Integrate FFMPEG library to manage the video export

app/build.gradle

@@ -129,6 +129,9 @@ dependencies {
     // Polynomial Regression
     implementation 'org.apache.commons:commons-math3:3.6.1'
 
+    // ffmpeg for encoding video (HH export)
+    implementation 'com.arthenica:mobile-ffmpeg-full:4.4.LTS'
+
     // Instrumented Tests
     androidTestImplementation 'androidx.test:core:1.2.0'
     androidTestImplementation 'androidx.test:runner:1.2.0'

app/src/main/java/net/pokeranalytics/android/ui/modules/handhistory/replayer/ReplayExportService.kt

@@ -7,6 +7,9 @@ import android.os.Binder
 import android.os.Environment
 import android.os.IBinder
 import androidx.core.content.FileProvider
+import com.arthenica.mobileffmpeg.Config.RETURN_CODE_CANCEL
+import com.arthenica.mobileffmpeg.Config.RETURN_CODE_SUCCESS
+import com.arthenica.mobileffmpeg.FFmpeg
 import io.realm.Realm
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.GlobalScope
@@ -16,6 +19,7 @@ import net.pokeranalytics.android.R
 import net.pokeranalytics.android.exceptions.PAIllegalStateException
 import net.pokeranalytics.android.model.realm.handhistory.HandHistory
 import net.pokeranalytics.android.ui.extensions.toByteArray
+import net.pokeranalytics.android.util.FFMPEG_DESCRIPTOR_FILE
 import net.pokeranalytics.android.util.TriggerNotification
 import net.pokeranalytics.android.util.extensions.dateTimeFileFormatted
 import net.pokeranalytics.android.util.extensions.findById
@@ -49,7 +53,7 @@ class ReplayExportService : Service() {
 
 	fun videoExport(handHistoryId: String) {
 		this@ReplayExportService.handHistoryId = handHistoryId
-		startVideoExport()
+		startFFMPEGVideoExport()
 	}
 
 	fun gifExport(handHistoryId: String) {
@@ -115,6 +119,57 @@ class ReplayExportService : Service() {
 
 	}
 
+	private fun startFFMPEGVideoExport() {
+
+		GlobalScope.launch(coroutineContext) {
+			val async = GlobalScope.async {
+
+				val realm = Realm.getDefaultInstance()
+				val handHistory = realm.findById<HandHistory>(handHistoryId) ?: throw PAIllegalStateException("HandHistory not found, id: $handHistoryId")
+
+				val context = this@ReplayExportService
+
+				val animator = ReplayerAnimator(handHistory, true)
+
+				val square = 1024
+
+				val width = square
+				val height = square
+
+				animator.setDimension(width.toFloat(), height.toFloat())
+				TableDrawer.configurePaints(context, animator)
+
+				// generates all images and file descriptor
+				Timber.d("Generating images for video...")
+				val tmpDir = animator.generateVideoContent(this@ReplayExportService)
+				val dpath = "${tmpDir.path}/$FFMPEG_DESCRIPTOR_FILE"
+
+				val directory = context.getExternalFilesDir(null) ?: throw PAIllegalStateException("File is invalid")
+				val output = "${directory.path}/video_${Date().dateTimeFileFormatted}.mp4"
+
+				Environment.getExternalStorageState(tmpDir)
+
+				Timber.d("Assembling images for video...")
+				FFmpeg.executeAsync("-f concat -safe 0 -i $dpath -vsync vfr -s ${width}x${height} -pix_fmt yuv420p $output") { id, rc ->
+
+					if (rc == RETURN_CODE_SUCCESS) {
+						Timber.d("FFMPEG command execution completed successfully")
+					} else if (rc == RETURN_CODE_CANCEL) {
+						Timber.d("Command execution cancelled by user.")
+					} else {
+						Timber.d(String.format("Command execution failed with rc=%d and the output below.", rc))
+					}
+					tmpDir.delete()
+
+					notifyUser(output)
+				}
+
+			}
+			async.await()
+		}
+
+	}
+
 	private fun startVideoExport() {
 
 		GlobalScope.launch(coroutineContext) {

app/src/main/java/net/pokeranalytics/android/ui/modules/handhistory/replayer/ReplayerAnimator.kt

@@ -4,14 +4,20 @@ import android.content.Context
 import android.graphics.Bitmap
 import android.graphics.Canvas
 import android.graphics.RectF
+import kotlinx.coroutines.delay
 import net.pokeranalytics.android.exceptions.PAIllegalStateException
 import net.pokeranalytics.android.model.handhistory.Street
 import net.pokeranalytics.android.model.realm.handhistory.Action
 import net.pokeranalytics.android.model.realm.handhistory.HandHistory
 import net.pokeranalytics.android.ui.modules.handhistory.model.ActionList
 import net.pokeranalytics.android.ui.modules.handhistory.model.ComputedAction
+import net.pokeranalytics.android.util.FFMPEG_DESCRIPTOR_FILE
+import net.pokeranalytics.android.util.FileUtils
 import net.pokeranalytics.android.util.MathUtils
+import net.pokeranalytics.android.util.extensions.dateTimeFileFormatted
 import timber.log.Timber
+import java.io.File
+import java.util.*
 
 class ReplayerAnimator(var handHistory: HandHistory, var export: Boolean) {
 
@@ -469,6 +475,62 @@ class ReplayerAnimator(var handHistory: HandHistory, var export: Boolean) {
 		return false
 	}
 
+	/***
+	 * Generates images and image descriptor to build the video using ffmpeg
+	 * Command line: https://trac.ffmpeg.org/wiki/Slideshow
+	 */
+	suspend fun generateVideoContent(context: Context): File {
+
+		var ffmpegImageDescriptor = ""
+		var count = 0
+		var imagePath = ""
+
+		val dirName = Date().dateTimeFileFormatted
+		val directory = context.getExternalFilesDir("tmp/$dirName") ?: throw PAIllegalStateException("File is invalid")
+		if (!directory.exists()) {
+			val mkdirs = directory.mkdirs()
+			Timber.d("Directories creation = $mkdirs")
+		}
+
+		(this.currentStepIndex until this.steps.size).forEach {
+
+			(0 until this.frameManager.totalFrames).forEach { _ ->
+
+				val bitmap = Bitmap.createBitmap(this.width.toInt(), this.height.toInt(), Bitmap.Config.ARGB_8888)
+				val canvas = Canvas(bitmap)
+				val vo = this.visualOccurences / 90.0 // this is needed before the call to drawTable which pass to the next frame
+
+				TableDrawer.drawTable(this, canvas, context)
+
+				imagePath = File(directory, "img_$count.png").path
+
+				FileUtils.writeBitmapToPNG(bitmap, imagePath)
+				bitmap.recycle()
+
+				ffmpegImageDescriptor = ffmpegImageDescriptor.plus("file '$imagePath'\n")
+				ffmpegImageDescriptor = ffmpegImageDescriptor.plus("duration $vo\n")
+
+				count++
+
+				Thread.sleep(100L)
+
+//				delay(100L)
+			}
+
+			nextStep()
+
+		}
+
+//		ffmpegImageDescriptor = ffmpegImageDescriptor.plus(imagePath) // adds path one more time due to "quirk", see doc above
+
+		FileUtils.writeToFile(ffmpegImageDescriptor, FFMPEG_DESCRIPTOR_FILE, directory)
+
+		Timber.d("desc = $ffmpegImageDescriptor")
+
+		return directory
+
+	}
+
 	/***
 	 * This method creates a bitmap for each step and frame
 	 * in order to create a playable video for the whole hand

app/src/main/java/net/pokeranalytics/android/util/FileUtils.kt

@@ -1,18 +1,31 @@
 package net.pokeranalytics.android.util
 
 import android.content.Context
+import android.graphics.Bitmap
 import timber.log.Timber
-import java.io.BufferedWriter
 import java.io.File
 import java.io.FileOutputStream
-import java.io.OutputStreamWriter
+import java.io.IOException
 
 class FileUtils {
 
-	companion object{
+	companion object {
 
 		/***
-		 * Writes a [string] into a file named [fileName], using a [context]
+		 * Writes some [content] into a file named [fileName] inside [directory]
+		 */
+		fun writeToFile(content: String, fileName: String, directory: File) {
+
+			val file = File(directory, fileName)
+
+			val fileOutputStream = FileOutputStream(file)
+			fileOutputStream.write(content.toByteArray())
+			fileOutputStream.close()
+		}
+
+		/***
+		 * Writes a [string] into a file named [fileName], inside the Files directory,
+		 * using a [context]
 		 * Should be surrounded by a try/catch IOException
 		 */
 		fun writeFileToFilesDir(string: String, fileName: String, context: Context) {
@@ -27,6 +40,18 @@ class FileUtils {
 
 		}
 
+		fun writeBitmapToPNG(bitmap: Bitmap, fileName: String) {
+
+			try {
+				FileOutputStream(fileName).use { out ->
+					bitmap.compress(Bitmap.CompressFormat.PNG, 100, out)
+				}
+			} catch (e: IOException) {
+				e.printStackTrace()
+			}
+
+		}
+
 	}
 
 }

app/src/main/java/net/pokeranalytics/android/util/Global.kt

@@ -2,3 +2,4 @@ package net.pokeranalytics.android.util
 
 const val NULL_TEXT: String = "--"
 const val RANDOM_PLAYER: String = "☺︎"
+const val FFMPEG_DESCRIPTOR_FILE = "descriptor.txt"