FFmpeg-Builds-AT

A BtbN/FFmpeg-Builds fork focusing on AudioToolbox/Win64.

Supports-c:a aac_at on Windows.

Packages removed from this fork:

• openh264 - left libx264.
• kvazaar - left libx265.
• aom - left dav1d, rav1e and svtav1.

Installation

Choose either one of the two:

• Install Apple iTunes using the official installer. No further steps needed.

• Extract files from iTunes. Same as QTFiles for qaac
  On x64 OS, The folder tree looks like this:

  |   ffmpeg.exe
  \-- QTfiles64
      |   ASL.dll
      |   CoreAudioToolbox.dll
      |   CoreFoundation.dll
      |   icudt62.dll
      |   libdispatch.dll
      |   libicuin.dll
      |   libicuuc.dll
      |   objc.dll

Tips

-q 0 gives the best quality, and -q 14 gives the smallest file.
Some useful parameters are:
-q 4 gives ~192 Kbps stereo, very high quality, recommended for movies.
-q 3 gives ~224 Kbps stereo, transparent, use it for opera, live, etc.

For low-res lectures, use -profile:a 4 -b:a 48k for HE-AAC at 48 Kbps.

Examples

# a movie:
ffmpeg -i input.mkv -c:a aac_at -q 4 output.mkv

# a lecture for watching at home:
ffmpeg -i input.mkv -c:a aac_at -profile:a 4 -b:a 64k output.mkv

# a lecture for listening in-car:
ffmpeg -i input.mkv -map 0:a -c:a aac_at -profile:a 4 -b:a 48k output.m4a

# To get some help
ffmpeg -h encoder=aac_at

Upstream Page

BtbN/FFmpeg-Builds