| /* |
| * 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.extractor.ogg; |
| |
| import static com.google.android.exoplayer2.util.Assertions.checkNotNull; |
| |
| import com.google.android.exoplayer2.Format; |
| import com.google.android.exoplayer2.audio.OpusUtil; |
| import com.google.android.exoplayer2.util.MimeTypes; |
| import com.google.android.exoplayer2.util.ParsableByteArray; |
| import java.util.Arrays; |
| import java.util.List; |
| import org.checkerframework.checker.nullness.qual.EnsuresNonNullIf; |
| |
| /** {@link StreamReader} to extract Opus data out of Ogg byte stream. */ |
| /* package */ final class OpusReader extends StreamReader { |
| |
| private static final int OPUS_CODE = 0x4f707573; |
| private static final byte[] OPUS_SIGNATURE = {'O', 'p', 'u', 's', 'H', 'e', 'a', 'd'}; |
| |
| private boolean headerRead; |
| |
| public static boolean verifyBitstreamType(ParsableByteArray data) { |
| if (data.bytesLeft() < OPUS_SIGNATURE.length) { |
| return false; |
| } |
| byte[] header = new byte[OPUS_SIGNATURE.length]; |
| data.readBytes(header, 0, OPUS_SIGNATURE.length); |
| return Arrays.equals(header, OPUS_SIGNATURE); |
| } |
| |
| @Override |
| protected void reset(boolean headerData) { |
| super.reset(headerData); |
| if (headerData) { |
| headerRead = false; |
| } |
| } |
| |
| @Override |
| protected long preparePayload(ParsableByteArray packet) { |
| return convertTimeToGranule(getPacketDurationUs(packet.getData())); |
| } |
| |
| @Override |
| @EnsuresNonNullIf(expression = "#3.format", result = false) |
| protected boolean readHeaders(ParsableByteArray packet, long position, SetupData setupData) { |
| if (!headerRead) { |
| byte[] headerBytes = Arrays.copyOf(packet.getData(), packet.limit()); |
| int channelCount = OpusUtil.getChannelCount(headerBytes); |
| List<byte[]> initializationData = OpusUtil.buildInitializationData(headerBytes); |
| setupData.format = |
| new Format.Builder() |
| .setSampleMimeType(MimeTypes.AUDIO_OPUS) |
| .setChannelCount(channelCount) |
| .setSampleRate(OpusUtil.SAMPLE_RATE) |
| .setInitializationData(initializationData) |
| .build(); |
| headerRead = true; |
| return true; |
| } else { |
| checkNotNull(setupData.format); // Has been set when the header was read. |
| boolean headerPacket = packet.readInt() == OPUS_CODE; |
| packet.setPosition(0); |
| return headerPacket; |
| } |
| } |
| |
| /** |
| * Returns the duration of the given audio packet. |
| * |
| * @param packet Contains audio data. |
| * @return Returns the duration of the given audio packet. |
| */ |
| private long getPacketDurationUs(byte[] packet) { |
| int toc = packet[0] & 0xFF; |
| int frames; |
| switch (toc & 0x3) { |
| case 0: |
| frames = 1; |
| break; |
| case 1: |
| case 2: |
| frames = 2; |
| break; |
| default: |
| frames = packet[1] & 0x3F; |
| break; |
| } |
| |
| int config = toc >> 3; |
| int length = config & 0x3; |
| if (config >= 16) { |
| length = 2500 << length; |
| } else if (config >= 12) { |
| length = 10000 << (length & 0x1); |
| } else if (length == 3) { |
| length = 60000; |
| } else { |
| length = 10000 << length; |
| } |
| return (long) frames * length; |
| } |
| } |