aac

Documentation

Overview

Copyright (c) 2019,CAOHONGJU All rights reserved. Use of this source code is governed by a MIT-style license that can be found in the LICENSE file.

Translate from FFmpeg mpeg4audio.h mpeg4audio.c

Index

• Constants
• Variables
• func Encode2BytesASC(objType, samplingIdx, channelConfig byte) []byte
• func MetadataIsReady(am *codec.AudioMeta) bool
• func SampleRate(index int) int
• func SamplingIndex(rate int) int
• type ADTSHeader
  • func NewADTSHeader(profile, sampleRateIdx, channelConfig byte, payloadSize int) ADTSHeader
  • func (h ADTSHeader) ChannelConfig() uint8
  • func (h ADTSHeader) Channels() uint8
  • func (h ADTSHeader) FrameLength() int
  • func (h ADTSHeader) PayloadSize() int
  • func (h ADTSHeader) Profile() uint8
  • func (h ADTSHeader) SampleRate() int
  • func (h ADTSHeader) SamplingIndex() uint8
  • func (h ADTSHeader) ToAsc() []byte
• type AudioSpecificConfig
  • func (asc *AudioSpecificConfig) Decode(config []byte) (err error)
  • func (asc *AudioSpecificConfig) DecodeString(config string) error
  • func (asc *AudioSpecificConfig) ToAdtsHeader(payloadSize int) ADTSHeader
• type RawSPS

Constants

const (
	AOT_NULL            = iota     ///< Support?                Name
	AOT_AAC_MAIN                   ///< Y                       Main
	AOT_AAC_LC                     ///< Y                       Low Complexity
	AOT_AAC_SSR                    ///< N (code in SoC repo)    Scalable Sample Rate
	AOT_AAC_LTP                    ///< Y                       Long Term Prediction
	AOT_SBR                        ///< Y                       Spectral Band Replication HE-AAC
	AOT_AAC_SCALABLE               ///< N                       Scalable
	AOT_TWINVQ                     ///< N                       Twin Vector Quantizer
	AOT_CELP                       ///< N                       Code Excited Linear Prediction
	AOT_HVXC                       ///< N                       Harmonic Vector eXcitation Coding
	AOT_TTSI            = 2 + iota ///< N(code = 12)            Text-To-Speech Interface
	AOT_MAINSYNTH                  ///< N                       Main Synthesis
	AOT_WAVESYNTH                  ///< N                       Wavetable Synthesis
	AOT_MIDI                       ///< N                       General MIDI
	AOT_SAFX                       ///< N                       Algorithmic Synthesis and Audio Effects
	AOT_ER_AAC_LC                  ///< N                       Error Resilient Low Complexity
	AOT_ER_AAC_LTP      = 3 + iota ///< N(code = 19)            Error Resilient Long Term Prediction
	AOT_ER_AAC_SCALABLE            ///< N                       Error Resilient Scalable
	AOT_ER_TWINVQ                  ///< N                       Error Resilient Twin Vector Quantizer
	AOT_ER_BSAC                    ///< N                       Error Resilient Bit-Sliced Arithmetic Coding
	AOT_ER_AAC_LD                  ///< N                       Error Resilient Low Delay
	AOT_ER_CELP                    ///< N                       Error Resilient Code Excited Linear Prediction
	AOT_ER_HVXC                    ///< N                       Error Resilient Harmonic Vector eXcitation Coding
	AOT_ER_HILN                    ///< N                       Error Resilient Harmonic and Individual Lines plus Noise
	AOT_ER_PARAM                   ///< N                       Error Resilient Parametric
	AOT_SSC                        ///< N                       SinuSoidal Coding
	AOT_PS                         ///< N                       Parametric Stereo
	AOT_SURROUND                   ///< N                       MPEG Surround
	AOT_ESCAPE                     ///< Y                       Escape Value
	AOT_L1                         ///< Y                       Layer 1
	AOT_L2                         ///< Y                       Layer 2
	AOT_L3                         ///< Y                       Layer 3
	AOT_DST                        ///< N                       Direct Stream Transfer
	AOT_ALS                        ///< Y                       Audio LosslesS
	AOT_SLS                        ///< N                       Scalable LosslesS
	AOT_SLS_NON_CORE               ///< N                       Scalable LosslesS (non core)
	AOT_ER_AAC_ELD                 ///< N                       Error Resilient Enhanced Low Delay
	AOT_SMR_SIMPLE                 ///< N                       Symbolic Music Representation Simple
	AOT_SMR_MAIN                   ///< N                       Symbolic Music Representation Main
	AOT_USAC_NOSBR                 ///< N                       Unified Speech and Audio Coding (no SBR)
	AOT_SAOC                       ///< N                       Spatial Audio Object Coding
	AOT_LD_SURROUND                ///< N                       Low Delay MPEG Surround
	AOT_USAC                       ///< N                       Unified Speech and Audio Coding
)

Auido Object Type

const (
	ProfileMain = AOT_AAC_MAIN - 1
	ProfileLow  = AOT_AAC_LC - 1
	ProfileSSR  = AOT_AAC_SSR - 1
	ProfileLTP  = AOT_AAC_LTP - 1
	ProfileHE   = AOT_SBR - 1
	ProfileLD   = AOT_ER_AAC_LD - 1
	ProfileHE2  = AOT_PS - 1
	ProfileELD  = AOT_ER_AAC_ELD - 1
)

AAC Profile 表示使用哪个级别的 AAC。 如 01 Low Complexity(LC) – AAC LC

const (
	SampleRate96000 = iota // 0
	SampleRate88200        // 1
	SampleRate64000        // 2
	SampleRate48000        // 3
	SampleRate44100        // 4
	SampleRate32000        // 5
	SampleRate24000        // 6
	SampleRate22050        // 7
	SampleRate16000        // 8
	SampleRate12000        // 9
	SampleRate11025        // 10
	SampleRate8000         // 11
	SampleRate7350         // 12
)

AAC 采样频率

const (
	ChannelSpecific     = iota // 0
	ChannelMono                // 1
	ChannelStereo              // 2
	ChannelThree               // 3
	ChannelFour                // 4
	ChannelFive                // 5
	ChannelFivePlusOne         // 6
	ChannelSevenPlusOne        // 7
	ChannelReserved            // 8
)

ACC ChannelConfig 声道配置 0x00 - defined in audioDecderSpecificConfig 0x01 单声道（center front speaker） 0x02 双声道（left, right front speakers） 0x03 三声道（center, left, right front speakers） 0x04 四声道（center, left, right front speakers, rear surround speakers） 0x05 五声道（center, left, right front speakers, left surround, right surround rear speakers） 0x06 5.1声道（center, left, right front speakers, left surround, right surround rear speakers, front low frequency effects speaker) 0x07 7.1声道（center, left, right center front speakers, left, right outside front speakers, left surround, right surround rear speakers, front low frequency effects speaker) 0x08-0x0F - reserved

const (
	ParameterSetConfig = 0
)

参数集索引

const (
	// SamplesPerFrame 每帧采样数
	SamplesPerFrame = 1024
)

Variables

var SampleRates = [16]int{
	96000, 88200, 64000, 48000,
	44100, 32000, 24000, 22050,
	16000, 12000, 11025, 8000,
	7350}

SampleRates 采用频率集合

Functions

func Encode2BytesASC

func Encode2BytesASC(objType, samplingIdx, channelConfig byte) []byte

func MetadataIsReady

func MetadataIsReady(am *codec.AudioMeta) bool

MetadataIsReady .

func SampleRate

func SampleRate(index int) int

SampleRate 获取采用频率具体值

func SamplingIndex

func SamplingIndex(rate int) int

SamplingIndex .

Types

type ADTSHeader

type ADTSHeader [7]byte

ADTSHeader adts header include fixed and varlable header

func NewADTSHeader

func NewADTSHeader(profile, sampleRateIdx, channelConfig byte, payloadSize int) ADTSHeader

func (ADTSHeader) ChannelConfig

func (h ADTSHeader) ChannelConfig() uint8

func (ADTSHeader) Channels

func (h ADTSHeader) Channels() uint8

func (ADTSHeader) FrameLength

func (h ADTSHeader) FrameLength() int

func (ADTSHeader) PayloadSize

func (h ADTSHeader) PayloadSize() int

func (ADTSHeader) Profile

func (h ADTSHeader) Profile() uint8

func (ADTSHeader) SampleRate

func (h ADTSHeader) SampleRate() int

func (ADTSHeader) SamplingIndex

func (h ADTSHeader) SamplingIndex() uint8

func (ADTSHeader) ToAsc

func (h ADTSHeader) ToAsc() []byte

type AudioSpecificConfig

type AudioSpecificConfig struct {
	ObjectType       uint8
	SamplingIndex    uint8
	SampleRate       int
	ChannelConfig    uint8
	Sbr              int ///< -1 implicit, 1 presence
	ExtObjectType    uint8
	ExtSamplingIndex uint8
	ExtSampleRate    int
	ExtChannelConfig uint8
	Channels         uint8
	Ps               int ///< -1 implicit, 1 presence
	FrameLengthShort int
}

AudioSpecificConfig .

func (*AudioSpecificConfig) Decode

func (asc *AudioSpecificConfig) Decode(config []byte) (err error)

Decode 从字节序列中解码 sps

func (*AudioSpecificConfig) DecodeString

func (asc *AudioSpecificConfig) DecodeString(config string) error

DecodeString 从 hex 字串解码 sps

func (*AudioSpecificConfig) ToAdtsHeader

func (asc *AudioSpecificConfig) ToAdtsHeader(payloadSize int) ADTSHeader

type RawSPS

type RawSPS = AudioSpecificConfig

RawSps AudioSpecificConfig 的别名