How to get audio file metadata from custom content provider?

Question

I have an app that serves as a content provider that stores .mp3 files.

F.e. content://.../player/audio.mp3

How can i get the metadata of these files?

When I stored the data in file:///.../player/audio.mp3 I used MediaMetadataRetriever() so the code looked like this:

    fun metadataDuration(uri: Uri): Long {
        val retriever = MediaMetadataRetriever()
        retriever.setDataSource(context, uri)
        return retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION)!!.toLong()
    }

But if I try to use uri as content://.../player/audio.mp3 I get errors:

W/System.err:     at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:188)
W/System.err:     at android.database.DatabaseUtils.readExceptionWithFileNotFoundExceptionFromParcel(DatabaseUtils.java:151)
W/System.err:     at android.content.ContentProviderProxy.openTypedAssetFile(ContentProviderNative.java:705)
W/System.err:     at android.content.ContentResolver.openTypedAssetFileDescriptor(ContentResolver.java:1687)
W/System.err:     at android.content.ContentResolver.openAssetFileDescriptor(ContentResolver.java:1503)
W/System.err:     at android.content.ContentResolver.openAssetFileDescriptor(ContentResolver.java:1420)
W/System.err:     at android.media.MediaMetadataRetriever.setDataSource(MediaMetadataRetriever.java:171)

"if I try to paste uri as content://.../player/audio.mp3 I get errors" -- if by "paste" you mean that you hard-coded that value, you will not hae permission to that content, most likely. — CommonsWare, Aug 12 '22 at 12:52
@CommonsWare, I have access to all content. I can read and write files using my content provider. — Bob, Aug 12 '22 at 12:56

score 0 · Accepted Answer · answered Aug 16 '22 at 19:56

In my case, I couldn't use MediaDataRetriever / FFmpegMediaMetadataRetriever with Content Provider URIs:

fun metadataDuration(uri: Uri): Long {
        val retriever = MediaMetadataRetriever()
        retriever.setDataSource(context, uri)
        return retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION)!!.toLong()
    }

so this code didn't work, as I said in the question.

The only thing I can do with each file from the Content Provider is to read the ByteArray of the file.

Solution:

I found a way to create file and get the File Descriptor , so I can use MediaDataRetriever / FFmpegMediaMetadataRetriever

I used: MemoryFile

val newMemoryFile = MemoryFile(memoryFileName, fileContent.size)
newMemoryFile.writeBytes(fileContent, 0, 0, fileContent.size)
val fd = getFileDescriptor(newMemoryFile)
val mmr = FFmpegMediaMetadataRetriever()
mmr.setDataSource(fd)
val duration = mmr.extractMetadata(FFmpegMediaMetadataRetriever.METADATA_KEY_DURATION).toLong()
mmr.release()
newMemoryFile.close()

To get File Descriptor I used this code: MemoryFileGetFileDescriptor

How to get audio file metadata from custom content provider?

1 Answers1