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)