CodecSpecificDataUtil

@UnstableApi
public final class CodecSpecificDataUtil

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

Summary

Public methods
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
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 byte[]
buildNalUnit(byte[] data, int offset, int length)

Constructs a NAL unit consisting of the NAL start code followed by the specified data.
static Pair<Integer, Integer>
getVideoResolutionFromMpeg4VideoConfig(byte[] videoSpecificConfig)

Parses an MPEG-4 Visual configuration information, as defined in ISO/IEC14496-2.
static Pair<Integer, Integer>
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

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.

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.

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.

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.

parseAlacAudioSpecificConfig

public static Pair<Integer, Integer> parseAlacAudioSpecificConfig(byte[] audioSpecificConfig)

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

Parameters
byte[] audioSpecificConfig

A byte array containing the AudioSpecificConfig to parse.
Returns
Pair<Integer, Integer>

A pair consisting of the sample rate in Hz and the channel count.

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.