“可搜索"与MediaRecorder Android 6.0(API 23)一起使用的文件描述符 [英] "Seekable" file descriptor to use with MediaRecorder Android 6.0 (API 23)

问题描述

因此，我试图将Android用作网络摄像头.我的代码非常适合API< =22.我正在使用ParcelFileDescriptor的createPipe()方法创建用于读取和写入的管道.

So I am trying to use my Android as a webcam. My code is working perfectly for API <= 22. I am using ParcelFileDescriptor's createPipe() method to create pipe for reading and writing.

简而言之，我写给管道的内容如下:

In short, my writing to the pipe looks like following:

ParcelFileDescriptor[] parcelFileDescriptors = ParcelFileDescriptor.createPipe();

ParcelFileDescriptor mParcelWrite =new ParcelFileDescriptor(mParcelFileDescriptors[1]);

MediaRecorder mMediaRecorder = new MediaRecorder();
mMediaRecorder.setOutputFile(mParcelWrite.getFileDescriptor());
..
..// Other settings.
mMediaRecorder.start();

运行此命令时，出现以下异常

When I run this, I get the following exception,

E/MediaRecorder: start failed: -2147483648
W/System.err: java.lang.RuntimeException: start failed. W/System.err: at android.media.MediaRecorder.start(Native Method)
W/System.err: at com.ksy.recordlib.service.recoder.RecoderVideoSource.prepare(RecoderVideoSource.java:105)
W/System.err: at com.ksy.recordlib.service.recoder.RecoderVideoSource.run(RecoderVideoSource.java:173) 
W/System.err: at java.lang.Thread.run(Thread.java:818)

我知道，在API 23中，他们制作了

I got to know, that in API 23, they made a change which prevented MediaRecorder to work with File descriptors that are not seekable.

ParcelFileDescriptor似乎不是可搜索的.

我的问题是，如何使它易于寻找?有其他选择吗? 谢谢.

My question is, How can I make it seekable? Is there any alternative to it? Thanks.

推荐答案

我已经对此进行了一周的调查.您可以设置的输出格式中有一个隐藏格式，即

I have been investigating this for a week. There is a hidden format in the output formats you can set which is

mMediaRecorder.setOutputFormat(8);

从文档中

**@hide H.264/AAC data encapsulated in MPEG2/TS 

public static final int OUTPUT_FORMAT_MPEG2TS = 8; **

public static final int OUTPUT_FORMAT_MPEG2TS = 8;**

但是，它仍然不能在棉花糖或牛轧糖上使用.我使它适用于kit kat.让我知道是否有帮助.

However it does not still work on Marshmallow or Nougat. I made it work for kit kat. Let me know if this helps.

这篇关于“可搜索"与MediaRecorder Android 6.0(API 23)一起使用的文件描述符的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！