Merge transformer video renderers.

This change merges `TransformerMuxingVideoRenderer` and
`TransformerTranscodingVideoRenderer` into `TransformerVideoRenderer`.
Besides all features supported by `TransformerTranscodingVideoRenderer`
the new merged `TransformerVideoRenderer` also supports SEF slow motion
flatting without re-encoding like the `TransformerMuxingVideoRenderer`.
To do this, it uses a `SefSlowMotionVideoSampleTransformer` with
the `PassthroughPipeline`.

PiperOrigin-RevId: 410531478

libraries/transformer/src/main/java/androidx/media3/transformer/TranscodingTransformer.java

@@ -736,8 +736,7 @@ public final class TranscodingTransformer {
       }
       if (!transformation.removeVideo) {
         renderers[index] =
-            new TransformerTranscodingVideoRenderer(
+            new TransformerVideoRenderer(context, muxerWrapper, mediaClock, transformation);
-                context, muxerWrapper, mediaClock, transformation);
         index++;
       }
       return renderers;

libraries/transformer/src/main/java/androidx/media3/transformer/Transformer.java

@@ -509,7 +509,7 @@ public final class Transformer {
             .build();
     player =
         new ExoPlayer.Builder(
-                context, new TransformerRenderersFactory(muxerWrapper, transformation))
+                context, new TransformerRenderersFactory(context, muxerWrapper, transformation))
             .setMediaSourceFactory(mediaSourceFactory)
             .setTrackSelector(trackSelector)
             .setLoadControl(loadControl)
@@ -594,11 +594,14 @@ public final class Transformer {
 
   private static final class TransformerRenderersFactory implements RenderersFactory {
 
+    private final Context context;
     private final MuxerWrapper muxerWrapper;
     private final TransformerMediaClock mediaClock;
     private final Transformation transformation;
 
-    public TransformerRenderersFactory(MuxerWrapper muxerWrapper, Transformation transformation) {
+    public TransformerRenderersFactory(
+        Context context, MuxerWrapper muxerWrapper, Transformation transformation) {
+      this.context = context;
       this.muxerWrapper = muxerWrapper;
       this.transformation = transformation;
       mediaClock = new TransformerMediaClock();
@@ -620,7 +623,7 @@ public final class Transformer {
       }
       if (!transformation.removeVideo) {
         renderers[index] =
-            new TransformerMuxingVideoRenderer(muxerWrapper, mediaClock, transformation);
+            new TransformerVideoRenderer(context, muxerWrapper, mediaClock, transformation);
         index++;
       }
       return renderers;

libraries/transformer/src/main/java/androidx/media3/transformer/TransformerAudioRenderer.java

@@ -101,8 +101,9 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
   }
 
   /**
-   * Attempts to write sample pipeline output data to the muxer, and returns whether it may be
+   * Attempts to write sample pipeline output data to the muxer.
-   * possible to write more data immediately by calling this method again.
+   *
+   * @return Whether it may be possible to write more data immediately by calling this method again.
    */
   @RequiresNonNull("samplePipeline")
   private boolean feedMuxerFromPipeline() {
@@ -136,8 +137,9 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
   }
 
   /**
-   * Attempts to pass input data to the sample pipeline, and returns whether it may be possible to
+   * Attempts to pass input data to the sample pipeline.
-   * pass more data immediately by calling this method again.
+   *
+   * @return Whether it may be possible to pass more data immediately by calling this method again.
    */
   @RequiresNonNull("samplePipeline")
   private boolean feedPipelineFromInput() {

libraries/transformer/src/main/java/androidx/media3/transformer/TransformerMuxingVideoRenderer.java

@@ -1,129 +0,0 @@
-/*
- * Copyright 2020 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package androidx.media3.transformer;
-
-import static androidx.media3.common.util.Assertions.checkNotNull;
-import static androidx.media3.exoplayer.source.SampleStream.FLAG_REQUIRE_FORMAT;
-
-import androidx.annotation.Nullable;
-import androidx.annotation.RequiresApi;
-import androidx.media3.common.C;
-import androidx.media3.common.Format;
-import androidx.media3.decoder.DecoderInputBuffer;
-import androidx.media3.exoplayer.FormatHolder;
-import androidx.media3.exoplayer.source.SampleStream.ReadDataResult;
-import java.nio.ByteBuffer;
-
-/** A video renderer that doesn't re-encoder the samples. */
-@RequiresApi(18)
-/* package */ final class TransformerMuxingVideoRenderer extends TransformerBaseRenderer {
-
-  private static final String TAG = "TransformerVideoRenderer";
-
-  private final DecoderInputBuffer buffer;
-
-  @Nullable private SampleTransformer sampleTransformer;
-
-  private boolean formatRead;
-  private boolean isBufferPending;
-  private boolean isInputStreamEnded;
-
-  public TransformerMuxingVideoRenderer(
-      MuxerWrapper muxerWrapper, TransformerMediaClock mediaClock, Transformation transformation) {
-    super(C.TRACK_TYPE_VIDEO, muxerWrapper, mediaClock, transformation);
-    buffer = new DecoderInputBuffer(DecoderInputBuffer.BUFFER_REPLACEMENT_MODE_DIRECT);
-  }
-
-  @Override
-  public String getName() {
-    return TAG;
-  }
-
-  @Override
-  public void render(long positionUs, long elapsedRealtimeUs) {
-    if (!isRendererStarted || isEnded()) {
-      return;
-    }
-
-    if (!formatRead) {
-      FormatHolder formatHolder = getFormatHolder();
-      @ReadDataResult int result = readSource(formatHolder, buffer, FLAG_REQUIRE_FORMAT);
-      if (result != C.RESULT_FORMAT_READ) {
-        return;
-      }
-      Format format = checkNotNull(formatHolder.format);
-      formatRead = true;
-      if (transformation.flattenForSlowMotion) {
-        sampleTransformer = new SefSlowMotionVideoSampleTransformer(format);
-      }
-      muxerWrapper.addTrackFormat(format);
-    }
-
-    while (true) {
-      // Read sample.
-      if (!isBufferPending && !readAndTransformBuffer()) {
-        return;
-      }
-      // Write sample.
-      isBufferPending =
-          !muxerWrapper.writeSample(
-              getTrackType(), buffer.data, buffer.isKeyFrame(), buffer.timeUs);
-      if (isBufferPending) {
-        return;
-      }
-    }
-  }
-
-  @Override
-  public boolean isEnded() {
-    return isInputStreamEnded;
-  }
-
-  /**
-   * Checks whether a sample can be read and, if so, reads it, transforms it and writes the
-   * resulting sample to the {@link #buffer}.
-   *
-   * <p>The buffer data can be set to null if the transformation applied discards the sample.
-   *
-   * @return Whether a sample has been read and transformed.
-   */
-  private boolean readAndTransformBuffer() {
-    buffer.clear();
-    @ReadDataResult int result = readSource(getFormatHolder(), buffer, /* readFlags= */ 0);
-    if (result == C.RESULT_FORMAT_READ) {
-      throw new IllegalStateException("Format changes are not supported.");
-    } else if (result == C.RESULT_NOTHING_READ) {
-      return false;
-    }
-
-    // Buffer read.
-
-    if (buffer.isEndOfStream()) {
-      isInputStreamEnded = true;
-      muxerWrapper.endTrack(getTrackType());
-      return false;
-    }
-    mediaClock.updateTimeForTrackType(getTrackType(), buffer.timeUs);
-    buffer.timeUs -= streamOffsetUs;
-    ByteBuffer data = checkNotNull(buffer.data);
-    data.flip();
-    if (sampleTransformer != null) {
-      sampleTransformer.transformSample(buffer);
-    }
-    return true;
-  }
-}

libraries/transformer/src/main/java/androidx/media3/transformer/TransformerVideoRenderer.java

@@ -33,18 +33,19 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 import org.checkerframework.checker.nullness.qual.RequiresNonNull;
 
 @RequiresApi(18)
-/* package */ final class TransformerTranscodingVideoRenderer extends TransformerBaseRenderer {
+/* package */ final class TransformerVideoRenderer extends TransformerBaseRenderer {
 
   private static final String TAG = "TransformerTranscodingVideoRenderer";
 
   private final Context context;
   private final DecoderInputBuffer decoderInputBuffer;
 
+  private @MonotonicNonNull SampleTransformer slowMotionSampleTransformer;
   private @MonotonicNonNull SamplePipeline samplePipeline;
   private boolean muxerWrapperTrackAdded;
   private boolean muxerWrapperTrackEnded;
 
-  public TransformerTranscodingVideoRenderer(
+  public TransformerVideoRenderer(
       Context context,
       MuxerWrapper muxerWrapper,
       TransformerMediaClock mediaClock,
@@ -105,12 +106,16 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
     } else {
       samplePipeline = new PassthroughSamplePipeline(decoderInputFormat);
     }
+    if (transformation.flattenForSlowMotion) {
+      slowMotionSampleTransformer = new SefSlowMotionVideoSampleTransformer(decoderInputFormat);
+    }
     return true;
   }
 
   /**
-   * Attempts to write sample pipeline output data to the muxer, and returns whether it may be
+   * Attempts to write sample pipeline output data to the muxer.
-   * possible to write more data immediately by calling this method again.
+   *
+   * @return Whether it may be possible to write more data immediately by calling this method again.
    */
   @RequiresNonNull("samplePipeline")
   private boolean feedMuxerFromPipeline() {
@@ -146,8 +151,15 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
   }
 
   /**
-   * Attempts to pass input data to the sample pipeline, and returns whether it may be possible to
+   * Attempts to:
-   * pass more data immediately by calling this method again.
+   *
+   * <ol>
+   *   <li>read input data,
+   *   <li>optionally, apply slow motion flattening, and
+   *   <li>pass input data to the sample pipeline.
+   * </ol>
+   *
+   * @return Whether it may be possible to read more data immediately by calling this method again.
    */
   @RequiresNonNull("samplePipeline")
   private boolean feedPipelineFromInput() {
@@ -160,9 +172,15 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
     int result = readSource(getFormatHolder(), samplePipelineInputBuffer, /* readFlags= */ 0);
     switch (result) {
       case C.RESULT_BUFFER_READ:
-        mediaClock.updateTimeForTrackType(getTrackType(), samplePipelineInputBuffer.timeUs);
+        if (samplePipelineInputBuffer.data != null
-        samplePipelineInputBuffer.timeUs -= streamOffsetUs;
+            && samplePipelineInputBuffer.data.position() > 0) {
-        samplePipelineInputBuffer.flip();
+          mediaClock.updateTimeForTrackType(getTrackType(), samplePipelineInputBuffer.timeUs);
+          samplePipelineInputBuffer.timeUs -= streamOffsetUs;
+          samplePipelineInputBuffer.flip();
+          if (slowMotionSampleTransformer != null) {
+            slowMotionSampleTransformer.transformSample(samplePipelineInputBuffer);
+          }
+        }
         samplePipeline.queueInputBuffer();
         return !samplePipelineInputBuffer.isEndOfStream();
       case C.RESULT_FORMAT_READ: