Fixed attachment table queries.

Attachment audio extras job.
Job manager supports parcelable types now.

src/org/thoughtcrime/securesms/attachments/AttachmentId.java

@@ -1,12 +1,15 @@
 package org.thoughtcrime.securesms.attachments;
 
+import android.os.Parcel;
+import android.os.Parcelable;
+
 import androidx.annotation.NonNull;
 
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 import org.thoughtcrime.securesms.util.Util;
 
-public class AttachmentId {
+public class AttachmentId implements Parcelable {
 
   @JsonProperty
   private final long rowId;
@@ -54,4 +57,33 @@ public class AttachmentId {
   public int hashCode() {
     return Util.hashCode(rowId, uniqueId);
   }
+
+  //region Parcelable implementation.
+  @Override
+  public int describeContents() {
+    return 0;
+  }
+
+  @Override
+  public void writeToParcel(Parcel dest, int flags) {
+    dest.writeLong(rowId);
+    dest.writeLong(uniqueId);
+  }
+
+  public static final Parcelable.Creator<AttachmentId> CREATOR =
+          new Parcelable.Creator<AttachmentId>() {
+
+    @Override
+    public AttachmentId createFromParcel(Parcel in) {
+      long rowId    = in.readLong();
+      long uniqueId = in.readLong();
+      return new AttachmentId(rowId, uniqueId);
+    }
+
+    @Override
+    public AttachmentId[] newArray(int size) {
+      return new AttachmentId[size];
+    }
+  };
+  //endregion
 }

src/org/thoughtcrime/securesms/attachments/DatabaseAttachmentAudioExtras.kt

@@ -1,6 +1,15 @@
 package org.thoughtcrime.securesms.attachments
 
-data class DatabaseAttachmentAudioExtras(val attachmentId: AttachmentId, val visualSamples: ByteArray, val durationMs: Long) {
+data class DatabaseAttachmentAudioExtras(
+        val attachmentId: AttachmentId,
+        /** Small amount of normalized audio byte samples to visualise the content (e.g. draw waveform). */
+        val visualSamples: ByteArray,
+        /** Duration of the audio track in milliseconds. May be [DURATION_UNDEFINED] when is not known. */
+        val durationMs: Long = DURATION_UNDEFINED) {
+
+    companion object {
+        const val DURATION_UNDEFINED = -1L
+    }
 
     override fun equals(other: Any?): Boolean {
         return other != null &&

src/org/thoughtcrime/securesms/database/AttachmentDatabase.java

@@ -73,6 +73,8 @@ import java.util.concurrent.Callable;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ExecutorService;
 
+import kotlin.jvm.Synchronized;
+
 public class AttachmentDatabase extends Database {
   
   private static final String TAG = AttachmentDatabase.class.getSimpleName();
@@ -106,8 +108,8 @@ public class AttachmentDatabase extends Database {
           static final String CAPTION                = "caption";
   public  static final String URL                    = "url";
   public  static final String DIRECTORY              = "parts";
-  // audio/* mime type only related columns.
+  // "audio/*" mime type only related columns.
-          static final String AUDIO_VISUAL_SAMPLES   = "audio_visual_samples";  // Small amount of audio byte samples to visualise the content (e.g. draw waveform)
+          static final String AUDIO_VISUAL_SAMPLES   = "audio_visual_samples";  // Small amount of audio byte samples to visualise the content (e.g. draw waveform).
           static final String AUDIO_DURATION         = "audio_duration";        // Duration of the audio track in milliseconds.
 
   public static final int TRANSFER_PROGRESS_DONE    = 0;
@@ -116,7 +118,7 @@ public class AttachmentDatabase extends Database {
   public static final int TRANSFER_PROGRESS_FAILED  = 3;
 
   private static final String PART_ID_WHERE = ROW_ID + " = ? AND " + UNIQUE_ID + " = ?";
-  private static final String PART_AUDIO_ONLY_WHERE = CONTENT_TYPE + " LIKE audio/%";
+  private static final String PART_AUDIO_ONLY_WHERE = CONTENT_TYPE + " LIKE \"audio/%\"";
 
   private static final String[] PROJECTION = new String[] {ROW_ID,
                                                            MMS_ID, CONTENT_TYPE, NAME, CONTENT_DISPOSITION,
@@ -834,6 +836,7 @@ public class AttachmentDatabase extends Database {
    * Retrieves the audio extra values associated with the attachment. Only "audio/*" mime type attachments are accepted.
    * @return the related audio extras or null in case any of the audio extra columns are empty or the attachment is not an audio.
    */
+  @Synchronized
   public @Nullable DatabaseAttachmentAudioExtras getAttachmentAudioExtras(@NonNull AttachmentId attachmentId) {
     try (Cursor cursor = databaseHelper.getReadableDatabase()
             // We expect all the audio extra values to be present (not null) or reject the whole record.
@@ -859,6 +862,7 @@ public class AttachmentDatabase extends Database {
    * Updates audio extra columns for the "audio/*" mime type attachments only.
    * @return true if the update operation was successful.
    */
+  @Synchronized
   public boolean setAttachmentAudioExtras(@NonNull DatabaseAttachmentAudioExtras extras) {
     ContentValues values = new ContentValues();
     values.put(AUDIO_VISUAL_SAMPLES, extras.getVisualSamples());

src/org/thoughtcrime/securesms/database/helpers/ClassicOpenHelper.java

@@ -103,9 +103,7 @@ public class ClassicOpenHelper extends SQLiteOpenHelper {
   private static final int GROUP_RECEIPT_TRACKING                          = 45;
   private static final int UNREAD_COUNT_VERSION                            = 46;
   private static final int MORE_RECIPIENT_FIELDS                           = 47;
-  private static final int AUDIO_ATTACHMENT_EXTRAS                         = 48;
+  private static final int DATABASE_VERSION                                = 47;
-
-  private static final int DATABASE_VERSION                                = 48;
 
   private static final String TAG = ClassicOpenHelper.class.getSimpleName();
 
@@ -1291,11 +1289,6 @@ public class ClassicOpenHelper extends SQLiteOpenHelper {
        */
     }
 
-    if (oldVersion < AUDIO_ATTACHMENT_EXTRAS) {
-      db.execSQL("ALTER TABLE part ADD COLUMN audio_visual_samples BLOB");
-      db.execSQL("ALTER TABLE part ADD COLUMN audio_duration INTEGER");
-    }
-
     db.setTransactionSuccessful();
     db.endTransaction();
   }

src/org/thoughtcrime/securesms/database/helpers/SQLCipherOpenHelper.java

@@ -92,8 +92,9 @@ public class SQLCipherOpenHelper extends SQLiteOpenHelper {
   private static final int lokiV13                          = 34;
   private static final int lokiV14_BACKUP_FILES             = 35;
   private static final int lokiV15                          = 36;
+  private static final int lokiV16_AUDIO_ATTACHMENT_EXTRAS  = 37;
 
-  private static final int    DATABASE_VERSION = lokiV15;
+  private static final int    DATABASE_VERSION = lokiV16_AUDIO_ATTACHMENT_EXTRAS;
   private static final String DATABASE_NAME    = "signal.db";
 
   private final Context        context;
@@ -632,6 +633,11 @@ public class SQLCipherOpenHelper extends SQLiteOpenHelper {
         db.execSQL(SharedSenderKeysDatabase.getCreateOldClosedGroupRatchetTableCommand());
       }
 
+      if (oldVersion < lokiV16_AUDIO_ATTACHMENT_EXTRAS) {
+          db.execSQL("ALTER TABLE part ADD COLUMN audio_visual_samples BLOB");
+          db.execSQL("ALTER TABLE part ADD COLUMN audio_duration INTEGER");
+      }
+
       db.setTransactionSuccessful();
     } finally {
       db.endTransaction();

src/org/thoughtcrime/securesms/jobmanager/Data.java

@@ -1,13 +1,20 @@
 package org.thoughtcrime.securesms.jobmanager;
 
+import android.os.Parcelable;
+
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+import org.thoughtcrime.securesms.attachments.AttachmentId;
+import org.thoughtcrime.securesms.util.ParcelableUtil;
+
 import java.util.HashMap;
 import java.util.Map;
 
+//TODO AC: For now parcelable objects utilize byteArrays field to store their data into.
+// Introduce a dedicated Map<String, byte[]> field specifically for parcelable needs.
 public class Data {
 
   public static final Data EMPTY = new Data.Builder().build();
@@ -213,6 +220,16 @@ public class Data {
     return byteArrays.get(key);
   }
 
+  public boolean hasParcelable(@NonNull String key) {
+    return byteArrays.containsKey(key);
+  }
+
+  public <T extends Parcelable> T getParcelable(@NonNull String key, @NonNull Parcelable.Creator<T> creator) {
+    throwIfAbsent(byteArrays, key);
+    byte[] bytes = byteArrays.get(key);
+    return ParcelableUtil.unmarshall(bytes, creator);
+  }
+
   private void throwIfAbsent(@NonNull Map map, @NonNull String key) {
     if (!map.containsKey(key)) {
       throw new IllegalStateException("Tried to retrieve a value with key '" + key + "', but it wasn't present.");
@@ -301,6 +318,12 @@ public class Data {
       return this;
     }
 
+    public Builder putParcelable(@NonNull String key, @NonNull Parcelable value) {
+      byte[] bytes = ParcelableUtil.marshall(value);
+      byteArrays.put(key, bytes);
+      return this;
+    }
+
     public Data build() {
       return new Data(strings,
                       stringArrays,

src/org/thoughtcrime/securesms/jobmanager/migration/WorkManagerFactoryMappings.java

@@ -45,6 +45,7 @@ import org.thoughtcrime.securesms.jobs.TrimThreadJob;
 import org.thoughtcrime.securesms.jobs.TypingSendJob;
 import org.thoughtcrime.securesms.jobs.UpdateApkJob;
 import org.thoughtcrime.securesms.loki.api.BackgroundPollJob;
+import org.thoughtcrime.securesms.loki.api.PrepareAttachmentAudioExtrasJob;
 import org.thoughtcrime.securesms.loki.protocol.ClosedGroupUpdateMessageSendJob;
 import org.thoughtcrime.securesms.loki.protocol.NullMessageSendJob;
 import org.thoughtcrime.securesms.loki.protocol.SessionRequestMessageSendJob;
@@ -102,6 +103,7 @@ public class WorkManagerFactoryMappings {
     put(TrimThreadJob.class.getName(), TrimThreadJob.KEY);
     put(TypingSendJob.class.getName(), TypingSendJob.KEY);
     put(UpdateApkJob.class.getName(), UpdateApkJob.KEY);
+    put(PrepareAttachmentAudioExtrasJob.class.getName(), PrepareAttachmentAudioExtrasJob.KEY);
   }};
 
   public static @Nullable String getFactoryKey(@NonNull String workManagerClass) {

src/org/thoughtcrime/securesms/jobs/JobManagerFactories.java

@@ -15,6 +15,7 @@ import org.thoughtcrime.securesms.jobmanager.impl.NetworkOrCellServiceConstraint
 import org.thoughtcrime.securesms.jobmanager.impl.SqlCipherMigrationConstraint;
 import org.thoughtcrime.securesms.jobmanager.impl.SqlCipherMigrationConstraintObserver;
 import org.thoughtcrime.securesms.loki.api.BackgroundPollJob;
+import org.thoughtcrime.securesms.loki.api.PrepareAttachmentAudioExtrasJob;
 import org.thoughtcrime.securesms.loki.protocol.ClosedGroupUpdateMessageSendJob;
 import org.thoughtcrime.securesms.loki.protocol.NullMessageSendJob;
 import org.thoughtcrime.securesms.loki.protocol.SessionRequestMessageSendJob;
@@ -79,6 +80,7 @@ public final class JobManagerFactories {
       put(TrimThreadJob.KEY,                         new TrimThreadJob.Factory());
       put(TypingSendJob.KEY,                         new TypingSendJob.Factory());
       put(UpdateApkJob.KEY,                          new UpdateApkJob.Factory());
+      put(PrepareAttachmentAudioExtrasJob.KEY,       new PrepareAttachmentAudioExtrasJob.Factory());
     }};
   }
 

src/org/thoughtcrime/securesms/loki/activities/HomeActivity.kt

@@ -26,11 +26,13 @@ import kotlinx.android.synthetic.main.activity_home.*
 import network.loki.messenger.R
 import org.thoughtcrime.securesms.ApplicationContext
 import org.thoughtcrime.securesms.PassphraseRequiredActionBarActivity
+import org.thoughtcrime.securesms.attachments.AttachmentId
 import org.thoughtcrime.securesms.conversation.ConversationActivity
 import org.thoughtcrime.securesms.database.DatabaseFactory
 import org.thoughtcrime.securesms.database.ThreadDatabase
 import org.thoughtcrime.securesms.database.model.ThreadRecord
 import org.thoughtcrime.securesms.jobs.MultiDeviceBlockedUpdateJob
+import org.thoughtcrime.securesms.loki.api.PrepareAttachmentAudioExtrasJob
 import org.thoughtcrime.securesms.loki.dialogs.ConversationOptionsBottomSheet
 import org.thoughtcrime.securesms.loki.dialogs.LightThemeFeatureIntroBottomSheet
 import org.thoughtcrime.securesms.loki.dialogs.MultiDeviceRemovalBottomSheet

src/org/thoughtcrime/securesms/loki/api/PrepareAttachmentAudioExtrasJob.kt

@@ -0,0 +1,169 @@
+package org.thoughtcrime.securesms.loki.api
+
+import android.media.MediaDataSource
+import android.os.Build
+import android.util.Log
+import androidx.annotation.RequiresApi
+import org.greenrobot.eventbus.EventBus
+import org.thoughtcrime.securesms.attachments.Attachment
+import org.thoughtcrime.securesms.attachments.AttachmentId
+import org.thoughtcrime.securesms.attachments.DatabaseAttachmentAudioExtras
+import org.thoughtcrime.securesms.database.DatabaseFactory
+import org.thoughtcrime.securesms.jobmanager.Data
+import org.thoughtcrime.securesms.jobmanager.Job
+import org.thoughtcrime.securesms.jobs.BaseJob
+import org.thoughtcrime.securesms.loki.utilities.audio.DecodedAudio
+import org.thoughtcrime.securesms.mms.PartAuthority
+import java.io.InputStream
+import java.lang.IllegalStateException
+import java.util.*
+import java.util.concurrent.TimeUnit
+
+/**
+ * Decodes the audio content of the related attachment entry
+ * and caches the result with [DatabaseAttachmentAudioExtras] data.
+ *
+ * It only process attachments with "audio" mime types.
+ *
+ * Due to [DecodedAudio] implementation limitations, it only works for API 23+.
+ * For any lower targets fake data will be generated.
+ *
+ * You can subscribe to [AudioExtrasUpdatedEvent] to be notified about the successful result.
+ */
+//TODO AC: Rewrite to WorkManager API when
+// https://github.com/loki-project/session-android/pull/354 is merged.
+class PrepareAttachmentAudioExtrasJob : BaseJob {
+
+    companion object {
+        private const val TAG = "AttachAudioExtrasJob"
+
+        const val KEY = "PrepareAttachmentAudioExtrasJob"
+        const val DATA_ATTACH_ID = "attachment_id"
+
+        const val VISUAL_RMS_FRAMES = 32 // The amount of values to be computed for the visualization.
+    }
+
+    private val attachmentId: AttachmentId
+
+    constructor(attachmentId: AttachmentId) : this(Parameters.Builder()
+            .setQueue(KEY)
+            .setLifespan(TimeUnit.DAYS.toMillis(1))
+            .build(),
+            attachmentId)
+
+    private constructor(parameters: Parameters, attachmentId: AttachmentId) : super(parameters) {
+        this.attachmentId = attachmentId
+    }
+
+    override fun serialize(): Data {
+        return Data.Builder().putParcelable(DATA_ATTACH_ID, attachmentId).build();
+    }
+
+    override fun getFactoryKey(): String { return KEY
+    }
+
+    override fun onShouldRetry(e: Exception): Boolean {
+        return false
+    }
+
+    override fun onCanceled() { }
+
+    override fun onRun() {
+        Log.v(TAG, "Processing attachment: $attachmentId")
+
+        val attachDb = DatabaseFactory.getAttachmentDatabase(context)
+        val attachment = attachDb.getAttachment(attachmentId)
+
+        if (attachment == null) {
+            throw IllegalStateException("Cannot find attachment with the ID $attachmentId")
+        }
+        if (!attachment.contentType.startsWith("audio/")) {
+            throw IllegalStateException("Attachment $attachmentId is not of audio type.")
+        }
+
+        // Check if the audio extras already exist.
+        if (attachDb.getAttachmentAudioExtras(attachmentId) != null) return
+
+        fun extractAttachmentRandomSeed(attachment: Attachment): Int {
+            return when {
+                attachment.digest != null -> attachment.digest!!.sum()
+                attachment.fileName != null -> attachment.fileName.hashCode()
+                else -> attachment.hashCode()
+            }
+        }
+
+        fun generateFakeRms(seed: Int, frames: Int = VISUAL_RMS_FRAMES): ByteArray {
+            return ByteArray(frames).apply { Random(seed.toLong()).nextBytes(this) }
+        }
+
+        var rmsValues: ByteArray
+        var totalDurationMs: Long = DatabaseAttachmentAudioExtras.DURATION_UNDEFINED
+
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
+            // Due to API version incompatibility, we just display some random waveform for older API.
+            rmsValues = generateFakeRms(extractAttachmentRandomSeed(attachment))
+        } else {
+            try {
+                @Suppress("BlockingMethodInNonBlockingContext")
+                val decodedAudio = PartAuthority.getAttachmentStream(context, attachment.dataUri!!).use {
+                    DecodedAudio.create(InputStreamMediaDataSource(it))
+                }
+                rmsValues = decodedAudio.calculateRms(VISUAL_RMS_FRAMES)
+                totalDurationMs = (decodedAudio.totalDuration / 1000.0).toLong()
+            } catch (e: Exception) {
+                Log.w(TAG, "Failed to decode sample values for the audio attachment \"${attachment.fileName}\".", e)
+                rmsValues = generateFakeRms(extractAttachmentRandomSeed(attachment))
+            }
+        }
+
+        val audioExtras = DatabaseAttachmentAudioExtras(
+                attachmentId,
+                rmsValues,
+                totalDurationMs
+        )
+
+        attachDb.setAttachmentAudioExtras(audioExtras)
+
+        EventBus.getDefault().post(AudioExtrasUpdatedEvent(audioExtras))
+    }
+
+    class Factory : Job.Factory<PrepareAttachmentAudioExtrasJob> {
+        override fun create(parameters: Parameters, data: Data): PrepareAttachmentAudioExtrasJob {
+            return PrepareAttachmentAudioExtrasJob(parameters, data.getParcelable(DATA_ATTACH_ID, AttachmentId.CREATOR))
+        }
+    }
+
+    /** Dispatched once the audio extras have been updated. */
+    data class AudioExtrasUpdatedEvent(val audioExtras: DatabaseAttachmentAudioExtras)
+
+    @RequiresApi(Build.VERSION_CODES.M)
+    private class InputStreamMediaDataSource: MediaDataSource {
+
+        private val data: ByteArray
+
+        constructor(inputStream: InputStream): super() {
+            this.data = inputStream.readBytes()
+        }
+
+        override fun readAt(position: Long, buffer: ByteArray, offset: Int, size: Int): Int {
+            val length: Int = data.size
+            if (position >= length) {
+                return -1 // -1 indicates EOF
+            }
+            var actualSize = size
+            if (position + size > length) {
+                actualSize -= (position + size - length).toInt()
+            }
+            System.arraycopy(data, position.toInt(), buffer, offset, actualSize)
+            return actualSize
+        }
+
+        override fun getSize(): Long {
+            return data.size.toLong()
+        }
+
+        override fun close() {
+            // We don't need to close the wrapped stream.
+        }
+    }
+}

src/org/thoughtcrime/securesms/loki/utilities/audio/DecodedAudio.kt

@@ -16,6 +16,7 @@ import java.nio.ByteOrder
 import java.nio.ShortBuffer
 import kotlin.jvm.Throws
 import kotlin.math.ceil
+import kotlin.math.roundToInt
 import kotlin.math.sqrt
 
 /**
@@ -246,7 +247,7 @@ class DecodedAudio {
         codec.release()
     }
 
-    fun calculateRms(maxFrames: Int): FloatArray {
+    fun calculateRms(maxFrames: Int): ByteArray {
         return calculateRms(this.samples, this.numSamples, this.channels, maxFrames)
     }
 }
@@ -264,9 +265,9 @@ class DecodedAudio {
  * If number of samples per channel is less than "maxFrames",
  * the result array will match the source sample size instead.
  *
- * @return RMS values float array where is each value is within [0..1] range.
+ * @return normalized RMS values as a signed byte array.
  */
-private fun calculateRms(samples: ShortBuffer, numSamples: Int, channels: Int, maxFrames: Int): FloatArray {
+private fun calculateRms(samples: ShortBuffer, numSamples: Int, channels: Int, maxFrames: Int): ByteArray {
     val numFrames: Int
     val frameStep: Float
 
@@ -310,7 +311,8 @@ private fun calculateRms(samples: ShortBuffer, numSamples: Int, channels: Int, m
 //    smoothArray(rmsValues, 1.0f)
     normalizeArray(rmsValues)
 
-    return rmsValues
+    // Convert normalized result to a signed byte array.
+    return rmsValues.map { value -> normalizedFloatToByte(value) }.toByteArray()
 }
 
 /**
@@ -345,3 +347,13 @@ private fun smoothArray(values: FloatArray, neighborWeight: Float = 1f): FloatAr
     }
     return result
 }
+
+/** Turns a signed byte into a [0..1] float. */
+inline fun byteToNormalizedFloat(value: Byte): Float {
+    return (value + 128f) / 255f
+}
+
+/** Turns a [0..1] float into a signed byte. */
+inline fun normalizedFloatToByte(value: Float): Byte {
+    return (255f * value - 128f).roundToInt().toByte()
+}

src/org/thoughtcrime/securesms/loki/views/MessageAudioView.kt

@@ -5,8 +5,6 @@ import android.content.res.ColorStateList
 import android.graphics.Color
 import android.graphics.PorterDuff
 import android.graphics.drawable.AnimatedVectorDrawable
-import android.media.MediaDataSource
-import android.os.Build
 import android.util.AttributeSet
 import android.view.View
 import android.view.View.OnTouchListener
@@ -15,7 +13,6 @@ import android.widget.FrameLayout
 import android.widget.ImageView
 import android.widget.TextView
 import androidx.annotation.ColorInt
-import androidx.annotation.RequiresApi
 import androidx.core.content.ContextCompat
 import androidx.core.graphics.ColorUtils
 import com.pnikosis.materialishprogress.ProgressWheel
@@ -24,18 +21,18 @@ import network.loki.messenger.R
 import org.greenrobot.eventbus.EventBus
 import org.greenrobot.eventbus.Subscribe
 import org.greenrobot.eventbus.ThreadMode
-import org.thoughtcrime.securesms.attachments.Attachment
+import org.thoughtcrime.securesms.ApplicationContext
+import org.thoughtcrime.securesms.attachments.DatabaseAttachment
 import org.thoughtcrime.securesms.audio.AudioSlidePlayer
 import org.thoughtcrime.securesms.components.AnimatingToggle
 import org.thoughtcrime.securesms.database.AttachmentDatabase
+import org.thoughtcrime.securesms.database.DatabaseFactory
 import org.thoughtcrime.securesms.events.PartProgressEvent
 import org.thoughtcrime.securesms.logging.Log
-import org.thoughtcrime.securesms.loki.utilities.audio.DecodedAudio
+import org.thoughtcrime.securesms.loki.api.PrepareAttachmentAudioExtrasJob
 import org.thoughtcrime.securesms.mms.AudioSlide
-import org.thoughtcrime.securesms.mms.PartAuthority
 import org.thoughtcrime.securesms.mms.SlideClickListener
 import java.io.IOException
-import java.io.InputStream
 import java.util.*
 import java.util.concurrent.TimeUnit
 
@@ -166,7 +163,7 @@ class MessageAudioView: FrameLayout, AudioSlidePlayer.Listener {
                 }
 
                 // Post to make sure it executes only when the view is attached to a window.
-                post(::updateSeekBarFromAudio)
+                post(::updateFromAttachmentAudioExtras)
             }
         }
         audioSlidePlayer = AudioSlidePlayer.createFor(context, audio, this)
@@ -254,69 +251,48 @@ class MessageAudioView: FrameLayout, AudioSlidePlayer.Listener {
         pauseToPlayDrawable.start()
     }
 
-    private fun updateSeekBarFromAudio() {
+    private fun obtainDatabaseAttachment(): DatabaseAttachment? {
-        if (audioSlidePlayer == null) return
+        audioSlidePlayer ?: return null
-
         val attachment = audioSlidePlayer!!.audioSlide.asAttachment()
-
+        return if (attachment is DatabaseAttachment) attachment else null
-        // Parse audio and compute RMS values for the WaveformSeekBar in the background.
-        asyncCoroutineScope!!.launch {
-            val rmsFrames = 32  // The amount of values to be computed for the visualization.
-
-            fun extractAttachmentRandomSeed(attachment: Attachment): Int {
-                return when {
-                    attachment.digest != null -> attachment.digest!!.sum()
-                    attachment.fileName != null -> attachment.fileName.hashCode()
-                    else -> attachment.hashCode()
-                }
     }
 
-            fun generateFakeRms(seed: Int, frames: Int = rmsFrames): FloatArray {
+    private fun updateFromAttachmentAudioExtras() {
-                return Random(seed.toLong()).let { (0 until frames).map { i -> it.nextFloat() }.toFloatArray() }
+        val attachment = obtainDatabaseAttachment() ?: return
+
+        val audioExtras = DatabaseFactory.getAttachmentDatabase(context)
+                .getAttachmentAudioExtras(attachment.attachmentId)
+
+        // Schedule a job request if no audio extras were generated yet.
+        if (audioExtras == null) {
+            ApplicationContext.getInstance(context).jobManager
+                    .add(PrepareAttachmentAudioExtrasJob(attachment.attachmentId))
+            return
         }
 
-            var rmsValues: FloatArray
-            var totalDurationMs: Long = -1
-
-            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
-                // Due to API version incompatibility, we just display some random waveform for older API.
-                rmsValues = generateFakeRms(extractAttachmentRandomSeed(attachment))
-            } else {
-                try {
-                    @Suppress("BlockingMethodInNonBlockingContext")
-                    val decodedAudio = PartAuthority.getAttachmentStream(context, attachment.dataUri!!).use {
-                        DecodedAudio.create(InputStreamMediaDataSource(it))
-                    }
-                    rmsValues = decodedAudio.calculateRms(rmsFrames)
-                    totalDurationMs = (decodedAudio.totalDuration / 1000.0).toLong()
-                } catch (e: Exception) {
-                    android.util.Log.w(TAG, "Failed to decode sample values for the audio attachment \"${attachment.fileName}\".", e)
-                    rmsValues = generateFakeRms(extractAttachmentRandomSeed(attachment))
-                }
-            }
-
-            android.util.Log.d(TAG, "RMS: ${rmsValues.joinToString()}")
-
-            post {
         loadingAnimation.stop()
-                seekBar.sampleData = rmsValues
+        seekBar.sampleData = audioExtras.visualSamples
 
-                if (totalDurationMs > 0) {
+        if (audioExtras.durationMs > 0) {
             totalDuration.visibility = View.VISIBLE
             totalDuration.text = String.format("%02d:%02d",
-                            TimeUnit.MILLISECONDS.toMinutes(totalDurationMs),
+                    TimeUnit.MILLISECONDS.toMinutes(audioExtras.durationMs),
-                            TimeUnit.MILLISECONDS.toSeconds(totalDurationMs))
+                    TimeUnit.MILLISECONDS.toSeconds(audioExtras.durationMs))
-                }
-            }
         }
     }
 
     @Subscribe(sticky = true, threadMode = ThreadMode.MAIN)
-    fun onEventAsync(event: PartProgressEvent) {
+    fun onEvent(event: PartProgressEvent) {
         if (audioSlidePlayer != null && event.attachment == audioSlidePlayer!!.audioSlide.asAttachment()) {
             downloadProgress.setInstantProgress(event.progress.toFloat() / event.total)
         }
     }
+
+    @Subscribe(threadMode = ThreadMode.MAIN)
+    fun onEvent(event: PrepareAttachmentAudioExtrasJob.AudioExtrasUpdatedEvent) {
+        if (event.audioExtras.attachmentId == obtainDatabaseAttachment()?.attachmentId) {
+            updateFromAttachmentAudioExtras()
+        }
     }
 
     private class SeekBarLoadingAnimation(
@@ -324,13 +300,13 @@ private class SeekBarLoadingAnimation(
             private val seekBar: WaveformSeekBar): Runnable {
 
         companion object {
-        private const val UPDATE_PERIOD = 500L // In milliseconds.
+            private const val UPDATE_PERIOD = 350L // In milliseconds.
             private val random = Random()
         }
 
         fun start() {
             stop()
-        run()
+            hostView.postDelayed(this, UPDATE_PERIOD)
         }
 
         fun stop() {
@@ -338,38 +314,10 @@ private class SeekBarLoadingAnimation(
         }
 
         override fun run() {
-        seekBar.sampleData = (0 until 64).map { random.nextFloat() * 0.5f }.toFloatArray()
+            // Generate a random samples with values up to the 50% of the maximum value.
+            seekBar.sampleData = ByteArray(PrepareAttachmentAudioExtrasJob.VISUAL_RMS_FRAMES)
+                { (random.nextInt(127) - 64).toByte() }
             hostView.postDelayed(this, UPDATE_PERIOD)
         }
     }
-
-@RequiresApi(Build.VERSION_CODES.M)
-private class InputStreamMediaDataSource: MediaDataSource {
-
-    private val data: ByteArray
-
-    constructor(inputStream: InputStream): super() {
-        this.data = inputStream.readBytes()
-    }
-
-    override fun readAt(position: Long, buffer: ByteArray, offset: Int, size: Int): Int {
-        val length: Int = data.size
-        if (position >= length) {
-            return -1 // -1 indicates EOF
-        }
-        var actualSize = size
-        if (position + size > length) {
-            actualSize -= (position + size - length).toInt()
-        }
-        System.arraycopy(data, position.toInt(), buffer, offset, actualSize)
-        return actualSize
-    }
-
-    override fun getSize(): Long {
-        return data.size.toLong()
-    }
-
-    override fun close() {
-        // We don't need to close the wrapped stream.
-    }
 }

src/org/thoughtcrime/securesms/loki/views/WaveformSeekBar.kt

@@ -7,7 +7,6 @@ import android.graphics.Color
 import android.graphics.Paint
 import android.graphics.RectF
 import android.util.AttributeSet
-import android.util.Log
 import android.util.TypedValue
 import android.view.MotionEvent
 import android.view.View
@@ -15,8 +14,11 @@ import android.view.ViewConfiguration
 import android.view.animation.DecelerateInterpolator
 import androidx.core.math.MathUtils
 import network.loki.messenger.R
+import org.thoughtcrime.securesms.loki.utilities.audio.byteToNormalizedFloat
 import java.lang.Math.abs
 import kotlin.math.max
+import kotlin.math.min
+import kotlin.math.roundToInt
 
 class WaveformSeekBar : View {
 
@@ -32,8 +34,8 @@ class WaveformSeekBar : View {
     }
 
     private val sampleDataHolder = SampleDataHolder(::invalidate)
-    /** An array if normalized to [0..1] values representing the audio signal. */
+    /** An array of signed byte values representing the audio signal. */
-    var sampleData: FloatArray?
+    var sampleData: ByteArray?
         get() {
             return sampleDataHolder.getSamples()
         }
@@ -155,7 +157,8 @@ class WaveformSeekBar : View {
         var lastBarRight = paddingLeft.toFloat()
 
         (0 until barAmount).forEach { barIdx ->
-            val barValue = sampleDataHolder.computeBarValue(barIdx, barAmount)
+            // Convert a signed byte to a [0..1] float.
+            val barValue = byteToNormalizedFloat(sampleDataHolder.computeBarValue(barIdx, barAmount))
 
             val barHeight = max(barMinHeight, getAvailableHeight() * barValue)
 
@@ -246,16 +249,17 @@ class WaveformSeekBar : View {
 
     private class SampleDataHolder(private val invalidateDelegate: () -> Any) {
 
-        private var sampleDataFrom: FloatArray? = null
+        private var sampleDataFrom: ByteArray? = null
-        private var sampleDataTo: FloatArray? = null
+        private var sampleDataTo: ByteArray? = null
         private var progress = 1f // Mix between from and to values.
 
         private var animation: ValueAnimator? = null
 
-        fun computeBarValue(barIdx: Int, barAmount: Int): Float {
+        fun computeBarValue(barIdx: Int, barAmount: Int): Byte {
-            fun getSampleValue(sampleData: FloatArray?): Float {
+            /** @return The array's value at the interpolated index. */
+            fun getSampleValue(sampleData: ByteArray?): Byte {
                 if (sampleData == null || sampleData.isEmpty())
-                    return 0f
+                    return Byte.MIN_VALUE
                 else {
                     val sampleIdx = (barIdx * (sampleData.size / barAmount.toFloat())).toInt()
                     return sampleData[sampleIdx]
@@ -268,12 +272,21 @@ class WaveformSeekBar : View {
 
             val fromValue = getSampleValue(sampleDataFrom)
             val toValue = getSampleValue(sampleDataTo)
-
+            val rawResultValue = fromValue * (1f - progress) + toValue * progress
-            return fromValue * (1f - progress) + toValue * progress
+            return rawResultValue.roundToInt().toByte()
         }
 
-        fun setSamples(sampleData: FloatArray?) {
+        fun setSamples(sampleData: ByteArray?) {
-            sampleDataFrom = sampleDataTo
+            /** @return a mix between [sampleDataFrom] and [sampleDataTo] arrays according to the current [progress] value. */
+            fun computeNewDataFromArray(): ByteArray? {
+                if (sampleDataTo == null) return null
+                if (sampleDataFrom == null) return sampleDataTo
+
+                val sampleSize = min(sampleDataFrom!!.size, sampleDataTo!!.size)
+                return ByteArray(sampleSize) { i -> computeBarValue(i, sampleSize) }
+            }
+
+            sampleDataFrom = computeNewDataFromArray()
             sampleDataTo = sampleData
             progress = 0f
 
@@ -281,7 +294,6 @@ class WaveformSeekBar : View {
             animation = ValueAnimator.ofFloat(0f, 1f).apply {
                 addUpdateListener { animation ->
                     progress = animation.animatedValue as Float
-                    Log.d("MTPHR", "Progress: $progress")
                     invalidateDelegate()
                 }
                 interpolator = DecelerateInterpolator(3f)
@@ -290,7 +302,7 @@ class WaveformSeekBar : View {
             }
         }
 
-        fun getSamples(): FloatArray? {
+        fun getSamples(): ByteArray? {
             return sampleDataTo
         }
     }

src/org/thoughtcrime/securesms/util/ParcelableUtil.kt

@@ -0,0 +1,32 @@
+package org.thoughtcrime.securesms.util
+
+import android.os.Parcel
+
+import android.os.Parcelable
+
+object ParcelableUtil {
+    @JvmStatic
+    fun marshall(parcelable: Parcelable): ByteArray {
+        val parcel = Parcel.obtain()
+        parcelable.writeToParcel(parcel, 0)
+        val bytes = parcel.marshall()
+        parcel.recycle()
+        return bytes
+    }
+
+    @JvmStatic
+    fun unmarshall(bytes: ByteArray): Parcel {
+        val parcel = Parcel.obtain()
+        parcel.unmarshall(bytes, 0, bytes.size)
+        parcel.setDataPosition(0) // This is extremely important!
+        return parcel
+    }
+
+    @JvmStatic
+    fun <T> unmarshall(bytes: ByteArray, creator: Parcelable.Creator<T>): T {
+        val parcel: Parcel = ParcelableUtil.unmarshall(bytes)
+        val result = creator.createFromParcel(parcel)
+        parcel.recycle()
+        return result
+    }
+}