FFmpeg Audio Build for Windows x64
==================================

Audio-focused 64-bit Windows build of FFmpeg with LAME 4.0 MP3 encoding.

This package is intended for local audio conversion and analysis. Network
support and ffplay are deliberately disabled to keep the distribution small
and predictable.

Included tools
--------------

ffmpeg.exe
    Audio conversion and processing tool.

ffprobe.exe
    Media and stream analysis tool.

Included external audio libraries
---------------------------------

libmp3lame-0.dll
    Cole Williams LAME 4.0 MP3 encoder build.

libopus-0.dll
    Opus encoder/decoder library.

libvorbis-0.dll
libvorbisenc-2.dll
libogg-0.dll
    Ogg Vorbis libraries.

libwinpthread-1.dll
    MinGW-w64 threading runtime required by this build.

FFmpeg also provides its normal built-in support for many audio formats,
including AAC, ALAC, FLAC, AC-3, E-AC-3, MP2, WavPack, PCM, ADPCM and others.

MP3 encoding with LAME 4.0
--------------------------

FFmpeg uses the included libmp3lame-0.dll for MP3 encoding.

Examples:

V0 VBR:
    ffmpeg -i input.wav -c:a libmp3lame -q:a 0 output.mp3

V2 VBR:
    ffmpeg -i input.wav -c:a libmp3lame -q:a 2 output.mp3

320 kbps CBR:
    ffmpeg -i input.wav -c:a libmp3lame -b:a 320k output.mp3

192 kbps ABR:
    ffmpeg -i input.wav -c:a libmp3lame -abr 1 -b:a 192k output.mp3

To display the options exposed by FFmpeg's libmp3lame wrapper:
    ffmpeg -hide_banner -h encoder=libmp3lame

Other examples
--------------

Opus:
    ffmpeg -i input.wav -c:a libopus -b:a 128k output.opus

Vorbis:
    ffmpeg -i input.wav -c:a libvorbis -q:a 5 output.ogg

Build information
-----------------

Platform:
    Windows x64

Compiler:
    GCC 16.2.0 (MSYS2 MinGW-w64)

FFmpeg revision:
    N-126846-g70570db898

FFmpeg configuration:
    --prefix=/e/cw-ffmpeg/dist-final
    --arch=x86_64
    --target-os=mingw32
    --disable-autodetect
    --enable-static
    --disable-shared
    --pkg-config-flags=--static
    --enable-libmp3lame
    --enable-libopus
    --enable-libvorbis
    --disable-ffplay
    --disable-network
    --disable-debug
    --disable-doc
    --extra-ldflags=-static-libgcc

The included LAME 4.0 library was built without its optional MP3 decoder,
because FFmpeg already provides MP3 decoding. This removes the otherwise
unnecessary mpg123 runtime dependency.

Validation
----------

This distribution was tested from an isolated directory with the Windows
PATH restricted to Windows system directories. MP3 (libmp3lame), Opus
(libopus), and Vorbis (libvorbis) encoding all completed successfully without
relying on an installed MSYS2 environment.

LAME 4.0 compatibility testing also confirmed standard VBR, ABR and CBR
operation through FFmpeg. Compared with LAME 3.100 using the same FFmpeg
interface, bitrate allocation remained extremely close while encoded MP3
bitstreams were distinct.

Notes
-----

Keep the supplied DLL files in the same directory as ffmpeg.exe and
ffprobe.exe unless they are otherwise available through the Windows DLL
search path.

This build does not include network protocol support and does not include
ffplay.

More information
----------------

FFmpeg and LAME:
    https://www.lamemp3.co.uk/ffmpeg-with-lame/

LAME 4.0:
    https://www.lamemp3.co.uk/

FFmpeg:
    https://ffmpeg.org/

Licensing
---------

FFmpeg and the bundled libraries remain copyright their respective authors
and are redistributed under their respective licences. See the LICENSES
folder and SOURCES.txt included with this package.

Cole Williams Software Limited
lamemp3.co.uk
