media: dvbproperty.rst: minor editorial changes

Do some minor editorial changes to make this chapter visually
better, and the example a little bit clearer.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This commit is contained in:
Mauro Carvalho Chehab 2017-08-26 06:07:14 -04:00
Родитель 1e1d9c9679
Коммит f3ee363fc1
1 изменённых файлов: 12 добавлений и 13 удалений

Просмотреть файл

@ -8,8 +8,8 @@ DVB Frontend properties
Tuning into a Digital TV physical channel and starting decoding it
requires changing a set of parameters, in order to control the tuner,
the demodulator, the Linear Low-noise Amplifier (LNA) and to set the
antenna subsystem via Satellite Equipment Control (SEC), on satellite
systems. The actual parameters are specific to each particular digital
antenna subsystem via Satellite Equipment Control - SEC (on satellite
systems). The actual parameters are specific to each particular digital
TV standards, and may change as the digital TV specs evolves.
In the past (up to DVB API version 3), the strategy used was to have a
@ -41,25 +41,24 @@ with suppports all digital TV delivery systems.
4. DVB API version 5 is also called *S2API*, as the first
new standard added to it was DVB-S2.
Example: with the properties based approach, in order to set the tuner
to a DVB-C channel at 651 kHz, modulated with 256-QAM, FEC 3/4 and
symbol rate of 5.217 Mbauds, those properties should be sent to
**Example**: in order to set the hardware to tune into a DVB-C channel
at 651 kHz, modulated with 256-QAM, FEC 3/4 and symbol rate of 5.217
Mbauds, those properties should be sent to
:ref:`FE_SET_PROPERTY <FE_GET_PROPERTY>` ioctl:
- :ref:`DTV_DELIVERY_SYSTEM <DTV-DELIVERY-SYSTEM>` =
SYS_DVBC_ANNEX_A
:ref:`DTV_DELIVERY_SYSTEM <DTV-DELIVERY-SYSTEM>` = SYS_DVBC_ANNEX_A
- :ref:`DTV_FREQUENCY <DTV-FREQUENCY>` = 651000000
:ref:`DTV_FREQUENCY <DTV-FREQUENCY>` = 651000000
- :ref:`DTV_MODULATION <DTV-MODULATION>` = QAM_256
:ref:`DTV_MODULATION <DTV-MODULATION>` = QAM_256
- :ref:`DTV_INVERSION <DTV-INVERSION>` = INVERSION_AUTO
:ref:`DTV_INVERSION <DTV-INVERSION>` = INVERSION_AUTO
- :ref:`DTV_SYMBOL_RATE <DTV-SYMBOL-RATE>` = 5217000
:ref:`DTV_SYMBOL_RATE <DTV-SYMBOL-RATE>` = 5217000
- :ref:`DTV_INNER_FEC <DTV-INNER-FEC>` = FEC_3_4
:ref:`DTV_INNER_FEC <DTV-INNER-FEC>` = FEC_3_4
- :ref:`DTV_TUNE <DTV-TUNE>`
:ref:`DTV_TUNE <DTV-TUNE>`
The code that would that would do the above is show in
:ref:`dtv-prop-example`.