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;
  
  import android.annotation.TargetApi;
  import android.content.Context;
  import android.media.AudioFormat;
  import android.media.AudioManager;
  import android.media.MediaCodec;
  import android.media.MediaFormat;
  import android.support.annotation.IntDef;
  import android.view.Surface;
  import com.google.android.exoplayer2.PlayerMessage.Target;
  import com.google.android.exoplayer2.util.Util;
  import java.lang.annotation.Retention;
  import java.lang.annotation.RetentionPolicy;
  import java.util.UUID;
  
  /**
   * Defines constants used by the library.
   */
  @SuppressWarnings("InlinedApi")
  public final class C {
  
    private C() {}
  
    /**
     * Special constant representing a time corresponding to the end of a source. Suitable for use in
     * any time base.
     */
    public static final long TIME_END_OF_SOURCE = Long.MIN_VALUE;
  
    /**
     * Special constant representing an unset or unknown time or duration. Suitable for use in any
     * time base.
     */
    public static final long TIME_UNSET = Long.MIN_VALUE + 1;
  
    /**
     * Represents an unset or unknown index.
     */
    public static final int INDEX_UNSET = -1;
  
    /**
     * Represents an unset or unknown position.
     */
    public static final int POSITION_UNSET = -1;
  
    /**
     * Represents an unset or unknown length.
     */
    public static final int LENGTH_UNSET = -1;
  
    /**
     * The number of microseconds in one second.
     */
    public static final long MICROS_PER_SECOND = 1000000L;
  
    /**
     * The number of nanoseconds in one second.
     */
    public static final long NANOS_PER_SECOND = 1000000000L;
  
    /**
     * The name of the ASCII charset.
     */
    public static final String ASCII_NAME = "US-ASCII";
    /**
     * The name of the UTF-8 charset.
     */
    public static final String UTF8_NAME = "UTF-8";
  
    /**
     * The name of the UTF-16 charset.
     */
    public static final String UTF16_NAME = "UTF-16";
  
    /**
     * The name of the serif font family.
     */
    public static final String SERIF_NAME = "serif";
  
    /**
     * The name of the sans-serif font family.
     */
    public static final String SANS_SERIF_NAME = "sans-serif";
  
    /**
     * Crypto modes for a codec.
     */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef({CRYPTO_MODE_UNENCRYPTED, CRYPTO_MODE_AES_CTR, CRYPTO_MODE_AES_CBC})
    public @interface CryptoMode {}
    /**
     * @see MediaCodec#CRYPTO_MODE_UNENCRYPTED
     */
    public static final int CRYPTO_MODE_UNENCRYPTED = MediaCodec.CRYPTO_MODE_UNENCRYPTED;
    /**
     * @see MediaCodec#CRYPTO_MODE_AES_CTR
     */
    public static final int CRYPTO_MODE_AES_CTR = MediaCodec.CRYPTO_MODE_AES_CTR;
    /**
     * @see MediaCodec#CRYPTO_MODE_AES_CBC
     */
    public static final int CRYPTO_MODE_AES_CBC = MediaCodec.CRYPTO_MODE_AES_CBC;
  
    /**
     * Represents an unset {@link android.media.AudioTrack} session identifier. Equal to
     * {@link AudioManager#AUDIO_SESSION_ID_GENERATE}.
     */
    public static final int AUDIO_SESSION_ID_UNSET = AudioManager.AUDIO_SESSION_ID_GENERATE;
  
    /** Represents an audio encoding, or an invalid or unset value. */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef({
      Format.NO_VALUE,
      ENCODING_INVALID,
      ENCODING_PCM_8BIT,
      ENCODING_PCM_16BIT,
      ENCODING_PCM_24BIT,
      ENCODING_PCM_32BIT,
      ENCODING_PCM_FLOAT,
      ENCODING_AC3,
      ENCODING_E_AC3,
      ENCODING_DTS,
      ENCODING_DTS_HD,
      ENCODING_DOLBY_TRUEHD
    })
    public @interface Encoding {}
  
    /**
     * Represents a PCM audio encoding, or an invalid or unset value.
     */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef({Format.NO_VALUE, ENCODING_INVALID, ENCODING_PCM_8BIT, ENCODING_PCM_16BIT,
        ENCODING_PCM_24BIT, ENCODING_PCM_32BIT, ENCODING_PCM_FLOAT})
    public @interface PcmEncoding {}
    /** @see AudioFormat#ENCODING_INVALID */
    public static final int ENCODING_INVALID = AudioFormat.ENCODING_INVALID;
    /** @see AudioFormat#ENCODING_PCM_8BIT */
    public static final int ENCODING_PCM_8BIT = AudioFormat.ENCODING_PCM_8BIT;
    /** @see AudioFormat#ENCODING_PCM_16BIT */
    public static final int ENCODING_PCM_16BIT = AudioFormat.ENCODING_PCM_16BIT;
    /** PCM encoding with 24 bits per sample. */
    public static final int ENCODING_PCM_24BIT = 0x80000000;
    /** PCM encoding with 32 bits per sample. */
    public static final int ENCODING_PCM_32BIT = 0x40000000;
    /** @see AudioFormat#ENCODING_PCM_FLOAT */
    public static final int ENCODING_PCM_FLOAT = AudioFormat.ENCODING_PCM_FLOAT;
    /** @see AudioFormat#ENCODING_AC3 */
    public static final int ENCODING_AC3 = AudioFormat.ENCODING_AC3;
    /** @see AudioFormat#ENCODING_E_AC3 */
    public static final int ENCODING_E_AC3 = AudioFormat.ENCODING_E_AC3;
    /** @see AudioFormat#ENCODING_DTS */
    public static final int ENCODING_DTS = AudioFormat.ENCODING_DTS;
    /** @see AudioFormat#ENCODING_DTS_HD */
    public static final int ENCODING_DTS_HD = AudioFormat.ENCODING_DTS_HD;
    /** @see AudioFormat#ENCODING_DOLBY_TRUEHD */
    public static final int ENCODING_DOLBY_TRUEHD = AudioFormat.ENCODING_DOLBY_TRUEHD;
  
    /**
     * @see AudioFormat#CHANNEL_OUT_7POINT1_SURROUND
     */
    @SuppressWarnings("deprecation")
    public static final int CHANNEL_OUT_7POINT1_SURROUND = Util.SDK_INT < 23
        ? AudioFormat.CHANNEL_OUT_7POINT1 : AudioFormat.CHANNEL_OUT_7POINT1_SURROUND;
  
    /**
     * Stream types for an {@link android.media.AudioTrack}.
     */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef({STREAM_TYPE_ALARM, STREAM_TYPE_DTMF, STREAM_TYPE_MUSIC, STREAM_TYPE_NOTIFICATION,
        STREAM_TYPE_RING, STREAM_TYPE_SYSTEM, STREAM_TYPE_VOICE_CALL, STREAM_TYPE_USE_DEFAULT})
    public @interface StreamType {}
    /**
     * @see AudioManager#STREAM_ALARM
     */
    public static final int STREAM_TYPE_ALARM = AudioManager.STREAM_ALARM;
    /**
     * @see AudioManager#STREAM_DTMF
     */
    public static final int STREAM_TYPE_DTMF = AudioManager.STREAM_DTMF;
    /**
     * @see AudioManager#STREAM_MUSIC
     */
    public static final int STREAM_TYPE_MUSIC = AudioManager.STREAM_MUSIC;
    /**
     * @see AudioManager#STREAM_NOTIFICATION
     */
    public static final int STREAM_TYPE_NOTIFICATION = AudioManager.STREAM_NOTIFICATION;
    /**
     * @see AudioManager#STREAM_RING
     */
    public static final int STREAM_TYPE_RING = AudioManager.STREAM_RING;
    /**
     * @see AudioManager#STREAM_SYSTEM
     */
    public static final int STREAM_TYPE_SYSTEM = AudioManager.STREAM_SYSTEM;
    /**
     * @see AudioManager#STREAM_VOICE_CALL
     */
    public static final int STREAM_TYPE_VOICE_CALL = AudioManager.STREAM_VOICE_CALL;
    /**
     * @see AudioManager#USE_DEFAULT_STREAM_TYPE
     */
    public static final int STREAM_TYPE_USE_DEFAULT = AudioManager.USE_DEFAULT_STREAM_TYPE;
    /**
     * The default stream type used by audio renderers.
     */
    public static final int STREAM_TYPE_DEFAULT = STREAM_TYPE_MUSIC;
  
    /**
     * Content types for {@link com.google.android.exoplayer2.audio.AudioAttributes}.
     */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef({CONTENT_TYPE_MOVIE, CONTENT_TYPE_MUSIC, CONTENT_TYPE_SONIFICATION, CONTENT_TYPE_SPEECH,
        CONTENT_TYPE_UNKNOWN})
    public @interface AudioContentType {}
    /**
     * @see android.media.AudioAttributes#CONTENT_TYPE_MOVIE
     */
    public static final int CONTENT_TYPE_MOVIE = android.media.AudioAttributes.CONTENT_TYPE_MOVIE;
    /**
     * @see android.media.AudioAttributes#CONTENT_TYPE_MUSIC
     */
    public static final int CONTENT_TYPE_MUSIC = android.media.AudioAttributes.CONTENT_TYPE_MUSIC;
    /**
     * @see android.media.AudioAttributes#CONTENT_TYPE_SONIFICATION
     */
    public static final int CONTENT_TYPE_SONIFICATION =
        android.media.AudioAttributes.CONTENT_TYPE_SONIFICATION;
    /**
     * @see android.media.AudioAttributes#CONTENT_TYPE_SPEECH
     */
    public static final int CONTENT_TYPE_SPEECH =
        android.media.AudioAttributes.CONTENT_TYPE_SPEECH;
    /**
     * @see android.media.AudioAttributes#CONTENT_TYPE_UNKNOWN
     */
    public static final int CONTENT_TYPE_UNKNOWN =
        android.media.AudioAttributes.CONTENT_TYPE_UNKNOWN;
  
    /**
     * Flags for {@link com.google.android.exoplayer2.audio.AudioAttributes}.
     * <p>
     * Note that {@code FLAG_HW_AV_SYNC} is not available because the player takes care of setting the
     * flag when tunneling is enabled via a track selector.
     */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef(flag = true, value = {FLAG_AUDIBILITY_ENFORCED})
    public @interface AudioFlags {}
    /**
     * @see android.media.AudioAttributes#FLAG_AUDIBILITY_ENFORCED
     */
    public static final int FLAG_AUDIBILITY_ENFORCED =
        android.media.AudioAttributes.FLAG_AUDIBILITY_ENFORCED;
  
    /**
     * Usage types for {@link com.google.android.exoplayer2.audio.AudioAttributes}.
     */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef({USAGE_ALARM, USAGE_ASSISTANCE_ACCESSIBILITY, USAGE_ASSISTANCE_NAVIGATION_GUIDANCE,
        USAGE_ASSISTANCE_SONIFICATION, USAGE_GAME, USAGE_MEDIA, USAGE_NOTIFICATION,
        USAGE_NOTIFICATION_COMMUNICATION_DELAYED, USAGE_NOTIFICATION_COMMUNICATION_INSTANT,
        USAGE_NOTIFICATION_COMMUNICATION_REQUEST, USAGE_NOTIFICATION_EVENT,
        USAGE_NOTIFICATION_RINGTONE, USAGE_UNKNOWN, USAGE_VOICE_COMMUNICATION,
        USAGE_VOICE_COMMUNICATION_SIGNALLING})
    public @interface AudioUsage {}
    /**
     * @see android.media.AudioAttributes#USAGE_ALARM
     */
    public static final int USAGE_ALARM = android.media.AudioAttributes.USAGE_ALARM;
    /**
     * @see android.media.AudioAttributes#USAGE_ASSISTANCE_ACCESSIBILITY
     */
    public static final int USAGE_ASSISTANCE_ACCESSIBILITY =
        android.media.AudioAttributes.USAGE_ASSISTANCE_ACCESSIBILITY;
    /**
     * @see android.media.AudioAttributes#USAGE_ASSISTANCE_NAVIGATION_GUIDANCE
     */
    public static final int USAGE_ASSISTANCE_NAVIGATION_GUIDANCE =
        android.media.AudioAttributes.USAGE_ASSISTANCE_NAVIGATION_GUIDANCE;
    /**
     * @see android.media.AudioAttributes#USAGE_ASSISTANCE_SONIFICATION
     */
    public static final int USAGE_ASSISTANCE_SONIFICATION =
        android.media.AudioAttributes.USAGE_ASSISTANCE_SONIFICATION;
    /**
     * @see android.media.AudioAttributes#USAGE_GAME
     */
    public static final int USAGE_GAME = android.media.AudioAttributes.USAGE_GAME;
    /**
     * @see android.media.AudioAttributes#USAGE_MEDIA
     */
    public static final int USAGE_MEDIA = android.media.AudioAttributes.USAGE_MEDIA;
    /**
     * @see android.media.AudioAttributes#USAGE_NOTIFICATION
     */
    public static final int USAGE_NOTIFICATION = android.media.AudioAttributes.USAGE_NOTIFICATION;
    /**
     * @see android.media.AudioAttributes#USAGE_NOTIFICATION_COMMUNICATION_DELAYED
     */
    public static final int USAGE_NOTIFICATION_COMMUNICATION_DELAYED =
        android.media.AudioAttributes.USAGE_NOTIFICATION_COMMUNICATION_DELAYED;
    /**
     * @see android.media.AudioAttributes#USAGE_NOTIFICATION_COMMUNICATION_INSTANT
     */
    public static final int USAGE_NOTIFICATION_COMMUNICATION_INSTANT =
        android.media.AudioAttributes.USAGE_NOTIFICATION_COMMUNICATION_INSTANT;
    /**
     * @see android.media.AudioAttributes#USAGE_NOTIFICATION_COMMUNICATION_REQUEST
     */
    public static final int USAGE_NOTIFICATION_COMMUNICATION_REQUEST =
        android.media.AudioAttributes.USAGE_NOTIFICATION_COMMUNICATION_REQUEST;
    /**
     * @see android.media.AudioAttributes#USAGE_NOTIFICATION_EVENT
     */
    public static final int USAGE_NOTIFICATION_EVENT =
        android.media.AudioAttributes.USAGE_NOTIFICATION_EVENT;
    /**
     * @see android.media.AudioAttributes#USAGE_NOTIFICATION_RINGTONE
     */
    public static final int USAGE_NOTIFICATION_RINGTONE =
        android.media.AudioAttributes.USAGE_NOTIFICATION_RINGTONE;
    /**
     * @see android.media.AudioAttributes#USAGE_UNKNOWN
     */
    public static final int USAGE_UNKNOWN = android.media.AudioAttributes.USAGE_UNKNOWN;
    /**
     * @see android.media.AudioAttributes#USAGE_VOICE_COMMUNICATION
     */
    public static final int USAGE_VOICE_COMMUNICATION =
        android.media.AudioAttributes.USAGE_VOICE_COMMUNICATION;
    /**
     * @see android.media.AudioAttributes#USAGE_VOICE_COMMUNICATION_SIGNALLING
     */
    public static final int USAGE_VOICE_COMMUNICATION_SIGNALLING =
        android.media.AudioAttributes.USAGE_VOICE_COMMUNICATION_SIGNALLING;
  
    /**
     * Flags which can apply to a buffer containing a media sample.
     */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef(flag = true, value = {BUFFER_FLAG_KEY_FRAME, BUFFER_FLAG_END_OF_STREAM,
        BUFFER_FLAG_ENCRYPTED, BUFFER_FLAG_DECODE_ONLY})
    public @interface BufferFlags {}
    /**
     * Indicates that a buffer holds a synchronization sample.
     */
    public static final int BUFFER_FLAG_KEY_FRAME = MediaCodec.BUFFER_FLAG_KEY_FRAME;
    /**
     * Flag for empty buffers that signal that the end of the stream was reached.
     */
    public static final int BUFFER_FLAG_END_OF_STREAM = MediaCodec.BUFFER_FLAG_END_OF_STREAM;
    /**
     * Indicates that a buffer is (at least partially) encrypted.
     */
    public static final int BUFFER_FLAG_ENCRYPTED = 0x40000000;
    /**
     * Indicates that a buffer should be decoded but not rendered.
     */
    public static final int BUFFER_FLAG_DECODE_ONLY = 0x80000000;
  
    /**
     * Video scaling modes for {@link MediaCodec}-based {@link Renderer}s.
     */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef(value = {VIDEO_SCALING_MODE_SCALE_TO_FIT, VIDEO_SCALING_MODE_SCALE_TO_FIT_WITH_CROPPING})
    public @interface VideoScalingMode {}
    /**
     * @see MediaCodec#VIDEO_SCALING_MODE_SCALE_TO_FIT
     */
    public static final int VIDEO_SCALING_MODE_SCALE_TO_FIT =
        MediaCodec.VIDEO_SCALING_MODE_SCALE_TO_FIT;
    /**
     * @see MediaCodec#VIDEO_SCALING_MODE_SCALE_TO_FIT
     */
    public static final int VIDEO_SCALING_MODE_SCALE_TO_FIT_WITH_CROPPING =
        MediaCodec.VIDEO_SCALING_MODE_SCALE_TO_FIT_WITH_CROPPING;
    /**
     * A default video scaling mode for {@link MediaCodec}-based {@link Renderer}s.
     */
    public static final int VIDEO_SCALING_MODE_DEFAULT = VIDEO_SCALING_MODE_SCALE_TO_FIT;
  
    /**
     * Track selection flags.
     */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef(flag = true, value = {SELECTION_FLAG_DEFAULT, SELECTION_FLAG_FORCED,
        SELECTION_FLAG_AUTOSELECT})
    public @interface SelectionFlags {}
    /**
     * Indicates that the track should be selected if user preferences do not state otherwise.
     */
    public static final int SELECTION_FLAG_DEFAULT = 1;
    /**
     * Indicates that the track must be displayed. Only applies to text tracks.
     */
    public static final int SELECTION_FLAG_FORCED = 2;
    /**
     * Indicates that the player may choose to play the track in absence of an explicit user
     * preference.
     */
    public static final int SELECTION_FLAG_AUTOSELECT = 4;
  
    /**
     * Represents an undetermined language as an ISO 639 alpha-3 language code.
     */
    public static final String LANGUAGE_UNDETERMINED = "und";
  
    /**
     * Represents a streaming or other media type.
     */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef({TYPE_DASH, TYPE_SS, TYPE_HLS, TYPE_OTHER})
    public @interface ContentType {}
    /**
     * Value returned by {@link Util#inferContentType(String)} for DASH manifests.
     */
    public static final int TYPE_DASH = 0;
    /**
     * Value returned by {@link Util#inferContentType(String)} for Smooth Streaming manifests.
     */
    public static final int TYPE_SS = 1;
    /**
     * Value returned by {@link Util#inferContentType(String)} for HLS manifests.
     */
    public static final int TYPE_HLS = 2;
    /**
     * Value returned by {@link Util#inferContentType(String)} for files other than DASH, HLS or
     * Smooth Streaming manifests.
     */
    public static final int TYPE_OTHER = 3;
  
    /**
     * A return value for methods where the end of an input was encountered.
     */
    public static final int RESULT_END_OF_INPUT = -1;
    /**
     * A return value for methods where the length of parsed data exceeds the maximum length allowed.
     */
    public static final int RESULT_MAX_LENGTH_EXCEEDED = -2;
    /**
     * A return value for methods where nothing was read.
     */
    public static final int RESULT_NOTHING_READ = -3;
    /**
     * A return value for methods where a buffer was read.
     */
    public static final int RESULT_BUFFER_READ = -4;
    /**
     * A return value for methods where a format was read.
     */
    public static final int RESULT_FORMAT_READ = -5;
  
    /**
     * A data type constant for data of unknown or unspecified type.
     */
    public static final int DATA_TYPE_UNKNOWN = 0;
    /**
     * A data type constant for media, typically containing media samples.
     */
    public static final int DATA_TYPE_MEDIA = 1;
    /**
     * A data type constant for media, typically containing only initialization data.
     */
    public static final int DATA_TYPE_MEDIA_INITIALIZATION = 2;
    /**
     * A data type constant for drm or encryption data.
     */
    public static final int DATA_TYPE_DRM = 3;
    /**
     * A data type constant for a manifest file.
     */
    public static final int DATA_TYPE_MANIFEST = 4;
    /**
     * A data type constant for time synchronization data.
     */
    public static final int DATA_TYPE_TIME_SYNCHRONIZATION = 5;
    /**
     * Applications or extensions may define custom {@code DATA_TYPE_*} constants greater than or
     * equal to this value.
     */
    public static final int DATA_TYPE_CUSTOM_BASE = 10000;
  
    /**
     * A type constant for tracks of unknown type.
     */
    public static final int TRACK_TYPE_UNKNOWN = -1;
    /**
     * A type constant for tracks of some default type, where the type itself is unknown.
     */
    public static final int TRACK_TYPE_DEFAULT = 0;
    /**
     * A type constant for audio tracks.
     */
    public static final int TRACK_TYPE_AUDIO = 1;
    /**
     * A type constant for video tracks.
     */
    public static final int TRACK_TYPE_VIDEO = 2;
    /**
     * A type constant for text tracks.
     */
    public static final int TRACK_TYPE_TEXT = 3;
    /**
     * A type constant for metadata tracks.
     */
    public static final int TRACK_TYPE_METADATA = 4;
    /**
     * A type constant for a dummy or empty track.
     */
    public static final int TRACK_TYPE_NONE = 5;
    /**
     * Applications or extensions may define custom {@code TRACK_TYPE_*} constants greater than or
     * equal to this value.
     */
    public static final int TRACK_TYPE_CUSTOM_BASE = 10000;
  
    /**
     * A selection reason constant for selections whose reasons are unknown or unspecified.
     */
    public static final int SELECTION_REASON_UNKNOWN = 0;
    /**
     * A selection reason constant for an initial track selection.
     */
    public static final int SELECTION_REASON_INITIAL = 1;
    /**
     * A selection reason constant for an manual (i.e. user initiated) track selection.
     */
    public static final int SELECTION_REASON_MANUAL = 2;
    /**
     * A selection reason constant for an adaptive track selection.
     */
    public static final int SELECTION_REASON_ADAPTIVE = 3;
    /**
     * A selection reason constant for a trick play track selection.
     */
    public static final int SELECTION_REASON_TRICK_PLAY = 4;
    /**
     * Applications or extensions may define custom {@code SELECTION_REASON_*} constants greater than
     * or equal to this value.
     */
    public static final int SELECTION_REASON_CUSTOM_BASE = 10000;
  
    /**
     * A default size in bytes for an individual allocation that forms part of a larger buffer.
     */
    public static final int DEFAULT_BUFFER_SEGMENT_SIZE = 64 * 1024;
  
    /**
     * A default size in bytes for a video buffer.
     */
    public static final int DEFAULT_VIDEO_BUFFER_SIZE = 200 * DEFAULT_BUFFER_SEGMENT_SIZE;
  
    /**
     * A default size in bytes for an audio buffer.
     */
    public static final int DEFAULT_AUDIO_BUFFER_SIZE = 54 * DEFAULT_BUFFER_SEGMENT_SIZE;
  
    /**
     * A default size in bytes for a text buffer.
     */
    public static final int DEFAULT_TEXT_BUFFER_SIZE = 2 * DEFAULT_BUFFER_SEGMENT_SIZE;
  
    /**
     * A default size in bytes for a metadata buffer.
     */
    public static final int DEFAULT_METADATA_BUFFER_SIZE = 2 * DEFAULT_BUFFER_SEGMENT_SIZE;
  
    /**
     * A default size in bytes for a muxed buffer (e.g. containing video, audio and text).
     */
    public static final int DEFAULT_MUXED_BUFFER_SIZE = DEFAULT_VIDEO_BUFFER_SIZE
        + DEFAULT_AUDIO_BUFFER_SIZE + DEFAULT_TEXT_BUFFER_SIZE;
  
    /**
     * "cenc" scheme type name as defined in ISO/IEC 23001-7:2016.
     */
    public static final String CENC_TYPE_cenc = "cenc";
  
    /**
     * "cbc1" scheme type name as defined in ISO/IEC 23001-7:2016.
     */
    public static final String CENC_TYPE_cbc1 = "cbc1";
  
    /**
     * "cens" scheme type name as defined in ISO/IEC 23001-7:2016.
     */
    public static final String CENC_TYPE_cens = "cens";
  
    /**
     * "cbcs" scheme type name as defined in ISO/IEC 23001-7:2016.
     */
    public static final String CENC_TYPE_cbcs = "cbcs";
  
    /**
     * The Nil UUID as defined by
     * <a href="https://tools.ietf.org/html/rfc4122#section-4.1.7">RFC4122</a>.
     */
    public static final UUID UUID_NIL = new UUID(0L, 0L);
  
    /**
     * UUID for the W3C
     * <a href="https://w3c.github.io/encrypted-media/format-registry/initdata/cenc.html">Common PSSH
     * box</a>.
     */
    public static final UUID COMMON_PSSH_UUID = new UUID(0x1077EFECC0B24D02L, 0xACE33C1E52E2FB4BL);
  
    /**
     * UUID for the ClearKey DRM scheme.
     * <p>
     * ClearKey is supported on Android devices running Android 5.0 (API Level 21) and up.
     */
    public static final UUID CLEARKEY_UUID = new UUID(0xE2719D58A985B3C9L, 0x781AB030AF78D30EL);
  
    /**
     * UUID for the Widevine DRM scheme.
     * <p>
     * Widevine is supported on Android devices running Android 4.3 (API Level 18) and up.
     */
    public static final UUID WIDEVINE_UUID = new UUID(0xEDEF8BA979D64ACEL, 0xA3C827DCD51D21EDL);
  
    /**
     * UUID for the PlayReady DRM scheme.
     * <p>
     * PlayReady is supported on all AndroidTV devices. Note that most other Android devices do not
     * provide PlayReady support.
     */
    public static final UUID PLAYREADY_UUID = new UUID(0x9A04F07998404286L, 0xAB92E65BE0885F95L);
  
    /**
     * The type of a message that can be passed to a video {@link Renderer} via {@link
     * ExoPlayer#createMessage(Target)}. The message payload should be the target {@link Surface}, or
     * null.
     */
    public static final int MSG_SET_SURFACE = 1;
  
    /**
     * A type of a message that can be passed to an audio {@link Renderer} via {@link
     * ExoPlayer#createMessage(Target)}. The message payload should be a {@link Float} with 0 being
     * silence and 1 being unity gain.
     */
    public static final int MSG_SET_VOLUME = 2;
  
    /**
     * A type of a message that can be passed to an audio {@link Renderer} via {@link
     * ExoPlayer#createMessage(Target)}. The message payload should be an {@link
     * com.google.android.exoplayer2.audio.AudioAttributes} instance that will configure the
     * underlying audio track. If not set, the default audio attributes will be used. They are
     * suitable for general media playback.
     *
     * <p>Setting the audio attributes during playback may introduce a short gap in audio output as
     * the audio track is recreated. A new audio session id will also be generated.
     *
     * <p>If tunneling is enabled by the track selector, the specified audio attributes will be
     * ignored, but they will take effect if audio is later played without tunneling.
     *
     * <p>If the device is running a build before platform API version 21, audio attributes cannot be
     * set directly on the underlying audio track. In this case, the usage will be mapped onto an
     * equivalent stream type using {@link Util#getStreamTypeForAudioUsage(int)}.
     *
     * <p>To get audio attributes that are equivalent to a legacy stream type, pass the stream type to
     * {@link Util#getAudioUsageForStreamType(int)} and use the returned {@link C.AudioUsage} to build
     * an audio attributes instance.
     */
    public static final int MSG_SET_AUDIO_ATTRIBUTES = 3;
  
    /**
     * The type of a message that can be passed to a {@link MediaCodec}-based video {@link Renderer}
     * via {@link ExoPlayer#createMessage(Target)}. The message payload should be one of the integer
     * scaling modes in {@link C.VideoScalingMode}.
     *
     * <p>Note that the scaling mode only applies if the {@link Surface} targeted by the renderer is
     * owned by a {@link android.view.SurfaceView}.
     */
    public static final int MSG_SET_SCALING_MODE = 4;
  
    /**
     * Applications or extensions may define custom {@code MSG_*} constants that can be passed to
     * {@link Renderer}s. These custom constants must be greater than or equal to this value.
     */
    public static final int MSG_CUSTOM_BASE = 10000;
  
    /**
     * The stereo mode for 360/3D/VR videos.
     */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef({
        Format.NO_VALUE,
        STEREO_MODE_MONO,
        STEREO_MODE_TOP_BOTTOM,
        STEREO_MODE_LEFT_RIGHT,
        STEREO_MODE_STEREO_MESH
    })
    public @interface StereoMode {}
    /**
     * Indicates Monoscopic stereo layout, used with 360/3D/VR videos.
     */
    public static final int STEREO_MODE_MONO = 0;
    /**
     * Indicates Top-Bottom stereo layout, used with 360/3D/VR videos.
     */
    public static final int STEREO_MODE_TOP_BOTTOM = 1;
    /**
     * Indicates Left-Right stereo layout, used with 360/3D/VR videos.
     */
    public static final int STEREO_MODE_LEFT_RIGHT = 2;
    /**
     * Indicates a stereo layout where the left and right eyes have separate meshes,
     * used with 360/3D/VR videos.
     */
    public static final int STEREO_MODE_STEREO_MESH = 3;
  
    /**
     * Video colorspaces.
     */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef({Format.NO_VALUE, COLOR_SPACE_BT709, COLOR_SPACE_BT601, COLOR_SPACE_BT2020})
    public @interface ColorSpace {}
    /**
     * @see MediaFormat#COLOR_STANDARD_BT709
     */
    public static final int COLOR_SPACE_BT709 = MediaFormat.COLOR_STANDARD_BT709;
    /**
     * @see MediaFormat#COLOR_STANDARD_BT601_PAL
     */
    public static final int COLOR_SPACE_BT601 = MediaFormat.COLOR_STANDARD_BT601_PAL;
    /**
     * @see MediaFormat#COLOR_STANDARD_BT2020
     */
    public static final int COLOR_SPACE_BT2020 = MediaFormat.COLOR_STANDARD_BT2020;
  
    /**
     * Video color transfer characteristics.
     */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef({Format.NO_VALUE, COLOR_TRANSFER_SDR, COLOR_TRANSFER_ST2084, COLOR_TRANSFER_HLG})
    public @interface ColorTransfer {}
    /**
     * @see MediaFormat#COLOR_TRANSFER_SDR_VIDEO
     */
    public static final int COLOR_TRANSFER_SDR = MediaFormat.COLOR_TRANSFER_SDR_VIDEO;
    /**
     * @see MediaFormat#COLOR_TRANSFER_ST2084
     */
    public static final int COLOR_TRANSFER_ST2084 = MediaFormat.COLOR_TRANSFER_ST2084;
    /**
     * @see MediaFormat#COLOR_TRANSFER_HLG
     */
    public static final int COLOR_TRANSFER_HLG = MediaFormat.COLOR_TRANSFER_HLG;
  
    /**
     * Video color range.
     */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef({Format.NO_VALUE, COLOR_RANGE_LIMITED, COLOR_RANGE_FULL})
    public @interface ColorRange {}
    /**
     * @see MediaFormat#COLOR_RANGE_LIMITED
     */
    public static final int COLOR_RANGE_LIMITED = MediaFormat.COLOR_RANGE_LIMITED;
    /**
     * @see MediaFormat#COLOR_RANGE_FULL
     */
    public static final int COLOR_RANGE_FULL = MediaFormat.COLOR_RANGE_FULL;
  
    /**
     * Priority for media playback.
     *
     * <p>Larger values indicate higher priorities.
     */
    public static final int PRIORITY_PLAYBACK = 0;
  
    /**
     * Priority for media downloading.
     *
     * <p>Larger values indicate higher priorities.
     */
    public static final int PRIORITY_DOWNLOAD = PRIORITY_PLAYBACK - 1000;
  
    /**
     * Converts a time in microseconds to the corresponding time in milliseconds, preserving
     * {@link #TIME_UNSET} and {@link #TIME_END_OF_SOURCE} values.
     *
     * @param timeUs The time in microseconds.
     * @return The corresponding time in milliseconds.
     */
    public static long usToMs(long timeUs) {
      return (timeUs == TIME_UNSET || timeUs == TIME_END_OF_SOURCE) ? timeUs : (timeUs / 1000);
    }
  
    /**
     * Converts a time in milliseconds to the corresponding time in microseconds, preserving
     * {@link #TIME_UNSET} values and {@link #TIME_END_OF_SOURCE} values.
     *
     * @param timeMs The time in milliseconds.
     * @return The corresponding time in microseconds.
     */
    public static long msToUs(long timeMs) {
      return (timeMs == TIME_UNSET || timeMs == TIME_END_OF_SOURCE) ? timeMs : (timeMs * 1000);
    }
  
    /**
     * Returns a newly generated {@link android.media.AudioTrack} session identifier.
     */
    @TargetApi(21)
    public static int generateAudioSessionIdV21(Context context) {
      return ((AudioManager) context.getSystemService(Context.AUDIO_SERVICE))
          .generateAudioSessionId();
    }
  
  }
  