Android 11 (R) file path access

问题

According to the docs file path access is granted in Android R:

Starting in Android 11, apps that have the READ_EXTERNAL_STORAGE permission can read a device's media files using direct file paths and native libraries. This new capability allows your app to work more smoothly with third-party media libraries.

The problem is that I can't get the file path from MediaStore, so how are we supposed to read a file path that we can't access/retrieve? Is there a way, I'm not aware of, that we can get the file path from MediaStore?

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Furthermore, the docs say the following:

All Files Access

Some apps have a core use case that requires broad file access, such as file management or backup & restore operations. They can get All Files Access by doing the following:

1. Declare the MANAGE_EXTERNAL_STORAGE permission.
2. Direct users to a system settings page where they can enable the Allow access to manage all files option for your app.

This permission grants the following:

• Read access and write access to all files within shared storage.
• Access to the contents of the MediaStore.Files table.

But I do not need all file access, I only want the user to select a video from MediaStore and pass the file path to FFmpeg(it requires a file path). I know that I can no longer use the _data column to retrieve a file path.

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Please note:

• I know a Uri is returned from MediaStore and does not point to a file.
• I know that I can copy the file to my application directory and pass that to FFmpeg, but I could do that before Android R.
• I can not pass FileDescriptor to FFmpeg and I can not use /proc/self/fd/ (I get /proc/7828/fd/70: Permission denied when selecting a file from the SD Card), have a look at this issue.

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So what am I supposed to do, am I missing something? What was meant with can read a device's media files using direct file paths and native libraries?

来源：https://stackoverflow.com/questions/60360368/android-11-r-file-path-access