diff options
Diffstat (limited to 'Documentation/media/dvb-drivers/avermedia.rst')
| -rw-r--r-- | Documentation/media/dvb-drivers/avermedia.rst | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/Documentation/media/dvb-drivers/avermedia.rst b/Documentation/media/dvb-drivers/avermedia.rst new file mode 100644 index 000000000000..e44c009ac6c5 --- /dev/null +++ b/Documentation/media/dvb-drivers/avermedia.rst @@ -0,0 +1,301 @@ +HOWTO: Get An Avermedia DVB-T working under Linux + ______________________________________________ + + Table of Contents + Assumptions and Introduction + The Avermedia DVB-T + Getting the card going + Receiving DVB-T in Australia + Known Limitations + Further Update + +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:512:65 +0:561 +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:Q +AM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:0:2311:56 +6 +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:512:650:158 +5 +TEN Digital 1:219500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:Q +AM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:1 +586 +TEN Digital 2:219500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:Q +AM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:1 +587 +TEN Digital 3:219500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:Q +AM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:1 +588 +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:512:650:158 +9 +TEN Digital 4:219500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:Q +AM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:512:650:1 +590 +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:512:650:159 +1 +TEN HD:219500000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QAM_64:T +RANSMISSION_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:512:650:159 +3 +Nine Digital:191625000:INVERSION_OFF:BANDWIDTH_7_MHZ:FEC_3_4:FEC_1_2:QA +M_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_16:HIERARCHY_NONE:513:660:10 +72 +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:512:0:1 +073 +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_6 +4: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:QA +M_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:833:834:133 +2 +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:T +RANSMISSION_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:Q +AM_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:Q +AM_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. + + February 14th 2006 |