From Wikipedia, the free encyclopedia

Jump to: navigation, search

The Dreambox is a Linux-powered DVB satellite, terrestrial and cable digital television decoder (set-top box), produced by German multimedia vendor Dream Multimedia. Its firmware is officially user-upgradable, since it is a Linux-based computer, as opposed to third-party "patching" of alternate receivers. All units support Dream's own DreamCrypt conditional access (CA) system, with software-emulated CA Modules (CAMs) available for many alternate CA systems. The Dreambox is based on the DBox2 units that were distributed by Kirch Media for its pay-TV services before its bankruptcy; it uses the same Linux-based software originally developed for the DBox2. The built-in Ethernet interface allows networked computers to access the recordings on the internal hard disks on some Dreambox models. It also enables the receiver to store digital copies of DVB transport streams on networked filesystems or broadcast the streams as IPTV to VideoLAN clients. Unlike many PC based PVR systems that use free-to-air type of DVB receiver cards, the built-in conditional access allows receiving and storing encrypted content.

The combination of third-party developers and network connectivity which facilitates card sharing, makes Dreambox use particularly common among enthusiasts and those who intend to obtain services without payment. Third-party software for this purpose is neither officially endorsed nor supported by Dream Multimedia and voids the official warranty; however, unofficial web sites support a very large community of enthusiasts.

In 2007, Dream Multimedia also introduced a non-Linux based Dreambox receiver, the DM100, their sole to date, running on unspecified hardware, but still featuring an Ethernet port and a USB port.[1] The speed of the USB port is not specified, the manufacturer only says it is of "B" type, the one found on peripherals connected to PCs.


[edit] Models

There have been a number of different models of Dreambox available. The numbers are suffixed with -S for Satellite, -T for Terrestrial and -C for Cable:

DM 7000 56x0 500(+) 600 7020 7025(+) 800 8000 100
Production discontinued discontinued 500+ avail. available available 7025+ avail. available available available
SoC STB04500 STB04500 STBx25xx STBx25xx STB04500 Xilleon 226 Broadcom 7401 Broadcom 7400  ?
CPU (MHz) 252 252 252 252 252 300 300 400  ?
RAM (MiB) 64 64 96 96 96 128 256 256 256
Flash (MiB) 8 8 32 32 32 32 64 256 64
DVB 1 × S 1 × S 1 × S / C / T 1 × S / C / T 1 × S 2 × S / C / T S+S2 / C / T  ? 1 × S
HDTV No No No No No Partial Yes Yes No
CI 1 2 0 0 1 1 0 4 0
CF 1 0 0 0 1 1 0 Yes 0
SC 2 1 1 1 2 2 1 2 1
USB 1.1 No No No 1.1 1.1 2.0 2.0 2.0
LAN (Mbit/s) 100 100 (DM5620) 100 100 100 100 100 100 100
HDD 3.5" No No 2.5" 3.5" 3.5" 2.5" 3.5"+DVD No
ATA parallel No No parallel parallel parallel serial serial No
RF mod. No Yes No No Yes Yes No No  ?
SCART 2 2 1 1 2 2 1 2 1
DVI 0 0 0 0 0 0 1 1 0

[edit] DM 7000 (discontinued)

DM 7000-S

The DM 7000 is based around the IBM STB04500 controller, featuring a PowerPC processor subsystem and hardware MPEG decoding, has 64 MB of RAM, 8 MB of NOR flash memory (directly executable), a Common Interface slot, a dual smart card reader, a Compact Flash card reader, a USB 1.1 port, and an IDE (also known as PATA) interface for attaching an internal 3.5" hard disk drive to convert the unit into a digital video recorder. Accepts only 220 V AC power.[2]

Because the boot loader resides in flash memory, this model may require the use of a JTAG in case of bad flashing which destroyed the boot loader. However, a bad flash will occur under rare scenarios, and rarely - near never will you need a JTAG.

[edit] DM 5600, DM 5620 (discontinued)

There was a DM 5600 and also a DM 5620 model. The only difference being that the DM 5620 included an Ethernet port. Otherwise, the DM 56X0 models were a cut down version of the DM 7000 without an IDE interface. They did, however, include an RF modulator allowing them to be used with older TVs that lack a SCART connector.

[edit] DM 500 (discontinued), DM 500+

The DM500 is the successor to the DM5620 and is the smallest and cheapest Dreambox. It is based around an IBM STBx25xx Digital Set-Top Box Integrated Controller, featuring notably a 252 MHz PowerPC processor subsystem, hardware MPEG 2 video and audio decoding and smart card interfaces. The DM500 features 32 MB of RAM and an unspecified amount of Flash memory, probably 8 MB, given that firmware images are about 5 MB. It has the standard features of a free-to-air (FTA) satellite receiver, plus extensive Fast Ethernet networking connectivity and a single smart card reader. It does not feature a 7-segment LED display, normally found in other FTA decoders.

Also has the ability to be used on Digital satellite, cable and terrestrial broadcasts (also known as DVB-S, DVB-C, DVB-T).

Counterfeit versions of the DM500-S are wide spread[3] and are often sold at a price close to the original.[citation needed]. As a result, Dream Multimedia introduced the DM500+, with changes to try to prevent further counterfeiting. The DM500+ model has 96 MB of RAM instead of 32, and 32 MB of NAND flash instead of 8 of NOR flash. This makes it similar to the DM600 PVR model. It is only available in DVB-S versions.

There also exist legal clones, built around the same commodity IBM SoC chip and hence having identical or slightly superior features but not sold under the Dreambox brand name, eg. the Envision 500S (with 48 megabytes of RAM instead of 32, also available in a 500C cable version), the Eagle box or the Linbox 5558. They have a retail price approaching the one of non-Linux receivers, generally a fraction of the Dreambox 500 price.

On April 2008, Dream Multimedia introduced a Time Bomb into their latest flash to disable the boot loader on counterfeit models. An unofficial firmware group called Gemini who used the latest flash drivers in their firmware, found that flash corruption would be caused on clone DM500-S receivers. Other developers of unofficial firmware groups would find boxes to be effected by this if they use the latest drivers, providing another time bomb is to be introduced.

[edit] DM 7020

The DM 7020 is essentially an updated DM 7000 with 96 MB of RAM, 32 MB of NAND flash (disk-like) and an RF modulator. Changes were also made on the software side, utilizing Open Embedded [1] for the base Linux operating system.

Because the flash memory of this model is not directly executable, the primary boot loader resides in ROM and can recover corrupted secondary boot loader in flash by loading from the serial port.

[edit] DM 7025, DM 7025+

The DM 7025 is similar to the DM7020 but with the ability to add a second "snap-in" tuner that makes it possible to watch one program while recording another. It is possible to change the tuner module, selecting between any two of Satellite, Terrestrial or Cable versions.

Internally, it features a Xilleon 226 system-on-a-chip from ATI, integrating a 300 MHz MIPS CPU core instead of the traditional PowerPC found in other models, and has 128 MB of RAM. It uses Enigma2, this is a complete rewrite of the original Enigma GUI, and is still going through growing pains as features that were present in Enigma are added to Enigma2. Enigma2 is Python-based instead of C code.

The DM 7025 has the ability to decode MPEG 2 HD as well. Unfortunately, it must downconvert this to 480i or 576i to display it. 720p works great but 1080i can stutter during fast motion scenes.

The DM 7025+ model features an OLED display instead of an LCD one, an eject button on the Common Interface slot and improved power supply.

[edit] DM 600 PVR

The DM 600 PVR is the same small size as the DM 500 but includes an IDE interface allowing to add an internal 2.5" laptop-type hard disk drive. On the outside it adds an S-Video output connector and an analog modem port. It is built around the same IBM STBx25xx integrated controller, but features 32 MB of flash and 96 MB of RAM, of which 64 MB are user-accessible. It is possible to change the tuner module, selecting between Satellite, Terrestrial and Cable versions. There is still just one SCART connector and no 7-segment LED display, just 2 status LEDs. The provided remote control unit is the same one supplied with the 7000, 7020 and 7025 and allows one to control the TV set as well.

[edit] DM 800 HD PVR

This is essentially a high definition version of the DM 600 PVR, featuring a single pluggable DVB tuner (S/S2, C or T), a 300 MHz MIPS processor, 64 Mbytes of Flash memory, 256 Mbytes of RAM and room for an internal SATA 2.5" disk.
It also features one DVI to HDMi Cable, two USB 2.0, one eSATA and one 10/100 Mbit/s Ethernet interfaces.
It has an OLED display.

[edit] DM 8000 HD PVR

This is the long-awaited high definition PVR. Like the DM-7025, it is supposed to support pluggable tuner modules. In addition to High Definition, it should also have a DVD drive and USB 2.0.

This product has been announced at beginning of 2007, but its release date has slipped. The planned features have been revised as well. Originally, this model was supposed to have 128 MB of RAM (now 256), 32 MB of flash (now 256 MB) and a 300 MHz processor (now 400 MHz Broadcom 7400). Other Linux-based HD receivers have become available in the meantime.

On 25 July 2008 a beta test was announced on by Dream Multimedia, probably indicating that the release is getting closer.

Beta testing is on-going. Selected active DM users were invited, though made pay for the testing and sign a quite strict NDA agreement.

[edit] Software

The Linux-based software used by Dreambox was originally developed for DBox2, by the Tuxbox project. The Dbox2 was a proprietary design distributed by KirchMedia for their pay TV services. The bankruptcy of Kirch Media flooded the market with unsold boxes available for Linux enthusiasts. The Dreambox shares the basic design of the DBox2, including the Ethernet port and the PowerPC processor.

The factory-installed distribution on the Dreambox is mostly available under the GNU General Public License (GPL) and uses standard Linux API's, including Linux DVB API and Linux Infrared Remote Control (LIRC). This configuration encourages enthusiasts to modify its functions, particularly in the form of so-called images such as PLi, View, Gemini, Neutrino, Colosseum.

In addition, unofficial third-party conditional access software modules (CAMs or emulators) are widely circulated on the Internet that emulate the CA systems developed by VideoGuard, Irdeto Access, Conax, Nagravision, Viaccess and other proprietary vendors. Many Dreambox owners use these softcams in conjunction with card sharing software to access pay TV services without a subscription card inserted in every connected box. This practice may be illegal in some jurisdictions.

There are also many 3rd party addons & plugins available that will extend the functionality of the Dreambox too. Some plugins are model specific, while others run all boxes. Plugins such as Jukebox and SHOUTcast playback, also external XMLTV guides, a web browser are available, and a VLC media player interface for on demand streaming media. Games are also abundant like PacMan and Tetris.

[edit] References

  1. ^ Dream-Multimedia-Tv GmbH
  2. ^ In order to use model DM 7000 within North America, a stepup transformer is needed to run the Dreambox on 220 V. This is the only model Dreambox that requires this when used in North America.
  3. ^ http://www.dream-multimedia-tv.de/english/dm500_copy_eng.php Plagiarisms of the Dreambox DM500-S are in the market

[edit] See also

[edit] External links

Personal tools