流式传输、过滤和公平播放。还支持一些最老的格式。FFmpeg 编译并运行，跨各种操作系统，如 Linux、Mac OS X、微软视窗、BSDs、Solaris 等。在大量的构建环境、机器架构和配置中。FFmpeg 中使用的编程语言有 C 语言和汇编语言。我们可以使用 Ffmpeg 做很多有趣的事情，比如，视频压缩，音频压缩，修剪视频，旋转视频，裁剪视频，给视频添加滤镜，反转视频，创建快速和慢速视频，淡入淡出，合并音频和视频，从图像创建视频，将视频从一种格式转换为另一种格式，从视频中提取图片或从视频中提取声音，Gifs 叠加等等。 FFmpeg 是其他数百个媒体相关软件项目工作流程的一部分，经常在幕后使用。而且，它是 VLC 媒体播放器、YouTube、Plex、iTunes、快捷方式、Blender、Kodi、手刹等软件的内部部分，它在谷歌 Chrome 和 Linux 版本的 Firefox 中处理视频和音频播放。FFmpeg 由大量的库和项目组成，用于处理视频、声音和其他多媒体文件和流。
FFmpeg 库
- libavutil 是一个帮助多功能媒体编程的实用程序库。它包含可移植的字符串函数、任意数字生成器、额外的算术能力、数据结构、加密和核心多媒体实用程序。
- libavcodec 是一个为视频/音频编解码器、字幕流和多个比特流通道提供编码器和解码器的库。
- libavformat 是一个为视频/音频编解码器、字幕流
- libavdevice 是一个包含输入/输出设备的库，用于从众多多媒体输入/输出编程系统(包括 Video4Linux、ALSA 和 VfW)获取和向其传递信息。
- libavfilter 库提供了一个包含多个过滤器和接收器的媒体过滤框架。
- libswscale 库执行异常增强的图片缩放和像素格式转换任务。
- libswresample 是一个执行高度优化但音频速率有损变化、通道布局变化(例如从立体声到单声道)和样本格式转换操作的库。
安卓没有高效、健壮的多媒体应用编程接口，无法提供像 FFmpeg 这样的功能。安卓唯一拥有的 API 是 MediaCodec API，但它比 FFmpeg 更快，因为它使用设备硬件进行视频处理。
使用 FFmpeg 在安卓工作室创建一个小视频编辑器应用
先决条件:
在开始之前，我们需要设置一个环境来运行我们的 FFmpeg 命令。这样做有两种选择:
- 通过建造我们自己的图书馆
- 通过使用社区提供的任何编译源。安卓系统中有很多库可以用来执行 FFmpeg 操作。例如，
- 书写数字
- 虚张声势
- tanner/mobile ffmpeg
- yanjie 10930/EpMedia:这个库中有许多内置的功能，您可以从中剪辑、裁剪、旋转、添加徽标、添加自定义滤镜、合并不同的视频。
虽然强烈建议构建您的库，因为这将减少您的 apk 大小，但您可以添加第三方库，并可以根据需要随时更新库。但是，这个过程非常耗时，需要额外的技能。因此，作为初学者，您可以使用上面提到的一些库，如果您遇到一些问题，您可以在他们各自的 GitHub 存储库中提出这个问题。在下面的例子中，我将使用 tanersener/mobile-ffmpeg，，因为它支持安卓 10 范围的存储，也是互联网上最好的 FFmpeg mobile 库。下面给出了一个 GIF 示例，来了解一下我们将在本文中做什么。注意，我们将使用 Java 语言来实现这个项目。
逐步实施
第一步:创建新项目
要在安卓工作室创建新项目，请参考如何在安卓工作室创建/启动新项目。注意选择 Java 作为编程语言。
第 2 步:向 build.gradle 文件添加依赖关系
我们将使用 tanersener/mobile-ffmpeg 库在我们的应用程序中实现 ffmpeg 功能。我们还需要一个 rangeseekbar 来选择视频的特定长度。所以在 build.gradle 文件中添加这些依赖项。
- 实现 com。arthenica:mobile-ffmpeg-full:4.4 '
- 实现组织。弗洛雷斯·库。安卓。rangeseekbar:rangeseekbar-库:0。3 .0'
步骤 3:使用 colors.xml 文件
下面是 colors.xml 文件的代码。
可扩展标记语言
<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="colorPrimary">#3F51B5</color>
<color name="colorPost">#0091EA</color>
<color name="colorPrimaryDark">#303F9F</color>
<color name="colorAccent">#E25E14</color>
<color name="colorAccentTrans">#BEE25E14</color>
<color name="maincolor">#E25E14</color>
<color name="yellow">#feeb3c</color>
<color name="white">#fff</color>
<color name="semitranswhitecolor">#00FFFFFF</color>
<color name="colorwhite_50">#CCffffff</color>
<color name="colorwhite_10">#1Affffff</color>
<color name="colorwhite_30">#4Dffffff</color>
<color name="black">#2F2F2F</color>
<color name="graycolor">#D3D3D3</color>
<color name="graycolor2">#C5C4C4</color>
<color name="gainsboro">#DCDCDC</color>
<color name="lightgraycolor">#f2f2f2</color>
<color name="darkgray">#93959A</color>
<color name="darkgraytrans">#9493959A</color>
<color name="darkgraytransPost">#9BC5C6C9</color>
<color name="dimgray">#696969</color>
<color name="lightblack">#5d5d5d</color>
<color name="delete_message_bg">#f2f2f2</color>
<color name="delete_message_text">#b8b8b8</color>
<color name="transparent">#00ffffff</color>
<color name="fifty_transparent_black">#802F2F2F</color>
<color name="redcolor">#ff0008</color>
<color name="semitransredcolor">#93FF0008</color>
<color name="semitransredcolornew">#918E8E</color>
<color name="color_gray_alpha">#65b7b7b7</color>
<color name="app_blue">#0e1f2f</color>
<color name="text_color">#000000</color>
<color name="seekbar_color">#3be3e3</color>
<color name="line_color">#FF15FF00</color>
<color name="shadow_color">#00000000</color>
<color name="app_color">#c52127</color>
</resources>
第 4 步:使用 activity_main.xml 文件
转到 activity_main.xml 文件，参考以下代码。下面是 activity_main.xml 文件的代码。
可扩展标记语言
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#43AF47"
tools:context=".MainActivity">
<RelativeLayout
android:id="@+id/relative1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_margin="10dp">
<Button
android:id="@+id/cancel_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:background="@color/transparent"
android:text="Select Video"
android:textColor="@color/white" />
</RelativeLayout>
<VideoView
android:id="@+id/layout_movie_wrapper"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="@+id/relative"
android:layout_below="@+id/relative1" />
<TextView
android:id="@+id/progressbar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:paddingBottom="5dp" />
<RelativeLayout
android:id="@+id/imagelinear"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="@+id/relative"
android:layout_below="@+id/relative1"
android:layout_centerInParent="true">
<TextView
android:id="@+id/overlaytextview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="Raghav"
android:textAppearance="@style/TextAppearance.AppCompat.Medium"
android:textColor="@color/white"
android:textStyle="bold"
android:visibility="gone" />
<ImageView
android:id="@+id/overlayimage"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true"
android:scaleType="fitXY" />
</RelativeLayout>
<LinearLayout
android:id="@+id/relative"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:orientation="vertical">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/textleft"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_marginBottom="10dp"
android:text="00:00"
android:textColor="@color/white" />
<TextView
android:id="@+id/textright"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:layout_marginBottom="10dp"
android:layout_weight="1"
android:text="00:00"
android:textAlignment="textEnd"
android:textColor="@color/white" />
</RelativeLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/white">
<org.florescu.android.rangeseekbar.RangeSeekBar
android:id="@+id/rangeSeekBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:activeColor="@color/white"
app:alwaysActive="true"
app:barHeight="2dp"
app:showLabels="false"
app:textAboveThumbsColor="#000000" />
</RelativeLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="10dp" />
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout
android:id="@+id/lineartime"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="@+id/text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="10dp"
android:text=""
android:textColor="@color/semitransredcolornew" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:layout_weight="1"
android:orientation="vertical">
<ImageButton
android:id="@+id/slow"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_gravity="center"
android:background="@color/transparent"
android:scaleType="fitXY"
android:src="@drawable/icon_effect_slow" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Slow Motion"
android:textAlignment="center"
android:textColor="@color/white" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:layout_weight="1"
android:orientation="vertical">
<ImageButton
android:id="@+id/reverse"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_gravity="center"
android:background="@color/transparent"
android:scaleType="fitXY"
android:src="@drawable/icon_effect_time" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Reverse"
android:textAlignment="center"
android:textColor="@color/white" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:layout_weight="1"
android:orientation="vertical">
<ImageButton
android:id="@+id/fast"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_gravity="center"
android:background="@color/transparent"
android:scaleType="fitXY"
android:src="@drawable/icon_effect_repeatedly" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Flash"
android:textAlignment="center"
android:textColor="@color/white" />
</LinearLayout>
</LinearLayout>
</LinearLayout>
<LinearLayout
android:id="@+id/lineareffects"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="@+id/text2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="10dp"
android:text="Tap to add effects"
android:textColor="@color/white" />
</LinearLayout>
</RelativeLayout>
</LinearLayout>
</RelativeLayout>
步骤 5:使用 MainActivity.java 文件
转到MainActivity.java文件，参考以下代码。以下是MainActivity.java文件的代码。代码中添加了注释，以更详细地理解代码。
Java 语言(一种计算机语言，尤用于创建网站)
import android.app.ProgressDialog;
import android.content.ContentValues;
import android.content.Intent;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.VideoView;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import com.arthenica.mobileffmpeg.Config;
import com.arthenica.mobileffmpeg.ExecuteCallback;
import com.arthenica.mobileffmpeg.FFmpeg;
import org.florescu.android.rangeseekbar.RangeSeekBar;
import java.io.File;
import static com.arthenica.mobileffmpeg.Config.RETURN_CODE_CANCEL;
import static com.arthenica.mobileffmpeg.Config.RETURN_CODE_SUCCESS;
public class MainActivity extends AppCompatActivity {
private ImageButton reverse, slow, fast;
private Button cancel;
private TextView tvLeft, tvRight;
private ProgressDialog progressDialog;
private String video_url;
private VideoView videoView;
private Runnable r;
private RangeSeekBar rangeSeekBar;
private static final String root = Environment.getExternalStorageDirectory().toString();
private static final String app_folder = root + "/GFG/";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
rangeSeekBar = (RangeSeekBar) findViewById(R.id.rangeSeekBar);
tvLeft = (TextView) findViewById(R.id.textleft);
tvRight = (TextView) findViewById(R.id.textright);
slow = (ImageButton) findViewById(R.id.slow);
reverse = (ImageButton) findViewById(R.id.reverse);
fast = (ImageButton) findViewById(R.id.fast);
cancel = (Button) findViewById(R.id.cancel_button);
fast = (ImageButton) findViewById(R.id.fast);
videoView = (VideoView) findViewById(R.id.layout_movie_wrapper);
// creating the progress dialog
progressDialog = new ProgressDialog(MainActivity.this);
progressDialog.setMessage("Please wait..");
progressDialog.setCancelable(false);
progressDialog.setCanceledOnTouchOutside(false);
// set up the onClickListeners
cancel.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// create an intent to retrieve the video
// file from the device storage
Intent intent = new Intent(
Intent.ACTION_PICK,
android.provider.MediaStore.Video.Media.EXTERNAL_CONTENT_URI);
intent.setType("video/*");
startActivityForResult(intent, 123);
}
});
slow.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// check if the user has selected any video or not
// In case a user hasn't selected any video and press the button,
// we will show an warning, stating "Please upload the video"
if (video_url != null) {
// a try-catch block to handle all necessary exceptions
// like File not found, IOException
try {
slowmotion(rangeSeekBar.getSelectedMinValue().intValue() * 1000, rangeSeekBar.getSelectedMaxValue().intValue() * 1000);
} catch (Exception e) {
Toast.makeText(MainActivity.this, e.toString(), Toast.LENGTH_SHORT).show();
e.printStackTrace();
}
} else
Toast.makeText(MainActivity.this, "Please upload video", Toast.LENGTH_SHORT).show();
}
});
fast.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (video_url != null) {
try {
fastforward(rangeSeekBar.getSelectedMinValue().intValue() * 1000, rangeSeekBar.getSelectedMaxValue().intValue() * 1000);
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(MainActivity.this, e.toString(), Toast.LENGTH_SHORT).show();
}
} else
Toast.makeText(MainActivity.this, "Please upload video", Toast.LENGTH_SHORT).show();
}
});
reverse.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (video_url != null) {
try {
reverse(rangeSeekBar.getSelectedMinValue().intValue() * 1000, rangeSeekBar.getSelectedMaxValue().intValue() * 1000);
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(MainActivity.this, e.toString(), Toast.LENGTH_SHORT).show();
}
} else
Toast.makeText(MainActivity.this, "Please upload video", Toast.LENGTH_SHORT).show();
}
});
// set up the VideoView.
// We will be using VideoView to view our video
videoView.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
@Override
public void onPrepared(MediaPlayer mp) {
// get the duration of the video
int duration = mp.getDuration() / 1000;
// initially set the left TextView to "00:00:00"
tvLeft.setText("00:00:00");
// initially set the right Text-View to the video length
// the getTime() method returns a formatted string in hh:mm:ss
tvRight.setText(getTime(mp.getDuration() / 1000));
// this will run he video in loop
// i.e. the video won't stop
// when it reaches its duration
mp.setLooping(true);
// set up the initial values of rangeSeekbar
rangeSeekBar.setRangeValues(0, duration);
rangeSeekBar.setSelectedMinValue(0);
rangeSeekBar.setSelectedMaxValue(duration);
rangeSeekBar.setEnabled(true);
rangeSeekBar.setOnRangeSeekBarChangeListener(new RangeSeekBar.OnRangeSeekBarChangeListener() {
@Override
public void onRangeSeekBarValuesChanged(RangeSeekBar bar, Object minValue, Object maxValue) {
// we seek through the video when the user
// drags and adjusts the seekbar
videoView.seekTo((int) minValue * 1000);
// changing the left and right TextView according to
// the minValue and maxValue
tvLeft.setText(getTime((int) bar.getSelectedMinValue()));
tvRight.setText(getTime((int) bar.getSelectedMaxValue()));
}
});
// this method changes the right TextView every 1 second
// as the video is being played
// It works same as a time counter we see in any Video Player
final Handler handler = new Handler();
handler.postDelayed(r = new Runnable() {
@Override
public void run() {
if (videoView.getCurrentPosition() >= rangeSeekBar.getSelectedMaxValue().intValue() * 1000)
videoView.seekTo(rangeSeekBar.getSelectedMinValue().intValue() * 1000);
handler.postDelayed(r, 1000);
}
}, 1000);
}
});
}
// Method for creating fast motion video
private void fastforward(int startMs, int endMs) throws Exception {
// startMs is the starting time, from where we have to apply the effect.
// endMs is the ending time, till where we have to apply effect.
// For example, we have a video of 5min and we only want to fast forward a part of video
// say, from 1:00 min to 2:00min, then our startMs will be 1000ms and endMs will be 2000ms.
// create a progress dialog and show it until this method executes.
progressDialog.show();
// creating a new file in storage
final String filePath;
String filePrefix = "fastforward";
String fileExtn = ".mp4";
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
// With introduction of scoped storage in Android Q the primitive method gives error
// So, it is recommended to use the below method to create a video file in storage.
ContentValues valuesvideos = new ContentValues();
valuesvideos.put(MediaStore.Video.Media.RELATIVE_PATH, "Movies/" + "Folder");
valuesvideos.put(MediaStore.Video.Media.TITLE, filePrefix + System.currentTimeMillis());
valuesvideos.put(MediaStore.Video.Media.DISPLAY_NAME, filePrefix + System.currentTimeMillis() + fileExtn);
valuesvideos.put(MediaStore.Video.Media.MIME_TYPE, "video/mp4");
valuesvideos.put(MediaStore.Video.Media.DATE_ADDED, System.currentTimeMillis() / 1000);
valuesvideos.put(MediaStore.Video.Media.DATE_TAKEN, System.currentTimeMillis());
Uri uri = getContentResolver().insert(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, valuesvideos);
// get the path of the video file created in the storage.
File file = FileUtils.getFileFromUri(this, uri);
filePath = file.getAbsolutePath();
} else {
// This else statement will work for devices with Android version lower than 10
// Here, "app_folder" is the path to your app's root directory in device storage
File dest = new File(new File(app_folder), filePrefix + fileExtn);
int fileNo = 0;
// check if the file name previously exist. Since we don't want
// to overwrite the video files
while (dest.exists()) {
fileNo++;
dest = new File(new File(app_folder), filePrefix + fileNo + fileExtn);
}
// Get the filePath once the file is successfully created.
filePath = dest.getAbsolutePath();
}
String exe;
// the "exe" string contains the command to process video.The details of command are discussed later in this post.
// "video_url" is the url of video which you want to edit. You can get this url from intent by selecting any video from gallery.
exe = "-y -i " + video_url + " -filter_complex [0:v]trim=0:" + startMs / 1000 + ",setpts=PTS-STARTPTS[v1];[0:v]trim=" + startMs / 1000 + ":" + endMs / 1000 + ",setpts=0.5*(PTS-STARTPTS)[v2];[0:v]trim=" + (endMs / 1000) + ",setpts=PTS-STARTPTS[v3];[0:a]atrim=0:" + (startMs / 1000) + ",asetpts=PTS-STARTPTS[a1];[0:a]atrim=" + (startMs / 1000) + ":" + (endMs / 1000) + ",asetpts=PTS-STARTPTS,atempo=2[a2];[0:a]atrim=" + (endMs / 1000) + ",asetpts=PTS-STARTPTS[a3];[v1][a1][v2][a2][v3][a3]concat=n=3:v=1:a=1 " + "-b:v 2097k -vcodec mpeg4 -crf 0 -preset superfast " + filePath;
// Here, we have used he Async task to execute our query because
// if we use the regular method the progress dialog
// won't be visible. This happens because the regular method and
// progress dialog uses the same thread to execute
// and as a result only one is a allowed to work at a time.
// By using we Async task we create a different thread which resolves the issue.
long executionId = FFmpeg.executeAsync(exe, new ExecuteCallback() {
@Override
public void apply(final long executionId, final int returnCode) {
if (returnCode == RETURN_CODE_SUCCESS) {
// after successful execution of ffmpeg command,
// again set up the video Uri in VideoView
videoView.setVideoURI(Uri.parse(filePath));
// change the video_url to filePath, so that we could
// do more manipulations in the
// resultant video. By this we can apply as many effects
// as we want in a single video.
// Actually there are multiple videos being formed in
// storage but while using app it
// feels like we are doing manipulations in only one video
video_url = filePath;
// play the result video in VideoView
videoView.start();
// remove the progress dialog
progressDialog.dismiss();
} else if (returnCode == RETURN_CODE_CANCEL) {
Log.i(Config.TAG, "Async command execution cancelled by user.");
} else {
Log.i(Config.TAG, String.format("Async command execution failed with returnCode=%d.", returnCode));
}
}
});
}
// Method for creating slow motion video for specific part of the video
// The below code is same as above only the command in string "exe" is changed
private void slowmotion(int startMs, int endMs) throws Exception {
progressDialog.show();
final String filePath;
String filePrefix = "slowmotion";
String fileExtn = ".mp4";
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
ContentValues valuesvideos = new ContentValues();
valuesvideos.put(MediaStore.Video.Media.RELATIVE_PATH, "Movies/" + "Folder");
valuesvideos.put(MediaStore.Video.Media.TITLE, filePrefix + System.currentTimeMillis());
valuesvideos.put(MediaStore.Video.Media.DISPLAY_NAME, filePrefix + System.currentTimeMillis() + fileExtn);
valuesvideos.put(MediaStore.Video.Media.MIME_TYPE, "video/mp4");
valuesvideos.put(MediaStore.Video.Media.DATE_ADDED, System.currentTimeMillis() / 1000);
valuesvideos.put(MediaStore.Video.Media.DATE_TAKEN, System.currentTimeMillis());
Uri uri = getContentResolver().insert(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, valuesvideos);
File file = FileUtils.getFileFromUri(this, uri);
filePath = file.getAbsolutePath();
} else {
File dest = new File(new File(app_folder), filePrefix + fileExtn);
int fileNo = 0;
while (dest.exists()) {
fileNo++;
dest = new File(new File(app_folder), filePrefix + fileNo + fileExtn);
}
filePath = dest.getAbsolutePath();
}
String exe;
exe = "-y -i " + video_url + " -filter_complex [0:v]trim=0:" + startMs / 1000 + ",setpts=PTS-STARTPTS[v1];[0:v]trim=" + startMs / 1000 + ":" + endMs / 1000 + ",setpts=2*(PTS-STARTPTS)[v2];[0:v]trim=" + (endMs / 1000) + ",setpts=PTS-STARTPTS[v3];[0:a]atrim=0:" + (startMs / 1000) + ",asetpts=PTS-STARTPTS[a1];[0:a]atrim=" + (startMs / 1000) + ":" + (endMs / 1000) + ",asetpts=PTS-STARTPTS,atempo=0.5[a2];[0:a]atrim=" + (endMs / 1000) + ",asetpts=PTS-STARTPTS[a3];[v1][a1][v2][a2][v3][a3]concat=n=3:v=1:a=1 " + "-b:v 2097k -vcodec mpeg4 -crf 0 -preset superfast " + filePath;
long executionId = FFmpeg.executeAsync(exe, new ExecuteCallback() {
@Override
public void apply(final long executionId, final int returnCode) {
if (returnCode == RETURN_CODE_SUCCESS) {
videoView.setVideoURI(Uri.parse(filePath));
video_url = filePath;
videoView.start();
progressDialog.dismiss();
} else if (returnCode == RETURN_CODE_CANCEL) {
Log.i(Config.TAG, "Async command execution cancelled by user.");
} else {
Log.i(Config.TAG, String.format("Async command execution failed with returnCode=%d.", returnCode));
}
}
});
}
// Method for reversing the video
// The below code is same as above only the command is changed.
private void reverse(int startMs, int endMs) throws Exception {
progressDialog.show();
String filePrefix = "reverse";
String fileExtn = ".mp4";
final String filePath;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
ContentValues valuesvideos = new ContentValues();
valuesvideos.put(MediaStore.Video.Media.RELATIVE_PATH, "Movies/" + "Folder");
valuesvideos.put(MediaStore.Video.Media.TITLE, filePrefix + System.currentTimeMillis());
valuesvideos.put(MediaStore.Video.Media.DISPLAY_NAME, filePrefix + System.currentTimeMillis() + fileExtn);
valuesvideos.put(MediaStore.Video.Media.MIME_TYPE, "video/mp4");
valuesvideos.put(MediaStore.Video.Media.DATE_ADDED, System.currentTimeMillis() / 1000);
valuesvideos.put(MediaStore.Video.Media.DATE_TAKEN, System.currentTimeMillis());
Uri uri = getContentResolver().insert(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, valuesvideos);
File file = FileUtils.getFileFromUri(this, uri);
filePath = file.getAbsolutePath();
} else {
filePrefix = "reverse";
fileExtn = ".mp4";
File dest = new File(new File(app_folder), filePrefix + fileExtn);
int fileNo = 0;
while (dest.exists()) {
fileNo++;
dest = new File(new File(app_folder), filePrefix + fileNo + fileExtn);
}
filePath = dest.getAbsolutePath();
}
long executionId = FFmpeg.executeAsync("-y -i " + video_url + " -filter_complex [0:v]trim=0:" + endMs / 1000 + ",setpts=PTS-STARTPTS[v1];[0:v]trim=" + startMs / 1000 + ":" + endMs / 1000 + ",reverse,setpts=PTS-STARTPTS[v2];[0:v]trim=" + (startMs / 1000) + ",setpts=PTS-STARTPTS[v3];[v1][v2][v3]concat=n=3:v=1 " + "-b:v 2097k -vcodec mpeg4 -crf 0 -preset superfast " + filePath, new ExecuteCallback() {
@Override
public void apply(final long executionId, final int returnCode) {
if (returnCode == RETURN_CODE_SUCCESS) {
videoView.setVideoURI(Uri.parse(filePath));
video_url = filePath;
videoView.start();
progressDialog.dismiss();
} else if (returnCode == RETURN_CODE_CANCEL) {
Log.i(Config.TAG, "Async command execution cancelled by user.");
} else {
Log.i(Config.TAG, String.format("Async command execution failed with returnCode=%d.", returnCode));
}
}
});
}
// Overriding the method onActivityResult()
// to get the video Uri form intent.
@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
if (requestCode == 123) {
if (data != null) {
// get the video Uri
Uri uri = data.getData();
try {
// get the file from the Uri using getFileFromUri() method present
// in FileUils.java
File video_file = FileUtils.getFileFromUri(this, uri);
// now set the video uri in the VideoView
videoView.setVideoURI(uri);
// after successful retrieval of the video and properly
// setting up the retried video uri in
// VideoView, Start the VideoView to play that video
videoView.start();
// get the absolute path of the video file. We will require
// this as an input argument in
// the ffmpeg command.
video_url = video_file.getAbsolutePath();
} catch (Exception e) {
Toast.makeText(this, "Error", Toast.LENGTH_SHORT).show();
e.printStackTrace();
}
}
}
}
}
// This method returns the seconds in hh:mm:ss time format
private String getTime(int seconds) {
int hr = seconds / 3600;
int rem = seconds % 3600;
int mn = rem / 60;
int sec = rem % 60;
return String.format("%02d", hr) + ":" + String.format("%02d", mn) + ":" + String.format("%02d", sec);
}
}
第 6 步:创建新的 Java 类 FileUtils.java
参考如何在 Android Studio 中创建类在 Android Studio 中创建新的 java 类。这是一个实用程序文件，有助于从 Uri 中检索文件。以下是FileUtils.java文件的代码。代码中添加了注释，以更详细地理解代码。
Java 语言(一种计算机语言，尤用于创建网站)
import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.provider.DocumentsContract;
import android.provider.MediaStore;
import java.io.File;
public class FileUtils {
// Get a file from a Uri.
// Framework Documents, as well as the _data field for the MediaStore and
// other file-based ContentProviders.
// @param context The context.
// @param uri The Uri to query
public static File getFileFromUri(final Context context, final Uri uri) throws Exception {
String path = null;
// DocumentProvider
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
if (DocumentsContract.isDocumentUri(context, uri)) { // TODO: 2015\. 11\. 17\. KITKAT
// ExternalStorageProvider
if (isExternalStorageDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
if ("primary".equalsIgnoreCase(type)) {
path = Environment.getExternalStorageDirectory() + "/" + split[1];
}
// TODO handle non-primary volumes
} else if (isDownloadsDocument(uri)) { // DownloadsProvider
final String id = DocumentsContract.getDocumentId(uri);
final Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
path = getDataColumn(context, contentUri, null, null);
} else if (isMediaDocument(uri)) { // MediaProvider
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
Uri contentUri = null;
if ("image".equals(type)) {
contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
} else if ("video".equals(type)) {
contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
} else if ("audio".equals(type)) {
contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
}
final String selection = "_id=?";
final String[] selectionArgs = new String[]{
split[1]
};
path = getDataColumn(context, contentUri, selection, selectionArgs);
} // MediaStore (and general)
} else if ("content".equalsIgnoreCase(uri.getScheme())) {
path = getDataColumn(context, uri, null, null);
}
// File
else if ("file".equalsIgnoreCase(uri.getScheme())) {
path = uri.getPath();
}
return new File(path);
} else {
Cursor cursor = context.getContentResolver().query(uri, null, null, null, null);
return new File(cursor.getString(cursor.getColumnIndex("_data")));
}
}
// Get the value of the data column for this Uri. This is useful for
// MediaStore Uris, and other file-based ContentProviders.
// @param context The context.
// @param uri The Uri to query.
// @param selection (Optional) Filter used in the query.
// @param selectionArgs (Optional) Selection arguments used in the query.
// @return The value of the _data column, which is typically a file path.
public static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) {
Cursor cursor = null;
final String column = MediaStore.Images.Media.DATA;
final String[] projection = {
column
};
try {
cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null);
if (cursor != null && cursor.moveToFirst()) {
final int column_index = cursor.getColumnIndexOrThrow(column);
return cursor.getString(column_index);
}
} finally {
if (cursor != null)
cursor.close();
}
return null;
}
// @param uri The Uri to check.
// @return Whether the Uri authority is ExternalStorageProvide
public static boolean isExternalStorageDocument(Uri uri) {
return "com.android.externalstorage.documents".equals(uri.getAuthority());
}
// @param uri The Uri to check.
// @return Whether the Uri authority is DownloadsProvider.
public static boolean isDownloadsDocument(Uri uri) {
return "com.android.providers.downloads.documents".equals(uri.getAuthority());
}
// @param uri The Uri to check.
// @return Whether the Uri authority is MediaProvider.
public static boolean isMediaDocument(Uri uri) {
return "com.android.providers.media.documents".equals(uri.getAuthority());
}
}
输出:
[https://media.geeksforgeeks.org/wp-content/uploads/20201202235833/output.mp4](https://media.geeksforgeeks.org/wp-content/uploads/20201202235833/output.mp4)Github 项目链接:https://github . com/raghavtilak/video editor
很少有可以使用的 FFmpeg 命令
- Tandem videos with different frame rates. Mkv format:
- -I input 1 . MP4-I input 2 . MP4-filter _ complex[0:v:0][0:a:0][1:v:0][1:a:0]concat = n = 2:v = 1:a = 1[out v][out a]-map[out v]-map[out a]输出。mkv
- [T0】 concat video without sound/audio:
- -y-I 输入. mp4-filter _ complex[0:0][0:v]微调=0:5,设定值= 0.5 *(PTS-STARTPTS)[v2]；[0:v]trim=5，设置 PTS = PTS-STARTPTS[v3]；[v1][v2][v3]concat = n = 3:v = 1:a = 0-b:v 2097k-vcodec mpeg 4-CRF 0-预设超高速 output.mp4
- 文字叠加:
- -y-I input . MP4-VF draw text = " font size = 30:font file =可爱。TTF:text = ' GFG ' ":x = w-tw-10:y = h-th-10-10(或)
- -I input . MP4-I input image . png-filter _ complex overlay =(main _ w-overlay _ w)/2:(main _ h-overlay _ h)/2:enable = '介于(t，0，7)' -c:副本 output.mp4
Add subtitles to video files
- -I input.mp4-I 字幕。SRT-地图 0-地图 1-副本-c:v libx 264-CRF 23-预设
- h –the height of the rectangle.
- x –the x coordinate of the rectangle.
- y -Y coordinate of the rectangle.
Add a poster image to the audio file
- -循环 1-I inputimage.jpg-I 输入音频 MP3-c:v lib x264-c:a AAC-严格实验-b:192k-最短 output.mp4
使用 FFmpeg 的优点
- 它也是高度便携的。
- 它对于将各种多媒体文件转码为单一的通用格式非常有价值。
- 您不需要像 Adobe Premiere Pro、Filmora 这样的大型第三方视频编辑器来完成小型编辑任务。
使用 FFmpeg 的缺点
- 初学者很难使用和实现。
- 需要一些时间来处理。我们不会在一两秒钟内得到结果。
- 官方文档相当混乱，而且对初学者不友好。
- APK 的规模变得非常大。仅 FFmpeg 库就将使用 30-70MB，这取决于您所包含的库。
FFmpeg 的替代方案
- Android 介质编解码器
- 升
- Gstreamer
- MP4Parser
- 面向移动设备的英特尔 INDE 媒体
备注:
1。如果你设置一个更高的值，比如说超快，那么视频处理将会很快，但是视频质量会受到影响。预设越低，视频质量越高。
2。您可以更改-crf 值来更改输出视频的质量。crf 值越低，视频质量越高。
3。如果在命令开始时使用-y，这意味着如果文件与输出文件名同名，则 FFmpeg 将覆盖现有文件。
4。在视频的情况下，要减慢视频设置-PTS 值大于 1。值越大，视频越慢，值越低，视频越快。但是在音频的情况下，情况正好相反，即值越大，音频越快，值越低，音频越慢。
5。atempo(音频)滤波器仅限于使用 0.5 到 2.0 之间的值(因此它可以将其减速到不低于原始速度的一半，并加速到不超过输入的两倍)
6。 FFmpeg 处理音频的时间太长。如果视频文件不包含音频，我们不需要命令 FFmpeg 来处理音频，因此这将减少工作量，并且我们将在更短的时间内快速获得处理后的视频。
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