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1 | FAQ |
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6 | This documentation is outdated.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 | ||
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9 | Some very frequently asked questions about linuxtv-dvb |
10 | ||
11 | 1. 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 | |
992caacf | 16 | is closed). The dvb-core.o module parameter "dvb_shutdown_timeout" |
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17 | allow you to change the timeout (default 5 seconds). Setting the |
18 | timeout to 0 disables the timeout feature. | |
19 | ||
20 | 2. 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 | ||
62 | 3. 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 | ||
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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 | ||
c0be9f79 | 82 | http://www.tuxbox.org/ and http://cvs.tuxbox.org/ |
1da177e4 LT |
83 | the TuxBox CVS many interesting DVB applications and the dBox2 |
84 | DVB source | |
85 | ||
991ce92f | 86 | https://linuxtv.org/downloads |
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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 | ||
c0be9f79 | 95 | http://xine.sourceforge.net/ and http://xinehq.de/ |
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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 | ||
107 | 4. 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 | ||
112 | 5. 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 | |
25985edc | 115 | into promiscuous mode so it accepts any packets from the PID |
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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 | ||
129 | 6. 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: | |
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134 | |
135 | .. code-block:: none | |
136 | ||
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137 | $ "echo 0 > /proc/sys/net/ipv4/conf/dvb0/rp_filter" |
138 | ||
139 | 7. 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 | ||
6c28f2c0 | 150 | - v4l1-compat: backward compatibility layer for Video4Linux-1 legacy |
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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 | ||
c1accaa2 | 162 | - videobuf-dma-sg: capture helper module for the saa7146_vv driver. This |
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163 | one is responsible to handle capture buffers. |
164 | ||
a2ffd275 | 165 | - dvb-ttpci: The main driver for AV7110 based, full-featured |
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166 | DVB-S/C/T cards |
167 |