Add checks to HW codecs to ensure unsupported features are not used.

Add checks to ensure encoder is not used below API level 19. Removes
global @TargetApi from MediaCodecUtils since it is also used by the
decoder. Ensures that texture mode is never enabled below API level 18.

Bug: webrtc:9821
Change-Id: I2ca1014bf8995719c970eb1449b0acbf7b3c883e
Reviewed-on: https://webrtc-review.googlesource.com/c/103701
Reviewed-by: Paulina Hensman <phensman@webrtc.org>
Commit-Queue: Sami Kalliomäki <sakal@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24990}

sdk/android/api/org/webrtc/HardwareVideoEncoderFactory.java

@@ -64,6 +64,11 @@ public class HardwareVideoEncoderFactory implements VideoEncoderFactory {
   @Nullable
   @Override
   public VideoEncoder createEncoder(VideoCodecInfo input) {
+    // HW encoding is not supported below Android Kitkat.
+    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
+      return null;
+    }
+
     VideoCodecType type = VideoCodecType.valueOf(input.name);
     MediaCodecInfo info = findCodecForType(type);
 
@@ -100,6 +105,11 @@ public class HardwareVideoEncoderFactory implements VideoEncoderFactory {
 
   @Override
   public VideoCodecInfo[] getSupportedCodecs() {
+    // HW encoding is not supported below Android Kitkat.
+    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
+      return new VideoCodecInfo[0];
+    }
+
     List<VideoCodecInfo> supportedCodecInfos = new ArrayList<VideoCodecInfo>();
     // Generate a list of supported codecs in order of preference:
     // VP8, VP9, H264 (high profile), and H264 (baseline profile).

sdk/android/src/java/org/webrtc/AndroidVideoDecoder.java

@@ -27,7 +27,6 @@ import org.webrtc.ThreadUtils.ThreadChecker;
 /**
  * Android hardware video decoder.
  */
-@TargetApi(16)
 @SuppressWarnings("deprecation")
 // Cannot support API 16 without using deprecated methods.
 // TODO(sakal): Rename to MediaCodecVideoDecoder once the deprecated implementation is removed.

sdk/android/src/java/org/webrtc/HardwareVideoEncoder.java

@@ -28,7 +28,11 @@ import java.util.concurrent.TimeUnit;
 import javax.annotation.Nullable;
 import org.webrtc.ThreadUtils.ThreadChecker;
 
-/** Android hardware video encoder. */
+/**
+ * Android hardware video encoder.
+ *
+ * @note This class is only supported on Android Kitkat and above.
+ */
 @TargetApi(19)
 @SuppressWarnings("deprecation") // Cannot support API level 19 without using deprecated methods.
 class HardwareVideoEncoder implements VideoEncoder {

sdk/android/src/java/org/webrtc/MediaCodecUtils.java

@@ -14,12 +14,12 @@ import android.annotation.TargetApi;
 import android.media.MediaCodec;
 import android.media.MediaCodecInfo;
 import android.media.MediaCodecInfo.CodecCapabilities;
+import android.os.Build;
 import java.util.HashMap;
 import java.util.Map;
 import javax.annotation.Nullable;
 
 /** Container class for static constants and helpers used with MediaCodec. */
-@TargetApi(18)
 // We are forced to use the old API because we want to support API level < 21.
 @SuppressWarnings("deprecation")
 class MediaCodecUtils {
@@ -56,7 +56,15 @@ class MediaCodecUtils {
       MediaCodecUtils.COLOR_QCOM_FORMATYUV420PackedSemiPlanar32m};
 
   // Color formats supported by texture mode encoding - in order of preference.
-  static final int[] TEXTURE_COLOR_FORMATS = {MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface};
+  static final int[] TEXTURE_COLOR_FORMATS = getTextureColorFormats();
+
+  private static int[] getTextureColorFormats() {
+    if (Build.VERSION.SDK_INT >= 18) {
+      return new int[] {MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface};
+    } else {
+      return new int[] {};
+    }
+  }
 
   static @Nullable Integer selectColorFormat(
       int[] supportedColorFormats, CodecCapabilities capabilities) {