diff options
Diffstat (limited to 'Documentation/media/uapi/dvb/dvb-frontend-parameters.rst')
| -rw-r--r-- | Documentation/media/uapi/dvb/dvb-frontend-parameters.rst | 126 |
1 files changed, 0 insertions, 126 deletions
diff --git a/Documentation/media/uapi/dvb/dvb-frontend-parameters.rst b/Documentation/media/uapi/dvb/dvb-frontend-parameters.rst deleted file mode 100644 index 67c2a316019f..000000000000 --- a/Documentation/media/uapi/dvb/dvb-frontend-parameters.rst +++ /dev/null @@ -1,126 +0,0 @@ -.. Permission is granted to copy, distribute and/or modify this -.. document under the terms of the GNU Free Documentation License, -.. Version 1.1 or any later version published by the Free Software -.. Foundation, with no Invariant Sections, no Front-Cover Texts -.. and no Back-Cover Texts. A copy of the license is included at -.. Documentation/media/uapi/fdl-appendix.rst. -.. -.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections - -.. c:type:: dvb_frontend_parameters - -******************* -frontend parameters -******************* - -The kind of parameters passed to the frontend device for tuning depend -on the kind of hardware you are using. - -The struct ``dvb_frontend_parameters`` uses a union with specific -per-system parameters. However, as newer delivery systems required more -data, the structure size weren't enough to fit, and just extending its -size would break the existing applications. So, those parameters were -replaced by the usage of -:ref:`FE_GET_PROPERTY/FE_SET_PROPERTY <FE_GET_PROPERTY>` -ioctl's. The new API is flexible enough to add new parameters to -existing delivery systems, and to add newer delivery systems. - -So, newer applications should use -:ref:`FE_GET_PROPERTY/FE_SET_PROPERTY <FE_GET_PROPERTY>` -instead, in order to be able to support the newer System Delivery like -DVB-S2, DVB-T2, DVB-C2, ISDB, etc. - -All kinds of parameters are combined as a union in the -``dvb_frontend_parameters`` structure: - - -.. code-block:: c - - struct dvb_frontend_parameters { - uint32_t frequency; /* (absolute) frequency in Hz for QAM/OFDM */ - /* intermediate frequency in kHz for QPSK */ - fe_spectral_inversion_t inversion; - union { - struct dvb_qpsk_parameters qpsk; - struct dvb_qam_parameters qam; - struct dvb_ofdm_parameters ofdm; - struct dvb_vsb_parameters vsb; - } u; - }; - -In the case of QPSK frontends the ``frequency`` field specifies the -intermediate frequency, i.e. the offset which is effectively added to -the local oscillator frequency (LOF) of the LNB. The intermediate -frequency has to be specified in units of kHz. For QAM and OFDM -frontends the ``frequency`` specifies the absolute frequency and is -given in Hz. - - -.. c:type:: dvb_qpsk_parameters - -QPSK parameters -=============== - -For satellite QPSK frontends you have to use the ``dvb_qpsk_parameters`` -structure: - - -.. code-block:: c - - struct dvb_qpsk_parameters { - uint32_t symbol_rate; /* symbol rate in Symbols per second */ - fe_code_rate_t fec_inner; /* forward error correction (see above) */ - }; - - -.. c:type:: dvb_qam_parameters - -QAM parameters -============== - -for cable QAM frontend you use the ``dvb_qam_parameters`` structure: - - -.. code-block:: c - - struct dvb_qam_parameters { - uint32_t symbol_rate; /* symbol rate in Symbols per second */ - fe_code_rate_t fec_inner; /* forward error correction (see above) */ - fe_modulation_t modulation; /* modulation type (see above) */ - }; - - -.. c:type:: dvb_vsb_parameters - -VSB parameters -============== - -ATSC frontends are supported by the ``dvb_vsb_parameters`` structure: - - -.. code-block:: c - - struct dvb_vsb_parameters { - fe_modulation_t modulation; /* modulation type (see above) */ - }; - - -.. c:type:: dvb_ofdm_parameters - -OFDM parameters -=============== - -DVB-T frontends are supported by the ``dvb_ofdm_parameters`` structure: - - -.. code-block:: c - - struct dvb_ofdm_parameters { - fe_bandwidth_t bandwidth; - fe_code_rate_t code_rate_HP; /* high priority stream code rate */ - fe_code_rate_t code_rate_LP; /* low priority stream code rate */ - fe_modulation_t constellation; /* modulation type (see above) */ - fe_transmit_mode_t transmission_mode; - fe_guard_interval_t guard_interval; - fe_hierarchy_t hierarchy_information; - }; |