^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) .. SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) FAQ
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) ===
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) .. note::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) 1. With Digital TV, a single physical channel may have different
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) contents inside it. The specs call each one as a *service*.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) This is what a TV user would call "channel". So, in order to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) avoid confusion, we're calling *transponders* as the physical
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) channel on this FAQ, and *services* for the logical channel.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 2. The LinuxTV community maintains some Wiki pages with contain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) a lot of information related to the media subsystem. If you
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) don't find an answer for your needs here, it is likely that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) you'll be able to get something useful there. It is hosted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) at:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) https://www.linuxtv.org/wiki/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) Some very frequently asked questions about Linux Digital TV support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 1. The signal seems to die a few seconds after tuning.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) It's not a bug, it's a feature. Because the frontends have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) significant power requirements (and hence get very hot), they
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) are powered down if they are unused (i.e. if the frontend device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) is closed). The ``dvb-core`` module parameter ``dvb_shutdown_timeout``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) allow you to change the timeout (default 5 seconds). Setting the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) timeout to 0 disables the timeout feature.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 2. How can I watch TV?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) Together with the Linux Kernel, the Digital TV developers support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) some simple utilities which are mainly intended for testing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) and to demonstrate how the DVB API works. This is called DVB v5
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) tools and are grouped together with the ``v4l-utils`` git repository:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) https://git.linuxtv.org/v4l-utils.git/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) You can find more information at the LinuxTV wiki:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) https://www.linuxtv.org/wiki/index.php/DVBv5_Tools
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) The first step is to get a list of services that are transmitted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) This is done by using several existing tools. You can use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) for example the ``dvbv5-scan`` tool. You can find more information
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) about it at:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) https://www.linuxtv.org/wiki/index.php/Dvbv5-scan
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) There are some other applications like ``w_scan`` [#]_ that do a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) blind scan, trying hard to find all possible channels, but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) those consumes a large amount of time to run.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) .. [#] https://www.linuxtv.org/wiki/index.php/W_scan
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) Also, some applications like ``kaffeine`` have their own code
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) to scan for services. So, you don't need to use an external
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) application to obtain such list.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) Most of such tools need a file containing a list of channel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) transponders available on your area. So, LinuxTV developers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) maintain tables of Digital TV channel transponders, receiving
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) patches from the community to keep them updated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) This list is hosted at:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) https://git.linuxtv.org/dtv-scan-tables.git
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) And packaged on several distributions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) Kaffeine has some blind scan support for some terrestrial standards.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) It also relies on DTV scan tables, although it contains a copy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) of it internally (and, if requested by the user, it will download
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) newer versions of it).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) If you are lucky you can just use one of the supplied channel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) transponders. If not, you may need to seek for such info at
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) the Internet and create a new file. There are several sites with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) contains physical channel lists. For cable and satellite, usually
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) knowing how to tune into a single channel is enough for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) scanning tool to identify the other channels. On some places,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) this could also work for terrestrial transmissions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) Once you have a transponders list, you need to generate a services
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) list with a tool like ``dvbv5-scan``.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) Almost all modern Digital TV cards don't have built-in hardware
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) MPEG-decoders. So, it is up to the application to get a MPEG-TS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) stream provided by the board, split it into audio, video and other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) data and decode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) 3. Which Digital TV applications exist?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) Several media player applications are capable of tuning into
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) digital TV channels, including Kaffeine, Vlc, mplayer and MythTV.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) Kaffeine aims to be very user-friendly, and it is maintained
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) by one of the Kernel driver developers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) A comprehensive list of those and other apps can be found at:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) https://www.linuxtv.org/wiki/index.php/TV_Related_Software
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) Some of the most popular ones are linked below:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) https://kde.org/applications/multimedia/org.kde.kaffeine
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) KDE media player, focused on Digital TV support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) https://www.linuxtv.org/vdrwiki/index.php/Main_Page
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) Klaus Schmidinger's Video Disk Recorder
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) https://linuxtv.org/downloads and https://git.linuxtv.org/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) Digital TV and other media-related applications and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) Kernel drivers. The ``v4l-utils`` package there contains
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) several swiss knife tools for using with Digital TV.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) http://sourceforge.net/projects/dvbtools/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) Dave Chapman's dvbtools package, including
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) dvbstream and dvbtune
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) http://www.dbox2.info/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) LinuxDVB on the dBox2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) http://www.tuxbox.org/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) the TuxBox CVS many interesting DVB applications and the dBox2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) DVB source
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) http://www.nenie.org/misc/mpsys/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) MPSYS: a MPEG2 system library and tools
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) https://www.videolan.org/vlc/index.pt.html
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) Vlc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) http://mplayerhq.hu/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) MPlayer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) http://xine.sourceforge.net/ and http://xinehq.de/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) Xine
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) http://www.mythtv.org/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) MythTV - analog TV and digital TV PVR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) http://dvbsnoop.sourceforge.net/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) DVB sniffer program to monitor, analyze, debug, dump
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) or view dvb/mpeg/dsm-cc/mhp stream information (TS,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) PES, SECTION)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 4. Can't get a signal tuned correctly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) That could be due to a lot of problems. On my personal experience,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) usually TV cards need stronger signals than TV sets, and are more
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) sensitive to noise. So, perhaps you just need a better antenna or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) cabling. Yet, it could also be some hardware or driver issue.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) For example, if you are using a Technotrend/Hauppauge DVB-C card
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) *without* analog module, you might have to use module parameter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) adac=-1 (dvb-ttpci.o).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) Please see the FAQ page at linuxtv.org, as it could contain some
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) valuable information:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) https://www.linuxtv.org/wiki/index.php/FAQ_%26_Troubleshooting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) If that doesn't work, check at the linux-media ML archives, to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) see if someone else had a similar problem with your hardware
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) and/or digital TV service provider:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) https://lore.kernel.org/linux-media/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) If none of this works, you can try sending an e-mail to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) linux-media ML and see if someone else could shed some light.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) The e-mail is linux-media AT vger.kernel.org.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 5. The dvb_net device doesn't give me any packets at all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) Run ``tcpdump`` on the ``dvb0_0`` interface. This sets the interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) into promiscuous mode so it accepts any packets from the PID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) you have configured with the ``dvbnet`` utility. Check if there
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) are any packets with the IP addr and MAC addr you have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) configured with ``ifconfig`` or with ``ip addr``.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) If ``tcpdump`` doesn't give you any output, check the statistics
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) which ``ifconfig`` or ``netstat -ni`` outputs. (Note: If the MAC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) address is wrong, ``dvb_net`` won't get any input; thus you have to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) run ``tcpdump`` before checking the statistics.) If there are no
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) packets at all then maybe the PID is wrong. If there are error packets,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) then either the PID is wrong or the stream does not conform to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) the MPE standard (EN 301 192, http://www.etsi.org/). You can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) use e.g. ``dvbsnoop`` for debugging.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 6. The ``dvb_net`` device doesn't give me any multicast packets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) Check your routes if they include the multicast address range.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) Additionally make sure that "source validation by reversed path
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) lookup" is disabled::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) $ "echo 0 > /proc/sys/net/ipv4/conf/dvb0/rp_filter"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 7. What are all those modules that need to be loaded?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) In order to make it more flexible and support different hardware
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) combinations, the media subsystem is written on a modular way.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) So, besides the Digital TV hardware module for the main chipset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) it also needs to load a frontend driver, plus the Digital TV
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) core. If the board also has remote controller, it will also
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) need the remote controller core and the remote controller tables.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) The same happens if the board has support for analog TV: the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) core support for video4linux need to be loaded.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) The actual module names are Linux-kernel version specific, as,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) from time to time, things change, in order to make the media
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) support more flexible.
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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