Ogg

Ogg is a way to save files.

It can hold music and movies. It can also hold words on a screen. This helps us watch and listen. It is free for everyone to use.

Different files have different names. Some end in .oga for sound. Some end in .ogv for video. This helps computers know what is inside. Ogg is used in many video games. It works on many different machines. It is a very useful tool for digital media.

Ogg is a way to hold digital files. It is called a container format. This means it acts like a box. It can hold many things at once. It can hold music, video, and text. This text might be subtitles for a movie.

Inside the box, information is split into parts. We call these parts Ogg pages. Every page starts with the letters "OggS". This helps a computer find the start of a page. Each page has a number. This helps the computer keep the pages in the right order. It also has a checksum. A checksum is a way to check for mistakes. It makes sure the data is not broken or lost.

Ogg is free for everyone. No one owns it with a patent. This means anyone can use it to make new tools. Many video games use Ogg. For example, Minecraft uses it for sound. You might also find it in GPS devices. Different files have different names. Files for sound end in .oga. Files for video end in .ogv. These names help computers know what to do.

Ogg is a special way to hold digital files. It is called a container format. Think of it like a box that holds different types of data. This box can hold music, video, and even text like subtitles.

This format is very useful for streaming media. It allows for easy moving and changing of digital files. The Xiph.Org Foundation maintains this format. It is free and open for everyone to use. No software patents restrict how people use it. This makes it a great tool for many different projects.

Inside the Ogg container, information is organized into small pieces. These pieces are called Ogg pages. Every single page starts with the letters "OggS". This acts as a signal to the computer. It helps the computer find the start of a new page. Each page also has a serial number and a page number. These numbers help the computer keep the pages in the right order.

A page also has a checksum. This is a math tool used to check for errors. If the data is broken, the computer can find the mistake. This keeps the music or video playing correctly.

The history of Ogg began a long time ago. The project started in 1993 as a simple audio tool. At first, the name was "Squish." However, someone else already owned that trademark. The team changed the name to "OggSquish." Later, in 2001, they shortened the name to just "Ogg." The Ogg project is part of the larger Xiph.org project. On September 2, 2000, the Ogg part was separated from the Vorbis part. This helped the different parts of the project grow on their own.

There are many specific details about how Ogg files are named. For a long time, everything used the .ogg extension. After 2007, the Xiph.Org Foundation suggested new names. Now, .oga is used for files that only have audio. The extension .ogv is used for video files. If a file has many different types of media, it uses .ogx. These specific names help computers understand what is inside the box. The current version of the main software is libogg 1.3.3. This software was released as free software under the New BSD License.

You might see Ogg working in many places today. Many famous video games use Ogg to play their sounds. For example, the game Minecraft uses it for its audio. Other games like Halo and Grand Theft Auto have used it too. You can also find Ogg in portable media players. Even some GPS receivers use this technology. It is a very common way to share digital media. Because it is free, many people choose it for their work. It connects many different types of technology together.

Ogg is a digital multimedia container format. It is designed for the efficient streaming and manipulation of digital media. Unlike a single audio file, a container acts as a framework. It can hold many different types of independent data streams at once. These streams can include audio, video, text like subtitles, and metadata.

The format is maintained by the Xiph.Org Foundation. It is free and open to everyone. This means it is not restricted by software patents. Because it is open, many different types of software can use it.

The Ogg format works by organizing data into small units called Ogg pages. Each page is a discrete chunk of information. Every page must begin with a specific capture pattern. This pattern is the four-character sequence "OggS". This sequence acts as a sync code. It helps a computer parser resynchronize if data becomes lost or corrupted.

Each page header also contains a version field. Currently, this version is mandated to be 0. This field allows for future expansions of the bitstream format.

Inside the page header, several fields manage the flow of data. A header type field uses flags to indicate the page's role. For example, a Beginning of Stream (BOS) flag marks the first page. An End of Stream (EOS) flag marks the final page. A continuation flag identifies a page that carries the rest of a previous packet. To keep data in order, each page has a serial number and a page sequence number. The serial number identifies which logical bitstream the page belongs to. This is vital when a file contains both audio and video. The sequence number helps the computer detect if any pages are missing.

Data integrity is maintained through a mathematical tool called a checksum. The Ogg page header includes a 32-bit CRC-32 checksum. This checksum covers the entire page, including the header itself. The computer uses this to verify that the data has not been corrupted. If a page fails this check, the system should discard it. To group data into meaningful units, Ogg uses a segment table. This table contains an array of 8-bit values. Each value indicates the length of a data segment. These segments are then combined into packets for the decoder to read.

The history of Ogg began in 1993. It started as a simple audio compression package. The project was originally named "Squish." However, the name was already trademarked by someone else. The team then used the name "OggSquish." In 2001, the project was renamed simply to "Ogg." This name is derived from "ogging," which was jargon from the computer game Netrek. In that game, the term referred to doing something forcefully. The Ogg project is part of the larger Xiph.org multimedia project. On September 2, 2000, the Ogg reference implementation was separated from Vorbis.

File extensions have changed over time to be more specific. Until 2007, the .ogg extension was used for all Ogg files. Now, the Xiph.Org Foundation recommends specific names for different content. The .oga extension is used for audio-only files. The .ogv extension is used for video files, which may include Theora video. The .ogx extension is used for multiplexed files containing multiple media types. These distinctions help software identify the content immediately. As of November 7, 2017, the reference implementation was version libogg 1.3.3. This software is released under the New BSD License.

Ogg is used in many famous digital systems. Many popular video game engines incorporate Ogg codecs. These include engines for games like Halo: Combat Evolved and Grand Theft Auto. The game Minecraft also uses Ogg for its audio. Beyond games, Ogg is found in portable media players and even GPS receivers. It is also used to encode free content on Wikimedia Foundation projects. This wide use shows how important open formats are for sharing digital media across different devices and platforms.