You may have noticed that each piece of audio and video material on verdigris.org comes in several formats. Why is that? Basically, it allows them be played everywhere as different systems support different formats. It's also to provide patent-free alternatives to the MPEG standards.

In doubt, you can download all the files formats for each entry on verdigris.org at once in a ZIP archive. If you want minimal downloads to save time and data then you can also choose a particular format that works for you.

Media players

There are several popular open-source software media players which support all common formats such as MPV and VLC. Both can be used with all major operating systems. Web browsers can also typically play most formats, so you should equally be able to play the content directly without downloading any files.

Audio formats

The 3 main audio formats used on verdigris.org are:

• Flac for the best sound quality. Files are fairly big so it takes longer to download and uses more storage than Ogg or MP3. No patents involved.
• Ogg Vorbis is a lossy compressed audio format. Files are smaller than Flac but at the cost of lower quality. No patents involved either.
• MP3 is similar to Ogg but has slightly lower quality for a same file size. Also, for many years it was subject to some patents which implied licensing fees for products able to play MP3 files.

Video formats

Likewise, several video formats are used for different reasons. This is in reality more complicated than audio, but here's a summary of what you'll find on verdigris.org:

• Ogg Theora, which is intended to be the video equivalent of Ogg Vorbis. No patents involved.
• MPEG-4 is a wide-ranging standard used in many applications. It is subject to numerous patents, which implies licensing fees for manufacturers of products able to play MPEG-4 files (in some countries).
• WebM was especially developed for the web. Providing videos in this format ensures they can be played in most browsers. About patents, it's complicated: it does involve some patents but no royalties apply any more and the software implementation is open-source.