fix: Fix Preview stretching on Android (#2377)

* fix: Fix Preview stretching on Android

* fix: Simplify Preview size computation

* fix: Catch `stopRepeating` error

* fix: Fix preview size calculation

* Format code

* Update CameraSession.kt

* Enable CodeScanner in example app

* fix: Also update size on surface change

* Format

* fix: Flip sizes

* Revert that stuff again

* Update PreviewView.kt

* fix: Swap width and height in SurfaceHolder::setFixedSize

package/android/src/main/java/com/mrousavy/camera/core/CameraSession.kt

@@ -28,7 +28,6 @@ import com.mrousavy.camera.core.outputs.BarcodeScannerOutput
 import com.mrousavy.camera.core.outputs.PhotoOutput
 import com.mrousavy.camera.core.outputs.SurfaceOutput
 import com.mrousavy.camera.core.outputs.VideoPipelineOutput
-import com.mrousavy.camera.extensions.bigger
 import com.mrousavy.camera.extensions.capture
 import com.mrousavy.camera.extensions.closestToOrMax
 import com.mrousavy.camera.extensions.createCaptureSession
@@ -38,7 +37,6 @@ import com.mrousavy.camera.extensions.getPreviewTargetSize
 import com.mrousavy.camera.extensions.getVideoSizes
 import com.mrousavy.camera.extensions.openCamera
 import com.mrousavy.camera.extensions.setZoom
-import com.mrousavy.camera.extensions.smaller
 import com.mrousavy.camera.frameprocessor.FrameProcessor
 import com.mrousavy.camera.types.Flash
 import com.mrousavy.camera.types.Orientation
@@ -48,6 +46,7 @@ import com.mrousavy.camera.types.Torch
 import com.mrousavy.camera.types.VideoStabilizationMode
 import com.mrousavy.camera.utils.ImageFormatUtils
 import java.io.Closeable
+import java.lang.IllegalStateException
 import java.util.concurrent.CancellationException
 import kotlin.coroutines.CoroutineContext
 import kotlinx.coroutines.CoroutineScope
@@ -246,6 +245,8 @@ class CameraSession(private val context: Context, private val cameraManager: Cam
 
   private fun destroyPreviewOutputSync() {
     Log.i(TAG, "Destroying Preview Output...")
+    // This needs to run synchronously because after this method returns, the Preview Surface is no longer valid,
+    // and trying to use it will crash. This might result in a short UI Thread freeze though.
     runBlocking {
       configure { config ->
         config.preview = CameraConfiguration.Output.Disabled.create()
@@ -379,12 +380,7 @@ class CameraSession(private val context: Context, private val cameraManager: Cam
     if (preview != null) {
       // Compute Preview Size based on chosen video size
       val videoSize = videoOutput?.size ?: format?.videoSize
-      val size = if (videoSize != null) {
+      val size = characteristics.getPreviewTargetSize(videoSize)
-        val formatAspectRatio = videoSize.bigger.toDouble() / videoSize.smaller
-        characteristics.getPreviewTargetSize(formatAspectRatio)
-      } else {
-        characteristics.getPreviewTargetSize(null)
-      }
 
       val enableHdr = video?.config?.enableHdr ?: false
 
@@ -396,7 +392,8 @@ class CameraSession(private val context: Context, private val cameraManager: Cam
         enableHdr
       )
       outputs.add(output)
-      previewView?.size = size
+      // Size is usually landscape, so we flip it here
+      previewView?.size = Size(size.height, size.width)
     }
 
     // CodeScanner Output
@@ -520,7 +517,11 @@ class CameraSession(private val context: Context, private val cameraManager: Cam
 
     if (!config.isActive) {
       isRunning = false
-      captureSession?.stopRepeating()
+      try {
+        captureSession?.stopRepeating()
+      } catch (e: IllegalStateException) {
+        // ignore - captureSession is already closed.
+      }
       return
     }
     if (captureSession == null) {

package/android/src/main/java/com/mrousavy/camera/core/PreviewView.kt

@@ -19,8 +19,8 @@ class PreviewView(context: Context, callback: SurfaceHolder.Callback) : SurfaceV
     set(value) {
       field = value
       UiThreadUtil.runOnUiThread {
-        Log.i(TAG, "Resizing PreviewView to ${value.width} x ${value.height}...")
+        Log.i(TAG, "Setting PreviewView Surface Size to $width x $height...")
-        holder.setFixedSize(value.width, value.height)
+        holder.setFixedSize(value.height, value.width)
         requestLayout()
         invalidate()
       }
@@ -44,20 +44,10 @@ class PreviewView(context: Context, callback: SurfaceHolder.Callback) : SurfaceV
     holder.addCallback(callback)
   }
 
-  /*fun resizeToInputCamera(cameraId: String, cameraManager: CameraManager, format: CameraDeviceFormat?) {
-    val characteristics = cameraManager.getCameraCharacteristics(cameraId)
-
-    val targetPreviewSize = format?.videoSize
-    val formatAspectRatio = if (targetPreviewSize != null) targetPreviewSize.bigger.toDouble() / targetPreviewSize.smaller else null
-    size = characteristics.getPreviewTargetSize(formatAspectRatio)
-  }*/
-
   private fun getSize(contentSize: Size, containerSize: Size, resizeMode: ResizeMode): Size {
-    val contentAspectRatio = contentSize.height.toDouble() / contentSize.width
+    val contentAspectRatio = contentSize.width.toDouble() / contentSize.height
     val containerAspectRatio = containerSize.width.toDouble() / containerSize.height
 
-    Log.i(TAG, "Content Size: $contentSize ($contentAspectRatio) | Container Size: $containerSize ($containerAspectRatio)")
-
     val widthOverHeight = when (resizeMode) {
       ResizeMode.COVER -> contentAspectRatio > containerAspectRatio
       ResizeMode.CONTAIN -> contentAspectRatio < containerAspectRatio

package/android/src/main/java/com/mrousavy/camera/extensions/CameraCharacteristics+getPreviewSize.kt

@@ -4,13 +4,12 @@ import android.content.res.Resources
 import android.hardware.camera2.CameraCharacteristics
 import android.util.Size
 import android.view.SurfaceHolder
-import kotlin.math.abs
 
 fun getMaximumPreviewSize(): Size {
   // See https://developer.android.com/reference/android/hardware/camera2/params/StreamConfigurationMap
   // According to the Android Developer documentation, PREVIEW streams can have a resolution
   // of up to the phone's display's resolution, with a maximum of 1920x1080.
-  val display1080p = Size(1920, 1080)
+  val display1080p = Size(1080, 1920)
   val displaySize = Size(
     Resources.getSystem().displayMetrics.widthPixels,
     Resources.getSystem().displayMetrics.heightPixels
@@ -20,28 +19,11 @@ fun getMaximumPreviewSize(): Size {
   return if (isHighResScreen) display1080p else displaySize
 }
 
-fun CameraCharacteristics.getPreviewSizeFromAspectRatio(aspectRatio: Double): Size {
+fun CameraCharacteristics.getPreviewTargetSize(targetSize: Size?): Size {
   val config = this.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP)!!
   val maximumPreviewSize = getMaximumPreviewSize()
   val outputSizes = config.getOutputSizes(SurfaceHolder::class.java)
-    .sortedByDescending { it.width * it.height }
+    .filter { it.bigger <= maximumPreviewSize.bigger && it.smaller <= maximumPreviewSize.smaller }
-    .sortedBy { abs(aspectRatio - (it.bigger.toDouble() / it.smaller)) }
 
-  return outputSizes.first { it.bigger <= maximumPreviewSize.bigger && it.smaller <= maximumPreviewSize.smaller }
+  return outputSizes.closestToOrMax(targetSize)
 }
-
-fun CameraCharacteristics.getAutomaticPreviewSize(): Size {
-  val config = this.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP)!!
-  val maximumPreviewSize = getMaximumPreviewSize()
-  val outputSizes = config.getOutputSizes(SurfaceHolder::class.java)
-    .sortedByDescending { it.width * it.height }
-
-  return outputSizes.first { it.bigger <= maximumPreviewSize.bigger && it.smaller <= maximumPreviewSize.smaller }
-}
-
-fun CameraCharacteristics.getPreviewTargetSize(aspectRatio: Double?): Size =
-  if (aspectRatio != null) {
-    getPreviewSizeFromAspectRatio(aspectRatio)
-  } else {
-    getAutomaticPreviewSize()
-  }

package/android/src/main/java/com/mrousavy/camera/extensions/Size+Extensions.kt

@@ -9,7 +9,7 @@ import kotlin.math.min
 
 fun List<Size>.closestToOrMax(size: Size?): Size =
   if (size != null) {
-    this.minBy { abs(it.width - size.width) + abs(it.height - size.height) }
+    this.minBy { abs((it.width * it.height) - (size.width * size.height)) }
   } else {
     this.maxBy { it.width * it.height }
   }

package/android/src/main/java/com/mrousavy/camera/frameprocessor/FrameProcessor.java

@@ -10,7 +10,6 @@ import com.facebook.proguard.annotations.DoNotStrip;
 /**
  * Represents a JS Frame Processor
  */
-@SuppressWarnings("JavaJniMissingFunction") // we're using fbjni.
 public final class FrameProcessor {
     /**
      * Call the JS Frame Processor function with the given Frame

package/example/android/gradle.properties

@@ -42,4 +42,4 @@ hermesEnabled=true
 # Can be set to true to disable the build setup
 #VisionCamera_disableFrameProcessors=true
 # Can be set to true to include the full 2.4 MB MLKit dependency
-#VisionCamera_enableCodeScanner=true
+VisionCamera_enableCodeScanner=true