dvbsnoop的手册

dvbsnoop -s ts -tssubdecode  -if Gqxsp.ts  -n 50


dvbsnoop(1)               DVB Analyzer, MPEG Analyzer               dvbsnoop(1)



Name
dvbsnoop - DVB and MPEG stream analyzer

SYNOPSIS
dvbsnoop [-s mode] [options] pid

dvbsnoop [-s mode] [options] -if filename [pid]

dvbsnoop [-s mode] [options] -b [pid] > binary.file

dvbsnoop [-s mode] [options]



Description
DVBSNOOP is a text based DVB and MPEG stream analyzer for viewing/debug‐
ging stream information, e.g. send via digital TV. You may also use dvb‐
snoop  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 (tran‐
port 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.).



Usage
Dvbsnoop provides an online and offline input and different snoop/decod‐
ing modes (see below).

Using   dvbsnoop   'online'   requires   dvb-api    compliant    devices
()  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



Basic Decoding Selection Mode Command Line Options
-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 val‐
ues.  Examples:  octal: 021, decimal: 17, hexadecimal: 0x11

If -s option is omitted, default mode is "-s sec" (Section mode).



General Command Line Options
-help
Print help text with command line options.

-hideproginfo
Do not print dvbsnoop header (version, etc.).



General Decoding Output Command Line Options
-pd
Specify print decoding verbose mode. Specify 0 for no output.   9
will be very verbose. Default is 6.

-npd
Same as -pd 0.


-ph
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.


-t
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 pro‐
gram.
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 '>'.



Device Selection Command Line Options
Dvbsnoop  uses  default  devices, defined by the DVB API.  On some plat‐
forms or if using multiple dvb cards, you may want to  override  default
settings, e.g. to select a different tuner.

-demux
Specify  for demux.  If not specified, dvbsnoop uses the
device specified by the linux  dvb-api.

-dvr
Specify for dvr.  If not specified,  dvbsnoop  uses  the
device specified by the linux  dvb-api.

-frontend
Specify    for frontend.  If not specified, dvbsnoop uses
the device specified by the linux  dvb-api.

-adapter
Specify DVB adapter/card by number (0-9) using  default  path
pattern  (e.g. /dev/dvb/adapter1/...). If not specified, dvbsnoop
uses the default adapter/card - usually 0.

-devnr
Specify DVB device number (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
Set demux read buffer size in KBytes.  Default is 0 (use internal
default value).


-n
Stop  after  reading  packets. Use this to limit the read
process.  Default is 0 (no limit).


-if
Read binary stream data from file instead of the demux device.
= '-' reads  from  standard  input.   Depending  on  the
decoding  mode this might be transport stream, packetized elemen‐
tary stream or sections.  Please aware, that you cannot e.g.  use
-s  pes  or  -s  sec  on  a  saved  transport stream.  The decod‐
ing/snooping mode has to match the saved stream format!



SECTION Mode (SEC) Specific Command Line Options
The following command line options are special to the 'SECTION' decoding
mode:

-s sec
Section mode.

-timeout
Section read timeout in ms. Default is 0 (no timeout).

-f
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
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
Stop after decoding 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.   Hard‐
ware/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 after specifying -spiderpid.

-privateprovider
Set provider string for decoding of special  private  tables
and  descriptors.  Use  -help  to display provider currently sup‐
ported. 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!)



Transport Stream (TS) Mode Specific Command Line Options
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
Stop after decoding 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).



PES or PS Mode Specific Command Line Options
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).




PID Scan Mode Specific Command Line Options
The  following command line options are special to the 'PID Scan'
discovery mode:

-s pidscan
Scan PIDs on transponder/frequency.

-maxdmx
Set maximum use of DMX filters.  Default is 0 (use  all  possible
filters).



Bandwidth Mode Specific Command Line Options
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 calcu‐
lating received ts packets in a timeslot.



Signal Mode Specific Command Line Options
There  are  no  special  command  line options for the 'Signal Strength'
display mode.

-s signal
Poll frontend signal status.

-timeout
Poll timing in msec.



Frontend Info Mode Specific Command Line Options
There are no special command line options for the 'Frontend  Info'  dis‐
play  mode.

-s feinfo
Display frontend information.



Examples
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 -





NOTES
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 sup‐
ported 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.



SIGNALS
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).



BUGS
Please check for bug reports.
Bug reports:


SEE ALSO
dvbtune (1), dvbstream (1).



Acknowledgments
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   '‐
snoop.sourceforge.net'.



Rainer Scherg (rasc)                                                dvbsnoop(1)