Add format fallback ranking.

Introduce an interface EncoderSelector for developers to filter out unwanted
encoders.

PiperOrigin-RevId: 425611421

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/Codec.java

@@ -47,7 +47,7 @@ public final class Codec {
   public interface DecoderFactory {
   public interface DecoderFactory {
 
 
     /** A default {@code DecoderFactory} implementation. */
     /** A default {@code DecoderFactory} implementation. */
-    DecoderFactory DEFAULT = new DefaultCodecFactory();
+    DecoderFactory DEFAULT = new DefaultCodecFactory(/* videoEncoderSelector= */ null);
 
 
     /**
     /**
      * Returns a {@link Codec} for audio decoding.
      * Returns a {@link Codec} for audio decoding.
@@ -76,7 +76,7 @@ public final class Codec {
   public interface EncoderFactory {
   public interface EncoderFactory {
 
 
     /** A default {@code EncoderFactory} implementation. */
     /** A default {@code EncoderFactory} implementation. */
-    EncoderFactory DEFAULT = new DefaultCodecFactory();
+    EncoderFactory DEFAULT = new DefaultCodecFactory(EncoderSelector.DEFAULT);
 
 
     /**
     /**
      * Returns a {@link Codec} for audio encoding.
      * Returns a {@link Codec} for audio encoding.

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/EncoderSelector.java

+/*
+ * Copyright 2022 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 com.google.android.exoplayer2.transformer;
+
+import android.media.MediaCodec;
+import android.media.MediaCodecInfo;
+import com.google.android.exoplayer2.util.MimeTypes;
+import java.util.List;
+
+/** Selector of {@link MediaCodec} encoder instances. */
+public interface EncoderSelector {
+
+  /**
+   * Default implementation of {@link EncoderSelector}, which returns the preferred encoders for the
+   * given {@link MimeTypes MIME type}.
+   */
+  EncoderSelector DEFAULT = EncoderUtil::getSupportedEncoders;
+
+  /**
+   * Returns a list of encoders that can encode media in the specified {@code mimeType}, in priority
+   * order.
+   *
+   * @param mimeType The {@link MimeTypes MIME type} for which an encoder is required.
+   * @return An unmodifiable list of {@link MediaCodecInfo encoders} that supports the {@code
+   *     mimeType}. The list may be empty.
+   */
+  List<MediaCodecInfo> selectEncoderInfos(String mimeType);
+}

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/EncoderUtil.java

@@ -22,7 +22,11 @@ import android.media.MediaCodec;
 import android.media.MediaCodecInfo;
 import android.media.MediaCodecInfo;
 import android.media.MediaCodecList;
 import android.media.MediaCodecList;
 import android.util.Pair;
 import android.util.Pair;
+import androidx.annotation.DoNotInline;
 import androidx.annotation.Nullable;
 import androidx.annotation.Nullable;
+import androidx.annotation.RequiresApi;
+import com.google.android.exoplayer2.util.MimeTypes;
+import com.google.android.exoplayer2.util.Util;
 import com.google.common.base.Ascii;
 import com.google.common.base.Ascii;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableList;
 import java.util.ArrayList;
 import java.util.ArrayList;
@@ -128,6 +132,42 @@ public final class EncoderUtil {
         .clamp(bitrate);
         .clamp(bitrate);
   }
   }
 
 
+  /** Checks if a {@link MediaCodecInfo codec} is hardware-accelerated. */
+  public static boolean isHardwareAccelerated(MediaCodecInfo encoderInfo, String mimeType) {
+    // TODO(b/214964116): Merge into MediaCodecUtil.
+    if (Util.SDK_INT >= 29) {
+      return Api29.isHardwareAccelerated(encoderInfo);
+    }
+    // codecInfo.isHardwareAccelerated() == !codecInfo.isSoftwareOnly() is not necessarily true.
+    // However, we assume this to be true as an approximation.
+    return !isSoftwareOnly(encoderInfo, mimeType);
+  }
+
+  private static boolean isSoftwareOnly(MediaCodecInfo encoderInfo, String mimeType) {
+    if (Util.SDK_INT >= 29) {
+      return Api29.isSoftwareOnly(encoderInfo);
+    }
+
+    if (MimeTypes.isAudio(mimeType)) {
+      // Assume audio decoders are software only.
+      return true;
+    }
+    String codecName = Ascii.toLowerCase(encoderInfo.getName());
+    if (codecName.startsWith("arc.")) {
+      // App Runtime for Chrome (ARC) codecs
+      return false;
+    }
+
+    // Estimate whether a codec is software-only, to emulate isSoftwareOnly on API < 29.
+    return codecName.startsWith("omx.google.")
+        || codecName.startsWith("omx.ffmpeg.")
+        || (codecName.startsWith("omx.sec.") && codecName.contains(".sw."))
+        || codecName.equals("omx.qcom.video.decoder.hevcswvdec")
+        || codecName.startsWith("c2.android.")
+        || codecName.startsWith("c2.google.")
+        || (!codecName.startsWith("omx.") && !codecName.startsWith("c2."));
+  }
+
   /**
   /**
    * Align to the closest resolution that respects the encoder's supported alignment.
    * Align to the closest resolution that respects the encoder's supported alignment.
    *
    *
@@ -152,5 +192,18 @@ public final class EncoderUtil {
     }
     }
   }
   }
 
 
+  @RequiresApi(29)
+  private static final class Api29 {
+    @DoNotInline
+    public static boolean isHardwareAccelerated(MediaCodecInfo encoderInfo) {
+      return encoderInfo.isHardwareAccelerated();
+    }
+
+    @DoNotInline
+    public static boolean isSoftwareOnly(MediaCodecInfo encoderInfo) {
+      return encoderInfo.isSoftwareOnly();
+    }
+  }
+
   private EncoderUtil() {}
   private EncoderUtil() {}
 }
 }