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dvbsnoop - DVB and MPEG stream analyzer
dvbsnoop [-s mode] [options] pid
dvbsnoop [-s mode] [options] -if filename [pid]
dvbsnoop [-s mode] [options] -b [pid] > binary.file
dvbsnoop [-s mode] [options]
DVBSNOOP is a text based DVB and MPEG stream analyzer for viewing/debugging stream information, e.g. send via digital TV. You may also use dvbsnoop to analyze mpeg compliant streams stored on DVD or other media. Dvbsnoop analyzes and displays MPEG, DVB, DSM-CC, MHP, etc. data and structures in human readable form. Possible stream types are TS (tranport streams), PS (program streams), PES (packetized elementary streams) or SECTIONS (service information streams).
DVBSNOOP also has some additional functionality to analyze receiver (set top box, dvb card) data, bandwidth of a transport stream, pid scan, etc.
Using special network programs like netcat (nc), dvbsnoop may also be used to do remote sniffing and decoding. For post-processing dvbsnoop output, you may use the full range of unix tools and scripting languages (grep, perl, python, mrtg, gnuplot, etc.).
Dvbsnoop provides an online and offline input and different snoop/decoding modes (see below).
Using dvbsnoop 'online' requires dvb-api compliant devices (http://www.linuxtv.org) to grab live stream information from e.g. satellite or cable tv or data streams. You will also need DVB compliant hardware (e.g. DVB-S pci card or a linux based setop box like dbox2 or Dreambox) to receive DVB data streams. To tune into a transponder or frequency, please use a program like 'szap', 'dvbtune' or a DVB-GUI like 'Enigma', 'Neutrino', 'MythTV', 'VDR', etc..
The 'offline' mode enables you to analyze binary stream files (e.g. transport stream files or PES files).
Some options are specific for the selected modes. You may try different combinations of command line options to get best results.
A short FAQ for common questions and example decoding output can be found at http://dvbsnoop.sourceforge.net.
-s [ts|ps|pes|sec|pidscan|bandwidth|signal|feinfo]
Basic snoop mode selection.
sec \= SI mode (SECTIONS)
ts \= transport stream mode
ps \= program stream mode (same as PES mode)
pes \= packetized elementary stream mode,
e.g. teletext, audio, video, data
pidscan \= scan and display PIDs on tuned
transponder/frequency.
bandwidth \= bandwidth measurement mode
for selected pid.
signal \= display tuner signal reception info.
feinfo \= display tuner data (frontend info).
The modes 'sec', "ps" or "pes" require the selection of a PID. The mode 'ts' requires either a PID specified or the option -tsraw.
A PID can be specified using octal, decimal or hexadecimal values. Examples: octal: 021, decimal: 17, hexadecimal: 0x11
If -s option is omitted, default mode is "-s sec" (Section mode).
-help
Print help text with command line options.
-hideproginfo
Do not print dvbsnoop header (version, etc.).
-pd lt;modegt;
Specify print decoding verbose mode. Specify 0 for no output. 9 will be very verbose. Default is 6.
-npd
Same as -pd 0.
-ph lt;modegt;
Specify print hex output verbose mode: 0\=no hexdump output, 1\=hex output, 2\=hex line, 3\=ascii line, 4\=alternate hex output. (default is 4)
-hexdumpbuffer
-nohexdumpbuffer
Switch on/off hexdump of stream input buffer. May be used to enhance -ph option. (e.g. -ph 4 -nohexdumpbuffer)
-nph
Obsolete, same as -nohexdumpbuffer.
-tlt;modegt;
Timestamp output mode:
-tf \= full timestamp -td \= delta timestamp mode, -tn \= no time stamp.
-b
Binary output of packets (disables other output). Use this option to store raw data in file or chain data to another program.
E.g.: dvbsnoop -s ts 0x00 -b > file
dvbsnoop -s pes 0x3FF -b
| ./myprogram
There might be a file limit on your system (mostly 2 GB) when writing files using '>'.
Dvbsnoop uses default devices, defined by the DVB API. On some platforms or if using multiple dvb cards, you may want to override default settings, e.g. to select a different tuner.
-demux lt;devicegt;
Specify lt;devicegt; for demux. If not specified, dvbsnoop uses the device specified by the linux dvb-api.
-dvr lt;devicegt;
Specify lt;devicegt; for dvr. If not specified, dvbsnoop uses the device specified by the linux dvb-api.
-frontend lt;devicegt;
Specify lt;devicegt; for frontend. If not specified, dvbsnoop uses the device specified by the linux dvb-api.
-adapter lt;ngt;
Specify DVB adapter/card by number <n> (0-9) using default path pattern (e.g. /dev/dvb/adapter1/...). If not specified, dvbsnoop uses the default adapter/card - usually 0.
-devnr lt;ngt;
Specify DVB device number <n> (0-9) on a DVB adapter/card using default path pattern (e.g. /dev/dvb/adapt.../demux1). If not specified, dvbsnoop uses the default device number - usually 0.
-buffersize lt;kbgt;
Set demux read buffer size in KBytes. Default is 0 (use internal default value).
-n lt;valuegt;
Stop after reading lt;valuegt; packets. Use this to limit the read process. Default is 0 (no limit).
-if lt;filegt;
Read binary stream data from file instead of the demux device.
<file> \= '-' reads from standard input.
Depending on the decoding mode this might be transport stream, packetized elementary stream or sections. Please aware, that you cannot e.g. use -s pes or -s sec on a saved transport stream. The decoding/snooping mode has to match the saved stream format!
The following command line options are special to the 'SECTION' decoding mode:
-s sec
Section mode.
-timeout lt;msgt;
Section read timeout in ms. Default is 0 (no timeout).
-f lt;filtergt;
Filter value for filtering section data e.g. table id's. Value may be decimal (49), octal (037) or hexadecimal (0x4F). You may use multibyte filters like: 0x4E.01.20.FF The filter comprises e.g. 16 bytes covering byte 0 and byte 3..17 in a section, thus excluding bytes 1 and 2 (the length field of a section). To check the filter values use -pd 9.
-m lt;maskgt;
Mask value to use for filters. Value may be decimal (49), octal (037) or hexadecimal (0x4F). You may use multibyte filters like: 0xFF.F0.FE.FF The filter comprises e.g. 16 bytes covering byte 0 and byte 3..17 in a section, thus excluding bytes 1 and 2 (the length field of a section). To check the filter values use -pd 9.
-N lt;valuegt;
Stop after decoding lt;valuegt; packets. Use this to limit the packet decoding process. Useful, when reading stream data from file. -n limits the read packet process, -N limits the decoding process. Using dvb hardware filters -n would be the same as -N. Default is 0 (no limit).
-crc
Do CRC checking, when reading section data. Default is off. This is only supported, if your DVB hardware/firmware supports CRC checking. Remark: Some section types may use Checksum instead of CRC.
-nocrc
Don't do hardware/firmware CRC, when reading section data (default). Some DVB sections do not have proper CRC set!
-softcrc
Do soft CRC checking, when reading section data. Hardware/firmware CRC should be preferred. Default is -nosoftcrc. Remark: Some section types may use Checksum instead of CRC.
-nosoftcrc
Don't do soft CRC, when reading sections. (default)
-spiderpid
Snoop referenced section PIDs. This option recursively reads all PIDs referenced by a section. This option also sets number of packets to be read to 1 (sets -n 1). To read more packets for a pid, use -n lt;countgt; after specifying -spiderpid.
-privateprovider lt;idgt;
Set provider lt;idgt; string for decoding of special private tables and descriptors. Use -help to display provider currently supported. If omitted, private data will be displayed as hexdump depending on -ph option. (If you have information on private data structures, currently not supported by dvbsnoop, please let us know!)
The following command line options are special to the 'Transport Stream' decoding mode:
-s ts
Transport Stream mode.
-sync
(obsolete as of 1.4.10, -sync is default. This option enforces software packet sync for TS and PS/PES).
-nosync
(obsolete as of 1.4.10).
-tssubdecode
Sub-decode SI data (sections) or PS/PES data from transport stream decoding. This reads transport stream packets and tries to decode its content. Useful to decode PES or SI data from a transport stream file.
-tsraw
Read full transport stream (all pids). Your hardware/firmware has to support this mode.
-N lt;valuegt;
Stop after decoding lt;valuegt; packets. Use this to limit the packet decoding process. Useful, when reading stream data from file. -n limits the read packet process, -N limits the decoding process. Using dvb hardware filters -n would be the same as -N. Default is 0 (no limit).
The following command line options are special to the 'PES' (packetized elementary stream) or 'PS' (program stream) decoding mode:
-s ps
Program Stream mode.
-s pes
Packetized Elementary Stream mode.
-sync
(obsolete as of 1.4.10, -sync is default. This option enforces software packet sync for TS and PS/PES).
-nosync
(obsolete as of 1.4.10).
The following command line options are special to the 'PID Scan' discovery mode:
-s pidscan
Scan PIDs on transponder/frequency.
-maxdmx lt;ngt;
Set maximum use of DMX filters. Default is 0 (use all possible filters).
There are no special command line options for the 'Bandwidth' display mode.
-s bandwidth
Determine bandwidth for a dvb stream. This will be done by calculating received ts packets in a timeslot.
There are no special command line options for the 'Signal Strength' display mode.
-s signal
Poll frontend signal status.
-timeout lt;msgt;
Poll timing in msec.
There are no special command line options for the 'Frontend Info' display mode.
-s feinfo
Display frontend information.
Examples how to use dvbsnoop:
Display EPG, 10 sections:
dvbsnoop -s sec -nph -n 10 0x12 dvbsnoop -s sec -ph 3 -n 10 -crc 0x12
Display sections tree (1 packet each) using private provider data:
dvbsnoop -s sec -spiderpid -privateprovider premiere.de 0x00
Display sections tree (1 packet each) skipping "empty" pids:
dvbsnoop -s sec -spiderpid -timeout 15000 0x00
Display PAT transport stream (ts) and do subdecoding of sections and descriptors:
dvbsnoop -s ts -pd 4 -tssubdecode -nph 0x00
Read PES (e.g. Videotext, Video, Audio) stream:
dvbsnoop -s pes 0x28F dvbsnoop -s pes 0x28F -b > pes.bin.file
Read PS from file and do not show hex dump:
dvbsnoop -if hdtv_ps_file.mpg -s ps -ph 0 -nohexdumpbuffer -n 30
Show current signal strength:
dvbsnoop -s signal dvbsnoop -s signal -pd 9 -n 100 -timeout 100
Show bandwidth usage of a PID 0x1FF:
dvbsnoop -s bandwidth -n 1000 -pd 2 0x1FF dvbsnoop -s bandwidth -buffersize 256 -n 1000 0x1FF
Do PID scan of a tuned transponder (different display levels):
dvbsnoop -s pidscan -pd 1 dvbsnoop -s pidscan -pd 6 dvbsnoop -s pidscan -pd 9 -maxdmx 12
Show frontend info:
dvbsnoop -s feinfo -pd 9
Try to scan all sections, read 2 packets per PID:
dvbsnoop -nohexdumpbuffer -spiderpid -n 2 0x0000
Save 1000 packets of a transport stream to a file:
dvbsnoop -b -n 1000 -s ts 0x200 > ts_file.pid0x200.bin dvbsnoop -b -n 1000 -s ts -tsraw > ts_file.bin
Read transport stream (ts) from file and decode:
dvbsnoop -s ts -if ts_stream.bin dvbsnoop -s ts -if ts_file.pid0x200.bin 0x200
Simple filter for some PID values, some examples:
dvbsnoop -n 5 -nph 0x00 | grep -i "PID: " dvbsnoop -spiderpid -nph -n 10 0x00 | grep -i "PID: " | sort | uniq dvbsnoop -s signal -pd 9 | ./perl-statistics-prog.pl
Other simple filter examples:
dvbsnoop -s sec -f 0x4E -m 0xFF 0x12 dvbsnoop -s sec -f 0x4E.34.00 -m 0xFF.FF.0F 0x12 dvbsnoop -s sec -f 16.00 -m 255.255 0x12 dvbsnoop -s sec -nph -n 5 0x10 | grep -i "frequency" dvbsnoop -s ts -nph 0x100 | grep -i 'Transport_error\|^PID'
Selecting devices:
dvbsnoop -s feinfo -pd 9 -frontend /dev/dvb/adapter0/frontend1 dvbsnoop -s feinfo -pd 9 -adapter 0 -devnr 1 dvbsnoop -s feinfo -pd 9 -adapter 2
Sending dvbsnoop data over network, using netcat:
dvbsnoop -s pes 0x28F -b \| nc -q ServerName 31337
Do remote decoding of dvb data over network using dvbsnoop and netcat:
streaming site:
dvbsnoop -s ts 0x0065 -b \| nc -q ServerName 31000
receiving site:
nc -l -p 31000 \| dvbsnoop -nph -s ts -tssubdecode -if -
You may also use e.g. dvbtools for sending dvb data over a network:
dvbstream .... --> dumprtp \| dvbsnoop -s ts -if -
For more examples and example output of dvbsnoop, please visit http://dvbsnoop.sourceforge.net.
dvbsnoop tries to decode all of the data it receives, e.g. if you try to decode a video or audio stream in section mode, dvbsnoop may assume a section table and will decode the data wrong. In this case the decoding will be garbage. Using the '-crc' option should prevent this (if supported at the hardware/driver level).
dvbsnoop does not do DVB stream validation. dvbsnoop assumes correct DVB streams. Corrupted streams or streams with wrong semantics (e.g. incorrect length information) will result in wrong decoding output. For this reason, the use of '-crc' options is strongly recommended.
Depending on the firmware of your dvb card, dvbsnoop may not be able to sniff on pids, which are occupied by other processes. This is no bug, this is a driver/firmware issue.
dvbsnoop catches signals to provide smooth program termination.
SIGHUP, SIGQUIT and SIGTERM will terminate dvbsnoop smoothly. SIGABORT will abort at once after flushing buffers. SIGKILL will just kill down dvbsnoop (OS specific).
Please check http://dvbsnoop.sourceforge.net for bug reports.
Bug reports: http://sourceforge.net/tracker/?group_id=85040
dvbtune (1), dvbstream (1).
DVBSNOOP was written by Rainer Scherg (rasc).
Copyright (c) 2001-2006 Rainer Scherg
Additional patches and bugfixes/-reports were provided by members of the tuxbox project - bringing digital TV to linux based set top boxes (e.g. "dbox2" digital tv receiver) and also by users of dvbsnoop (see the ChangeLog file for credits).
For more information about DVBSNOOP please visit 'http://dvbsnoop.sourceforge.net'.