Audio format

An audio format is a data format that describes the structure of an audio file or an audio data stream .

General

Usually it is a format that describes the complete sound curve of a sound signal.

There are also audio files that do not contain a complete audio signal. So-called music formats only store individual notes and possibly information about the structure of sounds. A distinction must be made here between two formats: those that do not use samples ( e.g. MIDI ) and those that are supplemented by samples, so-called tracker modules .

Another approach to storing audio data is parametric audio coding . Some voice codecs partially use this approach, and an audio format is then to be implemented and standardized with Harmonic and Individual Lines and Noise (HILN, MPEG-4 Parametric Audio Coding).

Data reduction or data compression

→ Main article : Audio data compression

If the data is compressed , a distinction is made between lossless and lossy compressed formats.
Uncompressed formats (usually PCM ), losslessly compressed and lossy compressed formats can also be stored together in so-called container files ( AIFF , MP4 , Matroska , Ogg , WAV and others).

List of common audio formats

Uncompressed

• Linear pulse code modulation in different forms:
  • Raw data (.pcm)
  • in Audio Interchange File Format (AIFF, container format ) (.aif, .aiff, .aifc, .ief, .snd)
  • in Au container (.au)
  • in Resource Interchange File Format : RIFF WAVE (container format) (.wav)
  • CompactDisc-Digital Audio
• .aud
• .svx
• .voc - " Creative Voice File " - "Creative Labs Sound Blaster (Pro)" - file format for speech
• IFF-8SVX
• IFF-16SV
• .smp - SampleVision format, 16-bit, mono
• Pulse Amplitude Modulation (PAM)

Compressed formats

Lossless

• Advanced Digital Audio (ADA)
• Apple Lossless Audio Codec (ALAC), also: Apple Lossless Encoding Apple Lossless (.m4a, .mp4)
• Bonk (Codec)
• Dakx WAV
• Direct Stream Transfer (DST)
• Dolby TrueHD (extended MLP)
• DTS-HD - optional lossless surround sound format for HD DVD and Blu-ray Disc , previously also known as DTS ++ known
• Entis Lab MIO
• Free Lossless Audio Codec (.flac, .fla, possibly .ogg)
• LiteWave
• LosslessAudio
• Lossless Predictive Audio Compression (LPAC) (.pac)
• Lossless Transform Audio Compression (LTAC)
• Marian's a-Pac
• Meridian Lossless Packing (MLP), also Packed PCM (PPCM)
• Monkey's Audio (.ape, .mac)
• MPEG-4 Audio Lossless Coding (MPEG-4 ALS)
• OptimFROG (.ofr [.ofs])
• Original Sound Quality (.osq)
• Pegasus PLC
• RealAudio Lossless (.ra, in Matroska container, if necessary .mka)
• RK Audio ( RKAU )
• Shorten (.shn)
• Sonarc
• Split2000
• True Audio (.tta)
• VocPack
• WavArc
• WaveZip / MUSICompress
• WavPack (.wv)
• Windows Media Audio Lossless (.wma)

See also: Audio data compression # Lossless audio formats

Lossy data reduction

• Adaptive Differential (or Delta ) Pulse Code Modulation (ADPCM) (depending on the container .aif / .aiff, .au, .wav etc.)
• .vox - Dialogic ADPCM
• ADX
• Adaptive Rate-Distortion Optimized Sound Coder ( ARDOR )
• Adaptive Transform Acoustic Coding (ATRAC)
• DTS Coherent Acoustics (.dts)
• Dolby Digital , also A / 52 or AC-3 (.ac3)
• A-law (depending on the container .aif / .aiff, .au, .wav etc.)
• μ-law (depending on the container .aif / .aiff, .au, .wav etc.)
• MPEG 1/2 / 2.5 audio
  • MPEG-1 Audio Layer 1 (.mp1)
  • MPEG-1 Audio Layer 2 (.mp2)
  • MPEG-1 Audio Layer 3 (MP3) (.mp3)
• MPEG 2/4 audio
  • Advanced Audio Coding (.aac, .mp4, .m4a)
  • High Efficiency Advanced Audio Coding (HE-AAC), also aacPlus or AAC +
  • Harmonic and Individual Lines and Noise (HILN, MPEG-4 Parametric Audio Coding )
• Musepack (.mpc, .mp +, .mpp)
• Perceptual audio coding
• QDesign Music Codec (QDMC)
• RealAudio (.ra)
• TwinVQ (.vqf)
• Ogg- Vorbis (.ogg)
• Opus (.opus)
• Windows Media Audio (.wma)

See also: audio data compression # Lossy audio formats

Speech codecs

• Advanced Multi-Band Excitation (AMBE)
• Code-Excited Linear Prediction (CELP)
• Digital Speech Standard (DSS)
• Enhanced Variable Rate Codec (EVRC)
• FS-1015 (LPC-10)
• FS-1016 (CELP)
• ITU-T standards:
  • G.711
    • G.711a - A-law
    • G.711u - μ-law
  • G.721 (32 kbit / s ADPCM, replaced by G.726)
  • G.722 (ADPCM based)
  • G.722.1 (transformation-based)
  • G.722.2 (AMR-WB, CELP-based)
  • G.723 (24 and 40 kbit / s DPCM, extension of G.721, replaced by G.726)
    • G.723.1 (MPC-MLQ or ACELP )
  • G.726 (ADPCM)
  • G.728 (LD-CELP)
  • G.729 (CS-ACELP)
    • G.729a (variant with reduced complexity)
    • G.729.1 (broadband variant)
• Global System for Mobile Communications (GSM):
  • Full Rate Codec (FR)
  • Half Rate Codec (HR)
  • Enhanced Full Rate Codec (EFR)
  • Adaptive Multirate Codec (AMR) (.amr)
    • Adaptive multirate wide band (AMR-WB)
• Harmonic Vector Excitation Coding (HVXC)
• internet low bit rate codec (iLBC)
• Improved Multi-Band Excitation ( IMBE )
• internet Speech Audio Codec (iSAC)
• Mixed-Excitation Linear Predictive (MELP)
• QCELP (also Qualcomm PureVoice )
• Relaxed Code Excited Linear Prediction ( RCELP )
• Selectable Mode Vocoder (SMV)
• Speex (.spx, possibly .ogg)
• SILK
• Vector Sum Excited Linear Prediction ( VSELP )

See also

• List of filename extensions
• Video format
• Streaming format
• Audio editor (can also be used for format conversion)

Web links

• Overview and explanations of the most popular audio formats
• Audio Formats Reference ( CC )
• Hydrogenaudio Knowledgebase Topic wiki for audio technology (English)