Sound Annotation Data Extraction

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/*
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 *   Copyright © 2020-2026 PSPDFKit GmbH. All rights reserved.
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 *
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 *   The PSPDFKit Sample applications are licensed with a modified BSD license.
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 *   Please see License for details. This notice may not be removed from this file.
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 */
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package com.pspdfkit.catalog.examples.kotlin
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import android.annotation.SuppressLint
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import android.content.Context
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import android.graphics.RectF
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import android.net.Uri
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import android.view.Menu
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import android.view.MenuItem
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import android.widget.Toast
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import androidx.activity.viewModels
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import androidx.annotation.UiThread
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import androidx.core.net.toUri
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import com.pspdfkit.annotations.SoundAnnotation
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import com.pspdfkit.annotations.sound.AudioExtractor
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import com.pspdfkit.annotations.sound.WavWriter
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import com.pspdfkit.catalog.R
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import com.pspdfkit.catalog.SdkExample
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import com.pspdfkit.catalog.tasks.ExtractAssetTask
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import com.pspdfkit.configuration.activity.PdfActivityConfiguration
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import com.pspdfkit.document.PdfDocument
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import com.pspdfkit.preferences.PSPDFKitPreferences
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import com.pspdfkit.ui.PdfActivity
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import com.pspdfkit.ui.PdfActivityIntentBuilder
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import com.pspdfkit.ui.special_mode.controller.AnnotationTool
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import kotlinx.coroutines.runBlocking
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import java.io.File
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import java.io.FileOutputStream
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import java.io.IOException
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/**
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 * An example on how to create a sound annotation programmatically and extract the audio data from it.
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 */
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class SoundAnnotationDataExtractionExample(context: Context) : SdkExample(context, R.string.soundAnnotationDataExtractionTitle, R.string.soundAnnotationDataExtractionDescription) {
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    override fun launchExample(context: Context, configuration: PdfActivityConfiguration.Builder) {
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        // Turn off saving, so we have the clean original document every time the example is launched.
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        configuration.autosaveEnabled(false)
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        configuration.enabledAnnotationTools(
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            listOf(
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                AnnotationTool.SOUND
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            )
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        )
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        // The annotation creator written into newly created annotations. If not set, or set to `null`
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        // a dialog will normally be shown when creating an annotation, asking the user to enter a name.
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        // We are going to skip this part and set it as "John Doe" only if it was not yet set.
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        if (!PSPDFKitPreferences.get(context).isAnnotationCreatorSet) {
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            PSPDFKitPreferences.get(context).setAnnotationCreator("John Doe")
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        }
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        // Extract the document from the assets. The launched activity will add annotations to that document.
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        ExtractAssetTask.extract(WELCOME_DOC, title, context) { documentFile ->
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            val intent = PdfActivityIntentBuilder.fromUri(context, Uri.fromFile(documentFile))
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                .configuration(configuration.build())
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                .activityClass(SoundAnnotationDataExtractionActivity::class)
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                .build()
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            context.startActivity(intent)
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        }
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    }
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}
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/**
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 * This activity creates a sound annotation when the document is loaded.
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 * It also adds a custom menu item to the toolbar that extracts the sound data from the annotation and saves it to a .wav file.
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 */
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class SoundAnnotationDataExtractionActivity : PdfActivity() {
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    private val viewModel: AnnotationCreationViewModel by viewModels()
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    @UiThread
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    override fun onDocumentLoaded(document: PdfDocument) {
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        viewModel.createObjects {
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            createSoundAnnotation()
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        }
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    }
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    override fun onCreateOptionsMenu(menu: Menu): Boolean {
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        super.onCreateOptionsMenu(menu)
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        menu.add(0, menuId, 0, "Extract sound .wav")
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        return true
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    }
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    override fun onOptionsItemSelected(item: MenuItem): Boolean {
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        return if (item.itemId == menuId) {
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            menuItemClicked()
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            true
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        } else {
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            super.onOptionsItemSelected(item)
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        }
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    }
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    private fun menuItemClicked() {
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        extractSoundData()
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    }
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    @SuppressLint("CheckResult")
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    private fun createSoundAnnotation() {
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        try {
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            // Extract first audio track from sample in assets.
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            // Audio extractor supports decoding audio tracks from all media formats that are supported by Android's `MediaExtractor`.
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            val audioExtractor = AudioExtractor(this, "file:///android_asset/media/audioLoop.wav".toUri())
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            audioExtractor.selectAudioTrack(0)
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            audioExtractor.extractAudioTrackAsync().subscribe { embeddedAudioSource ->
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                // Create new sound annotation from the extracted audio track.
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                val soundAnnotation = SoundAnnotation(0, RectF(580f, 700f, 600f, 685f), embeddedAudioSource)
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                requirePdfFragment().addAnnotationToPage(soundAnnotation, false)
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            }
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        } catch (e: IOException) {
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            // Handle possible IOException, thrown when the Uri does not point to correct file/asset.
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        }
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    }
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    private fun extractSoundData() {
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        val annotations = runBlocking { document?.annotationProvider?.getAnnotations(0) } ?: return
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        val soundAnnotation = annotations[0] as SoundAnnotation
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        val outputFile = File.createTempFile("tmp_", "sound.wav")
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        WavWriter.forAnnotation(soundAnnotation).writeToStream(FileOutputStream(outputFile))
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        Toast.makeText(this, "Wav file saved to: ${outputFile.path}", Toast.LENGTH_SHORT).show()
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        println("Wav: ${outputFile.path}")
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    }
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    companion object {
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        private const val menuId = 1
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    }
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}