content: /*
   * Copyright (C) 2016 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.decoder;
  
  import androidx.annotation.Nullable;
  import androidx.annotation.RequiresApi;
  import com.google.android.exoplayer2.C;
  import com.google.android.exoplayer2.util.Assertions;
  import com.google.android.exoplayer2.util.Util;
  
  /**
   * Metadata describing the structure of an encrypted input sample.
   *
   * <p>This class is a compatibility wrapper for {@link android.media.MediaCodec.CryptoInfo}.
   */
  public final class CryptoInfo {
  
    /**
     * The 16 byte initialization vector. If the initialization vector of the content is shorter than
     * 16 bytes, 0 byte padding is appended to extend the vector to the required 16 byte length.
     *
     * @see android.media.MediaCodec.CryptoInfo#iv
     */
    @Nullable public byte[] iv;
    /**
     * The 16 byte key id.
     *
     * @see android.media.MediaCodec.CryptoInfo#key
     */
    @Nullable public byte[] key;
    /**
     * The type of encryption that has been applied. Must be one of the {@link C.CryptoMode} values.
     *
     * @see android.media.MediaCodec.CryptoInfo#mode
     */
    public @C.CryptoMode int mode;
    /**
     * The number of leading unencrypted bytes in each sub-sample. If null, all bytes are treated as
     * encrypted and {@link #numBytesOfEncryptedData} must be specified.
     *
     * @see android.media.MediaCodec.CryptoInfo#numBytesOfClearData
     */
    @Nullable public int[] numBytesOfClearData;
    /**
     * The number of trailing encrypted bytes in each sub-sample. If null, all bytes are treated as
     * clear and {@link #numBytesOfClearData} must be specified.
     *
     * @see android.media.MediaCodec.CryptoInfo#numBytesOfEncryptedData
     */
    @Nullable public int[] numBytesOfEncryptedData;
    /**
     * The number of subSamples that make up the buffer's contents.
     *
     * @see android.media.MediaCodec.CryptoInfo#numSubSamples
     */
    public int numSubSamples;
    /**
     * @see android.media.MediaCodec.CryptoInfo.Pattern
     */
    public int encryptedBlocks;
    /**
     * @see android.media.MediaCodec.CryptoInfo.Pattern
     */
    public int clearBlocks;
  
    private final android.media.MediaCodec.CryptoInfo frameworkCryptoInfo;
    @Nullable private final PatternHolderV24 patternHolder;
  
    public CryptoInfo() {
      frameworkCryptoInfo = new android.media.MediaCodec.CryptoInfo();
      patternHolder = Util.SDK_INT >= 24 ? new PatternHolderV24(frameworkCryptoInfo) : null;
    }
  
    /**
     * @see android.media.MediaCodec.CryptoInfo#set(int, int[], int[], byte[], byte[], int)
     */
    public void set(
        int numSubSamples,
        int[] numBytesOfClearData,
        int[] numBytesOfEncryptedData,
        byte[] key,
        byte[] iv,
        @C.CryptoMode int mode,
        int encryptedBlocks,
        int clearBlocks) {
      this.numSubSamples = numSubSamples;
      this.numBytesOfClearData = numBytesOfClearData;
      this.numBytesOfEncryptedData = numBytesOfEncryptedData;
      this.key = key;
      this.iv = iv;
      this.mode = mode;
      this.encryptedBlocks = encryptedBlocks;
      this.clearBlocks = clearBlocks;
      // Update frameworkCryptoInfo fields directly because CryptoInfo.set performs an unnecessary
      // object allocation on Android N.
      frameworkCryptoInfo.numSubSamples = numSubSamples;
      frameworkCryptoInfo.numBytesOfClearData = numBytesOfClearData;
      frameworkCryptoInfo.numBytesOfEncryptedData = numBytesOfEncryptedData;
      frameworkCryptoInfo.key = key;
      frameworkCryptoInfo.iv = iv;
      frameworkCryptoInfo.mode = mode;
      if (Util.SDK_INT >= 24) {
        Assertions.checkNotNull(patternHolder).set(encryptedBlocks, clearBlocks);
      }
    }
  
    /**
     * Returns an equivalent {@link android.media.MediaCodec.CryptoInfo} instance.
     *
     * <p>Successive calls to this method on a single {@link CryptoInfo} will return the same
     * instance. Changes to the {@link CryptoInfo} will be reflected in the returned object. The
     * return object should not be modified directly.
     *
     * @return The equivalent {@link android.media.MediaCodec.CryptoInfo} instance.
     */
    public android.media.MediaCodec.CryptoInfo getFrameworkCryptoInfo() {
      return frameworkCryptoInfo;
    }
  
    /**
     * Increases the number of clear data for the first sub sample by {@code count}.
     *
     * <p>If {@code count} is 0, this method is a no-op. Otherwise, it adds {@code count} to {@link
     * #numBytesOfClearData}[0].
     *
     * <p>If {@link #numBytesOfClearData} is null (which is permitted), this method will instantiate
     * it to a new {@code int[1]}.
     *
     * @param count The number of bytes to be added to the first subSample of {@link
     *     #numBytesOfClearData}.
     */
    public void increaseClearDataFirstSubSampleBy(int count) {
      if (count == 0) {
        return;
      }
      if (numBytesOfClearData == null) {
        numBytesOfClearData = new int[1];
        frameworkCryptoInfo.numBytesOfClearData = numBytesOfClearData;
      }
      numBytesOfClearData[0] += count;
    }
  
    @RequiresApi(24)
    private static final class PatternHolderV24 {
  
      private final android.media.MediaCodec.CryptoInfo frameworkCryptoInfo;
      private final android.media.MediaCodec.CryptoInfo.Pattern pattern;
  
      private PatternHolderV24(android.media.MediaCodec.CryptoInfo frameworkCryptoInfo) {
        this.frameworkCryptoInfo = frameworkCryptoInfo;
        pattern = new android.media.MediaCodec.CryptoInfo.Pattern(0, 0);
      }
  
      private void set(int encryptedBlocks, int clearBlocks) {
        pattern.set(encryptedBlocks, clearBlocks);
        frameworkCryptoInfo.setPattern(pattern);
      }
    }
  }
  