Changes between Version 32 and Version 33 of Encode/AAC


Ignore:
Timestamp:
Sep 27, 2014, 2:11:46 AM (5 years ago)
Author:
bp0
Comment:

HAK links for details about low-pass filter, vbr modes, everything else

Legend:

Unmodified
Added
Removed
Modified
  • Encode/AAC

    v32 v33  
    1313== libfdk_aac ==#fdk_aac
    1414
    15 Fraunhofer FDK AAC codec library. This is currently the highest-quality AAC encoder available with ffmpeg. Requires ffmpeg to be configured with `--enable-libfdk_aac` (and additionally `--enable-nonfree` if you're also using `--enable-gpl`). But beware, it defaults to a low-pass filter of around 14kHz. If you want to preserve higher frequencies, use `-cutoff 18000`.  Adjust the number to the upper frequency limit you prefer.
     15The Fraunhofer FDK AAC codec library. This is currently the highest-quality AAC encoder available with ffmpeg. Requires ffmpeg to be configured with `--enable-libfdk_aac` (and additionally `--enable-nonfree` if you're also using `--enable-gpl`). But beware, it defaults to a low-pass filter of around 14kHz ([[http://wiki.hydrogenaud.io/index.php?title=Fraunhofer_FDK_AAC#Bandwidth|details]]). If you want to preserve higher frequencies, use `-cutoff 18000`.  Adjust the number to the upper frequency limit you prefer.
     16
     17Detailed information about the FDK AAC library (not FFmpeg specific) can be found at the [[http://wiki.hydrogenaud.io/index.php?title=Fraunhofer_FDK_AAC|Fraunhofer FDK AAC]] page in the HydrogenAudio Knowledgebase.
    1618
    1719=== Constant Bit Rate (CBR) mode ===#fdk_cbr
     
    4547VBR encoding in libfdk-aac is '''experimental''' and only works with some parameter combinations. Target a ''quality'', rather than a specific ''bit rate''. 1 is lowest quality and 5 is highest quality. This mode is not compatible with [[#fdk_he|AAC-HE]]. Set the VBR level with the `-vbr` flag.
    4648
    47 According to [[http://www.hydrogenaudio.org/forums/index.php?showtopic=95989|this hydrogenaudio post]], the VBR modes (on average, over a number of files) give the following bit rates per channel (so for stereo, double the bit rate; for 5.1 surround sound, multiply it by six):
     49VBR modes give the following bit rates per channel ([[http://wiki.hydrogenaud.io/index.php?title=Fraunhofer_FDK_AAC#Bitrate_Modes|details]]):
    4850
    4951||VBR||kb/s/channel||