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.video;
  
  import androidx.annotation.Nullable;
  import com.google.android.exoplayer2.C;
  import com.google.android.exoplayer2.Format;
  import com.google.android.exoplayer2.ParserException;
  import com.google.android.exoplayer2.util.CodecSpecificDataUtil;
  import com.google.android.exoplayer2.util.NalUnitUtil;
  import com.google.android.exoplayer2.util.ParsableByteArray;
  import java.util.Collections;
  import java.util.List;
  
  /** HEVC configuration data. */
  public final class HevcConfig {
  
    /**
     * Parses HEVC configuration data.
     *
     * @param data A {@link ParsableByteArray}, whose position is set to the start of the HEVC
     *     configuration data to parse.
     * @return A parsed representation of the HEVC configuration data.
     * @throws ParserException If an error occurred parsing the data.
     */
    public static HevcConfig parse(ParsableByteArray data) throws ParserException {
      try {
        data.skipBytes(21); // Skip to the NAL unit length size field.
        int lengthSizeMinusOne = data.readUnsignedByte() & 0x03;
  
        // Calculate the combined size of all VPS/SPS/PPS bitstreams.
        int numberOfArrays = data.readUnsignedByte();
        int csdLength = 0;
        int csdStartPosition = data.getPosition();
        for (int i = 0; i < numberOfArrays; i++) {
          data.skipBytes(1); // completeness (1), reserved (1), nal_unit_type (6)
          int numberOfNalUnits = data.readUnsignedShort();
          for (int j = 0; j < numberOfNalUnits; j++) {
            int nalUnitLength = data.readUnsignedShort();
            csdLength += 4 + nalUnitLength; // Start code and NAL unit.
            data.skipBytes(nalUnitLength);
          }
        }
  
        // Concatenate the codec-specific data into a single buffer.
        data.setPosition(csdStartPosition);
        byte[] buffer = new byte[csdLength];
        int bufferPosition = 0;
        int width = Format.NO_VALUE;
        int height = Format.NO_VALUE;
        @C.ColorSpace int colorSpace = Format.NO_VALUE;
        @C.ColorRange int colorRange = Format.NO_VALUE;
        @C.ColorTransfer int colorTransfer = Format.NO_VALUE;
        float pixelWidthHeightRatio = 1;
        @Nullable String codecs = null;
        for (int i = 0; i < numberOfArrays; i++) {
          int nalUnitType =
              data.readUnsignedByte() & 0x3F; // completeness (1), reserved (1), nal_unit_type (6)
          int numberOfNalUnits = data.readUnsignedShort();
          for (int j = 0; j < numberOfNalUnits; j++) {
            int nalUnitLength = data.readUnsignedShort();
            System.arraycopy(
                NalUnitUtil.NAL_START_CODE,
                0,
                buffer,
                bufferPosition,
                NalUnitUtil.NAL_START_CODE.length);
            bufferPosition += NalUnitUtil.NAL_START_CODE.length;
            System.arraycopy(
                data.getData(), data.getPosition(), buffer, bufferPosition, nalUnitLength);
            if (nalUnitType == SPS_NAL_UNIT_TYPE && j == 0) {
              NalUnitUtil.H265SpsData spsData =
                  NalUnitUtil.parseH265SpsNalUnit(
                      buffer, bufferPosition, bufferPosition + nalUnitLength);
              width = spsData.width;
              height = spsData.height;
              colorSpace = spsData.colorSpace;
              colorRange = spsData.colorRange;
              colorTransfer = spsData.colorTransfer;
              pixelWidthHeightRatio = spsData.pixelWidthHeightRatio;
              codecs =
                  CodecSpecificDataUtil.buildHevcCodecString(
                      spsData.generalProfileSpace,
                      spsData.generalTierFlag,
                      spsData.generalProfileIdc,
                      spsData.generalProfileCompatibilityFlags,
                      spsData.constraintBytes,
                      spsData.generalLevelIdc);
            }
            bufferPosition += nalUnitLength;
            data.skipBytes(nalUnitLength);
          }
        }
  
        List<byte[]> initializationData =
            csdLength == 0 ? Collections.emptyList() : Collections.singletonList(buffer);
        return new HevcConfig(
            initializationData,
            lengthSizeMinusOne + 1,
            width,
            height,
            pixelWidthHeightRatio,
            codecs,
            colorSpace,
            colorRange,
            colorTransfer);
      } catch (ArrayIndexOutOfBoundsException e) {
        throw ParserException.createForMalformedContainer("Error parsing HEVC config", e);
      }
    }
  
    private static final int SPS_NAL_UNIT_TYPE = 33;
  
    /**
     * List of buffers containing the codec-specific data to be provided to the decoder.
     *
     * <p>See {@link Format#initializationData}.
     */
    public final List<byte[]> initializationData;
  
    /** The length of the NAL unit length field in the bitstream's container, in bytes. */
    public final int nalUnitLengthFieldLength;
  
    /** The width of each decoded frame, or {@link Format#NO_VALUE} if unknown. */
    public final int width;
  
    /** The height of each decoded frame, or {@link Format#NO_VALUE} if unknown. */
    public final int height;
  
    /** The pixel width to height ratio. */
    public final float pixelWidthHeightRatio;
  
    /**
     * The {@link C.ColorSpace} of the video or {@link Format#NO_VALUE} if unknown or not applicable.
     */
    public final @C.ColorSpace int colorSpace;
  
    /**
     * The {@link C.ColorRange} of the video or {@link Format#NO_VALUE} if unknown or not applicable.
     */
    public final @C.ColorRange int colorRange;
  
    /**
     * The {@link C.ColorTransfer} of the video or {@link Format#NO_VALUE} if unknown or not
     * applicable.
     */
    public final @C.ColorTransfer int colorTransfer;
  
    /**
     * An RFC 6381 codecs string representing the video format, or {@code null} if not known.
     *
     * <p>See {@link Format#codecs}.
     */
    @Nullable public final String codecs;
  
    private HevcConfig(
        List<byte[]> initializationData,
        int nalUnitLengthFieldLength,
        int width,
        int height,
        float pixelWidthHeightRatio,
        @Nullable String codecs,
        @C.ColorSpace int colorSpace,
        @C.ColorRange int colorRange,
        @C.ColorTransfer int colorTransfer) {
      this.initializationData = initializationData;
      this.nalUnitLengthFieldLength = nalUnitLengthFieldLength;
      this.width = width;
      this.height = height;
      this.pixelWidthHeightRatio = pixelWidthHeightRatio;
      this.codecs = codecs;
      this.colorSpace = colorSpace;
      this.colorRange = colorRange;
      this.colorTransfer = colorTransfer;
    }
  }
  