Documentation

    Table of Content
    • 3D File Formats
      • 3D File Formats
      • 3D2
      • 3DS
      • 3MF
      • AMF
      • ASE
      • DAE
      • DRC
      • FBX
      • GLB
      • GLTF
      • IPT
      • JRXML
      • JT
      • OBJ
      • PLY
      • PRC
      • RVM
      • STEP
      • U3D
      • USD
      • USDZ
      • VRML
      • X
      • X3D
    • Audio File Formats
      • Audio File Formats
      • AAC
      • AC3
      • FLAC
      • M3U
      • MID
      • MKA
      • MP3
      • OGG
      • OPUS
      • RA
      • SDT
      • STAP
      • WAV
      • WMA
    • CAD File Formats
      • CAD File Formats
      • CF2
      • DC3
      • DGN
      • DWF
      • DWFX
      • DWG
      • DWT
      • DXF
      • HPGL
      • IFC
      • IGES
      • IGS
      • JVSG
      • NWC
      • NWD
      • NWF
      • PAT
      • PHJ
      • PLT
      • PSM
      • PSS
      • RVT
      • STL
    • Compression File Formats
      • Compression File Formats
      • 7Z
      • ARC
      • ARJ
      • BZ2
      • DAA
      • GZ
      • RAR
      • TAR
      • ZIM
      • ZIP
    • Database
      • Database File Formats
      • ACCDB
      • ACCDE
      • ACCDT
      • ACCFT
      • BAK
      • BCP
      • DDL
      • DTSX
      • LDF
      • MDB
      • MDF
      • MYI
      • NDF
      • NSF
      • SQL
      • SQLITE
    • EBook File Formats
      • EBook File Formats
      • AZW
      • AZW3
      • CBC
      • CBR
      • CBZ
      • EPUB
      • FB2
      • KFX
      • LRF
      • LRS
      • LRX
      • MOBI
      • TR
    • Email File Formats
      • Email File Formats
      • EDB
      • EML
      • EMLX
      • ICS
      • MBOX
      • MSG
      • OFT
      • OLM
      • OST
      • PST
      • TNEF
      • VCF - Virtual Contact File
    • Font
      • Font File Formats
      • CFF
      • CFF2
      • EOT
      • FNT
      • FON
      • JFPROJ
      • OTF
      • PFA
      • PFB
      • PFM
      • SFD
      • TTC
      • TTF
      • Type1
      • WOFF
    • GIS File Formats
      • GIS File Formats
      • E00
      • FileGDB
      • GeoJSON
      • GML
      • GPX
      • KML
      • KMZ
      • OSM
      • SHP
    • Image File Formats
      • Image File Formats
      • AI
      • APNG
      • AVIF
      • BMP
      • BPG
      • CDR
      • CMX
      • CPC
      • DCM
      • DIB
      • DICOM
      • DJVU
      • DNG
      • EMF
      • EMZ
      • EXIF
      • FLIF
      • FODG
      • GIF
      • ICO
      • J2C
      • J2K
      • JFIF
      • JP2
      • JPEG
      • JPF
      • JPM
      • JPX
      • JXR
      • ODG
      • OTG
      • PNG
      • PSB
      • PSD
      • SVGZ
      • TGA
      • TIFF
      • VDX
      • VSD
      • VSDM
      • VSDX
      • VSS
      • VSSM
      • VSSX
      • VST
      • VSTM
      • VSTX
      • VSX
      • VTX
      • WEBP
      • WMF
      • WMZ
    • Note Taking File Formats
      • Note Taking File Formats
      • ONE
      • ONETOC2
    • Page Description Language
      • Page Description Language
      • CGM
      • EPS
      • PCL
      • PS
      • SVG
      • SWF
      • TEX
      • XPS
      • XSLFO
    • PDF
      • PDF
      • PDF/A
      • PDF/E
      • PDF/UA
      • PDF/VT
      • PDF/X
    • Presentation File Formats
      • Presentation File Formats
      • ODP
      • OTP
      • POT
      • POTM
      • POTX
      • PPS
      • PPSM
      • PPSX
      • PPT
      • PPTM
      • PPTX
    • Programming
      • Programming
      • C
      • Class
      • CPP
      • CS
      • CSPROJ
      • Dart
      • H
      • JAR
      • Java
      • KT
      • MF
      • PDB
      • PHP
      • PY
      • SH
      • SLN
      • SWIFT
      • TOML
      • VB
      • VBPROJ
      • VCXPROJ
      • YAML
    • Project Management File Formats
      • Project Management File Formats
      • MPP
      • MPT
      • MPX
      • XER
    • Spreadsheet File Formats
      • Spreadsheet File Formats
      • CSV
      • DIF
      • FODS
      • NUMBERS
      • NUMBERS-TEF
      • ODS
      • OTS
      • SXC
      • TSV
      • XLA
      • XLAM
      • XLM
      • XLS
      • XLSB
      • XLSM
      • XLSX
      • XLT
      • XLTM
      • XLTX
    • Video File Formats
      • Video File Formats
      • 3G2
      • 3GP
      • ASF
      • AVI
      • F4V
      • FLV
      • M4V
      • MJPEG
      • MK3D
      • MKS
      • MKV
      • MOV
      • MP4
      • MXF
      • QT
      • RM
      • RMVB
      • RV
      • SRT
      • VOB
      • VP6
      • WEBM
      • WMV
      • Xvid
    • Web File Formats
      • Web File Formats
      • ASP
      • ASPX
      • CHM
      • CSS
      • HTM
      • HTML
      • IXBRL
      • JS
      • JSON
      • MHT
      • MHTML
      • Sass
      • SCSS
      • VDW
      • XAML
      • XBRL
      • XHTML
      • XML
      • XOML
      • XSLT
    • Word Processing File Formats
      • Word Processing File Formats
      • DOC
      • DOCM
      • DOCX
      • DOT
      • DOTM
      • DOTX
      • MD
      • ODT
      • OTT
      • RTF
      • TXT
    • Reporting
      • RDL
      • RDLC
      • RPL
    1. Home
    2. Audio File Formats
    3. AC3

    What's on this Page

      • What is an AC3 file?
      • AC3 File Format
        • Technical Details
      • References

    What is an AC3 file?

    A file with a .ac3 extension is an Audio Codec 3 file, introduced by Dolby Laboratories. It is an audio format that can contain up to six channels of audio output. The format had been originally used for audio but is now also used for other applications such as HDTV broadcast, DVDs, Blue-ray discs and game consoles. Applications that can open AC3 files include Apple QuickTime player, Microsoft Windows Media Player, Winamp, MPlayer and other similar.

    AC3 File Format

    AC3 files are binary in nature and based on the Modified Discrete Cosine Transform (MDCT) which is a lossy compression algorithm. Dolby Laboratories used the MDCT algorithm along with perceptual coding principles to develop the AC-3 audio format. This led to the release of the AC-3 format as the Dolby Digital standard in 1991. The format supports the provision of five channels for normal-range speakders (20 Hz - 20,000 Hz) and one channel (20 Hz - 120 Hz) for the subwoofer driven low-frequency effects. AC3 supports sample rates up to 48 kHz.

    Technical Details

    The Dolby Digital technology uses a very efficient way to compress the size of multichannel audio files without impairing the sound quality. This compression leads to smaller file size which makes it easy to distribute the sound files. Using Dolby Digital, it is possible to include a full 5.1-channel audio mix on a film print or a DVD.

    Specifications

    The Dolby Digital specifications are as follow.

    FieldSpecification
    Channels1.0 to 5.1, discrete
    DVD data rate, 5.1-channel audio384 or 448 kbps
    Blu-ray Disc data rate, 5.1-channel audio640 kbps
    Supports Dolby metadataYes
    ConnectionsS/PDIF, HDMI®, IEEE 1394
    Mixing/streaming capabilitiesYes

    MetaData Parameters

    Metadata ParamterInformationalControl
    Dialogue levelYes
    Channel modeYes
    LFE channelYes
    Bitstream modeYesYes
    Line mode compressionYes
    RF mode compressionYes
    RF overmodulation protectionYes
    Center downmix levelYes
    Surround downmix levelYes
    Dolby Surround modeYes
    Audio production informationYes
    Mix levelYes
    Room typeYes
    Copyright bitYes
    Original bitstreamYes
    Preferred stereo downmixYes
    Lt/Rt Center downmix levelYes
    Lt/Rt Surround downmix levelYes
    Lo/Ro Center downmix levelYes
    Lo/Ro Surround downmix levelYes
    Dolby Digital Surround EX™ modeYes
    A/D converter typeYes
    DC filterYes
    Lowpass filterYes
    LFE lowpass filterYes
    Surround 3 dB attenuationYes
    Surround phase shiftYes

    References

    • AC3 - By Wikiepedia
    • Dolby Digital 5.1

    See Also

    • AAC - Advanced Audio Coding File
    • MIDI File Format
    • AVIF File Format
    • MP3 - Audio File Format
    • RA File Format