CodecSpecificDataUtil

Kotlin |Java

@UnstableApi
public final class CodecSpecificDataUtil

Provides utilities for handling various types of codec-specific data.

Summary

Public methods
`static String`	`buildApvCodecString(byte[] initializationData)` Returns an APV codec string based on the provided initialization data.
`static String`	`buildAvcCodecString( int profileIdc, int constraintsFlagsAndReservedZero2Bits, int levelIdc )` Builds an RFC 6381 AVC codec string using the provided parameters.
`static List<byte[]>`	`buildCea708InitializationData(boolean isWideAspectRatio)` Returns initialization data for formats with MIME type `APPLICATION_CEA708`.
`static String`	`buildDolbyVisionCodecString(int profile, int level)` Builds a Dolby Vision codec string using profile and level.
`static byte[]`	`buildDolbyVisionInitializationData(int profile, int level)` Returns initialization data for Dolby Vision according to Dolby Vision ISO MediaFormat (section 2.2) specification.
`static String`	`buildH263CodecString(int profile, int level)` Builds an RFC 6381 H263 codec string using profile and level.
`static String`	`buildHevcCodecString( int generalProfileSpace, boolean generalTierFlag, int generalProfileIdc, int generalProfileCompatibilityFlags, int[] constraintBytes, int generalLevelIdc )` Builds an RFC 6381 HEVC codec string using the provided parameters.
`static @Nullable String`	`buildIamfCodecString(byte[] initializationData)` Builds an RFC 6381 IAMF codec string from the given `initializationData`.
`static byte[]`	`buildNalUnit(byte[] data, int offset, int length)` Constructs a NAL unit consisting of the NAL start code followed by the specified data.
`static ImmutableList<byte[]>`	`buildVp9CodecPrivateInitializationData( byte profile, byte level, byte bitDepth, byte chromaSubsampling )` Returns initialization data in CodecPrivate format of VP9.
`static int`	`dolbyVisionConstantToLevelNumber(int levelConstant)` Returns Dolby Vision level number corresponding to the level constant.
`static int`	`dolbyVisionConstantToProfileNumber(int profileConstant)` Returns Dolby Vision profile number corresponding to the profile constant.
`static @Nullable Pair<Integer, Integer>`	`getCodecProfileAndLevel(Format format)` Returns profile and level (as defined by `MediaCodecInfo.CodecProfileLevel`) corresponding to the codec description string (as defined by RFC 6381) of the given format.
`static @Nullable Pair<Integer, Integer>`	`getHevcProfileAndLevel( String codec, String[] parts, @Nullable ColorInfo colorInfo )` Returns Hevc profile and level corresponding to the codec description string (as defined by RFC 6381) and it `ColorInfo`.
`static Pair<Integer, Integer>`	`getVideoResolutionFromMpeg4VideoConfig(byte[] videoSpecificConfig)` Parses an MPEG-4 Visual configuration information, as defined in ISO/IEC14496-2.
`static ByteBuffer`	`getVorbisInitializationData(Format format)` Creates the Vorbis initialization data (CodecPrivate).
`static int[]`	`parseAlacAudioSpecificConfig(byte[] audioSpecificConfig)` Parses an ALAC AudioSpecificConfig (i.e. an ALACSpecificConfig).
`static boolean`	`parseCea708InitializationData(List<byte[]> initializationData)` Returns whether the CEA-708 closed caption service with the given initialization data is formatted for displays with 16:9 aspect ratio.
`static @Nullable byte[][]`	`splitNalUnits(byte[] data)` Splits an array of NAL units.

Public methods

buildApvCodecString

public static String buildApvCodecString(byte[] initializationData)

Returns an APV codec string based on the provided initialization data.

Reference: Codecs Parameter in APV ISO Base Media File Format

Parameters
`byte[] initializationData`	The initialization data containing profile, level, and band information.

Returns
`String`	The generated APV codec string.

buildAvcCodecString

public static String buildAvcCodecString(
    int profileIdc,
    int constraintsFlagsAndReservedZero2Bits,
    int levelIdc
)

Builds an RFC 6381 AVC codec string using the provided parameters.

Parameters
`int profileIdc`	The encoding profile.
`int constraintsFlagsAndReservedZero2Bits`	The constraint flags followed by the reserved zero 2 bits, all contained in the least significant byte of the integer.
`int levelIdc`	The encoding level.

Returns
`String`	An RFC 6381 AVC codec string built using the provided parameters.

buildCea708InitializationData

public static List<byte[]> buildCea708InitializationData(boolean isWideAspectRatio)

Returns initialization data for formats with MIME type APPLICATION_CEA708.

Parameters
`boolean isWideAspectRatio`	Whether the CEA-708 closed caption service is formatted for displays with 16:9 aspect ratio.

Returns
`List<byte[]>`	Initialization data for formats with MIME type `APPLICATION_CEA708`.

buildDolbyVisionCodecString

public static String buildDolbyVisionCodecString(int profile, int level)

Builds a Dolby Vision codec string using profile and level.

Reference: href="https://professionalsupport.dolby.com/s/article/What-is-Dolby-Vision-Profile?language=en_US", >, Dolby Vision Profile and Level (section 2.3)

buildDolbyVisionInitializationData

public static byte[] buildDolbyVisionInitializationData(int profile, int level)

Returns initialization data for Dolby Vision according to Dolby Vision ISO MediaFormat (section 2.2) specification.

Parameters
`int profile`	The Dolby Vision codec profile.
`int level`	The Dolby Vision codec level.

buildH263CodecString

public static String buildH263CodecString(int profile, int level)

Builds an RFC 6381 H263 codec string using profile and level.

buildHevcCodecString

public static String buildHevcCodecString(
    int generalProfileSpace,
    boolean generalTierFlag,
    int generalProfileIdc,
    int generalProfileCompatibilityFlags,
    int[] constraintBytes,
    int generalLevelIdc
)

Builds an RFC 6381 HEVC codec string using the provided parameters.

buildIamfCodecString

public static @Nullable String buildIamfCodecString(byte[] initializationData)

Builds an RFC 6381 IAMF codec string from the given initializationData.

The format is defined by the IAMF Codec Parameters String specification.

buildNalUnit

public static byte[] buildNalUnit(byte[] data, int offset, int length)

Constructs a NAL unit consisting of the NAL start code followed by the specified data.

Parameters
`byte[] data`	An array containing the data that should follow the NAL start code.
`int offset`	The start offset into `data`.
`int length`	The number of bytes to copy from `data`

Returns
`byte[]`	The constructed NAL unit.

buildVp9CodecPrivateInitializationData

public static ImmutableList<byte[]> buildVp9CodecPrivateInitializationData(
    byte profile,
    byte level,
    byte bitDepth,
    byte chromaSubsampling
)

Returns initialization data in CodecPrivate format of VP9.

Each feature of VP9 CodecPrivate is defined by the binary format of ID (1 byte), length (1 byte), and data (1 byte). See href="https://www.webmproject.org/docs/container/#vp9-codec-feature-metadata-codecprivate", >, CodecPrivate format of VP9 for more details.

Parameters
`byte profile`	The VP9 codec profile.
`byte level`	The VP9 codec level.
`byte bitDepth`	The bit depth of the luma and color components.
`byte chromaSubsampling`	The chroma subsampling.

dolbyVisionConstantToLevelNumber

public static int dolbyVisionConstantToLevelNumber(int levelConstant)

Returns Dolby Vision level number corresponding to the level constant.

Parameters
`int levelConstant`	The Dolby Vision level constant.

Returns
`int`	The Dolby Vision level number.

Throws
`java.lang.IllegalArgumentException`	if the level constant is not recognized.

dolbyVisionConstantToProfileNumber

public static int dolbyVisionConstantToProfileNumber(int profileConstant)

Returns Dolby Vision profile number corresponding to the profile constant.

Parameters
`int profileConstant`	The Dolby Vision profile constant.

Returns
`int`	The Dolby Vision profile number.

Throws
`java.lang.IllegalArgumentException`	if the profile constant is not recognized.

getCodecProfileAndLevel

public static @Nullable Pair<Integer, Integer> getCodecProfileAndLevel(Format format)

Returns profile and level (as defined by MediaCodecInfo.CodecProfileLevel) corresponding to the codec description string (as defined by RFC 6381) of the given format.

Parameters
`Format format`	Media format with a codec description string, as defined by RFC 6381.

Returns
`@Nullable Pair<Integer, Integer>`	A pair (profile constant, level constant) if the codec of the `format` is well-formed and recognized, or null otherwise.

getHevcProfileAndLevel

public static @Nullable Pair<Integer, Integer> getHevcProfileAndLevel(
    String codec,
    String[] parts,
    @Nullable ColorInfo colorInfo
)

Returns Hevc profile and level corresponding to the codec description string (as defined by RFC 6381) and it ColorInfo.

Parameters
`String codec`	The codec description string (as defined by RFC 6381).
`String[] parts`	The codec string split by ".".
`@Nullable ColorInfo colorInfo`	The `ColorInfo`.

Returns
`@Nullable Pair<Integer, Integer>`	A pair (profile constant, level constant) if profile and level are recognized, or `null` otherwise.

getVideoResolutionFromMpeg4VideoConfig

public static Pair<Integer, Integer> getVideoResolutionFromMpeg4VideoConfig(byte[] videoSpecificConfig)

Parses an MPEG-4 Visual configuration information, as defined in ISO/IEC14496-2.

Parameters
`byte[] videoSpecificConfig`	A byte array containing the MPEG-4 Visual configuration information to parse.

Returns
`Pair<Integer, Integer>`	A pair of the video's width and height.

getVorbisInitializationData

public static ByteBuffer getVorbisInitializationData(Format format)

Creates the Vorbis initialization data (CodecPrivate).

The format is as follows:

Byte 1: The number of packets minus one. This is 2 for Vorbis, representing the Identification, Comment, and Setup headers.
Bytes 2..n: The lengths of the first two packets (Identification and Comment headers), encoded using Xiph lacing. The length of the final packet (Setup header) is not explicitly stored.
Bytes n+1 onwards: The Vorbis identification header, Vorbis comment header and the codec setup header.

See A_VORBIS for CodecPrivate format of Vorbis.

Parameters
`Format format`	The `Format`.

Returns
`ByteBuffer`	A `ByteBuffer` containing the assembled Vorbis CodecPrivate data.

parseAlacAudioSpecificConfig

public static int[] parseAlacAudioSpecificConfig(byte[] audioSpecificConfig)

Parses an ALAC AudioSpecificConfig (i.e. an ALACSpecificConfig).

Parameters
`byte[] audioSpecificConfig`	A byte array containing the AudioSpecificConfig to parse.

Returns
`int[]`	An int array consisting of the sample rate in Hz, the channel count and the bit depth.

parseCea708InitializationData

public static boolean parseCea708InitializationData(List<byte[]> initializationData)

Returns whether the CEA-708 closed caption service with the given initialization data is formatted for displays with 16:9 aspect ratio.

Parameters
`List<byte[]> initializationData`	The initialization data to parse.

Returns
`boolean`	Whether the CEA-708 closed caption service is formatted for displays with 16:9 aspect ratio.

splitNalUnits

public static @Nullable byte[][] splitNalUnits(byte[] data)

Splits an array of NAL units.

If the input consists of NAL start code delimited units, then the returned array consists of the split NAL units, each of which is still prefixed with the NAL start code. For any other input, null is returned.

Parameters
`byte[] data`	An array of data.

Returns
`@Nullable byte[][]`	The individual NAL units, or null if the input did not consist of NAL start code delimited units.