在的Nexus 7和LG擎天柱LTE应用的不同行为 [英] different behaviour of app in Nexus 7 and LG Optimus LTE

问题描述

我的应用程序在/ SD卡的文件夹结果写入一个名为 filename.dat
我可以在平板电脑中删除亚行这个文件，使用命令
亚行外壳RM /sdcard/filename.dat 结果
我用这个平板电脑仅用于开发，没有别的，所以我安装了很少的应用程序，而这些也特定于事情，我发展的需要，如文件浏览器结果
我想，正在被应用于LG擎天柱LTE手机同样的事情，所以有很多安装其他应用程序，包括那些需要personl日常工作结果的
当我尝试相同的命令，结果
亚行外壳RM /sdcard/filename.dat 结果
在LG的手机，它拒绝这样做的结果
RM失败/sdcard/filename.dat，权限被拒绝结果
为什么表现这种方式？

My app writes a file called filename.dat in the /sdcard folder
I can delete this file from adb in the tablet, using the command adb shell rm /sdcard/filename.dat
I use this tablet only for development and nothing else, so I have very few apps installed on it, and those are also specific to things that I need to develop, such as file explorer
I tried the same thing in LG Optimus LTE phone that is actively being used, and so has lots of other apps installed, including those needed for personl daily work
When I try the same command,
adb shell rm /sdcard/filename.dat
in the LG phone, it refuses to do so
rm failed for /sdcard/filename.dat, Permission denied
Why is it behaving this way?

更重要的是，在我测试程序，它工作正常，所有的时间都在的Nexus 7，但是当我尝试在手机上运行它，它工作正常的第一次，但是当我这样做第二时间，在程序中的变量中的一个开始越来越NaN值（我已经跟踪它是由于一种无限/无限分裂发生在一条线路），然后每次我再次执行它，它显示了这些NaN值。该计划是太长排除有人不熟悉它，我猜，但它使用AudioTrack和AudioRecord类以声音输入，就可以执行一些FFT和DSP操作，然后回放。

More importantly, in the program that I am testing, it works fine all the time in the Nexus 7, but when I try to run it on the phone, it works fine the first time, but when I do so the second time, one of the variables in the program starts getting NaN values (I have tracked it down to be due to an Infinity/Infinity division taking place on one of the lines), then everytime I execute it again, it shows these NaN values. The program is too long to troubleshoot for someone unfamiliar with it I guess, but it uses AudioTrack and AudioRecord classes to take sound input, perform some FFT and DSP operations on it, then play it back.

我真正需要知道的是，它是什么，是平板电脑和手机之间的不同，这可能会导致这样的问题，有什么其他的事情，我可能需要考虑？

What I really need to know is, what is it that is different between tablet and phone, that might be causing a problem like this, and what are the other things I might need to consider?

我初始化AudioRecord和AudioTrack为

I initialize the AudioRecord and AudioTrack as

int min = AudioRecord.getMinBufferSize(16000, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT);
record = new AudioRecord(MediaRecorder.AudioSource.VOICE_COMMUNICATION, 16000, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT, min);
int maxJitter = AudioTrack.getMinBufferSize(SAMPLE_FREQUENCY, AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT);
track = new AudioTrack(AudioManager.MODE_IN_COMMUNICATION, 16000, AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT, maxJitter, AudioTrack.MODE_STREAM);  

我认为这可能是相关与这个特定的程序，因为使用比MODE_IN_COMMUNICATION，如MODE_VOICE_CALL以外的东西，看起来编译正常，但给出了类似的问题，即使是在的Nexus 7。

I think this might be relevant to this particular program, since using something other than MODE_IN_COMMUNICATION, such as MODE_VOICE_CALL, seems to compile fine but gives similar problems, even in the Nexus 7.

推荐答案

您可以尝试 System.getenv（EXTERNAL_STORAG​​E）来获取外部存储目录，而不是使用 / SD卡/ 。在我的经验，这是在大多数情况下是相同的。但是，这应该每次给你一个正确的输出目录。

You could try System.getenv("EXTERNAL_STORAGE") to get the external storage directory instead of using /sdcard/. In my experiences this was the same in most cases. But this should give you a correct output directory every time.

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