1FAQ 2=== 3 4.. note:: 5 6 This documentation is outdated. Please check at the DVB wiki 7 at https://linuxtv.org/wiki for more updated info. 8 9Some very frequently asked questions about linuxtv-dvb 10 111. The signal seems to die a few seconds after tuning. 12 13 It's not a bug, it's a feature. Because the frontends have 14 significant power requirements (and hence get very hot), they 15 are powered down if they are unused (i.e. if the frontend device 16 is closed). The dvb-core.o module parameter "dvb_shutdown_timeout" 17 allow you to change the timeout (default 5 seconds). Setting the 18 timeout to 0 disables the timeout feature. 19 202. How can I watch TV? 21 22 The driver distribution includes some simple utilities which 23 are mainly intended for testing and to demonstrate how the 24 DVB API works. 25 26 Depending on whether you have a DVB-S, DVB-C or DVB-T card, use 27 apps/szap/szap, czap or tzap. You must supply a channel list 28 in ~/.[sct]zap/channels.conf. If you are lucky you can just copy 29 one of the supplied channel lists, or you can create a new one 30 by running apps/scan/scan. If you run scan on an unknown network 31 you might have to supply some start data in apps/scan/initial.h. 32 33 If you have a card with a built-in hardware MPEG-decoder the 34 drivers create a video4linux device (/dev/v4l/video0) which 35 you can use to watch TV with any v4l application. xawtv is known 36 to work. Note that you cannot change channels with xawtv, you 37 have to zap using [sct]zap. If you want a nice application for 38 TV watching and record/playback, have a look at VDR. 39 40 If your card does not have a hardware MPEG decoder you need 41 a software MPEG decoder. Mplayer or xine are known to work. 42 Newsflash: MythTV also has DVB support now. 43 Note: Only very recent versions of Mplayer and xine can decode. 44 MPEG2 transport streams (TS) directly. Then, run 45 '[sct]zap channelname -r' in one xterm, and keep it running, 46 and start 'mplayer - < /dev/dvb/adapter0/dvr0' or 47 'xine stdin://mpeg2 < /dev/dvb/adapter0/dvr0' in a second xterm. 48 That's all far from perfect, but it seems no one has written 49 a nice DVB application which includes a builtin software MPEG 50 decoder yet. 51 52 Newsflash: Newest xine directly supports DVB. Just copy your 53 channels.conf to ~/.xine and start 'xine dvb://', or select 54 the DVB button in the xine GUI. Channel switching works using the 55 numpad pgup/pgdown (NP9 / NP3) keys to scroll through the channel osd 56 menu and pressing numpad-enter to switch to the selected channel. 57 58 Note: Older versions of xine and mplayer understand MPEG program 59 streams (PS) only, and can be used in conjunction with the 60 ts2ps tool from the Metzler Brother's dvb-mpegtools package. 61 623. Which other DVB applications exist? 63 64 http://www.cadsoft.de/people/kls/vdr/ 65 Klaus Schmidinger's Video Disk Recorder 66 67 http://www.metzlerbros.org/dvb/ 68 Metzler Bros. DVB development; alternate drivers and 69 DVB utilities, include dvb-mpegtools and tuxzap. 70 71 http://sourceforge.net/projects/dvbtools/ 72 Dave Chapman's dvbtools package, including 73 dvbstream and dvbtune 74 75 http://www.linuxdvb.tv/ 76 Henning Holtschneider's site with many interesting 77 links and docs 78 79 http://www.dbox2.info/ 80 LinuxDVB on the dBox2 81 82 http://www.tuxbox.org/ and http://cvs.tuxbox.org/ 83 the TuxBox CVS many interesting DVB applications and the dBox2 84 DVB source 85 86 https://linuxtv.org/downloads 87 DVB Swiss Army Knife library and utilities 88 89 http://www.nenie.org/misc/mpsys/ 90 MPSYS: a MPEG2 system library and tools 91 92 http://mplayerhq.hu/ 93 mplayer 94 95 http://xine.sourceforge.net/ and http://xinehq.de/ 96 xine 97 98 http://www.mythtv.org/ 99 MythTV - analog TV PVR, but now with DVB support, too 100 (with software MPEG decode) 101 102 http://dvbsnoop.sourceforge.net/ 103 DVB sniffer program to monitor, analyze, debug, dump 104 or view dvb/mpeg/dsm-cc/mhp stream information (TS, 105 PES, SECTION) 106 1074. Can't get a signal tuned correctly 108 109 If you are using a Technotrend/Hauppauge DVB-C card *without* analog 110 module, you might have to use module parameter adac=-1 (dvb-ttpci.o). 111 1125. The dvb_net device doesn't give me any packets at all 113 114 Run tcpdump on the dvb0_0 interface. This sets the interface 115 into promiscuous mode so it accepts any packets from the PID 116 you have configured with the dvbnet utility. Check if there 117 are any packets with the IP addr and MAC addr you have 118 configured with ifconfig. 119 120 If tcpdump doesn't give you any output, check the statistics 121 which ifconfig outputs. (Note: If the MAC address is wrong, 122 dvb_net won't get any input; thus you have to run tcpdump 123 before checking the statistics.) If there are no packets at 124 all then maybe the PID is wrong. If there are error packets, 125 then either the PID is wrong or the stream does not conform to 126 the MPE standard (EN 301 192, http://www.etsi.org/). You can 127 use e.g. dvbsnoop for debugging. 128 1296. The dvb_net device doesn't give me any multicast packets 130 131 Check your routes if they include the multicast address range. 132 Additionally make sure that "source validation by reversed path 133 lookup" is disabled: 134 135.. code-block:: none 136 137 $ "echo 0 > /proc/sys/net/ipv4/conf/dvb0/rp_filter" 138 1397. What the hell are all those modules that need to be loaded? 140 141 For a dvb-ttpci av7110 based full-featured card the following 142 modules are loaded: 143 144 - videodev: Video4Linux core module. This is the base module that 145 gives you access to the "analog" tv picture of the av7110 mpeg2 146 decoder. 147 148 - v4l2-common: common functions for Video4Linux-2 drivers 149 150 - v4l1-compat: backward compatibility layer for Video4Linux-1 legacy 151 applications 152 153 - dvb-core: DVB core module. This provides you with the 154 /dev/dvb/adapter entries 155 156 - saa7146: SAA7146 core driver. This is need to access any SAA7146 157 based card in your system. 158 159 - saa7146_vv: SAA7146 video and vbi functions. These are only needed 160 for full-featured cards. 161 162 - videobuf-dma-sg: capture helper module for the saa7146_vv driver. This 163 one is responsible to handle capture buffers. 164 165 - dvb-ttpci: The main driver for AV7110 based, full-featured 166 DVB-S/C/T cards 167 168