From 871480933a1c28f8a9fed4c4d34d06c439a7a422 Mon Sep 17 00:00:00 2001
From: Srikant Patnaik
Date: Sun, 11 Jan 2015 12:28:04 +0530
Subject: Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
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+Introduction
+
+
+What you need to know
+
+The reader of this document is required to have some knowledge in
+the area of digital video broadcasting (DVB) 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 DVB standards documents are available from
+ and/or
+.
+
+It is also necessary to know how to access unix/linux devices and
+how to use ioctl calls. This also includes the knowledge of C or C++.
+
+
+
+
+History
+
+The first API for DVB 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 DVB cards and their new features like recording MPEG streams
+and filtering several section and PES data streams at the same time.
+
+
+In early 2000, we were approached by Nokia with a proposal for a
+new standard Linux DVB 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
+ in September 2000.
+Convergence is the maintainer of the Linux DVB API. Together with the
+LinuxTV community (i.e. you, the reader of this document), the Linux DVB
+API will be constantly reviewed and improved. With the Linux driver for
+the Siemens/Hauppauge DVB PCI card Convergence provides a first
+implementation of the Linux DVB API.
+
+
+
+Overview
+
+
+Components of a DVB card/STB
+
+
+
+
+
+
+
+
+
+
+A DVB PCI card or DVB set-top-box (STB) usually consists of the
+following main hardware components:
+
+
+
+
+Frontend consisting of tuner and DVB demodulator
+
+Here the raw signal reaches the DVB 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.
+
+
+
+ Demultiplexer which filters the incoming DVB 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.
+
+
+
+
+MPEG2 audio and video decoder
+
+The main targets of the demultiplexer are the MPEG2 audio and
+video decoders. After decoding they pass on the uncompressed audio and
+video to the computer screen or (through a PAL/NTSC encoder) to a TV
+set.
+
+
+
+
+
+ shows a crude schematic of the control and data flow
+between those components.
+
+On a DVB PCI card not all of these have to be present since some
+functionality can be provided by the main CPU of the PC (e.g. MPEG
+picture and sound decoding) or is not needed (e.g. for data-only uses
+like “internet over satellite”). Also not every card or STB
+provides conditional access hardware.
+
+
+
+
+Linux DVB Devices
+
+The Linux DVB 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 DVB 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 DVB PCI 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 dicussion
+of these devices. The naming scheme for the devices is the same wheter
+devfs is used or not.
+
+More details about the data structures and function calls of all
+the devices are described in the following chapters.
+
+
+
+
+API include files
+
+For each of the DVB devices a corresponding include file exists.
+The DVB API include files should be included in application sources with
+a partial path like:
+
+
+ #include <linux/dvb/audio.h>
+
+
+ #include <linux/dvb/ca.h>
+
+
+ #include <linux/dvb/dmx.h>
+
+
+ #include <linux/dvb/frontend.h>
+
+
+ #include <linux/dvb/net.h>
+
+
+ #include <linux/dvb/osd.h>
+
+
+ #include <linux/dvb/video.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 5.4.
+
+
+
+
--
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