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+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 paramter "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?
+ Klaus Schmidinger's Video Disk Recorder
+ Metzler Bros. DVB development; alternate drivers and
+ DVB utilities, include dvb-mpegtools and tuxzap.
+ Dave Chapman's dvbtools package, including
+ dvbstream and dvbtune
+ Henning Holtschneider's site with many interesting
+ links and docs
+ LinuxDVB on the dBox2
+ the TuxBox CVS many interesting DVB applications and the dBox2
+ DVB source
+ DVB Swiss Army Knife library and utilities
+ MPSYS: a MPEG2 system library and tools
+ MythTV - analog TV PVR, but now with DVB support, too
+ (with software MPEG decode)
+ 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 promiscous 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
+ - v4l2-common: common functions for Video4Linux-2 drivers
+ - v4l1-compat: backward compatiblity layer for Video4Linux-1 legacy
+ - 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.
+ - video-buf: 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-featued
+ DVB-S/C/T cards