以编程方式裁剪MP3文件

Question

以编程方式裁剪MP3文件

3

嗨 <> 我需要在我的应用程序中修剪/切割/编辑音频文件，我尝试使用ffmpeg，但我不知道如何安装该库或如何使用它...所以，有人可以给我一个好的指南，如何在windows 7 64位中使用android ndk r10和ffmpeg 2.3？或者有其他建议如何切割mp3文件吗？

当我将ffmpeg库添加到我的项目中时，在控制台上出现以下错误：

    [2014-07-29 00:04:06 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:04:06 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:04:06 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:04:06 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:04:06 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:04:06 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:04:06 - RecordTheLast20Minutes] C:\Users\David\Workspace\RecordTheLast20Minutes\res\values\styles.xml:7: error: Error retrieving parent for item: No resource found that matches the given name 'Theme.AppCompat.Light'.
[2014-07-29 00:04:06 - RecordTheLast20Minutes] C:\Users\David\Workspace\RecordTheLast20Minutes\res\values-v14\styles.xml:8: error: Error retrieving parent for item: No resource found that matches the given name 'Theme.AppCompat.Light.DarkActionBar'.
[2014-07-29 00:04:06 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:04:06 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:04:06 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:04:06 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:04:06 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:04:06 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:04:06 - RecordTheLast20Minutes] C:\Users\David\Workspace\RecordTheLast20Minutes\res\values\styles.xml:7: error: Error retrieving parent for item: No resource found that matches the given name 'Theme.AppCompat.Light'.
[2014-07-29 00:04:06 - RecordTheLast20Minutes] C:\Users\David\Workspace\RecordTheLast20Minutes\res\values-v14\styles.xml:8: error: Error retrieving parent for item: No resource found that matches the given name 'Theme.AppCompat.Light.DarkActionBar'.
[2014-07-29 00:07:28 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:07:28 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:07:28 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:07:28 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:07:28 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:07:28 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:07:29 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:07:29 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:07:29 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:07:29 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:07:29 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:07:29 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:07:32 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:07:32 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:07:32 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:07:32 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:07:32 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:07:32 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:07:50 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:07:50 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:07:50 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:07:50 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:07:50 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:07:50 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:07:52 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:07:52 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:07:52 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:07:52 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:07:52 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:07:52 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:10:18 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:10:18 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:10:18 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:10:18 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:10:18 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:10:18 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:10:19 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:10:19 - RecordTheLast20Minutes] res\drawable-hdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:10:19 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:10:19 - RecordTheLast20Minutes] res\drawable-mdpi\ic_launcher.jpg:0: Originally defined here.
[2014-07-29 00:10:19 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.png:0: error: Resource entry ic_launcher is already defined.
[2014-07-29 00:10:19 - RecordTheLast20Minutes] res\drawable-xhdpi\ic_launcher.jpg:0: Originally defined here.

所有类似R.raw.music或R.menu.actionbarmenuR.layout.activity的内容现在都是错误：R无法解析为变量，而且这一行ffmpeg -t 30 -i inputfile.mp3 -acodec copy outputfile.mp3也是错误的：

Multiple markers at this line
    - Syntax error on token "copy", @ expected
    - Syntax error on token "inputfile", delete this 
     token
    - Syntax error on token(s), misplaced 
     construct(s)
    - Syntax error on token(s), misplaced 
     construct(s)
    - Syntax error on token "30", delete this token

感谢您的帮助：）

- DAVIDBALAS1

在 Stack Overflow 上，询问我们推荐或寻找工具、库或喜爱的外部资源的问题是不被允许的，因为它们往往会吸引带有个人观点的答案和垃圾信息。相反，请描述问题以及已经采取的解决方案。 - AStopher

@zyboxinternational 我还没有做任何事情，我不知道如何使用工具或库，所以我来这里了。 - DAVIDBALAS1

Stack Overflow 不是用来让人们寻求库的地方。 - AStopher

@zyboxinternational，你能看到我在Mick回答下面的评论吗？ - DAVIDBALAS1

当然需要。你需要准确地评论你遇到了什么错误，因为“我遇到了一个错误”并没有什么帮助。 - AStopher

1

@zyboxinternational 已编辑 :) - DAVIDBALAS1

1个回答

网页内容由stack overflow 提供, 点击上面的

可以查看英文原文，
原文链接

- Mick · Accepted Answer

有许多开源的Android ffmpeg项目，其中似乎最常用或讨论的是：

https://github.com/guardianproject/android-ffmpeg

这提供了在Android平台上使用ffmpeg的方法，同时相关项目提供了一个Java包装器（使用Runtime.getRuntime().exec方法，而不是我最初想到的JNI）来允许您从常规Java Android应用程序中使用它：

https://github.com/guardianproject/android-ffmpeg-java

上面的顶级项目包括构建说明和一些示例以测试安装。

以下是使用ffmpeg二进制文件的Java Wrapper项目方法声明的一些示例。您可以在下载的android-ffmpeg-java项目中的文件“android-ffmpeg-java/src/org/ffmpeg/android/FfmpegController.java”中查看完整代码：

public void extractAudio (Clip mdesc, String audioFormat, File audioOutPath, ShellCallback sc) throws IOException, InterruptedException 
    { ...

public void concatAndTrimFilesMPEG (ArrayList<Clip> videos,Clip out, boolean preConvert, ShellCallback sc) throws Exception
{ ...

public Clip convertToMPEG (Clip mediaIn, String outPath, ShellCallback sc) throws Exception
{ ...

如果您查看这些内容，应该能够看到如何添加一个完全符合您要求的方法。基本上，这些方法使用 Runtime.getRuntime().exec 函数调用 cmd 行 ffmpeg 并使用特定任务所需的参数。

从过去在 Android 上使用 Runtime.getRuntime().exec 的经验中需要注意以下几点：

早期版本的 Android 存在一个错误，即 Runtime.getRuntime().exec 有时会挂起: https://dev59.com/hmoy5IYBdhLWcg3wPLn0#11411709
需要谨慎使用 Runtime.getRuntime().exec - 可以查看此链接获取更多信息：http://www.javaworld.com/article/2071275/core-java/when-runtime-exec---won-t.html
据我所知，您需要在已 root 的设备上才能在 Android 上使用 Runtime.getRuntime().exec。自从我上次查看以来，这可能已经改变，但是如果这对您的应用程序很重要，则值得检查。