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+.. SPDX-License-Identifier: GPL-2.0
+
+==============================
+Using the Digital TV Framework
+==============================
+
+Introduction
+~~~~~~~~~~~~
+
+One significant difference between Digital TV and Analogue TV that the
+unwary (like myself) should consider is that, although the component
+structure of 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 frames
+per second in Europe) rasterised using an interlacing technique.
+Interlacing takes two fields to represent one frame. 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 -
+ using NICAM signaling.)
+
+* 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.
+
+Getting the card going
+~~~~~~~~~~~~~~~~~~~~~~
+
+The Device Driver API for DVB under Linux will the following
+device nodes via the devfs filesystem:
+
+* /dev/dvb/adapter0/demux0
+* /dev/dvb/adapter0/dvr0
+* /dev/dvb/adapter0/frontend0
+
+The ``/dev/dvb/adapter0/dvr0`` device node is used to read the MPEG2
+Data Stream and the ``/dev/dvb/adapter0/frontend0`` device node is used
+to tune the frontend tuner module. The ``/dev/dvb/adapter0/demux0`` is
+used to control what programs will be received.
+
+Depending on the card's feature set, the Device Driver API could also
+expose other device nodes:
+
+* /dev/dvb/adapter0/ca0
+* /dev/dvb/adapter0/audio0
+* /dev/dvb/adapter0/net0
+* /dev/dvb/adapter0/osd0
+* /dev/dvb/adapter0/video0
+
+The ``/dev/dvb/adapter0/ca0`` is used to decode encrypted channels. The
+other device nodes are found only on devices that use the av7110
+driver, with is now obsoleted, together with the extra API whose such
+devices use.
+
+Receiving a digital TV channel
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+This section attempts to explain how it works and how this affects the
+configuration of a Digital TV card.
+
+On this example, we're considering tuning into DVB-T channels in
+Australia, at the Melbourne region.
+
+The frequencies broadcast by Mount Dandenong transmitters are,
+currently:
+
+Table 1. Transponder Frequencies Mount Dandenong, Vic, Aus.
+
+=========== ===========
+Broadcaster Frequency
+=========== ===========
+Seven 177.500 Mhz
+SBS 184.500 Mhz
+Nine 191.625 Mhz
+Ten 219.500 Mhz
+ABC 226.500 Mhz
+Channel 31 557.625 Mhz
+=========== ===========
+
+The digital TV Scan utilities (like dvbv5-scan) have use a set of
+compiled-in defaults for various countries and regions. Those are
+currently provided as a separate package, called dtv-scan-tables. It's
+git tree is located at LinuxTV.org:
+
+ https://git.linuxtv.org/dtv-scan-tables.git/
+
+If none of the tables there suit, 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, in the old "channel"
+format::
+
+ # 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 177500000 7MHz AUTO AUTO QAM64 8k 1/16 NONE
+ T 184500000 7MHz AUTO AUTO QAM64 8k 1/8 NONE
+ T 191625000 7MHz AUTO AUTO QAM64 8k 1/16 NONE
+ T 219500000 7MHz AUTO AUTO QAM64 8k 1/16 NONE
+ T 226500000 7MHz AUTO AUTO QAM64 8k 1/16 NONE
+ T 557625000 7MHz AUTO AUTO QPSK 8k 1/16 NONE
+
+Nowadays, we prefer to use a newer format, with is more verbose and easier
+to understand. With the new format, the "Seven" channel transponder's
+data is represented by::
+
+ [Seven]
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 177500000
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = AUTO
+ CODE_RATE_LP = AUTO
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+ INVERSION = AUTO
+
+For an updated version of the complete table, please see:
+
+ https://git.linuxtv.org/dtv-scan-tables.git/tree/dvb-t/au-Melbourne
+
+When the Digital TV scanning utility runs, it will output a file
+containing the information for all the audio and video programs that
+exists into each channel's transponders which the card's frontend can
+lock onto. (i.e. any whose signal is strong enough at your antenna).
+
+Here's the output of the dvbv5 tools from a channel scan took from
+Melburne::
+
+ [ABC HDTV]
+ SERVICE_ID = 560
+ VIDEO_PID = 2307
+ AUDIO_PID = 0
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 226500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 3/4
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [ABC TV Melbourne]
+ SERVICE_ID = 561
+ VIDEO_PID = 512
+ AUDIO_PID = 650
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 226500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 3/4
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [ABC TV 2]
+ SERVICE_ID = 562
+ VIDEO_PID = 512
+ AUDIO_PID = 650
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 226500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 3/4
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [ABC TV 3]
+ SERVICE_ID = 563
+ VIDEO_PID = 512
+ AUDIO_PID = 650
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 226500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 3/4
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [ABC TV 4]
+ SERVICE_ID = 564
+ VIDEO_PID = 512
+ AUDIO_PID = 650
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 226500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 3/4
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [ABC DiG Radio]
+ SERVICE_ID = 566
+ VIDEO_PID = 0
+ AUDIO_PID = 2311
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 226500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 3/4
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [TEN Digital]
+ SERVICE_ID = 1585
+ VIDEO_PID = 512
+ AUDIO_PID = 650
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 219500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 1/2
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [TEN Digital 1]
+ SERVICE_ID = 1586
+ VIDEO_PID = 512
+ AUDIO_PID = 650
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 219500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 1/2
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [TEN Digital 2]
+ SERVICE_ID = 1587
+ VIDEO_PID = 512
+ AUDIO_PID = 650
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 219500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 1/2
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [TEN Digital 3]
+ SERVICE_ID = 1588
+ VIDEO_PID = 512
+ AUDIO_PID = 650
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 219500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 1/2
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [TEN Digital]
+ SERVICE_ID = 1589
+ VIDEO_PID = 512
+ AUDIO_PID = 650
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 219500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 1/2
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [TEN Digital 4]
+ SERVICE_ID = 1590
+ VIDEO_PID = 512
+ AUDIO_PID = 650
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 219500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 1/2
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [TEN Digital]
+ SERVICE_ID = 1591
+ VIDEO_PID = 512
+ AUDIO_PID = 650
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 219500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 1/2
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [TEN HD]
+ SERVICE_ID = 1592
+ VIDEO_PID = 514
+ AUDIO_PID = 0
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 219500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 1/2
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [TEN Digital]
+ SERVICE_ID = 1593
+ VIDEO_PID = 512
+ AUDIO_PID = 650
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 219500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 1/2
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [Nine Digital]
+ SERVICE_ID = 1072
+ VIDEO_PID = 513
+ AUDIO_PID = 660
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 191625000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 1/2
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [Nine Digital HD]
+ SERVICE_ID = 1073
+ VIDEO_PID = 512
+ AUDIO_PID = 0
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 191625000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 1/2
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [Nine Guide]
+ SERVICE_ID = 1074
+ VIDEO_PID = 514
+ AUDIO_PID = 670
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 191625000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 3/4
+ CODE_RATE_LP = 1/2
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/16
+ HIERARCHY = NONE
+
+ [7 Digital]
+ SERVICE_ID = 1328
+ VIDEO_PID = 769
+ AUDIO_PID = 770
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 177500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 2/3
+ CODE_RATE_LP = 2/3
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/8
+ HIERARCHY = NONE
+
+ [7 Digital 1]
+ SERVICE_ID = 1329
+ VIDEO_PID = 769
+ AUDIO_PID = 770
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 177500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 2/3
+ CODE_RATE_LP = 2/3
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/8
+ HIERARCHY = NONE
+
+ [7 Digital 2]
+ SERVICE_ID = 1330
+ VIDEO_PID = 769
+ AUDIO_PID = 770
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 177500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 2/3
+ CODE_RATE_LP = 2/3
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/8
+ HIERARCHY = NONE
+
+ [7 Digital 3]
+ SERVICE_ID = 1331
+ VIDEO_PID = 769
+ AUDIO_PID = 770
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 177500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 2/3
+ CODE_RATE_LP = 2/3
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/8
+ HIERARCHY = NONE
+
+ [7 HD Digital]
+ SERVICE_ID = 1332
+ VIDEO_PID = 833
+ AUDIO_PID = 834
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 177500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 2/3
+ CODE_RATE_LP = 2/3
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/8
+ HIERARCHY = NONE
+
+ [7 Program Guide]
+ SERVICE_ID = 1334
+ VIDEO_PID = 865
+ AUDIO_PID = 866
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 177500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 2/3
+ CODE_RATE_LP = 2/3
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/8
+ HIERARCHY = NONE
+
+ [SBS HD]
+ SERVICE_ID = 784
+ VIDEO_PID = 102
+ AUDIO_PID = 103
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 536500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 2/3
+ CODE_RATE_LP = 2/3
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/8
+ HIERARCHY = NONE
+
+ [SBS DIGITAL 1]
+ SERVICE_ID = 785
+ VIDEO_PID = 161
+ AUDIO_PID = 81
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 536500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 2/3
+ CODE_RATE_LP = 2/3
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/8
+ HIERARCHY = NONE
+
+ [SBS DIGITAL 2]
+ SERVICE_ID = 786
+ VIDEO_PID = 162
+ AUDIO_PID = 83
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 536500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 2/3
+ CODE_RATE_LP = 2/3
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/8
+ HIERARCHY = NONE
+
+ [SBS EPG]
+ SERVICE_ID = 787
+ VIDEO_PID = 163
+ AUDIO_PID = 85
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 536500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 2/3
+ CODE_RATE_LP = 2/3
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/8
+ HIERARCHY = NONE
+
+ [SBS RADIO 1]
+ SERVICE_ID = 798
+ VIDEO_PID = 0
+ AUDIO_PID = 201
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 536500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 2/3
+ CODE_RATE_LP = 2/3
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/8
+ HIERARCHY = NONE
+
+ [SBS RADIO 2]
+ SERVICE_ID = 799
+ VIDEO_PID = 0
+ AUDIO_PID = 202
+ DELIVERY_SYSTEM = DVBT
+ FREQUENCY = 536500000
+ INVERSION = OFF
+ BANDWIDTH_HZ = 7000000
+ CODE_RATE_HP = 2/3
+ CODE_RATE_LP = 2/3
+ MODULATION = QAM/64
+ TRANSMISSION_MODE = 8K
+ GUARD_INTERVAL = 1/8
+ HIERARCHY = NONE