content: /*
   * Copyright (C) 2018 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.audio;
  
  import com.google.android.exoplayer2.C;
  import com.google.android.exoplayer2.Format;
  import com.google.android.exoplayer2.util.Util;
  
  /** Utilities for handling WAVE files. */
  public final class WavUtil {
  
    /** Four character code for "RIFF". */
    public static final int RIFF_FOURCC = 0x52494646;
    /** Four character code for "WAVE". */
    public static final int WAVE_FOURCC = 0x57415645;
    /** Four character code for "fmt ". */
    public static final int FMT_FOURCC = 0x666d7420;
    /** Four character code for "data". */
    public static final int DATA_FOURCC = 0x64617461;
    /** Four character code for "RF64". */
    public static final int RF64_FOURCC = 0x52463634;
    /** Four character code for "ds64". */
    public static final int DS64_FOURCC = 0x64733634;
  
    /** WAVE type value for integer PCM audio data. */
    public static final int TYPE_PCM = 0x0001;
    /** WAVE type value for float PCM audio data. */
    public static final int TYPE_FLOAT = 0x0003;
    /** WAVE type value for 8-bit ITU-T G.711 A-law audio data. */
    public static final int TYPE_ALAW = 0x0006;
    /** WAVE type value for 8-bit ITU-T G.711 mu-law audio data. */
    public static final int TYPE_MLAW = 0x0007;
    /** WAVE type value for IMA ADPCM audio data. */
    public static final int TYPE_IMA_ADPCM = 0x0011;
    /** WAVE type value for extended WAVE format. */
    public static final int TYPE_WAVE_FORMAT_EXTENSIBLE = 0xFFFE;
  
    /**
     * Returns the WAVE format type value for the given {@link C.PcmEncoding}.
     *
     * @param pcmEncoding The {@link C.PcmEncoding} value.
     * @return The corresponding WAVE format type.
     * @throws IllegalArgumentException If {@code pcmEncoding} is not a {@link C.PcmEncoding}, or if
     *     it's {@link C#ENCODING_INVALID} or {@link Format#NO_VALUE}.
     */
    public static int getTypeForPcmEncoding(@C.PcmEncoding int pcmEncoding) {
      switch (pcmEncoding) {
        case C.ENCODING_PCM_8BIT:
        case C.ENCODING_PCM_16BIT:
        case C.ENCODING_PCM_24BIT:
        case C.ENCODING_PCM_32BIT:
          return TYPE_PCM;
        case C.ENCODING_PCM_FLOAT:
          return TYPE_FLOAT;
        case C.ENCODING_PCM_16BIT_BIG_ENDIAN: // Not TYPE_PCM, because TYPE_PCM is little endian.
        case C.ENCODING_INVALID:
        case Format.NO_VALUE:
        default:
          throw new IllegalArgumentException();
      }
    }
  
    /**
     * Returns the {@link C.PcmEncoding} for the given WAVE format type value, or {@link
     * C#ENCODING_INVALID} if the type is not a known PCM type.
     */
    public static @C.PcmEncoding int getPcmEncodingForType(int type, int bitsPerSample) {
      switch (type) {
        case TYPE_PCM:
        case TYPE_WAVE_FORMAT_EXTENSIBLE:
          return Util.getPcmEncoding(bitsPerSample);
        case TYPE_FLOAT:
          return bitsPerSample == 32 ? C.ENCODING_PCM_FLOAT : C.ENCODING_INVALID;
        default:
          return C.ENCODING_INVALID;
      }
    }
  
    private WavUtil() {
      // Prevent instantiation.
    }
  }
  