AAC, MPEG-2 Advanced Audio Coding File (.aac)

The AAC Audio file format

AAC files were designed with the intention of replacing MP3’s. The lossy compression provides better audio quality at similar bit rates. AAC files are standardized by the ISO/IEC as part of the MPEG-2 and MPEG-4 families though it was first introduced into the MPEG-2 Part 7 family. AAC files contain more sample frequencies than MP3’s, as well as up to 48 channels, higher efficiency of coding and filter banks, and higher coding accuracy for transient signals. Much like MP3 files, AAC files remove audio at frequencies the human ear cannot process to create smaller and more manageable files. The file size is significantly smaller with AAC files compared to MP3 files.

Technical details of AAC files

The MPEG-2 part 7 is defined with three profiles: Low Complexity (AAC-LC), Main profile (AAC Main), and Scalable Sampling Rate profile (AAC-SSR). AAC files allows temporal noise shaping, a non-uniform quantizer, and reworking of bitstream format (for 16 stereo channels, 16 mono channels, 16 low-frequency channels, and 16 commentary channels in a single bitstream). In 1999, the MPEG-2 part 7 was included in the MPEG-4 Part 3. This added Audio Object Types and Perceptual Noise Substitution. The current AAC standard is specified in ISO/IEC standard 14496-3. Audio masking is used in the lossy compression of the audio to discard of unneeded data while retaining quality.

More information about the AAC file format

File extension .aac
File category Audio
Example file Download example.aac file (1.2 MiB)
Associated programs Windows Media Player
iTunes
KMPlayer
RealPlayer
VideoLAN VLC Media Player
Useful links More information on AAC
File conversion Convert a file to AAC
Developer Fraunhofer IIS, AT&T Bell Laboratories, Dolby, and Sony Corporation

Convert your AAC file to another file format

  1. AAC to AIFF
  2. AAC to FLAC
  3. AAC to M4A
  4. AAC to MMF
  5. AAC to MP3
  6. AAC to OGG
  7. AAC to OPUS
  8. AAC to WAV
  9. AAC to WMA
  10. AAC to AVI
  11. AAC to 3GP
  12. AAC to MOV
  13. AAC to MP4
  14. AAC to ZIP

Convert your audio file to the AAC format

  1. FLAC to AAC
  2. PPTX to AAC
  3. AUP to AAC
  4. URL to AAC
  5. JPEG to AAC
  6. MOV to AAC
  7. 3GPP to AAC
  8. JPG to AAC
  9. WAV to AAC
  10. PDF to AAC
  11. M4R to AAC
  12. OGG to AAC
  13. WMV to AAC
  14. ZIP to AAC
  15. COM to AAC
  16. MKA to AAC
  17. MP4 to AAC
  18. FLV to AAC
  19. PNG to AAC
  20. AMR to AAC

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