基本介紹
- 中文名:音頻編解碼器
- 外文名:Audio codec
介紹,音頻編解碼,非壓縮,無損壓縮,有損壓縮,文字,視頻,無損壓縮,有損壓縮,
介紹
在軟體層面,音頻編解碼器是一個執行算法的電腦程式,能壓縮與解壓縮數字音頻數據到音頻檔案或流媒體音頻編碼格式。該算法的目的是保證質量的前提下使用最少的比特表示高保真音頻信號。這可以有效地減少存儲空間和傳輸已存儲音頻檔案所需的頻寬。大多數編解碼器是實現為一個具有接口的庫供一個或多個媒體播放器使用。
在硬體層面,音頻編解碼器指一個能編碼模擬音頻到數字音頻和解碼數字音頻到模擬音頻的獨立設備。換種說法,它包含運行在同樣時鐘的模數轉換器(ADC)和數模轉換器(DAC)。這在音效卡中被使用以支持音頻輸入和輸出。
音頻編解碼
非壓縮
- 脈衝編碼調製(Pulse-code modulation,簡稱PCM)是一種非壓縮的音頻編碼格式。此格式是CD-DA的標準。在計算機中,使用 PCM 編碼的音頻可以直接以原始音頻格式儲存。不過它們通常會被儲存在容器中,如WAV、AIFF、AU等(但在技術上這並不是必須的)。注意,有時 PCM 和 LPCM 都被籠統的稱作 PCM,但實際上它們相似卻不相同。
- 線性脈衝編碼調製(Pulse-code modulation,簡稱LPCM)是一種非壓縮的音頻編碼格式。這是一個 PCM 的變種。
脈衝密度調製(Pulse-density modulation,簡稱PDM)是一種非壓縮的音頻編碼格式。
脈衝強度調製(Pulse-Amplitude Modulation,簡稱PAM)是一種非壓縮的音頻編碼格式。
無損壓縮
- Apple LosslessAudio Codec(ALAC)
- Direct Stream Transfer(DST)
- 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)
有損壓縮
主條目:Lossy data compression §Audio
通用
- Adaptive Differential(or Delta)pulse-code modulation(ADPCM,見脈衝編碼調製)
- Adaptive Rate-Distortion Optimised sound codeR(ARDOR)
- Adaptive Transform Acoustic Coding(ATRAC,使用於MiniDisc設備)
- 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.722.1
MPEG audio
- HE-AAC
- layer-1(MP1)
- Harmonic and Individual Lines and Noise(HILN, MPEG-4Parametric Audio Coding)
Perceptual Audio Coding
QDesign
Vorbis
Windows Media Audio(WMA)
人聲(低比特率;為人聲最佳化)
主條目: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.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)
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
- Continuous Media Markup Language(CMML)
- MPEG-4 Part 17(e.g. 3GPP Timed Text)
- Ogg Kate
- Ogg Writ
- ttyrec
視頻
主條目:視頻壓縮
無損壓縮
- Alpary
- Animation(qtrle)
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
- CorePNG
- FFmpeg
ScreenPressor
SheerVideo
Snowlossless
- FFmpeg
TechSmith Screen Capture Codec (TSCC)
- FFmpeg (decoder only)
Ut Video
- FFmpeg
VMNC
YULS
有損壓縮
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
- FFmpegH.261 (libavcodec)
MPEG-1 Part 2 (MPEG-1Video)
- Cinema Craft Encoder
- ElecardMPEG-1 Decoder/Encoder
- MainConceptMPEG-1
H.262/MPEG-2 Part 2(MPEG-2 Video)
- Cinema Craft Encoder
- ElecardMPEG-2 Video Decoder/Encoder
- InterVideoVideo Decoder
- MainConcept MPEG-2
- FFmpegH.263 (libavcodec)
MPEG-4 Part 2(MPEG-4 Advanced Simple Profile)
- 3ivx
- ElecardMPEG-4 Decoder/Encoder
- libavcodec
- HDX4
- Nero Digital
H.264/MPEG-4 AVCor MPEG-4 Part 10 (MPEG-4 Advanced Video Coding), approved forBlu-ray
- ElecardAVC Decoder/Encoder
- MainConcept
- Nero Digital
- QuickTime H.264
- Sorenson AVC Pro codec,Sorenson's new implementation
- x264(encoder only)
- FFmpeg (decoder only)
- 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
- FFmpeg
SnowWavelet Codec
Sorenson Video,Sorenson Spark
- FFmpeg
Tarkin
- FFmpeg (decoding only)
- libtheora
VC-1(SMPTE standard, subset ofWindows Media Video)
- FFmpeg (decoder only)
Windows Media Video(WMV)
- WAX (Part of the Windows Media Series)
- FFmpeg
Intra-only
- Morgan Multimedia M-JPEG
- Pegasus PICVideo M-JPEG
- MainConcept M-JPEG
JPEG 2000intra frame video codec
- libopenjpeg
- FFmpeg (experimental)
Apple ProRes 422/4444
- FFmpeg
- FFmpeg
- FFmpeg
VC-2SMPTE standard (a.k.a. Dirac Pro)
- Schrödinger
- dirac-research
VC-3SMPTE standard
- AvidDNxHD
GoProCineForm
REDCODERAW - used byRedcameras
Grass ValleyCodec