linuxdebug/Documentation/admin-guide/media/avermedia.rst

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.. SPDX-License-Identifier: GPL-2.0
======================================
Avermedia DVB-T on BT878 Release Notes
======================================
February 14th 2006
.. note::
Several other Avermedia devices are supported. For a more
broader and updated content about that, please check:
https://linuxtv.org/wiki/index.php/AVerMedia
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
~~~~~~~~~~~~~~~~~~~~~~
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).
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.