From fed88cf6f5cbb6c57f884a4e2a39c68e562d605c Mon Sep 17 00:00:00 2001
From: huangdarwin <huangdarwin@google.com>
Date: Fri, 27 Oct 2023 05:21:26 -0700
Subject: [PATCH] Flush: Disallow flushing when there's no active input.

Throws when calling flush when there's no active input, for example
before an input stream is registered or after all output streams have
ended.

PiperOrigin-RevId: 577165419
---
 .../DefaultVideoFrameProcessorFlushTest.java      | 15 +++------------
 .../media3/effect/DefaultVideoFrameProcessor.java |  3 ---
 2 files changed, 3 insertions(+), 15 deletions(-)

diff --git a/libraries/effect/src/androidTest/java/androidx/media3/effect/DefaultVideoFrameProcessorFlushTest.java b/libraries/effect/src/androidTest/java/androidx/media3/effect/DefaultVideoFrameProcessorFlushTest.java
index 119335191a..2d497c51ce 100644
--- a/libraries/effect/src/androidTest/java/androidx/media3/effect/DefaultVideoFrameProcessorFlushTest.java
+++ b/libraries/effect/src/androidTest/java/androidx/media3/effect/DefaultVideoFrameProcessorFlushTest.java
@@ -18,6 +18,7 @@ package androidx.media3.effect;
 import static androidx.media3.common.util.Assertions.checkNotNull;
 import static androidx.media3.test.utils.BitmapPixelTestUtil.readBitmapUnpremultipliedAlpha;
 import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertThrows;
 
 import android.graphics.Bitmap;
 import androidx.media3.common.C;
@@ -60,20 +61,10 @@ public class DefaultVideoFrameProcessorFlushTest {
 
   @Test
   @RequiresNonNull({"testId"})
-  public void imageInput_flushBeforeInput_outputsAllFrames() throws Exception {
+  public void imageInput_flushBeforeInput_throwsException() throws Exception {
     videoFrameProcessorTestRunner = createDefaultVideoFrameProcessorTestRunner(testId);
-    Bitmap bitmap = readBitmapUnpremultipliedAlpha(ORIGINAL_PNG_ASSET_PATH);
-    int inputFrameCount = 3;
 
-    videoFrameProcessorTestRunner.flush();
-    videoFrameProcessorTestRunner.queueInputBitmap(
-        bitmap,
-        /* durationUs= */ inputFrameCount * C.MICROS_PER_SECOND,
-        /* offsetToAddUs= */ 0L,
-        /* frameRate= */ 1);
-    videoFrameProcessorTestRunner.endFrameProcessing();
-
-    assertThat(outputFrameCount).isEqualTo(inputFrameCount);
+    assertThrows(IllegalStateException.class, videoFrameProcessorTestRunner::flush);
   }
 
   // This tests a condition that is difficult to synchronize, and is subject to a race condition. It
diff --git a/libraries/effect/src/main/java/androidx/media3/effect/DefaultVideoFrameProcessor.java b/libraries/effect/src/main/java/androidx/media3/effect/DefaultVideoFrameProcessor.java
index df4ffcf622..da0b9bd814 100644
--- a/libraries/effect/src/main/java/androidx/media3/effect/DefaultVideoFrameProcessor.java
+++ b/libraries/effect/src/main/java/androidx/media3/effect/DefaultVideoFrameProcessor.java
@@ -559,9 +559,6 @@ public final class DefaultVideoFrameProcessor implements VideoFrameProcessor {
    */
   @Override
   public void flush() {
-    if (!inputSwitcher.hasActiveInput()) {
-      return;
-    }
     try {
       videoFrameProcessingTaskExecutor.flush();