I have made a simple app to populate recycler view with video or audio files. The recycler view get populated when installing app on any android device through android studio but I have a mobile device which is rooted. On this device, no audio or video file is detected nor recycler view get populated. Any solution for this problem please?
#Klox
private var videosPaths:ArrayList<File> = ArrayList()
private lateinit var pathsViewModel: PathsViewModel
private val videoFormat = arrayOf(".mp4", ".MP4", ".mkv", ".MKV")
// here I'm inserting video/audio files in database created
// room database files are not shown here
val pathsDao = PathsDatabase.getPathsInstance(applicationContext).pathsDao()
val pathsRepository = PathsRepository(pathsDao)
val pathsMainDatabase = PathsMainDatabase()
pathsViewModel = ViewModelProvider(this, PathsViewModelFactory(pathsRepository))[PathsViewModel::class.java]
// I have created database with name "video_paths"
if(!applicationContext.getDatabasePath("videos_paths").exists()) {
videosPaths = getVideoFolders()
// here videoPaths returns 0 video folders on rooted device and as app
// opens, it gives toast message: "shell granted superuser access"
videosPaths.forEach{ file ->
pathsViewModel.insertPath(Paths(0, file.absolutePath))
}
}
// my custom code for extracting video/audio files in device w/o using cursor library
//getting video folders
fun getVideoFolders() : ArrayList<File> {
searchVideoFiles(Environment.getExternalStorageDirectory())
return videoFolders
}
// a recursive function to scan video files in device all folders
private fun searchVideoFiles(file: File) {
val dir = file.listFiles() ?: return
for (f in dir) {
if (f.isDirectory) {
searchVideoFiles(f)
if (isVideoFolder(f)) videoFolders.add(f)
}
}
}
// return true if at least one video file is found
private fun isVideoFolder(file: File?): Boolean {
assert(file != null)
assert(file!!.isDirectory)
val dir = file.listFiles() ?: return false
for (f in dir) {
val path = f.absolutePath
for(v in videoFormat) {
if(path.endsWith(v)) return true
}
}
return false
}
I have a lot of pictures on a path , and i move picture to this path , loading pictures and displaying them on recyclerView take a lot of time , and i am using a fragment , when i change fragment and back to the one that display pictures , it take again a lot of time to load pictures .
any suggestion to load pictures fast ?
suspend fun getImages() = try {
val path = Environment.getExternalStorageDirectory()
.toString() + "Here folder path "
val directory = File(path)
val files = directory.listFiles()
if (files.isEmpty()) {
//
} else {
}
for (i in files.indices) {
println( files[i].name)
val myBitmap = BitmapFactory.decodeFile(files[i].getAbsolutePath())
var path = files[i].getAbsolutePath()
var fileName = files[i].name
var picture = Picture(myBitmap, path, fileName)
if (picture != null) {
listPictures.add(picture)
}
}
withContext(Dispatchers.Main){
myAdapter.notifyDataSetChanged()
}
} catch (e: Exception) {
}
```
Background
I want to be able to parse APK files from various sources, or various kinds. I want to get only very specific, basic information about them:
package-name
version-code
version-name
label (app name)
icon
minSdkVersion
whether it's a split APK or not (available when parsing the manifest)
The Android framework has a single function to parse APK files (PackageManager.getPackageArchiveInfo), but it has 2 disadvantages:
It requires a file-path. This isn't always available, as you might have a Uri to deal with, or you have the APK file being inside some ZIP file.
It can't handle split APK files. Only the base one of them. If you try it on split APK files, you just get null.
Because of this, I've tried to find a reliable, Java&Kotlin solution that can handle them easily.
The problem
Each solution I've found has its own disadvatanges. Some libraries I couldn't even find how to use, and some don't have any way to parse APK files without having a real file path. Some of them just create new files instead of returning you objects in Java/Kotlin. Some are even in other programming languages, making me wonder if it's possible to use them.
So far, the only one that I've found as good enough, is "hsiafan" apk-parser, which needs only 2 files within the APK: manifest and resources files. It has some issues, but usually it can get you the information I've mentioned.
Thing is, as I wrote, it's not always working, so I want to return to the basics, at least when I notice it fails to parse, at least for the case that it's a normal APK of base of split-APK files. Some cases it couldn't handle well are:
Sometimes the app name couldn't be fetched correctly (here).
Some resources are somehow hidden in some apps (here). Even tools such as Jadx fail to show them, but others can.
Adaptive icon is hard to parse, including drawable XML files. I succeed parsing VectorDrawable though (here), but it's quite a workaround.
And a few others.
What I've tried
So, I wanted to try out the Android framework again, but this time with a new idea: instead of handling the entire original APK, I could extract only what it really needs, based on the current observation of it.
For example, if I know the resources I need to handle, I can copy only them (and some key files that are needed) into a new APK, and ditch the rest. This could reduce the need to copy/download huge amount of data just to parse the APK and get information about it. If the APK file is 100MB, for example, there is no need to get it all when all we need is just a tiny portion of it.
As a start, I wanted to see how I can create a new APK that can be parsed, so for now I copied all of the entries of the original APK (currently of the current app) into a new file, and chose to parse it:
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
if (savedInstanceState != null)
return
thread {
val originalApplicationInfo = packageManager.getApplicationInfo(packageName, 0)
val filePath = originalApplicationInfo.publicSourceDir
val outputFile = File(cacheDir, "test.apk")
outputFile.parentFile!!.mkdirs()
outputFile.delete()
ZipFile(filePath).use { zipFile ->
ZipOutputStream(FileOutputStream(outputFile)).use { zipOutputStream ->
for (entry in zipFile.entries()) {
val name = entry.name
zipOutputStream.putNextEntry(ZipEntry(name))
zipFile.getInputStream(entry).use { it.copyTo(zipOutputStream.buffered()) }
zipOutputStream.closeEntry()
}
}
}
val originalLabel = originalApplicationInfo.loadLabel(packageManager)
val originalIcon: Drawable? = originalApplicationInfo.loadIcon(packageManager)
Log.d("AppLog", "originalPackageInfo: label:$originalLabel appIcon:${originalIcon?.javaClass?.simpleName}")
//
val packageArchiveInfo = packageManager.getPackageArchiveInfo(outputFile.absolutePath, 0)
val label = packageArchiveInfo?.applicationInfo?.loadLabel(packageManager)?.toString()
val appIcon = packageArchiveInfo?.applicationInfo?.loadIcon(packageManager)
Log.d("AppLog", "packageArchiveInfo!=null?${packageArchiveInfo != null} label:$label appIcon:${appIcon?.javaClass?.simpleName}")
}
}
}
The file indeed gets generated, but for some reason the Android framework failed to parse it, as packageArchiveInfo is null.
The questions
How come the sample I've made doesn't work? How come the new APK can't be parsed?
What is the minimal set of files the getPackageArchiveInfo function requires to be able to parse the APK, just for the information I've mentioned above?
If this kind of solution doesn't work, is there perhaps a library that could handle APK files of all kinds with all the information I've mentioned, no matter the source (including Uri and within zip files)?
Edit: as suggested, I could copy just those of folder "AndroidManifest.xml", "resources.arsc", "res" , but it seems it can still not always work well, as the icons don't always get to be the same:
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
if (savedInstanceState != null)
return
thread {
val installedApplications = packageManager.getInstalledPackages(0)
Log.d("AppLog", "checking ${installedApplications.size} apps")
for (originalPackageInfo in installedApplications) {
val originalApplicationInfo = originalPackageInfo.applicationInfo
val filePath = originalApplicationInfo.publicSourceDir
val outputFile = File(cacheDir, "test.apk")
outputFile.parentFile!!.mkdirs()
outputFile.delete()
val toExtract = setOf<String>("AndroidManifest.xml", "resources.arsc", "res")
ZipFile(filePath).use { zipFile ->
ZipOutputStream(FileOutputStream(outputFile)).use { zipOutputStream ->
for (entry in zipFile.entries()) {
val name = entry.name
if (toExtract.contains(name.split("/")[0])) {
zipOutputStream.putNextEntry(ZipEntry(name))
zipFile.getInputStream(entry).use { inStream ->
zipOutputStream.buffered().apply {
inStream.copyTo(this)
}.flush()
}
}
}
}
}
val packageName = originalApplicationInfo.packageName
val originalLabel = originalApplicationInfo.loadLabel(packageManager)
val originalIcon: Drawable? = originalApplicationInfo.loadIcon(packageManager)
val originalIconBitmap = originalIcon?.toBitmap()
//
val packageArchiveInfo = packageManager.getPackageArchiveInfo(outputFile.absolutePath, 0)
if (packageArchiveInfo == null) {
Log.e("AppLog", "$packageName could not parse generated APK")
continue
}
val label = packageArchiveInfo.applicationInfo.loadLabel(packageManager).toString()
val appIcon = packageArchiveInfo?.applicationInfo?.loadIcon(packageManager)
val appIconBitmap = appIcon?.toBitmap()
when {
label != originalLabel ->
Log.e("AppLog", "$packageName got wrong label $label vs $originalLabel")
packageArchiveInfo.versionName != originalPackageInfo.versionName ->
Log.e("AppLog", "$packageName got wrong versionName ${packageArchiveInfo.versionName} vs ${originalPackageInfo.versionName}")
packageArchiveInfo.versionCode != originalPackageInfo.versionCode ->
Log.e("AppLog", "$packageName got wrong versionCode ${packageArchiveInfo.versionCode} vs ${originalPackageInfo.versionCode}")
Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && packageArchiveInfo.applicationInfo.minSdkVersion != originalApplicationInfo.minSdkVersion ->
Log.e("AppLog", "$packageName got wrong minSdkVersion ${packageArchiveInfo.applicationInfo.minSdkVersion} vs ${originalApplicationInfo.minSdkVersion}")
appIcon?.javaClass?.name != originalIcon?.javaClass?.name ->
Log.e("AppLog", "$packageName got different app icon type: ${appIcon?.javaClass?.simpleName} vs ${originalIcon?.javaClass?.simpleName}")
originalIconBitmap != null && appIconBitmap != null && (originalIconBitmap.width != appIconBitmap.width || originalIconBitmap.height != appIconBitmap.height) ->
Log.e("AppLog", "$packageName got wrong app icons sizes:${appIconBitmap.width}x${appIconBitmap.height} vs ${originalIconBitmap.width}x${originalIconBitmap.height}")
originalIconBitmap != null && appIconBitmap != null && !areBitmapsSame(originalIconBitmap, appIconBitmap) ->
Log.e("AppLog", "$packageName got wrong app icons content ")
(originalIconBitmap == null && appIconBitmap != null) || (originalIconBitmap != null && appIconBitmap == null) ->
Log.e("AppLog", "$packageName null vs non-null app icon: ${appIconBitmap != null} vs ${originalIconBitmap != null}")
}
}
Log.d("AppLog", "done")
}
}
fun areBitmapsSame(bitmap: Bitmap, bitmap2: Bitmap): Boolean {
if (bitmap.width != bitmap2.width || bitmap.height != bitmap2.height)
return false
for (x in 0 until bitmap.width)
for (y in 0 until bitmap.height)
if (bitmap.getPixel(x, y) != bitmap2.getPixel(x, y))
return false
return true
}
}
I think that since app icons are very complex and depend on various resources (which might even be hidden in weird ways), there is no other choice than to actually have the file on the file system.
EDIT: about getting the app icons, I actually didn't use it well for the APK file. I used something a bit different on my own app, which seems to work well here too, except for some cases that the icon is a bit different (shape/color might be different for example), probably due to different configurations. But at least it won't return you the default app icon of Android when the app clearly has a non-default app icon.
Sadly though, it didn't always get good app icon when creating the minimized APKs (sometimes returned me ColorStateListDrawable or ColorDrawable, for example), probably because sometimes the original APK has hidden resources in non-conventional paths. So this is how you can get the app icon, assuming you have the whole APK:
Before getting it, use:
packageArchiveInfo.applicationInfo.publicSourceDir = targetFilePath
packageArchiveInfo.applicationInfo.sourceDir = targetFilePath
And then call this function:
fun getAppIcon(context: Context, applicationInfo: ApplicationInfo): Drawable? {
val packageManager = context.packageManager
try {
val iconResId = applicationInfo.icon
if (iconResId != 0) {
val resources: Resources = packageManager.getResourcesForApplication(applicationInfo)
val density = context.resources.displayMetrics.densityDpi
var result = ResourcesCompat.getDrawableForDensity(resources, iconResId, density, null)
if (result != null)
return result
}
} catch (e: Exception) {
// e.printStackTrace()
}
try {
val applicationIcon = packageManager.getApplicationIcon(applicationInfo)
// Log.d("AppLog", "getApplicationIcon type:${applicationIcon.javaClass.simpleName}")
return applicationIcon
} catch (ignored: Exception) {
}
return null
}
To convert to Bitmap, you can use:
val appIconBitmap = try {
appIcon?.toBitmap(appIconSize, appIconSize)
} catch (e: Exception) {
e.printStackTrace()
null
}
And to get the app icon size, you can use:
fun getAppIconSize(context: Context): Int {
val activityManager = context.getSystemService<ActivityManager>()
val appIconSize = try {
activityManager.launcherLargeIconSize
} catch (e: Exception) {
TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 48f, context.resources.displayMetrics).toInt()
}
return appIconSize
}
Change the copy code from
zipFile.getInputStream(entry).use { it.copyTo(zipOutputStream.buffered()) }
to
zipFile.getInputStream(entry).use {
val bufStream = zipOutputStream.buffered()
it.copyTo(bufStream)
bufStream.flush()
}
or something similar to make sure that all the data gets written out.
I thought that the APK was failing certificate verification, but that is not the case. The foregoing will get you the label and the icon.
With the original code I was seeing the following error
chunk size is bigger than given data
Failed to load 'resources.arsc' in APK '/data/user/0/com
which indicates to me that something went awry with the output. With the aforementioned change, I see the following:
originalPackageInfo: label:APK Copy and Read appIcon:AdaptiveIconDrawable
packageArchiveInfo!=null?true label:APK Copy and Read appIcon:AdaptiveIconDrawable
If I open the created APK from the Device Explorer in Android Studio, it parses out nicely.
As for the minimum, I think, for your purposes, you will need the manifest, the resource.arsc file and the res directory. Here is how to get a reduced APK that will parse with just these elements:
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
if (savedInstanceState != null)
return
thread {
val originalApplicationInfo = packageManager.getApplicationInfo(packageName, 0)
val filePath = originalApplicationInfo.publicSourceDir
val outputFile = File(cacheDir, "test.apk")
outputFile.parentFile!!.mkdirs()
outputFile.delete()
val toExtract = setOf<String>("AndroidManifest.xml", "resources.arsc","res")
ZipFile(filePath).use { zipFile ->
ZipOutputStream(FileOutputStream(outputFile)).use { zipOutputStream ->
for (entry in zipFile.entries()) {
val name = entry.name
if (toExtract.contains(name.split("/")[0])) {
zipOutputStream.putNextEntry(ZipEntry(name))
zipFile.getInputStream(entry).use { inStream ->
zipOutputStream.buffered().apply {
inStream.copyTo(this)
}.flush()
}
}
}
}
}
val originalLabel = originalApplicationInfo.loadLabel(packageManager)
val originalIcon: Drawable? = originalApplicationInfo.loadIcon(packageManager)
Log.d(
"AppLog",
"originalPackageInfo: label:$originalLabel appIcon:${originalIcon?.javaClass?.simpleName}"
)
//
val packageArchiveInfo =
packageManager.getPackageArchiveInfo(outputFile.absolutePath, 0)
val label = packageArchiveInfo?.applicationInfo?.loadLabel(packageManager)?.toString()
val appIcon = packageArchiveInfo?.applicationInfo?.loadIcon(packageManager)
Log.d(
"AppLog",
"packageArchiveInfo!=null?${packageArchiveInfo != null} label:$label appIcon:${appIcon?.javaClass?.simpleName}"
)
}
}
}
I have a ViewModel. Inside it, I have a function which fetches some images from the phones internal storage.
Before the fetching is complete it is exposing livedata in mainactivity. How to make coroutines to wait for the task to complete and expose the live data.
// This is my ViewModel
private val _image = MutableLiveData<ArrayList<File>>()
val images: LiveData<ArrayList<File>> get() = _image
fun fetchImage(){
val file = Path.imageDirectory // returns a directory where images are stored
val files = arrayListOf<File>()
viewModelScope.launch {
withContext(Dispatchers.IO) {
if (file.exists()) {
file.walk().forEach {
if (it.isFile && it.path.endsWith("jpeg")) {
files.add(it)
}
}
}
files.sortByDescending { it.lastModified() } // sort the files to get newest
// ones at top of the list
}
}
_image.postValue(files)
}
Is there any other approach to make this code much faster by any other methods?
Do it like this:
fun fetchImage() = viewModelScope.launch {
val file = Path.imageDirectory // returns a directory where images are stored
val files = arrayListOf<File>()
withContext(Dispatchers.IO) {
if (file.exists()) {
file.walk().forEach {
if (it.isFile && it.path.endsWith("jpeg")) {
files.add(it)
}
}
}
files.sortByDescending { it.lastModified() } // sort the files to get newest
// ones at top of the list
}
_image.value = files
}
Background
Android supports various audio files encoding and decoding.
I record audio into an audio file using android.media.MediaRecorder class, but I also wish to show information about the files I've recorded (not standard data, but still just text, maybe even configurable by user), and I think it's best to store this information within the files.
examples of possible data to store: when it was recorded, where it was recorded, notes by the user...
The problem
The MediaRecorder class doesn't have any function that I can find, to add or even read metadata of the recorded audio file.
I also can't find a similar class that does it.
What I've tried
I tried searching how to do it for specific files types, and also tried to find a library that does it.
I haven't find even a clue about this information.
The only thing I've found for MediaRecorder class, is a function called "setLocation" , which is used to indicate where the recording has started (geographically), and looking at its code, I can see it sets parameters:
public void setLocation(float latitude, float longitude) {
int latitudex10000 = (int) (latitude * 10000 + 0.5);
int longitudex10000 = (int) (longitude * 10000 + 0.5);
if (latitudex10000 > 900000 || latitudex10000 < -900000) {
String msg = "Latitude: " + latitude + " out of range.";
throw new IllegalArgumentException(msg);
}
if (longitudex10000 > 1800000 || longitudex10000 < -1800000) {
String msg = "Longitude: " + longitude + " out of range";
throw new IllegalArgumentException(msg);
}
setParameter("param-geotag-latitude=" + latitudex10000);
setParameter("param-geotag-longitude=" + longitudex10000);
}
But setParameter is private, and I'm not sure if it's ok to put anything I want into it, even if I had a way to access it (reflection, for example) :
private native void setParameter(String nameValuePair);
I also don't get, given an audio/video file, how to get/modify this kind of information. It's not available for SimpleExoPlayer, for example.
The questions
How can I read,write, and modify metadata inside supported audio files of Android?
Are there any limitations/restrictions for those actions?
Which file formats are available for this?
Is it possible to add the metadata while I record the audio?
Is it possible perhaps via MediaStore ? But then how do I do those operations? And which files are supported? And does the metadata stay within the file?
EDIT: ok I've looked at the solution offered to me (here, repo here, based on here) , and it seems to work well. However, it doesn't work on latest version of the library that it uses (org.mp4parser.isoparser:1.9.37 dependency of mp4parser) , so I leave this question to be answered : Why doesn't it work on latest version of this library?
Code:
object MediaMetaDataUtil {
interface PrepareBoxListener {
fun prepareBox(existingBox: Box?): Box
}
#WorkerThread
fun <T : Box> readMetadata(mediaFilePath: String, boxType: String): T? {
return try {
val isoFile = IsoFile(FileDataSourceImpl(FileInputStream(mediaFilePath).channel))
val nam = Path.getPath<T>(isoFile, "/moov[0]/udta[0]/meta[0]/ilst/$boxType")
isoFile.close()
nam
} catch (e: Exception) {
null
}
}
/**
* #param boxType the type of the box. Example is "©nam" (AppleNameBox.TYPE). More available here: https://kdenlive.org/en/project/adding-meta-data-to-mp4-video/
* #param listener used to prepare the existing or new box
* */
#WorkerThread
#Throws(IOException::class)
fun writeMetadata(mediaFilePath: String, boxType: String, listener: PrepareBoxListener) {
val videoFile = File(mediaFilePath)
if (!videoFile.exists()) {
throw FileNotFoundException("File $mediaFilePath not exists")
}
if (!videoFile.canWrite()) {
throw IllegalStateException("No write permissions to file $mediaFilePath")
}
val isoFile = IsoFile(mediaFilePath)
val moov = isoFile.getBoxes<MovieBox>(MovieBox::class.java)[0]
var freeBox = findFreeBox(moov)
val correctOffset = needsOffsetCorrection(isoFile)
val sizeBefore = moov.size
var offset: Long = 0
for (box in isoFile.boxes) {
if ("moov" == box.type) {
break
}
offset += box.size
}
// Create structure or just navigate to Apple List Box.
var userDataBox: UserDataBox? = Path.getPath(moov, "udta")
if (userDataBox == null) {
userDataBox = UserDataBox()
moov.addBox(userDataBox)
}
var metaBox: MetaBox? = Path.getPath(userDataBox, "meta")
if (metaBox == null) {
metaBox = MetaBox()
val hdlr = HandlerBox()
hdlr.handlerType = "mdir"
metaBox.addBox(hdlr)
userDataBox.addBox(metaBox)
}
var ilst: AppleItemListBox? = Path.getPath(metaBox, "ilst")
if (ilst == null) {
ilst = AppleItemListBox()
metaBox.addBox(ilst)
}
if (freeBox == null) {
freeBox = FreeBox(128 * 1024)
metaBox.addBox(freeBox)
}
// Got Apple List Box
var nam: Box? = Path.getPath(ilst, boxType)
nam = listener.prepareBox(nam)
ilst.addBox(nam)
var sizeAfter = moov.size
var diff = sizeAfter - sizeBefore
// This is the difference of before/after
// can we compensate by resizing a Free Box we have found?
if (freeBox.data.limit() > diff) {
// either shrink or grow!
freeBox.data = ByteBuffer.allocate((freeBox.data.limit() - diff).toInt())
sizeAfter = moov.size
diff = sizeAfter - sizeBefore
}
if (correctOffset && diff != 0L) {
correctChunkOffsets(moov, diff)
}
val baos = BetterByteArrayOutputStream()
moov.getBox(Channels.newChannel(baos))
isoFile.close()
val fc: FileChannel = if (diff != 0L) {
// this is not good: We have to insert bytes in the middle of the file
// and this costs time as it requires re-writing most of the file's data
splitFileAndInsert(videoFile, offset, sizeAfter - sizeBefore)
} else {
// simple overwrite of something with the file
RandomAccessFile(videoFile, "rw").channel
}
fc.position(offset)
fc.write(ByteBuffer.wrap(baos.buffer, 0, baos.size()))
fc.close()
}
#WorkerThread
#Throws(IOException::class)
fun splitFileAndInsert(f: File, pos: Long, length: Long): FileChannel {
val read = RandomAccessFile(f, "r").channel
val tmp = File.createTempFile("ChangeMetaData", "splitFileAndInsert")
val tmpWrite = RandomAccessFile(tmp, "rw").channel
read.position(pos)
tmpWrite.transferFrom(read, 0, read.size() - pos)
read.close()
val write = RandomAccessFile(f, "rw").channel
write.position(pos + length)
tmpWrite.position(0)
var transferred: Long = 0
while (true) {
transferred += tmpWrite.transferTo(0, tmpWrite.size() - transferred, write)
if (transferred == tmpWrite.size())
break
//System.out.println(transferred);
}
//System.out.println(transferred);
tmpWrite.close()
tmp.delete()
return write
}
#WorkerThread
private fun needsOffsetCorrection(isoFile: IsoFile): Boolean {
if (Path.getPath<Box>(isoFile, "moov[0]/mvex[0]") != null) {
// Fragmented files don't need a correction
return false
} else {
// no correction needed if mdat is before moov as insert into moov want change the offsets of mdat
for (box in isoFile.boxes) {
if ("moov" == box.type) {
return true
}
if ("mdat" == box.type) {
return false
}
}
throw RuntimeException("I need moov or mdat. Otherwise all this doesn't make sense")
}
}
#WorkerThread
private fun findFreeBox(c: Container): FreeBox? {
for (box in c.boxes) {
// System.err.println(box.type)
if (box is FreeBox)
return box
if (box is Container) {
val freeBox = findFreeBox(box as Container)
if (freeBox != null) {
return freeBox
}
}
}
return null
}
#WorkerThread
private fun correctChunkOffsets(movieBox: MovieBox, correction: Long) {
var chunkOffsetBoxes = Path.getPaths<ChunkOffsetBox>(movieBox as Box, "trak/mdia[0]/minf[0]/stbl[0]/stco[0]")
if (chunkOffsetBoxes.isEmpty())
chunkOffsetBoxes = Path.getPaths(movieBox as Box, "trak/mdia[0]/minf[0]/stbl[0]/st64[0]")
for (chunkOffsetBox in chunkOffsetBoxes) {
val cOffsets = chunkOffsetBox.chunkOffsets
for (i in cOffsets.indices)
cOffsets[i] += correction
}
}
private class BetterByteArrayOutputStream : ByteArrayOutputStream() {
val buffer: ByteArray
get() = buf
}
}
Sample usage for writing&reading title:
object MediaMetaData {
#JvmStatic
#Throws(IOException::class)
fun writeTitle(mediaFilePath: String, title: String) {
MediaMetaDataUtil.writeMetadata(mediaFilePath, AppleNameBox.TYPE, object : MediaMetaDataUtil.PrepareBoxListener {
override fun prepareBox(existingBox: Box?): Box {
var nam: AppleNameBox? = existingBox as AppleNameBox?
if (nam == null)
nam = AppleNameBox()
nam.dataCountry = 0
nam.dataLanguage = 0
nam.value = title
return nam
}
})
}
#JvmStatic
fun readTitle(mediaFilePath: String): String? {
return MediaMetaDataUtil.readMetadata<AppleNameBox>(mediaFilePath, AppleNameBox.TYPE)?.value
}
}
It seems there's no way to do it uniformly for all supported audio formats in Android. There are some limited options for particular formats though, so I suggest to stick with one format.
MP3 is the most popular one and there should be a lot of options like this one.
If you don't want to deal with encoding/decoding, there are some options for a WAV format.
There's also a way to add a metadata track to a MP4 container using MediaMuxer (you can have an audio-only MP4 file) or like this.
Regarding MediaStore: here's an example (at the end of page 318) on how to add metadata to it just after using MediaRecorder. Though as far as I know the data won't be recorded inside the file.
Update
I compiled an example app using this MP4 parser library and MediaRecorder example from SDK docs. It records an audio, puts it in MP4 container and adds String metadata like this:
MetaDataInsert cmd = new MetaDataInsert();
cmd.writeRandomMetadata(fileName, "lore ipsum tralalala");
Then on the next app launch this metadata is read and displayed:
MetaDataRead cmd = new MetaDataRead();
String text = cmd.read(fileName);
tv.setText(text);
Update #2
Regarding m4a file extension: m4a is just an alias for an mp4 file with AAC audio and has the same file format. So you can use my above example app and just change the file name from audiorecordtest.mp4 to audiorecordtest.m4a and change audio encoder from MediaRecorder.AudioEncoder.AMR_NB to MediaRecorder.AudioEncoder.AAC.