diff options
Diffstat (limited to 'Documentation/admin-guide/media/avermedia.rst')
| -rw-r--r-- | Documentation/admin-guide/media/avermedia.rst | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/Documentation/admin-guide/media/avermedia.rst b/Documentation/admin-guide/media/avermedia.rst new file mode 100644 index 000000000000..bf35fd88e164 --- /dev/null +++ b/Documentation/admin-guide/media/avermedia.rst @@ -0,0 +1,273 @@ +.. SPDX-License-Identifier: GPL-2.0 + +HOWTO: Get An Avermedia DVB-T working under Linux +------------------------------------------------- + +February 14th 2006 + +.. note:: + + This documentation is outdated. Please check at the DVB wiki + at https://linuxtv.org/wiki for more updated info. + + There's a section there specific for Avermedia boards at: + https://linuxtv.org/wiki/index.php/AVerMedia + + +Assumptions and Introduction +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +It is assumed that the reader understands the basic structure +of the Linux Kernel DVB drivers and the general principles of +Digital TV. + +One significant difference between Digital TV and Analogue TV +that the unwary (like myself) should consider is that, +although the component structure of budget DVB-T cards are +substantially similar to Analogue TV cards, they function in +substantially different ways. + +The purpose of an Analogue TV is to receive and display an +Analogue Television signal. An Analogue TV signal (otherwise +known as composite video) is an analogue encoding of a +sequence of image frames (25 per second) rasterised using an +interlacing technique. Interlacing takes two fields to +represent one frame. Computers today are at their best when +dealing with digital signals, not analogue signals and a +composite video signal is about as far removed from a digital +data stream as you can get. Therefore, an Analogue TV card for +a PC has the following purpose: + +* Tune the receiver to receive a broadcast signal +* demodulate the broadcast signal +* demultiplex the analogue video signal and analogue audio + signal. **NOTE:** some countries employ a digital audio signal + embedded within the modulated composite analogue signal - + NICAM.) +* digitize the analogue video signal and make the resulting + datastream available to the data bus. + +The digital datastream from an Analogue TV card is generated +by circuitry on the card and is often presented uncompressed. +For a PAL TV signal encoded at a resolution of 768x576 24-bit +color pixels over 25 frames per second - a fair amount of data +is generated and must be processed by the PC before it can be +displayed on the video monitor screen. Some Analogue TV cards +for PCs have onboard MPEG2 encoders which permit the raw +digital data stream to be presented to the PC in an encoded +and compressed form - similar to the form that is used in +Digital TV. + +The purpose of a simple budget digital TV card (DVB-T,C or S) +is to simply: + +* Tune the received to receive a broadcast signal. +* Extract the encoded digital datastream from the broadcast + signal. +* Make the encoded digital datastream (MPEG2) available to + the data bus. + +The significant difference between the two is that the tuner +on the analogue TV card spits out an Analogue signal, whereas +the tuner on the digital TV card spits out a compressed +encoded digital datastream. As the signal is already +digitised, it is trivial to pass this datastream to the PC +databus with minimal additional processing and then extract +the digital video and audio datastreams passing them to the +appropriate software or hardware for decoding and viewing. + +The Avermedia DVB-T +~~~~~~~~~~~~~~~~~~~ + +The Avermedia DVB-T is a budget PCI DVB card. It has 3 inputs: + +* RF Tuner Input +* Composite Video Input (RCA Jack) +* SVIDEO Input (Mini-DIN) + +The RF Tuner Input is the input to the tuner module of the +card. The Tuner is otherwise known as the "Frontend" . The +Frontend of the Avermedia DVB-T is a Microtune 7202D. A timely +post to the linux-dvb mailing list ascertained that the +Microtune 7202D is supported by the sp887x driver which is +found in the dvb-hw CVS module. + +The DVB-T card is based around the BT878 chip which is a very +common multimedia bridge and often found on Analogue TV cards. +There is no on-board MPEG2 decoder, which means that all MPEG2 +decoding must be done in software, or if you have one, on an +MPEG2 hardware decoding card or chipset. + + +Getting the card going +~~~~~~~~~~~~~~~~~~~~~~ + +In order to fire up the card, it is necessary to load a number +of modules from the DVB driver set. Prior to this it will have +been necessary to download these drivers from the linuxtv CVS +server and compile them successfully. + +Depending on the card's feature set, the Device Driver API for +DVB under Linux will expose some of the following device files +in the /dev tree: + +* /dev/dvb/adapter0/audio0 +* /dev/dvb/adapter0/ca0 +* /dev/dvb/adapter0/demux0 +* /dev/dvb/adapter0/dvr0 +* /dev/dvb/adapter0/frontend0 +* /dev/dvb/adapter0/net0 +* /dev/dvb/adapter0/osd0 +* /dev/dvb/adapter0/video0 + +The primary device nodes that we are interested in (at this +stage) for the Avermedia DVB-T are: + +* /dev/dvb/adapter0/dvr0 +* /dev/dvb/adapter0/frontend0 + +The dvr0 device node is used to read the MPEG2 Data Stream and +the frontend0 node is used to tune the frontend tuner module. + +At this stage, it has not been able to ascertain the +functionality of the remaining device nodes in respect of the +Avermedia DVBT. However, full functionality in respect of +tuning, receiving and supplying the MPEG2 data stream is +possible with the currently available versions of the driver. +It may be possible that additional functionality is available +from the card (i.e. viewing the additional analogue inputs +that the card presents), but this has not been tested yet. If +I get around to this, I'll update the document with whatever I +find. + +To power up the card, load the following modules in the +following order: + +* modprobe bttv (normally loaded automatically) +* modprobe dvb-bt8xx (or place dvb-bt8xx in /etc/modules) + +Insertion of these modules into the running kernel will +activate the appropriate DVB device nodes. It is then possible +to start accessing the card with utilities such as scan, tzap, +dvbstream etc. + +The frontend module sp887x.o, requires an external firmware. +Please use the command "get_dvb_firmware sp887x" to download +it. Then copy it to /usr/lib/hotplug/firmware or /lib/firmware/ +(depending on configuration of firmware hotplug). + +Receiving DVB-T in Australia +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +I have no experience of DVB-T in other countries other than +Australia, so I will attempt to explain how it works here in +Melbourne and how this affects the configuration of the DVB-T +card. + +The Digital Broadcasting Australia website has a Reception +locatortool which provides information on transponder channels +and frequencies. My local transmitter happens to be Mount +Dandenong. + +The frequencies broadcast by Mount Dandenong are: + +Table 1. Transponder Frequencies Mount Dandenong, Vic, Aus. + +=========== ======= =========== +Broadcaster Channel Frequency +=========== ======= =========== +ABC VHF 12 226.5 MHz +TEN VHF 11 219.5 MHz +NINE VHF 8 191.625 MHz +SEVEN VHF 6 177.5 MHz +SBS UHF 29 536.5 MHz +=========== ======= =========== + +The Scan utility has a set of compiled-in defaults for various +countries and regions, but if they do not suit, or if you have +a pre-compiled scan binary, you can specify a data file on the +command line which contains the transponder frequencies. Here +is a sample file for the above channel transponders: + +:: + + # Data file for DVB scan program + # + # C Frequency SymbolRate FEC QAM + # S Frequency Polarisation SymbolRate FEC + # T Frequency Bandwidth FEC FEC2 QAM Mode Guard Hier + T 226500000 7MHz 2/3 NONE QAM64 8k 1/8 NONE + T 191625000 7MHz 2/3 NONE QAM64 8k 1/8 NONE + T 219500000 7MHz 2/3 NONE QAM64 8k 1/8 NONE + T 177500000 7MHz 2/3 NONE QAM64 8k 1/8 NONE + T 536500000 7MHz 2/3 NONE QAM64 8k 1/8 NONE + +The defaults for the transponder frequency and other +modulation parameters were obtained from www.dba.org.au. + +When Scan runs, it will output channels.conf information for +any channel's transponders which the card's frontend can lock +onto. (i.e. any whose signal is strong enough at your +antenna). + +Here's my channels.conf file for anyone who's interested: + +:: + + ABC HDTV:226500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:2307:0:560 + ABC TV Melbourne:226500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:561 + ABC TV 2:226500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:562 + ABC TV 3:226500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:563 + ABC TV 4:226500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:564 + ABC DiG Radio:226500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_3_4:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:0:2311:566 + TEN Digital:219500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:1585 + TEN Digital 1:219500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:1586 + TEN Digital 2:219500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:1587 + TEN Digital 3:219500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:1588 + TEN Digital:219500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:1589 + TEN Digital 4:219500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:1590 + TEN Digital:219500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:1591 + TEN HD:219500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:514:0:1592 + TEN Digital:219500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:1593 + Nine Digital:191625000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:513:660:1072 + Nine Digital HD:191625000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:0:1073 + Nine Guide:191625000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:514:670:1074 + 7 Digital:177500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_2_3:FEC_2_3:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:769:770:1328 + 7 Digital 1:177500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_2_3:FEC_2_3:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:769:770:1329 + 7 Digital 2:177500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_2_3:FEC_2_3:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:769:770:1330 + 7 Digital 3:177500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_2_3:FEC_2_3:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:769:770:1331 + 7 HD Digital:177500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_2_3:FEC_2_3:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:833:834:1332 + 7 Program Guide:177500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_2_3:FEC_2_3:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:865:866:1334 + SBS HD:536500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_2_3:FEC_2_3:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:102:103:784 + SBS DIGITAL 1:536500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_2_3:FEC_2_3:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:161:81:785 + SBS DIGITAL 2:536500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_2_3:FEC_2_3:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:162:83:786 + SBS EPG:536500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_2_3:FEC_2_3:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:163:85:787 + SBS RADIO 1:536500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_2_3:FEC_2_3:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:0:201:798 + SBS RADIO 2:536500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_2_3:FEC_2_3:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:0:202:799 + +Known Limitations +~~~~~~~~~~~~~~~~~ + +At present I can say with confidence that the frontend tunes +via /dev/dvb/adapter{x}/frontend0 and supplies an MPEG2 stream +via /dev/dvb/adapter{x}/dvr0. I have not tested the +functionality of any other part of the card yet. I will do so +over time and update this document. + +There are some limitations in the i2c layer due to a returned +error message inconsistency. Although this generates errors in +dmesg and the system logs, it does not appear to affect the +ability of the frontend to function correctly. + +Further Update +~~~~~~~~~~~~~~ + +dvbstream and VideoLAN Client on windows works a treat with +DVB, in fact this is currently serving as my main way of +viewing DVB-T at the moment. Additionally, VLC is happily +decoding HDTV signals, although the PC is dropping the odd +frame here and there - I assume due to processing capability - +as all the decoding is being done under windows in software. + +Many thanks to Nigel Pearson for the updates to this document +since the recent revision of the driver. |