Some very frequently asked questions about linuxtv-dvb
  
  1. The signal seems to die a few seconds after tuning.
  
  	It's not a bug, it's a feature. Because the frontends have
  	significant power requirements (and hence get very hot), they
  	are powered down if they are unused (i.e. if the frontend device

  	is closed). The dvb-core.o module parameter "dvb_shutdown_timeout"

  	allow you to change the timeout (default 5 seconds). Setting the
  	timeout to 0 disables the timeout feature.
  
  2. How can I watch TV?
  
  	The driver distribution includes some simple utilities which
  	are mainly intended for testing and to demonstrate how the
  	DVB API works.
  
  	Depending on whether you have a DVB-S, DVB-C or DVB-T card, use
  	apps/szap/szap, czap or tzap. You must supply a channel list
  	in ~/.[sct]zap/channels.conf. If you are lucky you can just copy
  	one of the supplied channel lists, or you can create a new one
  	by running apps/scan/scan. If you run scan on an unknown network
  	you might have to supply some start data in apps/scan/initial.h.
  
  	If you have a card with a built-in hardware MPEG-decoder the
  	drivers create a video4linux device (/dev/v4l/video0) which
  	you can use to watch TV with any v4l application. xawtv is known
  	to work. Note that you cannot change channels with xawtv, you
  	have to zap using [sct]zap. If you want a nice application for
  	TV watching and record/playback, have a look at VDR.
  
  	If your card does not have a hardware MPEG decoder you need
  	a software MPEG decoder. Mplayer or xine are known to work.
  	Newsflash: MythTV also has DVB support now.
  	Note: Only very recent versions of Mplayer and xine can decode.
  	MPEG2 transport streams (TS) directly. Then, run
  	'[sct]zap channelname -r' in one xterm, and keep it running,
  	and start 'mplayer - < /dev/dvb/adapter0/dvr0' or
  	'xine stdin://mpeg2 < /dev/dvb/adapter0/dvr0' in a second xterm.
  	That's all far from perfect, but it seems no one has written
  	a nice DVB application which includes a builtin software MPEG
  	decoder yet.
  
  	Newsflash: Newest xine directly supports DVB. Just copy your
  	channels.conf to ~/.xine and start 'xine dvb://', or select
  	the DVB button in the xine GUI. Channel switching works using the
  	numpad pgup/pgdown (NP9 / NP3) keys to scroll through the channel osd
  	menu and pressing numpad-enter to switch to the selected channel.
  
  	Note: Older versions of xine and mplayer understand MPEG program
  	streams (PS) only, and can be used in conjunction with the
  	ts2ps tool from the Metzler Brother's dvb-mpegtools package.
  
  3. Which other DVB applications exist?
  
  	http://www.cadsoft.de/people/kls/vdr/
  		Klaus Schmidinger's Video Disk Recorder
  
  	http://www.metzlerbros.org/dvb/
  		Metzler Bros. DVB development; alternate drivers and
  		DVB utilities, include dvb-mpegtools and tuxzap.

  	http://sourceforge.net/projects/dvbtools/
  		Dave Chapman's dvbtools package, including
  		dvbstream and dvbtune
  
  	http://www.linuxdvb.tv/
  		Henning Holtschneider's site with many interesting
  		links and docs
  
  	http://www.dbox2.info/
  		LinuxDVB on the dBox2
  
  	http://www.tuxbox.org/
  	http://cvs.tuxbox.org/
  		the TuxBox CVS many interesting DVB applications and the dBox2
  		DVB source

  	http://www.linuxtv.org/downloads/	

  		DVB Swiss Army Knife library and utilities
  
  	http://www.nenie.org/misc/mpsys/
  		MPSYS: a MPEG2 system library and tools
  
  	http://mplayerhq.hu/
  		mplayer
  
  	http://xine.sourceforge.net/
  	http://xinehq.de/
  		xine
  
  	http://www.mythtv.org/
  		MythTV - analog TV PVR, but now with DVB support, too
  		(with software MPEG decode)
  
  	http://dvbsnoop.sourceforge.net/
  		DVB sniffer program to monitor, analyze, debug, dump
  		or view dvb/mpeg/dsm-cc/mhp stream information (TS,
  		PES, SECTION)
  
  4. Can't get a signal tuned correctly
  
  	If you are using a Technotrend/Hauppauge DVB-C card *without* analog
  	module, you might have to use module parameter adac=-1 (dvb-ttpci.o).
  
  5. The dvb_net device doesn't give me any packets at all
  
  	Run tcpdump on the dvb0_0 interface. This sets the interface

  	into promiscuous mode so it accepts any packets from the PID

  	you have configured with the dvbnet utility. Check if there
  	are any packets with the IP addr and MAC addr you have
  	configured with ifconfig.
  
  	If tcpdump doesn't give you any output, check the statistics
  	which ifconfig outputs. (Note: If the MAC address is wrong,
  	dvb_net won't get any input; thus you have to run tcpdump
  	before checking the statistics.) If there are no packets at
  	all then maybe the PID is wrong. If there are error packets,
  	then either the PID is wrong or the stream does not conform to
  	the MPE standard (EN 301 192, http://www.etsi.org/). You can
  	use e.g. dvbsnoop for debugging.
  
  6. The dvb_net device doesn't give me any multicast packets
  
  	Check your routes if they include the multicast address range.
  	Additionally make sure that "source validation by reversed path
  	lookup" is disabled:
  	  $ "echo 0 > /proc/sys/net/ipv4/conf/dvb0/rp_filter"
  
  7. What the hell are all those modules that need to be loaded?
  
  	For a dvb-ttpci av7110 based full-featured card the following
  	modules are loaded:
  
  	- videodev: Video4Linux core module. This is the base module that
  	  gives you access to the "analog" tv picture of the av7110 mpeg2
  	  decoder.
  
  	- v4l2-common: common functions for Video4Linux-2 drivers

  	- v4l1-compat: backward compatibility layer for Video4Linux-1 legacy

  	  applications
  
  	- dvb-core: DVB core module. This provides you with the
  	  /dev/dvb/adapter entries
  
  	- saa7146: SAA7146 core driver. This is need to access any SAA7146
  	  based card in your system.
  
  	- saa7146_vv: SAA7146 video and vbi functions. These are only needed
  	  for full-featured cards.

  	- videobuf-dma-sg: capture helper module for the saa7146_vv driver. This

  	  one is responsible to handle capture buffers.

  	- dvb-ttpci: The main driver for AV7110 based, full-featured

  	  DVB-S/C/T cards
  
  eof