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diff --git a/Documentation/media/uapi/dvb/intro.rst b/Documentation/media/uapi/dvb/intro.rst deleted file mode 100644 index f1384616ac4e..000000000000 --- a/Documentation/media/uapi/dvb/intro.rst +++ /dev/null @@ -1,190 +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 - -.. _dvb_introdution: - -************ -Introduction -************ - - -.. _requisites: - -What you need to know -===================== - -The reader of this document is required to have some knowledge in the -area of digital video broadcasting (Digital TV) and should be familiar with -part I of the MPEG2 specification ISO/IEC 13818 (aka ITU-T H.222), i.e -you should know what a program/transport stream (PS/TS) is and what is -meant by a packetized elementary stream (PES) or an I-frame. - -Various Digital TV standards documents are available for download at: - -- European standards (DVB): http://www.dvb.org and/or http://www.etsi.org. -- American standards (ATSC): https://www.atsc.org/standards/ -- Japanese standards (ISDB): http://www.dibeg.org/ - -It is also necessary to know how to access Linux devices and how to -use ioctl calls. This also includes the knowledge of C or C++. - - -.. _history: - -History -======= - -The first API for Digital TV cards we used at Convergence in late 1999 was an -extension of the Video4Linux API which was primarily developed for frame -grabber cards. As such it was not really well suited to be used for Digital -TV cards and their new features like recording MPEG streams and filtering -several section and PES data streams at the same time. - -In early 2000, Convergence was approached by Nokia with a proposal for a new -standard Linux Digital TV API. As a commitment to the development of terminals -based on open standards, Nokia and Convergence made it available to all -Linux developers and published it on https://linuxtv.org in September -2000. With the Linux driver for the Siemens/Hauppauge DVB PCI card, -Convergence provided a first implementation of the Linux Digital TV API. -Convergence was the maintainer of the Linux Digital TV API in the early -days. - -Now, the API is maintained by the LinuxTV community (i.e. you, the reader -of this document). The Linux Digital TV API is constantly reviewed and -improved together with the improvements at the subsystem's core at the -Kernel. - - -.. _overview: - -Overview -======== - - -.. _stb_components: - -.. kernel-figure:: dvbstb.svg - :alt: dvbstb.svg - :align: center - - Components of a Digital TV card/STB - -A Digital TV card or set-top-box (STB) usually consists of the -following main hardware components: - -Frontend consisting of tuner and digital TV demodulator - Here the raw signal reaches the digital TV hardware from a satellite dish or - antenna or directly from cable. The frontend down-converts and - demodulates this signal into an MPEG transport stream (TS). In case - of a satellite frontend, this includes a facility for satellite - equipment control (SEC), which allows control of LNB polarization, - multi feed switches or dish rotors. - -Conditional Access (CA) hardware like CI adapters and smartcard slots - The complete TS is passed through the CA hardware. Programs to which - the user has access (controlled by the smart card) are decoded in - real time and re-inserted into the TS. - - .. note:: - - Not every digital TV hardware provides conditional access hardware. - -Demultiplexer which filters the incoming Digital TV MPEG-TS stream - The demultiplexer splits the TS into its components like audio and - video streams. Besides usually several of such audio and video - streams it also contains data streams with information about the - programs offered in this or other streams of the same provider. - -Audio and video decoder - The main targets of the demultiplexer are audio and video - decoders. After decoding, they pass on the uncompressed audio and - video to the computer screen or to a TV set. - - .. note:: - - Modern hardware usually doesn't have a separate decoder hardware, as - such functionality can be provided by the main CPU, by the graphics - adapter of the system or by a signal processing hardware embedded on - a Systems on a Chip (SoC) integrated circuit. - - It may also not be needed for certain usages (e.g. for data-only - uses like “internet over satellite”). - -:ref:`stb_components` shows a crude schematic of the control and data -flow between those components. - - - -.. _dvb_devices: - -Linux Digital TV Devices -======================== - -The Linux Digital TV API lets you control these hardware components through -currently six Unix-style character devices for video, audio, frontend, -demux, CA and IP-over-DVB networking. The video and audio devices -control the MPEG2 decoder hardware, the frontend device the tuner and -the Digital TV demodulator. The demux device gives you control over the PES -and section filters of the hardware. If the hardware does not support -filtering these filters can be implemented in software. Finally, the CA -device controls all the conditional access capabilities of the hardware. -It can depend on the individual security requirements of the platform, -if and how many of the CA functions are made available to the -application through this device. - -All devices can be found in the ``/dev`` tree under ``/dev/dvb``. The -individual devices are called: - -- ``/dev/dvb/adapterN/audioM``, - -- ``/dev/dvb/adapterN/videoM``, - -- ``/dev/dvb/adapterN/frontendM``, - -- ``/dev/dvb/adapterN/netM``, - -- ``/dev/dvb/adapterN/demuxM``, - -- ``/dev/dvb/adapterN/dvrM``, - -- ``/dev/dvb/adapterN/caM``, - -where ``N`` enumerates the Digital TV cards in a system starting from 0, and -``M`` enumerates the devices of each type within each adapter, starting -from 0, too. We will omit the “``/dev/dvb/adapterN/``\ ” in the further -discussion of these devices. - -More details about the data structures and function calls of all the -devices are described in the following chapters. - - -.. _include_files: - -API include files -================= - -For each of the Digital TV devices a corresponding include file exists. The -Digital TV API include files should be included in application sources with a -partial path like: - - -.. code-block:: c - - #include <linux/dvb/ca.h> - - #include <linux/dvb/dmx.h> - - #include <linux/dvb/frontend.h> - - #include <linux/dvb/net.h> - - -To enable applications to support different API version, an additional -include file ``linux/dvb/version.h`` exists, which defines the constant -``DVB_API_VERSION``. This document describes ``DVB_API_VERSION 5.10``. |