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[科普中国]-音频编解码器

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音频编解码器是指能编码或解码音频数字数据流的设备或计算机程序。

介绍在软件层面,音频编解码器是一个执行算法的计算机程序,能压缩与解压缩数字音频数据到音频文件或流媒体音频编码格式。该算法的目的是保证质量的前提下使用最少的比特表示高保真音频信号。这可以有效地减少存储空间和传输已存储音频文件所需的带宽。大多数编解码器是实现为一个具有接口的库供一个或多个媒体播放器使用1。

在硬件层面,音频编解码器指一个能编码模拟音频到数字音频和解码数字音频到模拟音频的独立设备。换种说法,它包含运行在同样时钟的模数转换器(ADC)和数模转换器(DAC)。这在声卡中被使用以支持音频输入和输出。

音频编解码非压缩脉冲编码调制(Pulse-code modulation,简称PCM)是一种非压缩的音频编码格式。此格式是CD-DA的标准。在计算机中,使用 PCM 编码的音频可以直接以原始音频格式储存。不过它们通常会被储存在容器中,如WAV、AIFF、AU等(但在技术上这并不是必须的)。注意,有时 PCM 和 LPCM 都被笼统的称作 PCM,但实际上它们相似却不相同。

线性脉冲编码调制(Pulse-code modulation,简称LPCM)是一种非压缩的音频编码格式。这是一个 PCM 的变种。

脉冲密度调制(Pulse-density modulation,简称PDM)是一种非压缩的音频编码格式。

脉冲强度调制(Pulse-Amplitude Modulation,简称PAM)是一种非压缩的音频编码格式。

无损压缩Apple LosslessAudio Codec(ALAC)

Direct Stream Transfer(DST)

Dolby TrueHD– Optionallosslesssurround soundformat used byHD DVDandBlu-ray, it usesMLPbut adds higher sample rates, bit rates, and more channels

DTS-HD Master Audio– Optionallosslesssurround soundformat used byHD DVDandBlu-ray, it was previously known as DTS++ and DTS-HD

Free Lossless Audio Codec(FLAC)

Lossless Audio(LA)

Lossless Predictive Audio Compression(LPAC)

Lossless Transform Audio Compression(LTAC)

MPEG-4Audio Lossless Coding(MPEG-4 ALS)

MPEG-4Advanced Audio Coding - Scalable to lossless(AAC-SLS, also known as HD-AAC)

Meridian Lossless Packing(MLP),also known asPacked PCM(PPCM), it is the standard lossless compression method forDVD-Audiocontent

Monkey's Audio(APE)

OptimFROG(OFR)

RealAudioLossless

RK Audio(RKAU)

Shorten(SHN)

True Audio(TTA)

WavPack(WV)

Windows Media Audio 9 Lossless(WMALossless)

有损压缩主条目:Lossy data compression §Audio

通用

Adaptive Differential(or Delta)pulse-code modulation(ADPCM,见脉冲编码调制)

ADX

Adaptive Rate-Distortion Optimised sound codeR(ARDOR)

Adaptive Transform Acoustic Coding(ATRAC,使用于MiniDisc设备)

Dolby Digital(A/52, AC3)

DTS Coherent Acoustics(DTS, Digital Theatre System Coherent Acoustics)

ImpalaFORscene audio codec

ITU standards:

G.722.1 Annex C

G.719

G.722

G.722.1

MPEG audio

HE-AAC

layer-1(MP1)

layer-2(MP2,MPEG-1,MPEG-2 and non-ISO MPEG-2.5)

layer-3(MP3,MPEG-1,MPEG-2 and non-ISO MPEG-2.5)

Advanced Audio Coding(AAC,MPEG-2 andMPEG-4)

Harmonic and Individual Lines and Noise(HILN, MPEG-4Parametric Audio Coding)

Musepack

Perceptual Audio Coding

QDesign

TwinVQ

Vorbis

Windows Media Audio(WMA)

人声(低比特率;为人声优化)

主条目:Speech encoding

Advanced Multi-Band Excitation(AMBE)

Algebraic Code Excited Linear Prediction(ACELP)

Code Excited Linear Prediction(CELP)

Continuously variable slope delta modulation(CVSD)

Dialogic ADPCM(VOX)

Digital Speech Standard(DSS)

Enhanced Variable Rate Codec(EVRC)

FS-1015(LPC-10)

FS-1016(CELP)

ITU standards:

G.729a

G.729.1

G.722.1

G.722.2(AMR-WB)

G.711(a-law and μ-law)

G.718

G.719

G.721(superseded by G.726)

G.722

G.723(24 and 40 kbit/s DPCM, extension to G.721, superseded by G.726)

G.723.1(MPC-MLQ or ACELP)

G.726(ADPCM)

G.728(LD-CELP)

G.729(CS-ACELP)

GSMcodecs:

AMR-NB

AMR-WB

AMR-WB+

Full Rate

Half Rate

Enhanced Full Rate

Adaptive Multi-Rate(AMR)

Harmonic Vector Excitation Coding(HVXC)

Internet Low Bit Rate Codec(iLBC)

Improved Multi-Band Excitation(IMBE)

internet Speech Audio Codec(iSAC)

Mixed Excitation Linear Prediction(MELP)

QCELP

Relaxed Code Excited Linear Prediction(RCELP)

RTAudio- used byMicrosoft Live Communication Server

Selectable Mode Vocoder(SMV)

Speex, patent free

Triple Rate CODER(TRC)-used in some pocket recorders.

Vector Sum Excited Linear Prediction(VSELP)

文字BiM

Continuous Media Markup Language(CMML)

MPEG-4 Part 17(e.g. 3GPP Timed Text)

Ogg Kate

Ogg Writ

ttyrec

视频主条目:视频压缩

无损压缩Alpary

Animation(qtrle)

QuickTime

FFmpeg

ArithYuv

AVIzlib

LCL (VfW codec) MSZH and ZLIB

FFmpeg

CamStudio GZIP/LZO

FFmpeg (decoder only)

Diraclossless

libdirac

libschroedinger

GStreamer

FFmpeg

FastCodec

FFV1FFV1's compression factor is comparable toMotion JPEG 2000, but based on quicker algorithms (allows real-time capture). Written by Michael Niedermayer and published as part ofFFmpegunder toGNU LGPL.

FFmpeg

H.264lossless

x264(encoder only)

FFmpeg (decoder only, uses x264 for encoding)

HuffyuvHuffyuv (or HuffYUV) was written by Ben Rudiak-Gould and published under the terms of theGNU GPLas free software, meant to replace uncompressed YCbCr as a video capture format. It uses very little cpu but takes a lot of disk space.

FFmpeg

JPEG 2000lossless

libopenjpeg

LagarithA more up-to-date fork of Huffyuv is available as Lagarith.

Lagarith Codec (VfW codec)

FFmpeg (decoder only)

LOCO

FFmpeg (decoder only)

LZO

MSU Lossless Video Codec

PNG

CorePNG

FFmpeg

ScreenPressor

SheerVideo

Snowlossless

FFmpeg

TechSmith Screen Capture Codec (TSCC)

FFmpeg (decoder only)

Ut Video

FFmpeg

VMNC

YULS

有损压缩一般

Apple Intermediate Codec

Audio Video Standard (AVS)

OpenAVS

FFmpeg (decoding only)

Bink Video,Smacker video

FFmpeg

libavcodec

BlackbirdFORscene video codec

Cinepak

FFmpeg (decoder only)

Dirac

Schrödinger

dirac-research

FFmpeg (decoder only)

FirebirdOriginal FORscene video codec

H.261

FFmpegH.261 (libavcodec)

MPEG-1 Part 2 (MPEG-1Video)

Cinema Craft Encoder

ElecardMPEG-1 Decoder/Encoder

FFmpeg

MainConceptMPEG-1

TMPGEnc

H.262/MPEG-2 Part 2(MPEG-2 Video)

CanopusProCoder

Cinema Craft Encoder

ElecardMPEG-2 Video Decoder/Encoder

FFmpeg

InterVideoVideo Decoder

MainConcept MPEG-2

TMPGEnc

H.263

FFmpegH.263 (libavcodec)

MPEG-4 Part 2(MPEG-4 Advanced Simple Profile)

3ivx

DivX

ElecardMPEG-4 Decoder/Encoder

libavcodec

HDX4

Nero Digital

Xvid

H.264/MPEG-4 AVCor MPEG-4 Part 10 (MPEG-4 Advanced Video Coding), approved forBlu-ray

CoreAVC

ElecardAVC Decoder/Encoder

MainConcept

Nero Digital

QuickTime H.264

Sorenson AVC Pro codec,Sorenson's new implementation

x264(encoder only)

FFmpeg (decoder only)

HEVC

x265(encoder only)

HomerHEVC(encoder only) A HEVC video encoder under LGPL license.

Indeo3/4/5

FFmpeg (decoder only)

OMS Video

On2 TechnologiesTrueMotionVP3/VP4,VP5,VP6,VP7,VP8; under the nameThe Duck Corporation:TrueMotion S, TrueMotion 2

FFmpeg (decoder only)

Pixlet

RealVideo

FFmpeg

SnowWavelet Codec

Sorenson Video,Sorenson Spark

FFmpeg

Tarkin

Theora

FFmpeg (decoding only)

libtheora

VC-1(SMPTE standard, subset ofWindows Media Video)

FFmpeg (decoder only)

VP9byGoogle

Windows Media Video(WMV)

WAX (Part of the Windows Media Series)

FFmpeg

Intra-only

MJPEG

FFmpeg

Morgan Multimedia M-JPEG

Pegasus PICVideo M-JPEG

MainConcept M-JPEG

JPEG 2000intra frame video codec

libopenjpeg

FFmpeg (experimental)

Apple ProRes 422/4444

FFmpeg

AVC-Intra

FFmpeg

DV

FFmpeg

VC-2SMPTE standard (a.k.a. Dirac Pro)

Schrödinger

dirac-research

VC-3SMPTE standard

AvidDNxHD

FFmpeg

GoProCineForm

REDCODERAW - used byRedcameras

Grass ValleyCodec

本词条内容贡献者为:

鄢志丹 - 副教授 - 中国石油大学(华东)