Open source licences

The extractor on this site is FFmpeg. That comes with obligations, and this page meets them.

Free on iPhone and iPad, for the videos already in your camera roll. Works offline; one free conversion, then a subscription.

FFmpeg

This site serves @ffmpeg/core 0.12.10, a WebAssembly build of FFmpeg, from /vendor/ffmpeg/0.12.10/. The build is configured with --enable-gpl and includes GPL-licensed components, so the whole build is distributed under the GNU General Public License version 2 or later.

Source: ffmpeg.org · git.ffmpeg.org · licence text at gnu.org.

ffmpeg.wasm

What is inside this build

Library	Used for	Licence
LAME	MP3 encoding	LGPL 2.1+
libvorbis	OGG Vorbis encoding	BSD-3-Clause
libopus	Opus decoding (there is no Opus encoding here — see why)	BSD-3-Clause
FFmpeg native	AAC, FLAC, PCM, and decoding for AC-3, DTS, WMA, Vorbis and more	LGPL 2.1+ / GPL 2+
zlib	Compression inside containers	zlib

How the claims on this site are checked

The tables on the home page are generated from the same module the extractor runs on, so a page cannot advertise a conversion the engine will not perform. On top of that, a measurement suite builds real video files — MP4 with AAC, MKV with three soundtracks, WebM with Opus, AVI with MP3, a QuickTime master with 24-bit PCM, an MPEG-TS capture and a WMV — runs the engine's own plans against them, and checks that every “copy” really does produce a soundtrack identical to the one inside the video.

Everything else

The rest of this site — the page generator, the stylesheet, the extractor interface and the decision engine — is written by AppsOverflow LLC and is not open source. It contains no third-party JavaScript at all: no framework, no analytics, no font loader, no CDN.

Source requests

For a copy of the FFmpeg source corresponding to the build served here, write to ceo@appsoverflow.com.