Rockbox

Rockbox

iPod Video, ipodVision theme
Developer:	The Rockbox Crew
Latest release:	2.5 / 22 September 2005 and current build Daily
Genre:	Firmware
License:	GNU General Public License
Website:	http://www.rockbox.org/

Rockbox is a free software replacement for the firmware held on various forms of digital audio players (DAPs). Rockbox offers an alternative to the host device's operating system firmware (in many cases without removing the original firmware) which provides a plug-in architecture for adding various enhancements and functionality to DAPs which are not present in the original OS. Enhancements include PDA functionality, applications, utilities, and games. Rockbox can also retrofit video playback functionality onto DAPs first released in mid-2000. Rockbox also includes a voice-driven user-interface suitable for operation by blind and visually impaired users.

Rockbox runs on a wide variety of portable audio devices with very different hardware abilities: from early Archos players with 1-bit charcell-based displays to modern players with high resolution color displays, digital optical audio hardware and advanced recording capabilities. In many instances, rather than being run from flash memory, a minimal bootloader is installed in the supported device's flash which is capable of loading either Rockbox from the hard disk or, alternatively, the original factory firmware. Installing to flash is also supported on certain devices.

Released under the GNU General Public License, Rockbox is free software.

Development

The Rockbox project began in late 2001 and was first implemented on the early Archos series of hard-disk based MP3 players and player/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 CPUs and instead offload music playback to dedicated hardware MP3 decoding chips (called the MAS). Rockbox, therefore, was unable to significantly alter playback capabilities. Instead, it offered a greatly improved user interface and added plugin functionality not present in the factory firmware. Rockbox is capable of being permanently flashed into flash memory on the Archos devices, making it a literal firmware replacement.

Versions of Rockbox have since been produced for more sophisticated devices. These perform audio decoding in software, allowing Rockbox to potentially support many more music formats than the original firmware as well as bringing the extensibility and increased functionality already present in the Archos ports. Rockbox is run from the hard disk on these devices, after being started with a custom bootloader, so to upgrade Rockbox users need only copy the files onto the player's drive and restart the device. Reflashing is only necessary when changing the bootloader, and on some platforms, is not required 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). Approximately one year later a port for the H3xx series became functional, offering similar functionality.

In late 2005, work began on a port of Rockbox to Apple iPod portable players. Throughout 2006, Rockbox ports were made available for a variety of iPod models (iPod photo, iPod nano, iPod 4g, iPod mini, iPod Video, and iPod 5g), as well as the Cowon iAUDIO X5 series. As of February 2007, usable ports are also available for the iriver H10 and Toshiba Gigabeat F & X series. As of March 5th, 2007, a new port for the Cowon iAUDIO M5 became functional. On March 11th, 2007, the SanDisk Sansa e200 series became the next addition to the Rockbox lineup. On May 23rd, 2007, support for the iPod video 80 GB model was added, completing the iPod video lineup. On July 27, 2007, initial support was added for the iPod 1G and 2G. On September 23, 2007, the Sansa c200 series was welcomed into the lineup. Rockbox now includes video-support for MPEG playback through the included work-in-progress mpegplayer plugin.^[1]

To date, all Rockbox ports have been accomplished by reverse engineering with little or no manufacturer assistance. However, 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. To date, 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 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 SVN builds being released after every source change.

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 can be used to create themes for the menu and while-playing screens. These themes can include background and other images (such as icons), plus various formats for filenames, ID3 tags, file progress, time and system information. Album art is not supported by the main builds, but can be added by patches.

Rockbox has been essentially a file-tree based player, to which folders could be dragged and dropped, then navigated by folder structure. More recent versions, however, have included a database feature which allows the player to compile information from the files' ID3 tags. The user can then navigate the files using this database regardless of file structure.

Features

Codecs

Rockbox on software decoding platforms (non-Archos) supports playback (depending on how you count them) of eight lossy codecs, five lossless, two uncompressed and four miscellaneous formats. This makes a conservative total of 19 supported audio formats, although a few of them do not operate in realtime on all platforms.

MPEG audio layers I-III (MP3/MP2/MP1), Ogg Vorbis, MPEG-4 AAC, Musepack, AC3, WMA, Speex, and the lossy portion of WavPack hybrid files are supported lossy formats. Lossless formats include FLAC, WavPack, Shorten, Apple Lossless and Monkey's Audio. Rockbox plays Intel-style WAV and Apple AIFF uncompressed audio. In addition, there are playback of game audio types ADX, SID, NSF and SPC.

Note that Monkey's Audio support is in the early stages with only the lowest compression settings playing in realtime on most devices.

Rockbox features

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

Gapless playback
Replay Gain^[2]
5 band fully parametric equalizer^[2]
OTF ("on the fly") playlists
True random shuffle (fresh randomly shuffled list every time)
Custom UI themes
Stereo recording to WAV/AIFF/WavPack (lossless) and MP3^[3] (supporting devices)
FM radio, including FM recording (supporting devices)
Remote control (supporting devices)
Digital SPDIF input/output (supporting devices)
Last.fm support (even on players lacking RTC)
Cue sheet support
Changeable selector bar

Plug-ins

Developers of Rockbox are able to create new plug-ins, which provide the user with other enhancements that may not be available on various firmware modules.

At the current development stage, the following plug-ins are available.

JPEG viewer (16 bit color/33 shade greyscale) ^[4]
Rockboy Game Boy emulator (port of Gnuboy) ^[5]
ZXBox ZX Spectrum emulator (port of Spectemu) ^[6]
Doom (port of the PrBoom engine)
WAV to MP3 encoder
WAV to WavPack encoder
MPEG video player ^[1]
Various games including sudoku, solitaire, minesweeper, pong and many others (see http://www.rockbox.org/twiki/bin/view/Main/PluginIndex for an official list of plugins)
MIDI player, realtime on some targets. Requires external instrument set, available on Rockbox page.

Unsupported features

Rockbox development is always ongoing. However, either due to the lack of support from external companies or platform drawbacks, Rockbox has a few features which are not yet implemented.

Firewire
Digital rights management (intentionally)
USB host capability ("USB On-The-Go") (this is part of a Google summer of code 2007 project)

Architecture

Rockbox uses a simple kernel ^[7], with a flat memory model (allowing it to run on platforms without a memory management unit) and single process. Thin threads run cooperatively, returning control to a scheduler that prioritizes the audio thread; the only form of preemption is through interrupts. The operating system and plugins are written in C, with assembler used for device- and platform-specific code, in addition to performance sensitive code. 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 300 MHz. Rockbox also provides limited support for multicore and asymmetric multiprocessor systems.

Supported devices

iPod mini with Rockbox software

Only Archos devices have been declared to be officially supported in a release. The following should be considered to be a list of devices that at least substantially work (listed as "Supported" or "Usable" on the Rockbox wiki Device Chart). See the Rockbox Device Chart for details.

Archos

Archos Jukebox Series:
FM Recorder
Recorder v2
Ondio FM
Ondio SP

iriver

H10 series (H10 5, 6, and 20 GB)
H100 series (H100/H110/H115/H120/H140, aka iHP-100/110/115/120/140)
H300 series (H320/H340)

Cowon iAUDIO

X5 and X5L
X5V
M5 and M5L

Apple

iPod 1^st generation
iPod 2^nd generation
iPod 3^rd generation
iPod 4^th generation (Grayscale)
iPod 4^th generation (Color/Photo)
iPod 5^th and 5.5^th generation (Video)
iPod mini 1^st generation
iPod mini 2^nd generation
iPod nano 1^st generation

Toshiba

Gigabeat F series (F10/F11/F20/F21/F30/F31/F40/F41/F60)
Gigabeat X series

SanDisk

Ports in development

Rockbox is developed by users of various portable players. Users interested in porting Rockbox to their platform are always welcome to join development efforts. [1] In principle, any device based on a CPU with a GCC port is a possible target for Rockbox, however devices that are based on components already used by existing rockbox ports are easiest to develop. Devices based on parts with no public documentation or that aggressively protect their firmware with hash checking or encryption are more difficult to port.

Toshiba Gigabeat S

Work has begun on a port to the Toshiba Gigabeat S, with the beginnings of a display driver committed to SVN.

iriver iFP-xxx

A port to the iFP-xxx flash-based devices (starting with the iFP-790) is underway. Runs and is being actively developed, however limited memory and CPU power prevent it from playing most formats. An open source emulator to aid in development for the iFP is available. ^[8]

Tatung Elio TPJ-1022

The Elio TPJ-1022 is another PortalPlayer based target with initial work that has been committed to SVN.

Archos AV300

The Archos AV300 series is the first PMP (portable media player) and hybrid SWCODEC/HWCODEC device to have a Rockbox port developed. The AV320/340/380 contains both an MAS and a general purpose CPU capable of software decoding. The port is currently suitable only for developers, SWCODEC functionality has not yet been implemented. A working UI simulator exists.

Olympus m:robe 100

Initial work has begun on a port to the Olympus m:robe 100, a PortalPlayer-based DAP with many similarities to the iPod mini.^{[citation needed]}

Olympus m:robe 500

A small flurry of recent SVN activity has indicated that a port to the m:robe 500 series is being worked on.

Additional Targets

Preliminary investigation of the 2nd generation iPod nano, the Creative Zen Vision:M and Microsoft Zune has been performed, however no method for running code on any of these targets has been found, and so development has not begun.

Gallery

iriver H120/iPod 4G, LlamaBeta theme	iPod Video, Minty theme	iPod Video, iPodVision theme	iAudio X5, zenX5 theme
iPod Nano, Black Glass MGr theme	iPod Nano, Tango theme	iriver H320/iPod Photo, DGT theme	Archos Jukebox Recorder/FM Recorder/Ondio, WPS by Jens Arnold
Toshiba Gigabeat, beatMP WPS by Kirill Lanchev	IHP 140 recording screen with VU and peak meters	Main menu with Tango iconset, zenX5 theme, iAudio X5