undo even scale changes

WebRTC m97 handles odd dimensions
livekit · Feb 18, 2022 · a62e4dc · a62e4dc
1 parent 1b81a82
commit a62e4dc
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Showing 3 changed files with 8 additions and 70 deletions.
diff --git a/livekit-android-sdk/src/main/java/io/livekit/android/room/participant/LocalParticipant.kt b/livekit-android-sdk/src/main/java/io/livekit/android/room/participant/LocalParticipant.kt
@@ -14,7 +14,6 @@ import io.livekit.android.room.DefaultsManager
 import io.livekit.android.room.RTCEngine
 import io.livekit.android.room.track.*
 import io.livekit.android.room.util.EncodingUtils
-import io.livekit.android.room.util.EncodingUtils.findEvenScaleDownBy
 import io.livekit.android.util.LKLog
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.cancel
@@ -323,7 +322,6 @@ internal constructor(
             val midPreset = presets[1]
             val lowPreset = presets[0]
 
-
             fun addEncoding(videoEncoding: VideoEncoding, scale: Double) {
                 if (encodings.size >= EncodingUtils.VIDEO_RIDS.size) {
                     throw IllegalStateException("Attempting to add more encodings than we have rids for!")
@@ -336,18 +334,19 @@ internal constructor(
             // if resolution is high enough, we send both h and q res.
             // otherwise only send h
             val size = max(width, height)
+
+            fun calculateScaleDown(captureParam: VideoCaptureParameter): Double {
+                val targetSize = max(captureParam.width, captureParam.height)
+                return size / targetSize.toDouble()
+            }
             if (size >= 960) {
-                var lowScale = findEvenScaleDownBy(width, height, lowPreset.capture.width, lowPreset.capture.height)
-                var midScale = findEvenScaleDownBy(width, height, midPreset.capture.width, midPreset.capture.height)
+                val lowScale = calculateScaleDown(lowPreset.capture)
+                val midScale = calculateScaleDown(midPreset.capture)
 
-                if (midScale == null || lowScale == null) {
-                    lowScale = 4.0
-                    midScale = 2.0
-                }
                 addEncoding(lowPreset.encoding, lowScale)
                 addEncoding(midPreset.encoding, midScale)
             } else {
-                val lowScale = findEvenScaleDownBy(width, height, lowPreset.capture.width, lowPreset.capture.height) ?: 2.0
+                val lowScale = calculateScaleDown(lowPreset.capture)
                 addEncoding(lowPreset.encoding, lowScale)
             }
             addEncoding(encoding, 1.0)

diff --git a/livekit-android-sdk/src/main/java/io/livekit/android/room/util/EncodingUtils.kt b/livekit-android-sdk/src/main/java/io/livekit/android/room/util/EncodingUtils.kt
@@ -32,39 +32,6 @@ internal object EncodingUtils {
         VideoPreset43.FHD
     )
 
-
-    /**
-     * Encoders will often not be able to handle odd dimensions, so we should try to find a scale that will
-     * result in even dimensions.
-     *
-     * @return a scale that will result in dimensions that are both even, or null if none found.
-     */
-    fun findEvenScaleDownBy(
-        sourceWidth: Int,
-        sourceHeight: Int,
-        targetWidth: Int,
-        targetHeight: Int,
-    ): Double? {
-        fun Int.isEven() = this % 2 == 0
-
-        val sourceSize = min(sourceWidth, sourceHeight)
-        val targetSize = min(targetWidth, targetHeight)
-        for (i in 0..20) {
-            val scaleDownBy = sourceSize.toDouble() / (targetSize + i)
-            // Internally, WebRTC casts directly to int without rounding.
-            // https://github.com/webrtc-sdk/webrtc/blob/8c7139f8e6fa19ddf2c91510c177a19746e1ded3/media/engine/webrtc_video_engine.cc#L3676
-            val scaledWidth = (sourceWidth / scaleDownBy).toInt()
-            val scaledHeight = (sourceHeight / scaleDownBy).toInt()
-
-            if (scaledHeight.isEven() && scaledWidth.isEven()) {
-                return scaleDownBy
-            }
-        }
-
-        return null
-    }
-
-
     fun determineAppropriateEncoding(width: Int, height: Int): VideoEncoding {
         val presets = presetsForResolution(width, height)
 

diff --git a/livekit-android-sdk/src/test/java/io/livekit/android/room/util/EncodingUtilsTest.kt b/livekit-android-sdk/src/test/java/io/livekit/android/room/util/EncodingUtilsTest.kt
@@ -1,32 +1,4 @@
 package io.livekit.android.room.util
 
-import org.junit.Assert
-import org.junit.Test
-
 class EncodingUtilsTest {
-    @Test
-    fun evenScale() {
-        fun Int.isEven() = this % 2 == 0
-
-        val sourceWidth = 800
-        val sourceHeight = 600
-        val scaleDownBy = EncodingUtils.findEvenScaleDownBy(sourceWidth, sourceHeight, 240, 180)
-            ?: throw Exception("scale should not be null!")
-
-        Assert.assertTrue((sourceWidth / scaleDownBy).toInt().isEven())
-        Assert.assertTrue((sourceHeight / scaleDownBy).toInt().isEven())
-    }
-
-    @Test
-    fun evenScaleWeirdSource() {
-        fun Int.isEven() = this % 2 == 0
-
-        val sourceWidth = 800
-        val sourceHeight = 602
-        val scaleDownBy = EncodingUtils.findEvenScaleDownBy(sourceWidth, sourceHeight, 240, 180)
-            ?: throw Exception("scale should not be null!")
-
-        Assert.assertTrue((sourceWidth / scaleDownBy).toInt().isEven())
-        Assert.assertTrue((sourceHeight / scaleDownBy).toInt().isEven())
-    }
 }