tjh.dev
Linux kernel mirror (for testing)
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1.. SPDX-License-Identifier: GPL-2.0
2
3======================================
4Avermedia DVB-T on BT878 Release Notes
5======================================
6
7February 14th 2006
8
9.. note::
10
11 Several other Avermedia devices are supported. For a more
12 broader and updated content about that, please check:
13
14 https://linuxtv.org/wiki/index.php/AVerMedia
15
16The Avermedia DVB-T
17~~~~~~~~~~~~~~~~~~~
18
19The Avermedia DVB-T is a budget PCI DVB card. It has 3 inputs:
20
21* RF Tuner Input
22* Composite Video Input (RCA Jack)
23* SVIDEO Input (Mini-DIN)
24
25The RF Tuner Input is the input to the tuner module of the
26card. The Tuner is otherwise known as the "Frontend" . The
27Frontend of the Avermedia DVB-T is a Microtune 7202D. A timely
28post to the linux-dvb mailing list ascertained that the
29Microtune 7202D is supported by the sp887x driver which is
30found in the dvb-hw CVS module.
31
32The DVB-T card is based around the BT878 chip which is a very
33common multimedia bridge and often found on Analogue TV cards.
34There is no on-board MPEG2 decoder, which means that all MPEG2
35decoding must be done in software, or if you have one, on an
36MPEG2 hardware decoding card or chipset.
37
38
39Getting the card going
40~~~~~~~~~~~~~~~~~~~~~~
41
42At this stage, it has not been able to ascertain the
43functionality of the remaining device nodes in respect of the
44Avermedia DVBT. However, full functionality in respect of
45tuning, receiving and supplying the MPEG2 data stream is
46possible with the currently available versions of the driver.
47It may be possible that additional functionality is available
48from the card (i.e. viewing the additional analogue inputs
49that the card presents), but this has not been tested yet. If
50I get around to this, I'll update the document with whatever I
51find.
52
53To power up the card, load the following modules in the
54following order:
55
56* modprobe bttv (normally loaded automatically)
57* modprobe dvb-bt8xx (or place dvb-bt8xx in /etc/modules)
58
59Insertion of these modules into the running kernel will
60activate the appropriate DVB device nodes. It is then possible
61to start accessing the card with utilities such as scan, tzap,
62dvbstream etc.
63
64The frontend module sp887x.o, requires an external firmware.
65Please use the command "get_dvb_firmware sp887x" to download
66it. Then copy it to /usr/lib/hotplug/firmware or /lib/firmware/
67(depending on configuration of firmware hotplug).
68
69Known Limitations
70~~~~~~~~~~~~~~~~~
71
72At present I can say with confidence that the frontend tunes
73via /dev/dvb/adapter{x}/frontend0 and supplies an MPEG2 stream
74via /dev/dvb/adapter{x}/dvr0. I have not tested the
75functionality of any other part of the card yet. I will do so
76over time and update this document.
77
78There are some limitations in the i2c layer due to a returned
79error message inconsistency. Although this generates errors in
80dmesg and the system logs, it does not appear to affect the
81ability of the frontend to function correctly.
82
83Further Update
84~~~~~~~~~~~~~~
85
86dvbstream and VideoLAN Client on windows works a treat with
87DVB, in fact this is currently serving as my main way of
88viewing DVB-T at the moment. Additionally, VLC is happily
89decoding HDTV signals, although the PC is dropping the odd
90frame here and there - I assume due to processing capability -
91as all the decoding is being done under windows in software.
92
93Many thanks to Nigel Pearson for the updates to this document
94since the recent revision of the driver.