dvbsnoop - A DVB Stream Analyzer Tool

dvbsnoop Quicklinks

http://dvbsnoop.sourceforge.net/
Get tarballs at: http://sourceforge.net/projects/dvbsnoop
Get the latest source at: http://cvs.tuxbox.org/
Get DVB drivers at: http://www.linuxtv.org

What is dvbsnoop?

dvbsnoop is a DVB / MPEG stream analyzer program.

Its purpose is to debug, dump or view stream information (e.g. digital television broadcasts) send via satellite, cable or terrestrial. Streams can be SI, PES or transport streams. DSM-CC and MHP will follow...
Basically you can describe dvbsnoop as a simple stream analyzing program, similar to TCP network sniffer programs like snoop on Sun Solaris or tcpdump under Linux.

The programm was mainly written to learn and understand the DVB protocol structures and streams sent via sattelites. Out of this reason, the programm ist not performance optimized, but it will hopefully do its job.

Rainer Scherg (rasc)

Under what Licence is dvbsnoop?

dvbsnoop is published under GPL:

License: 

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA

Is there any disclaimer?

Yes, the standard disclaimer for all non-commercial software (;-)):
You may use this program freely, but on your own risk.
There is no garantee, that this programm will fit your needs in any way. Also this program might not compile on your computer - and if so, it may crash your computer or even eat your cat.

By the way: It is strictly forbidden to use this program for hacking encrypted TV channels.

Installation...

dvbsnoop is based on the linux dvb api. You need the dvb driver installed on your computer to use dvbsnoop. dvbsnoop is text-based, so it should work on any unix based system, which offers shell access and dvb support installed.

Getting the Source

Download a tarball for dvbsnoop at: http://sourceforge.net/projects/dvbsnoop.
Unpack the tar archive using the 'gzip -d / bzip2 -d...' and 'tar xvf ...' commands.

Or get the latest source from the cvs at: http://cvs.tuxbox.org/:
Please read the checkout information.
dvbsnoop is part of the tuxbox/dbox2 project and located in the /apps/dvb directory.

Cross Compiling for the dbox2 (ppc)

dvbsnoop is part of the dbox2 cdk. The dbox2 is a powerful digital satellite receiver (set top box) with a network interface.
Just follow the installation instructions of the dbox2 cdk:

cd cdk
./autogen.sh
./configure
make .dvbsnoop

Native Compilation (e.g. i386 linux)

Check out dvbsnoop from the cvs or download a tarball. If your distribution still uses Linux kernel 2.4, then you probably need to set the path to your DVB API header files by appending

CPPFLAGS=-I/path/to/dvb-kernel/linux/include

to the configure command.

cd dvbsnoop
./autogen.sh
./configure
make

Important: Currently I'm working with a dbox2 only (I do not own a dvb card for my linux server) - so I do not know if dvbsnoop is working on a linux based PC smoothly.

How to use dvbsnoop?

dvbsnoop is a commandline tool.
To tune in a transponder, use a proper tuning program like dvbtune (see: http://www.linuxtv.org) or a GUI based DVB program like Neutrino or Enigma which is running on a dbox2 or on a Linux-PC (see: http://www.tuxbox.org).

The Command Line

dvbsnoop [options] pid

pid can be any unsigned number within the legal pid number range.
The PID can be specified in hex, octal or decimal version (using C-syntax -notation).
e.g.: hex: 0x1A, octal: 0722 , decimal: 6932

Options	Description	Default

-demux device	demux device	default device
-dvr device	dvr device	default device
-frontend device	fe device	default device
-s [sec\|ts\|pes\| pidscan\| bandwidth\|signal\|feinfo]	snoop type sec = Sections, ts = Transport Stream pes = Packetized Elementary Stream., pidscan = transponder PID scan bandwidth = pid data rate statistics signal = frequency/transponder signal statistics feinfo = show information and parameters of frontend	[-s sec]
-f filter	filtervalue for '-s sec' demux max demux filter usage value in "-s bandwidth"	[-f 0]
-m mask	maskvalue for 'sec' demux	[-m 0]
-crc	CRC check when reading 'sec' (depends on your driver implementation)	[-nocrc]
-nocrc	No CRC check when reading 'sec'	[-nocrc]
-sync	Simple packet header sync when reading 'ts' or 'pes'	[-snyc]
-nosync	No header sync when reading 'ts' or 'pes'	[-snyc]
-buffersize KB	demux buffersize in KBytes (sec, ts, pes) e.g. -buffersize 512 or -buffersize 1024 0 = use dvbsnoop default buffersize for a snoop type. (default buffersize is 256 KB)	[-buffersize 0]
-n count	receive count packets (0=no limit)	[-n 0]
-timeout ms	Section read timeout in ms (0=no timeout)	[-timeout 0]
-spiderpid	follow up referenced PIDs (sections only). Sets "-n 1"
-tssubdecode	Subdecode PES or Section from TS packets
-b	binary output of packets (disables other output) ("stream" output)
-if	input file, reads from binary file instead of demux device
-ph mode	print hex buffer, modes: 0=none, 1=hexdump, 2=hex line, 3=ascii line, 4=hexdump2	[-ph 1]
-nph	don't print hex dump (= -nohexdumpbuffer -ph 0)
-pd verbose	print stream decode (verbose level 0..9)	[-pd 7]
-npd	don't print decoded stream (= -pd 0)
-hexdumpbuffer	print read data as hexdump prior to decoding	[-hexdumpbuffer]
-nohexdumpbuffer	suppress hexdump print of read buffer	[-hexdumpbuffer]
-t[n\|d\|f]	print timestamp (no, delta, full)	[-tf]
-hideproginfo	hide copyright and program info header at program start
-help	usage information...

(default values are in square brackets...), bold options are most used...

Examples:

dvbsnoop 0x10; dvbsnoop 020; dvbsnoop -crc 16

dump PID Hex 10 (sections mode). This command will dump the NIT transmission within the dvb data stream.
To ensure data integrity on hardware/driver level, use the -crc option - otherwise you may get garbage data analyzed... (E.g.: Trying to decode a mpeg2 video stream PID as section, will fail with -crc switch on. With -nocrc) you may get odd results!) Also on DVB-T signal strength may vary and result in garbage sections....

~/bin > ./dvbsnoop 0x10 | more
DvbSnoop   Vers. 1.0a   -- (c) Rainer Scherg

---------------------------------------------------------
SECT-Packet: 00000001   PID: 16 (0x0010), Length: 282 (0x011a)
Time received: Thu 16.10.2003  21:43:07.954
---------------------------------------------------------
  0000:   @  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 
  0000:  40 f1 17 00 01 e9 01 01 f0 00 f1 0a 04 ff 00 01 
  0010:   .  .  C  .  .  .  .  P  .  .  .  .  u  .  .  . 
  [...]
  0100:      .  .  .  S  .  .  .  .  C  .  .  %  D  u  . 
  0100:  20 00 04 04 53 00 01 f0 0d 43 0b 01 25 44 75 01 
  0110:   .  .  .     .  .  l  .  .  z 
  0110:  92 81 02 20 00 04 6c d5 b5 7a 

PID:  16 (0x0010)
NIT-decoding....
Table_ID: 64 (0x40)  [= network_information_section - actual network]
section_syntax_indicator: 1 (0x01)
reserved_1: 1 (0x01)
reserved_2: 3 (0x03)
Section_length: 279 (0x0117)
Network_ID: 1 (0x0001)  [= Astra Satellite Network 19.2E / Satellite / SES]
reserved_3: 3 (0x03)
Version_number: 20 (0x14)
Current_next_indicator: 1 (0x01)
Section_number: 1 (0x01)
Last_Section_number: 1 (0x01)
reserved_4: 15 (0x0f)
Network_descriptor_length: 0 (0x0000)

reserved_5: 15 (0x0f)
Transport_stream_loop_length: 266 (0x010a)
    
    Transport_stream_ID: 1279 (0x04ff)
    Original_network_ID: 1 (0x0001)  [= Astra Satellite Network 19,2°E | Société Européenne des Satellites]
    reserved_1: 15 (0x0f)
    Transport_descriptor_length: 13 (0x000d)
        
        DVB-DescriptorTag: 67 (0x43)  [= satellite_delivery_system_descriptor]
        Descriptor_length: 11 (0x000b)
        Frequency: 18453072 (=  11.99250 GHz)
        Orbital_position: 402 (=  19.2)
        West_East_flag: 1 (0x01)  [= EAST]
        Polarisation: 0 (0x00)  [= linear - horizontal]
        Modulation (Sat): 1 (0x01)  [= QPSK]
        Symbol_rate: 2576384 (=  27.5000)
        FEC_inner: 3 (0x03)  [= 3/4 conv. code rate]
        
    Transport_stream_ID: 1115 (0x045b)
    Original_network_ID: 1 (0x0001)  [= Astra Satellite Network 19,2°E | Société Européenne des Satellites]
    reserved_1: 15 (0x0f)
    Transport_descriptor_length: 13 (0x000d)
        
        DVB-DescriptorTag: 67 (0x43)  [= satellite_delivery_system_descriptor]
        Descriptor_length: 11 (0x000b)
        Frequency: 19292789 (=  12.66275 GHz)
        Orbital_position: 402 (=  19.2)
        West_East_flag: 1 (0x01)  [= EAST]
        Polarisation: 0 (0x00)  [= linear - horizontal]
        Modulation (Sat): 1 (0x01)  [= QPSK]
        Symbol_rate: 2228224 (=  22.0000)
        FEC_inner: 4 (0x04)  [= 5/6 conv. code rate]
        
    Transport_stream_ID: 1117 (0x045d)
    Original_network_ID: 1 (0x0001)  [= Astra Satellite Network 19,2°E | Société Européenne des Satellites]
    reserved_1: 15 (0x0f)
    Transport_descriptor_length: 13 (0x000d)
        
        DVB-DescriptorTag: 67 (0x43)  [= satellite_delivery_system_descriptor]
        Descriptor_length: 11 (0x000b)
        Frequency: 19304997 (=  12.69225 GHz)
        Orbital_position: 402 (=  19.2)
        West_East_flag: 1 (0x01)  [= EAST]
        Polarisation: 0 (0x00)  [= linear - horizontal]
        Modulation (Sat): 1 (0x01)  [= QPSK]
        Symbol_rate: 2228224 (=  22.0000)
        FEC_inner: 4 (0x04)  [= 5/6 conv. code rate]
        
    Transport_stream_ID: 1119 (0x045f)
    Original_network_ID: 1 (0x0001)  [= Astra Satellite Network 19,2°E | Société Européenne des Satellites]
    reserved_1: 15 (0x0f)
    Transport_descriptor_length: 13 (0x000d)
        
        DVB-DescriptorTag: 67 (0x43)  [= satellite_delivery_system_descriptor]
        Descriptor_length: 11 (0x000b)
        Frequency: 19341685 (=  12.72175 GHz)
        Orbital_position: 402 (=  19.2)
        West_East_flag: 1 (0x01)  [= EAST]

[...]

dvbsnoop -n 10 -crc -td -f 0x50 -m 0xff -nph -pd 3 0x12

dump 10 packets of PID 0x12 (EIT, ...) in sections mode, using the fpid filter 0x50 and pid mask 0xff.
-nph and -pd 3 tells dvbsnoop not to print a hexdump and restrict output to print decoded streams at verbose level 3. Timestamps should be printed in 'delta'-mode... Also check crc, to ensure packets are vaild! (invalid packets will not be displayed - this is driver dependent..)

~/bin > ./dvbsnoop -n 10 -td -f 0x50 -m 0xff -nph -pd 3 0x12
DvbSnoop   Vers. 1.0a   -- (c) Rainer Scherg

---------------------------------------------------------
SECT-Packet: 00000001   PID: 18 (0x0012), Length: 528 (0x0210)
Time (delta) received: 0.068 (sec)
---------------------------------------------------------
PID:  18 (0x0012)
EIT-decoding....
Table_ID: 80 (0x50)  [= event_information_section - actual transport stream, schedule]
section_syntax_indicator: 1 (0x01)
Service_ID: 12003 (0x2ee3)  [=  --> refers to PMS program_number]
Version_number: 6 (0x06)
Current_next_indicator: 1 (0x01)
Section_number: 112 (0x70)
Last_Section_number: 176 (0xb0)
Transport_stream_ID: 1089 (0x0441)
Original_network_ID: 1 (0x0001)  [= Astra Satellite Network 19,2°E | Société Européenne des Satellites]
Segment_last_Section_number: 112 (0x70)
Last_table_id: 80 (0x50)  [= event_information_section - actual transport stream, schedule]
    
    Event_ID: 674 (0x02a2)
    Start_time: 0xcec0181500 (=2003-10-16 18:15:00 [UTC])
    Duration: 0x0010000 (= 01:00:00 [UTC])
    Running_status: 0 (0x00)  [= undefined]
    Free_CA_mode: 0 (0x00)  [= unscrambled]
    
    Event_ID: 675 (0x02a3)
    Start_time: 0xcec0191500 (=2003-10-16 19:15:00 [UTC])
    Duration: 0x0010000 (= 01:00:00 [UTC])
    Running_status: 0 (0x00)  [= undefined]
    Free_CA_mode: 0 (0x00)  [= unscrambled]
    
    Event_ID: 676 (0x02a4)
    Start_time: 0xcec0201500 (=2003-10-16 20:15:00 [UTC])
    Duration: 0x0010000 (= 01:00:00 [UTC])
    Running_status: 0 (0x00)  [= undefined]
    Free_CA_mode: 0 (0x00)  [= unscrambled]
==========================================================


---------------------------------------------------------
SECT-Packet: 00000002   PID: 18 (0x0012), Length: 774 (0x0306)
Time (delta) received: 0.048 (sec)
---------------------------------------------------------
PID:  18 (0x0012)
EIT-decoding....
Table_ID: 80 (0x50)  [= event_information_section - actual transport stream, schedule]
section_syntax_indicator: 1 (0x01)
Service_ID: 12040 (0x2f08)  [=  --> refers to PMS program_number]
Version_number: 6 (0x06)
Current_next_indicator: 1 (0x01)

[...]

dvbsnoop -n 1 -nph -crc 0x12

~/bin > ./dvbsnoop -n 1 -nph 0x12
dvbsnoop  Vers. 1.1.7   -- http://dvbsnoop.sourceforge.net/ 

---------------------------------------------------------
SECT-Packet: 00000001   PID: 18 (0x0012), Length: 185 (0x00b9)
Time received: Tue 2003-11-11  00:02:22.485
---------------------------------------------------------
PID:  18 (0x0012)
EIT-decoding....
Table_ID: 79 (0x4f)  [= event_information_section - other transport stream, present/following]
section_syntax_indicator: 1 (0x01)
reserved_1: 1 (0x01)
reserved_2: 3 (0x03)
Section_length: 182 (0x00b6)
Service_ID: 28206 (0x6e2e)  [=  --> refers to PMS program_number]
reserved_3: 3 (0x03)
Version_number: 15 (0x0f)
Current_next_indicator: 1 (0x01)
Section_number: 1 (0x01)
Last_Section_number: 1 (0x01)
Transport_stream_ID: 1073 (0x0431)
Original_network_ID: 1 (0x0001)  [= Astra Satellite Network 19,2°E | Société Européenne des Satellites]
Segment_last_Section_number: 1 (0x01)
Last_table_id: 79 (0x4f)  [= event_information_section - other transport stream, present/following]
    
    Event_ID: 25605 (0x6405)
    Start_time: 0xceda010500 (=2003-11-11 01:05:00 [UTC])
    Duration: 0x0003000 (= 00:30:00 [UTC])
    Running_status: 1 (0x01)  [= not running]
    Free_CA_mode: 0 (0x00)  [= unscrambled]
    Descriptors_loop_length: 155 (0x9b)
        
        DVB-DescriptorTag: 77 (0x4d)  [= short_event_descriptor]
        Descriptor_length: 16 (0x10)
          ISO639_2_language_code:  deu
        Event_name_length: 11 (0x0b)
        Event_name: "Abendschau"  -- Charset: Latin alphabet no. 5
        Text_length: 0 (0x00)
        Text: ""
        
        DVB-DescriptorTag: 80 (0x50)  [= component_descriptor]
        Descriptor_length: 6 (0x06)
        reserved_1: 15 (0x0f)
        Stream_content: 1 (0x01)
        Component_type: 1 (0x01)
           == Content&Component: (= video, 4:3  aspect ratio, 25 Hz)
        Component_tag: 1 (0x01)
        ISO639_2_language_code:  deu
        Component-Description: ""
        
        DVB-DescriptorTag: 80 (0x50)  [= component_descriptor]
        Descriptor_length: 6 (0x06)
        reserved_1: 15 (0x0f)
        Stream_content: 2 (0x02)
        Component_type: 3 (0x03)
           == Content&Component: (= audio, stereo (2 channels))
        Component_tag: 2 (0x02)
        ISO639_2_language_code:  deu
        Component-Description: ""
        
        DVB-DescriptorTag: 84 (0x54)  [= content_descriptor]
        Descriptor_length: 6 (0x06)
            Content_nibble_level_1: 2 (0x02)
            Content_nibble_level_2: 0 (0x00)
               [= news/current affairs (general)]
            User_nibble_1: 0 (0x00)
            User_nibble_2: 0 (0x00)
            
            Content_nibble_level_1: 8 (0x08)
            Content_nibble_level_2: 0 (0x00)
               [= social/political issues/economics (general)]
            User_nibble_1: 0 (0x00)
            User_nibble_2: 0 (0x00)
            
            Content_nibble_level_1: 11 (0x0b)
            Content_nibble_level_2: 15 (0x0f)
               [= user defined]
            User_nibble_1: 2 (0x02)
            User_nibble_2: 0 (0x00)
            
            
        DVB-DescriptorTag: 78 (0x4e)  [= extended_event_descriptor]
        Descriptor_length: 85 (0x55)
        Descriptor_number: 0 (0x00)
        Last_descriptor_number: 0 (0x00)
        ISO639_2_language_code:  deu
        Length_of_items: 0 (0x00)
            
        Text_length: 79 (0x4f)
        Text: "* Sondersitzung Abgeordnetenhauses<br>* Untreue im Amt<br>* S-Bahnhof Kolonnenstraße"  -- Charset: Latin alphabet no. 5
        
        DVB-DescriptorTag: 105 (0x69)  [= PDC_descriptor]
        Descriptor_length: 3 (0x03)
        reserved_1: 15 (0x0f)
        Programme_identification_label: 0x5d805 [= month=11  day=11   hour=0  min=5]
        
        DVB-DescriptorTag: 95 (0x5f)  [= private_data_specifier_descriptor]
        Descriptor_length: 4 (0x04)
        PrivateDataSpecifier: 5 (0x00000005)  [= ARD, ZDF, ORF]
        
        DVB-DescriptorTag: 130 (0x82)  [= User defined]
        Descriptor_length: 13 (0x0d)
        Descriptor-Data:
          0000:   0  0  :  0  5  1  1  .  1  1  #  0  0 
          0000:  30 30 3a 30 35 31 31 2e 31 31 23 30 30 
CRC: 3952000829 (0xeb8ebf3d)
==========================================================

dvbsnoop -n 200 -s ts -b 0x00 > ts-stream.pid0x00.file

Dump 200 packets of PID 0x00 in transport stream mode to an image file.
The raw datastream will be dumped in the specified stream mode (PES, SECTION or TS).
This file can be used, to postprocess the dvb data streams.

dvbsnoop -if ts-stream.pid0x00.file -s ts

dvbsnoop -if ts-stream.pid0x00.file -s ts 0x00

Read a data stream from file and analyze the stream.
It is important that you specify mode (si, pes, ts) and optional the pid !

dvbsnoop -pd 3 -s pidscan

dvbsnoop -pd 9 -f 24 -s pidscan

Scan tuned transponder for PIDs.
This mode tries to reveal all pids transmitted on a transponder, even pids which are not present in PAT, PMT, etc.

This scan may take 1-3 minutes, depending on how many demux filters dvbsnoop is using. By default dvbsnoop tries to get all demux filters it can allocate! On some dvb cards this can result in strange behavior. To avoid this you can use the "-f"-option to set maximum filter usage by dvbsnoop (less filters takes more time to complete the scan).

A good practice would be to check how many dmx filters dvbsnoop can allocate on your dvb card (-pd 9 option) and then lower this number by at least 4 filters (using -f option).

Remark: The PID-SCAN snoop will only detect pids, which are transmitted during the scan phase. Pids with a low repetition rate or pids grabbed by other applications may not be detected.

dvbsnoop -pd 2 -n 1000 -s bandwidth

Analyze bandwidth usage of a PID.
In this example, stop if more than 1000 packets are read. for different output information, you can tweak the -pd option.

dvbsnoop -pd 2 -n 100 -s signal

Show signal strength statistics of tuned frequency/transponder.
Statistics will show signal strength, bit error rate, signal-noise ratio, uncorrected blocks ans frontend status...

Pitfalls...

dvbsnoop tries to decode every data it gets....
E.g. if you try to decode a video or audio stream in section mode - dvbsnoop may assume a section table and will decode wrong data. In this case the decoding will be garbage! Using the '-crc' option should prevent this (if supported at hardware/driver level). Also the '-sync' option is very helpful, when using '-s pes' or '-s ts'. The '-sync' option tries to find TS or PES packet start sync bytes before decoding...
dvbsnoop doesn't do DVB stream validation....
dvbsnoop assumes correct dvb streams. Getting garbage, corrupted streams or streams with wrong semantics (e.g. incorrect length information) will result in wrong decoding output. Because od this, the usage of the options '-crc' and '-sync' is strongly recommended!!
Bugs and wrong decoding:
If you see any odd output, please report this.
Wrong decoding can be mostly avoided, using the options '-crc' and '-sync'.

Authors, Co-Authors, Thanks, ...

Authors are:
Rainer Scherg	(rasc)	<rasc@users.sourceforge.net>
Andreas Oberritter	(obi)	<obi@saftware.de>

Thanks a lot to all the members and developers of the tuxbox@dbox2 project!!!
These heros ;-) do great support and also bugfixing - see also the history information in the source!!

Where to send bugreports, requests?

If you find a bug or odd behavior of dvbsnoop, please save the stream to a binary file using option '-b ... > file'. This way I could do a post-analyze.

Please send bugreports with a detailed description to: rasc@users.sourceforge.net
Do NOT send saved stream files or large files without permission via email!
Bugfixes, code snipsets, etc. are welcome

Some keywords related to dvbsnoop...

DVB stream analyzer, mpeg stream analyzer, ts stream analyzer, MPEG, MPG, descriptor, digital television, satellite TV, cable TV, dvb-c, dvb-s, dvb-t, MHP, DSM-CC, SI, PES, TOT, PAT, PMT, SDT, EIT, NIT, TDST, RST, SIT, DIT, BAT, EMM, ECM, SI Tables, SSU, INT, UNT, AIT, datagram, sections, transport stream analyzer, packet elementary stream, DEMUX, ISO/IEC 13818-1, ISO/IEC 13818-6, ETSI EN 300468, ETSI EN 301162, ETSI TS 102006, ETSI EN 301192, ETSI TR 101202, ITU H.222.0, data carousel, object carousel, dvb snoop, sniff, analyze, analyse, analyser, mpeg2, IOR, BIOP, TS, PES

http://dvbsnoop.sourceforge.net/
(c) 2001-2004 Rainer Scherg (rasc)

http://dvbsnoop.sourceforge.net/		This page, dvbsnoop homepage.
http://sourceforge.net/projects/dvbsnoop		The project homepage of dvbsnoop, currently the dvbsnoop cvs is hosted at www.tuxbox.org. To check out the source, read the cvs information on tuxbox.org. Tarballs will be published on this site.
http://www.tuxbox.org		Website for linux on a *dbox2* (a set top box mainly sold/"provided" in Europe). Here you will also find a support forum for linux@dbox2.
cvs.tuxbox.org http://cvs.tuxbox.org/cgi-bin/viewcvs.cgi/tuxbox/apps/dvb/dvbsnoop/		The CVS for linux@dbox2. dvbsnoop is part of the linux@dbox2 project applications...
http://tuxbox.berlios.de		The old dbox2@linux homepage. For more links on this topic, have a look on the FAQ-Section of the forum!
http://www.linuxtv.org		Linux based TV, the mother of all Linux based DVB related stuff!!! To get drivers or docs about the DVB-API, this will be your first choice!
http://www.dvb.org		Information about DVB
http://www.mhp.org		Information about MHP
http://www.etsi.org		Standards documents: e.g. EN 300 468
http://www.iso.ch		Standards documents: e.g. ISO/IEC 13818-1, ISO/IEC 13818-6
irc:#dbox2		IRC Support channel for dbox2. (use e.g. IRC server irc.freenet.de:6667)
http://www.linuxstb.org/		another very good site, with a punch of good tools!
http://www.magicality.org/code/dvbdata/		A tool for saving data from the Data Carousell. (from Richard Palmer )
http://sourceforge.net/projects/dvbsak/		dvbsak is a general-purpose Digital Video Broadcasting library with tools.
http://ardmore.net/~thepaces/vk_tools/		MPEG analyzing tool
http://www.linuxdvb.tv/		... just have a look
http://www.dbox2.info		a portal site about the dbox2 set top box.
http://www.cadsoft.de/people/kls/vdr/		... not directly related with dvbsnoop, but mui mucho cool! a DVB personal video recorder running on Unix...