2016-07-09 23:06:26 +08:00
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.. -*- coding: utf-8; mode: rst -*-
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============
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Introduction
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============
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This document covers the Linux Kernel to Userspace API's used by video
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and radio streaming devices, including video cameras, analog and digital
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TV receiver cards, AM/FM receiver cards, Software Defined Radio (SDR),
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streaming capture and output devices, codec devices and remote controllers.
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A typical media device hardware is shown at :ref:`typical_media_device`.
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.. _typical_media_device:
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docs-rst: auto-generate PDF image files
The PDF files that contain media images were actually generated
offline from their SVG or PNG source files.
Sphinx can handle PNG sources automatially. So, let's just
drop their PDF counterparts.
For SVG, however, Sphinx doesn't produce the right tags to
use the TexLive SVG support. Also, the SVG support is done via
shell execution, with is not nice.
So, while we don't have any support for SVG inside Sphinx
core or as an extension, move the logic to build them to Makefile,
producing the PDF images on runtime.
NOTE: due to the way Sphinx works, the PDF images should be
generated inside the Kernel source tree, as otherwise Sphinx
won't find it, not obeying what's specified by "O=" makefile
parameter.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2016-11-15 00:32:32 +08:00
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.. figure:: typical_media_device.*
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:alt: typical_media_device.pdf / typical_media_device.svg
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2016-07-09 23:06:26 +08:00
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:align: center
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Typical Media Device
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The media infrastructure API was designed to control such devices. It is
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divided into five parts.
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1. The :ref:`first part <v4l2spec>` covers radio, video capture and output,
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cameras, analog TV devices and codecs.
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2. The :ref:`second part <dvbapi>` covers the API used for digital TV and
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Internet reception via one of the several digital tv standards. While it is
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called as DVB API, in fact it covers several different video standards
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including DVB-T/T2, DVB-S/S2, DVB-C, ATSC, ISDB-T, ISDB-S, DTMB, etc. The
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complete list of supported standards can be found at
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2016-08-30 21:21:03 +08:00
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:c:type:`fe_delivery_system`.
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2016-07-09 23:06:26 +08:00
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3. The :ref:`third part <remote_controllers>` covers the Remote Controller API.
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4. The :ref:`fourth part <media_controller>` covers the Media Controller API.
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5. The :ref:`fifth part <cec>` covers the CEC (Consumer Electronics Control) API.
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It should also be noted that a media device may also have audio components, like
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mixers, PCM capture, PCM playback, etc, which are controlled via ALSA API. For
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additional information and for the latest development code, see:
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`https://linuxtv.org <https://linuxtv.org>`__. For discussing improvements,
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reporting troubles, sending new drivers, etc, please mail to: `Linux Media
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Mailing List (LMML) <http://vger.kernel.org/vger-lists.html#linux-media>`__.
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