Rockbox is a

free and open-source software Free and open-source software (FOSS) is software available under a license that grants users the right to use, modify, and distribute the software modified or not to everyone free of charge. FOSS is an inclusive umbrella term encompassing free ...

replacement for the OEM

firmware In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computer, computing machinery. It includes the study and experimentation of algorithmic processes, and the development of both computer hardware, h ...

in various forms of

digital audio players A portable media player (PMP) or digital audio player (DAP) is a portable consumer electronics device capable of storing and playing digital media such as audio, images, and video files. Normally they refer to small, battery-powered devices ...

(DAPs) with an original kernel. It offers an alternative to the player's

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

, in many cases without removing the original firmware, which provides a plug-in architecture for adding various enhancements and functions. Enhancements include

personal digital assistant A personal digital assistant (PDA) is a multi-purpose mobile device which functions as a personal information manager. Following a boom in the 1990s and 2000s, PDAs were mostly displaced by the widespread adoption of more highly capable smar ...

(PDA) functions, applications, utilities, and games. Rockbox can also retrofit video playback functions on players first released in mid-2000. Rockbox includes a voice-driven user-interface suitable for operation by visually impaired users. Rockbox runs on a wide variety of devices with very different hardware abilities: from early

Archos Archos (, stylized as ARCHOS) is a French Multinational corporation, multinational consumer electronics, electronics company that was established in 1988 by Henri Crohas. Archos manufactures tablet computers, tablets, smartphones, portable media ...

players with 1-bit character cell-based displays, to modern players with high resolution color displays, digital optical audio hardware and advanced recording abilities.

History

The Rockbox project was founded by the three Swedish developers Linus Feltzing, Björn Stenberg and

Daniel Stenberg Magnus Daniel Stenberg is a Swedish developer and recipient of the 2017 Polhem Prize (for a high-level technological innovation or an ingenious solution to a technical problem) for his work on the cURL utility. Stenberg was born and raised in Hu ...

in late 2001. It was first implemented on the early

series of hard-disk based MP3 players/recorders (including the flash-only model Ondio), because of owner frustration with severe limitations in the manufacturer-supplied user interface and device operations. These devices have relatively weak main

central processing unit A central processing unit (CPU), also called a central processor, main processor, or just processor, is the primary Processor (computing), processor in a given computer. Its electronic circuitry executes Instruction (computing), instructions ...

s (CPU), and instead offload music playback to dedicated hardware MP3 decoding chips (MAS). Rockbox was unable to significantly alter playback abilities. Instead, it offered a greatly improved user interface and added plug-in functions absent in the factory firmware. Rockbox can be permanently flashed into flash memory on the Archos devices, making it a firmware replacement. Versions of Rockbox have since been produced for more sophisticated devices. These perform audio decoding in

software Software consists of computer programs that instruct the Execution (computing), execution of a computer. Software also includes design documents and specifications. The history of software is closely tied to the development of digital comput ...

, allowing Rockbox to potentially support many more music formats than the original firmware, and adding the extensibility and increased functions already present in the Archos ports. Rockbox is run from the hard drive or flash memory after being started with a custom boot loader, so to upgrade Rockbox, users need only copy the files onto the player's drive and restart the device. Reflashing is only needed when changing the boot loader, and on some platforms is not needed at all. The first of these ports, beginning in late 2004, was for the ColdFire-powered devices manufactured by iriver, focusing on the H1xx series of hard drive players (H110/H120/H140). About one year later, a port for the H3xx series became functional, offering similar functions. In late 2005, work began on a port of Rockbox to Apple's iPod portable players based on CPUs from ARM Ltd. incorporated into systems on a chip sold by

PortalPlayer PortalPlayer, Inc., founded in 1999, was a fabless semiconductor company that supplied system-on-a-chip semiconductors, firmware and software for personal media players. The company handled semiconductor design and firmware development, while su ...

. Throughout 2006, Rockbox ports were made available for a variety of iPod models. Beginning in 2007, ports became available for a large number of additional ARM based targets, including players from Sandisk,

Toshiba is a Japanese multinational electronics company headquartered in Minato, Tokyo. Its diversified products and services include power, industrial and social infrastructure systems, elevators and escalators, electronic components, semiconductors ...

, Olympus and

Philips Koninklijke Philips N.V. (), simply branded Philips, is a Dutch multinational health technology company that was founded in Eindhoven in 1891. Since 1997, its world headquarters have been situated in Amsterdam, though the Benelux headquarter ...

in addition to newer Apple and iRiver players based on a variety of ARM7, ARM9 and ARM11 series processors. During this time, extensive work was conducted optimizing open source audio decoders for each of the ARM series processors. In 2008, porting began to processors based on the

MIPS architecture MIPS (Microprocessor without Interlocked Pipelined Stages) is a family of reduced instruction set computer (RISC) instruction set architectures (ISA)Price, Charles (September 1995). ''MIPS IV Instruction Set'' (Revision 3.2), MIPS Technologies ...

. In 2010, work began on supporting "hosted" architectures where Rockbox runs as an application inside a of more complex

. , all Rockbox ports have been accomplished by reverse engineering with little or no manufacturer assistance. As free software, many Rockbox developers and supporters hope to eventually see official manufacturer support for new ports, or at least unofficial assistance in porting Rockbox to new devices. Only a few companies have expressed interest in Rockbox, and none have officially contributed code to the project or included it with their hardware. The Sansa e200v1 port is the first to be started at the request of the hardware manufacturer, who gave the Rockbox team samples of their devices. Rockbox is continuously developed, with new

Git Git () is a distributed version control system that tracks versions of files. It is often used to control source code by programmers who are developing software collaboratively. Design goals of Git include speed, data integrity, and suppor ...

builds being released after every source change, and stable releases every 4 months for targets deemed sufficiently mature. Additionally builds are often available to developers of unsupported targets, which, while somewhat functional, are typically not ready for general users due to incomplete features or poor stability. As of 2025, the latest stable build is 4.0. As of 2024, there have been no new ports released.

Future

Rockbox is targeted primarily at

, rather than the much more powerful general-purpose devices (such as

smartphone A smartphone is a mobile phone with advanced computing capabilities. It typically has a touchscreen interface, allowing users to access a wide range of applications and services, such as web browsing, email, and social media, as well as multi ...

s and

tablet computer A tablet computer, commonly shortened to tablet, is a mobile device, typically with a mobile operating system and touchscreen display processing circuitry, and a rechargeable battery in a single, thin and flat package. Tablets, being computers ...

s) that have been increasing in popularity since 2010.

, a founder of the Rockbox project, envisions the project evolving away from a standalone Rockbox operating system to Rockbox as a media player application that runs under

mobile operating system A mobile operating system is an operating system used for smartphones, tablets, smartwatches, smartglasses, or other non-laptop personal mobile computing devices. While computers such as laptops are "mobile", the operating systems used on the ...

s, such as Android,

iOS Ios, Io or Nio (, ; ; locally Nios, Νιός) is a Greek island in the Cyclades group in the Aegean Sea. Ios is a hilly island with cliffs down to the sea on most sides. It is situated halfway between Naxos and Santorini. It is about long an ...

, Sailfish OS or

Tizen Tizen () is a Linux-based operating system primarily developed by Samsung Electronics and supported by the Linux Foundation. The project was originally conceived as an HTML5-based platform for mobile devices to succeed MeeGo. It was backed by o ...

: A project to port Rockbox to run as an application under a full-fledged operating system was accepted for

Google Google LLC (, ) is an American multinational corporation and technology company focusing on online advertising, search engine technology, cloud computing, computer software, quantum computing, e-commerce, consumer electronics, and artificial ...

's 2010 Summer of Code and completed. Currently, Rockbox runs on Android based players, but integration into Android and conversion to work with touch based devices is ongoing. Subsequently, an anonymous Chinese developer unofficially ported Rockbox to

Palm Palm most commonly refers to: * Palm of the hand, the central region of the front of the hand * Palm plants, of family Arecaceae ** List of Arecaceae genera **Palm oil * Several other plants known as "palm" Palm or Palms may also refer to: Music ...

WebOS webOS, also known as LG webOS, is a Linux kernel-based multitasking operating system for smart devices, such as smart TVs, that has also been used as a mobile operating system. Initially developed by Palm, Inc. (which was acquired by Hewlett ...

Customization

Subject to the limitations of each particular platform, the appearance of Rockbox can be customised in various ways. Fonts and foreground and background colours can be added and selected, while a simple

markup language A markup language is a Encoding, text-encoding system which specifies the structure and formatting of a document and potentially the relationships among its parts. Markup can control the display of a document or enrich its content to facilitate au ...

can be used to create themes for the menu and playback screens. These themes can include backgrounds and other images (such as icons), plus various formats for file names, ID3 tags, album art, file progress, and time and system information. Rockbox has essentially been a file-tree based player, to which folders could be dragged and dropped and then navigated by folder structure. However, more recent versions have included a complementary database feature which allows the player to compile information from the files' ID3 tags. The user can then navigate the files regardless of file structure.

Features

Target status

Rockbox has many features additional to those supported by the original operating firmware, but in many cases there are limitations. On platforms classified as "stable" and supported, the device can be used as a digital music player, but even on some such platforms Rockbox does not support charging or USB; the player must be dual-booted into the original firmware to be charged or to transfer files. Some platforms are classified as "unstable", but supported; those deemed "unusable" are not supported, and their use is not recommended. Some porting projects are in a pre-development hunting and gathering stage, with no code written.Rockbox Target Status
/ref>

Codecs

Rockbox on software decoding platforms (non-Archos) supports playback of twelve

lossy In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size ...

codecs (depending on how one counts), five lossless, two uncompressed and twelve miscellaneous formats. This makes a conservative total of 30 supported audio formats, although a few of them do not operate in realtime on all platforms. Extensive work has gone into optimizing each codec, with FLAC, Ogg Vorbis, WMA, APE, TTA, MPC, Wavpack, ATRAC3, Cook and WMA Pro among the fastest known integer implementations for those formats.

Lossy formats

* MPEG audio layers I-III (MP3/ MP2/ MP1) *

Ogg Vorbis Vorbis is a free and open-source software project headed by the Xiph.Org Foundation. The project produces an audio coding format and software reference encoder/decoder (codec) for lossy audio compression, libvorbis. Vorbis is most common ...

* MPEG-4 AAC(-LC/HE/HEv2 profiles) (in MP4 or RM containers) * Musepack * AC3 (raw or RM container) * WMA Standard * WMA Professional *

Speex {{More citations needed, date=May 2025 The Speex project is an attempt to create a free software speech codec, unencumbered by patent restrictions. Speex is licensed under the BSD License and is used with the Xiph.org Foundation's Ogg containe ...

Cook Cook or The Cook may refer to: Food preparation * Cooking, the preparation of food * Cook (domestic worker), a household staff member who prepares food * Cook (profession), an individual who prepares food for consumption in the food industry * C ...

* ATRAC3 * The lossy portion of

WavPack WavPack is a free and open-source lossless audio compression format and application implementing the format. It is unique in the way that it supports hybrid audio compression alongside normal compression which is similar to how FLAC works. ...

hybrid files * Opus

Lossless formats

FLAC FLAC (; Free Lossless Audio Codec) is an audio coding format for lossless compression of digital audio, developed by the Xiph.Org Foundation, and is also the name of the free software project producing the FLAC tools, the reference software ...

* ALAC *

* Shorten *

Monkey's Audio Monkey's Audio is an algorithm and file format for lossless audio data compression. Lossless data compression does not discard data during the process of encoding, unlike lossy compression methods such as Advanced Audio Coding, MP3, Vorbis ...

* TTA

Uncompressed formats

* WAV *

AIFF AIFF may refer to: * Audio Interchange File Format * All India Football Federation, the national governing body of Association football in India Film festivals * Addis International Film Festival, Addis Ababa, Ethiopia * Alexandria Internation ...

Together they include over a dozen different

PCM Pulse-code modulation (PCM) is a method used to Digital signal (signal processing), digitally represent analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio application ...

and

ADPCM Adaptive differential pulse-code modulation (ADPCM) is a variant of differential pulse-code modulation (DPCM) that varies the size of the quantization step, to allow further reduction of the required data bandwidth for a given signal-to-noise rati ...

formats.

Miscellaneous formats

In addition, there are playback of game audio types ADX, SID, NSF, SAP, SPC, AY, GBS, HES, KSS, SGC, VGM, and VGZ. The MOD tracker format, and the Yamaha SMAF are also now supported. Some profiles in Monkey's Audio are not real time on all targets due to very high CPU needs. Also, Rockbox will not play files with a

digital rights management Digital rights management (DRM) is the management of legal access to digital content. Various tools or technological protection measures, such as access control technologies, can restrict the use of proprietary hardware and copyrighted works. DRM ...

(DRM) scheme.

Rockbox features

Beside the ability of playing and recording audio files, Rockbox offers many playback enhancements that other firmware packages may not have implemented yet. Listed below are a handful of these features. *

Gapless playback Gapless playback is the uninterrupted playback of consecutive audio tracks, such that relative time distances in the original audio source are preserved over track boundaries on playback. For this to be useful, other artifacts (than timing-related ...

* Crossfading *

ReplayGain ReplayGain is a proposed technical standard published by David Robinson in 2001 to measure and normalize the perceived loudness of audio in computer audio formats such as MP3 and Ogg Vorbis. It allows media players to normalize loudness for in ...

Software decoding targets only * 10 band fully parametric equalizer * Variable speed decoding with pitch correction * Crossfeed * OTF ("on the fly") playlists * True random shuffle (fresh randomly shuffled list every time) * Custom UI themes * Dynamic Playlists (queue files to play next, or in other parts of a dynamic playlist) * Stereo voice/MIC & FM radio recording to WAV/AIFF/WavPack (lossless) and MP3 (limited model/device/target support) * Remote control (supporting devices) * Digital

S/PDIF S/PDIF (Sony/Philips Digital Interface) is a type of digital audio interface used in consumer audio equipment to output audio over relatively short distances. The signal is transmitted over either a coaxial cable using RCA connector, RCA or BN ...

input/output (supporting devices) * Last.fm support (even on players lacking RTC) * Cue sheet support * Album art * Sleep timer

Plug-ins

Rockbox developers can create plug-ins, which provide the user with other enhancements that may not be available on various

modules. Available plug-ins include: *

JPEG JPEG ( , short for Joint Photographic Experts Group and sometimes retroactively referred to as JPEG 1) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degr ...

viewer (16 bit color/129 shade greyscale) * Rockboy

Game Boy The is a handheld game console developed by Nintendo, launched in the Japanese home market on April 21, 1989, followed by North America later that year and other territories from 1990 onwards. Following the success of the Game & Watch single-ga ...

emulator (port of Gnuboy) * ZXBox

ZX Spectrum The ZX Spectrum () is an 8-bit computing, 8-bit home computer developed and marketed by Sinclair Research. One of the most influential computers ever made and one of the all-time bestselling British computers, over five million units were sold. ...

emulator (port of Spectemu) * '' Doom'' (port of the PrBoom engine) * ''

Duke Nukem 3D ''Duke Nukem 3D'' is a 1996 first-person shooter, first-person shooter game developed by 3D Realms and published by FormGen for MS-DOS. It is a sequel to the platform games ''Duke Nukem (video game), Duke Nukem'' and ''Duke Nukem II'', published ...

'', '' Quake'', and ''

Wolfenstein 3D ''Wolfenstein 3D'' is a 1992 first-person shooter game developed by id Software and published by Apogee Software and FormGen for DOS. It was inspired by the 1981 Muse Software video game '' Castle Wolfenstein'', and is the third installment ...

'' running atop a version of the Simple DirectMedia Layer runtime * XWorld, a clone of Another World * WAV to MP3 and Wavpack encoder * MPEG video playerThe mpegplayer plug-in supports

MPEG-1 MPEG-1 is a Technical standard, standard for lossy compression of video and Audio frequency, audio. It is designed to compress VHS-quality raw digital video and CD audio down to about 1.5 Mbit/s (26:1 and 6:1 compression ratios respectively ...

and

MPEG-2 MPEG-2 (a.k.a. H.222/H.262 as was defined by the ITU) is a standard for "the generic coding of moving pictures and associated audio information". It describes a combination of lossy video compression and lossy audio data compression methods ...

video streams with MPEG audio (layer II/III) multiplexed into .mpg files with no hard limits on

frame rate Frame rate, most commonly expressed in frame/s, or FPS, is typically the frequency (rate) at which consecutive images (Film frame, frames) are captured or displayed. This definition applies to film and video cameras, computer animation, and moti ...

bit rate In telecommunications and computing, bit rate (bitrate or as a variable ''R'') is the number of bits that are conveyed or processed per unit of time. The bit rate is expressed in the unit bit per second (symbol: bit/s), often in conjunction ...

. Files must be encoded at native screen resolution. Seeking is now implemented

/ref> * PictureFlow, an album art viewer similar to Apple's Cover Flow * Various games including 2048, Sudoku,

Solitaire Solitaire may refer to: Film and television *'' Le Solitaire'', a 1987 French film * ''Solitaire'' (1991 film), a Canadian drama film * ''Solitaire'' (2008 film), a drama film *''Solitaire'', 2016 Lebanese comedy film with Bassam Kousa *"Solit ...

, Chess, Minesweeper, Pong and many others (see https://www.rockbox.org/wiki/PluginIndex for an official list of plug-ins) *

Musical Instrument Digital Interface Musical Instrument Digital Interface (; MIDI) is an American-Japanese technical standard that describes a communication protocol, digital interface, and electrical connectors that connect a wide variety of electronic musical instruments, ...

(MIDI) player, real-time on some targets. * MikMod, used to play multiple

module file Module file (MOD music, tracker music) is a family of music file formats originating from the MOD file format on Amiga systems used in the late 1980s. Those who produce these files (using the software called music trackers) and listen to them ...

formats

Retired ports

Source: * ArchosFAQ - Archos Player/Studio, Recorder v1, v2 and FM * ArchosOndio - Archos Ondio SP/FM Port index

Stable and functional ports

Source: * AgptekRocker - AGPtek Rocker Port Index * AIGOErosQK - AIGO EROS Q / K Port Index * CreativeZENMozaicPort - Creative Zen Mozaic Port Index * CreativeZENXFiPort - Creative Zen X-Fi Port Index * CreativeZENXFi3Port - Creative Zen X-Fi 3 Port Index * CreativeZENXFiStylePort - Creative ZEN X-Fi Style Port Index * FiioM3K - FiiO M3K Port Index * GigabeatFXPort - Toshiba Gigabeat F and X Series Port Index * GigabeatSPort - Gigabeat S Port Index * IaudioPort - iAudio X5/M5/M3 Port Index * IpodPort - iPod Port Index * IriverH10Port - iriver H10 Port Index * IriverPort - iriver h1x0 and h3x0 Port Index * MPIOHD300Port - MPIO HD300 Port Index * OlympusMR100Port - Olympus M:Robe 100 Port Index * OlympusMR500Info - Olympus M:Robe 500 Port Index * PackardBellVibe500Port - Packard Bell Vibe 500 Port Index * GoGearHDD6330 - Philips GoGear HDD1630/63X0 Port Index * GoGearSA9200info - Philips GoGearSA9200 Port Index * SamsungYH92xPort -Samsung YH-820, YH-920 and YH-925 Port Index * SansaC200Port - Sandisk Sansa c200 Port index * SansaE200Port - Sandisk Sansa e200 and e200R Port Index * SansaAMS - Sandisk Sansa AMS (c200v2, e200v2, m200v4, Clip, Fuze) Port Index * SansaFuzePlusPort - Sansa Fuze+ Port Index * SonyNWZE360Port - Sony NWZ-E360 Port Index * SonyNWZE370Port - Sony NWZ-E370 Port Index * SonyNWZE380 - Sony NWZ-E380 Port Index * XDuooX3 - XDuoo X3 Port Index * XDuooX3ii - XDuoo X3ii & X20 Port Index

Unstable ports

Source: * CowonD2Info - Cowon D2 Port Index * CreativeZENPort - Creative Zen Port Index * CreativeZENXFi2Port - Creative Zen X-Fi 2 Port Index * HifietMAPort - HiFi E.T. MA8 and MA9 Port Index * HifimanPort - HiFiMAN HM-60x and HM-801 Port Index * IhifiPort -iHIFI 760/960, 770, 770C, 800 Port Index * MPIOHD200Port - MPIO HD200 Port Index * OndaVX747 - Onda VX747 Port Index * Rockchip27xxPort - Rockchip 27xx Port Index * SamsungYPR0 - Samsung YP-R0 Port Index * SamsungYPR1 - Samsung YP-R1 Port Index * SamsungZ5 - Samsung YP-Z5 Port Index * SansaConnect - Sandisk Sansa Connect Port Index * ShanlingQ1Port - Shanling Q1 Port Index * ShanlingM2sPort - Shanling M2s Port Index * SonyNWLinuxPort - Linux-based Sony Port Index

Architecture

Rockbox uses a simple kernel, with a flat memory model and single

process A process is a series or set of activities that interact to produce a result; it may occur once-only or be recurrent or periodic. Things called a process include: Business and management * Business process, activities that produce a specific s ...

, letting it run on platforms without a

memory management unit A memory management unit (MMU), sometimes called paged memory management unit (PMMU), is a computer hardware unit that examines all references to computer memory, memory, and translates the memory addresses being referenced, known as virtual mem ...

. Thin threads run cooperatively, returning control to a scheduler that prioritizes the audio thread; the only form of preemption is through

interrupt In digital computers, an interrupt (sometimes referred to as a trap) is a request for the processor to ''interrupt'' currently executing code (when permitted), so that the event can be processed in a timely manner. If the request is accepted ...

s. The operating system and plug-ins are written in C, with assembly used for code that is device- and platform-specific, and performance sensitive. The simple and lightweight architecture allows Rockbox to run on a variety of targets, with memory ranging from 1 to 64 MB, and CPU speeds ranging 12 to 532 MHz. Rockbox also provides support for multicore and asymmetric multiprocessor systems based on ARM, ColdFire, MIPS and SH. Several codecs can be parallelized across 2 CPU cores for increased power efficiency, and the HWCODEC interface allows for dedicated audio decoder DSPs.

Rockbox Utility

The Rockbox Utility is a free computer application, available for

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

Mac OS X macOS, previously OS X and originally Mac OS X, is a Unix, Unix-based operating system developed and marketed by Apple Inc., Apple since 2001. It is the current operating system for Apple's Mac (computer), Mac computers. With ...

, and

Microsoft Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

, built using Digia Qt platform, that is used to install and manage Rockbox on DAPs. Rockbox Utility provides automatic installation of Rockbox, as well as themes and voice files, directly onto a DAP with minimal user interaction. Rockbox Utility is updated frequently as support for new devices is added.

References

External links

* * FLOSS Weekly �
43: Rockbox
TWiT.tv (network) podcast with Paul Louden of Rockbox {{Media player (application software), free Custom firmware Digital audio players Embedded operating systems Free software projects Free software primarily written in assembly language Free software programmed in C Free media players Free and open-source Android software IPod software Lua (programming language)-scriptable software Portable media players