| Message ID | 49A6EB4D.70208@gmx.de (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
Hi wk, Let's commit what we currently have. Could you please re-submit the patch again, this time providing a proper description, and your SOB? Cheers, Mauro. On Thu, 26 Feb 2009 20:19:41 +0100 wk <handygewinnspiel@gmx.de> wrote: > Mauro Carvalho Chehab wrote: > >> + > >> +For this API documentation applies an even/odd versioning scheme, stating > >> +unstable or stable versions of that API. Only stable API versions should > >> +be used for developing drivers and applications. > >> > > > > Hmm... I wouldn't add the above. I don't think we should use such versioning scheme for docs. > > > > > > I removed that lines. > > Can you please comment, how the dvb-developers want to deal with in > future with the transition to a updated documentation? > By looking at the differences between headers and doc, it will take at > least one year or even longer to finish. > > Only a comment "currently under review" is probably not sufficient here. > Would it help to add a extra page "Revision History" like its done on > v4l api? If so, please suggest a format for the page. > > > >> > >> +In 2003 Convergence and Toshiba Electronics Europe GmbH started the > >> development > >> +of > >> +\href > >> {http://www.linuxtv.org/downloads/linux-dvb-api-v4/linux-dvb-api-v4-0-3.pdf}{DVB > >> API Version 4} > >> +with public discussion on the linux-dvb mailing list. The goal was a > >> complete > >> +new API, reflecting that PCs and embedded platforms are diverging. On a PC > >> +usually a budget card provides the full raw transport stream and decoding > >> +and processing is main CPU's task. On embedded platforms, however, data is > >> +multiplexed by specialized hardware or firmware for direct application use > >> +which relieves the main CPU from these tasks. Therefore, Linux DVB > >> +API Version 4 was suggested, but unfortunally never completed. > >> > > > > It seems better to say, instead, that "Version 4 was suggested, but it weren't completed nor implemented". > > > > > > I put in here as suggested by Derek: > > "Version 4 was suggested but neither completed, nor implemented" > > > >> +Today, the LinuxTV project is an independend and non-profit community > >> project > >> > > > > s/independend/independent/ > > > > > > Changed. > > >> +by DVB/V4L enthusiasts and developers interested in Digital TV and > >> Analog TV, > >> +sharing the same hg tree. > >> + > >> +However, this document describes only the digital TV part. > >> > > > > I would replace the last paragraph by: > > > > "This document describes the digital TV API. For Analog TV and radio, please consult V4L2 API." > > > > IMO, we should also add such cross-reference at the V4L2 API, and point both to > > linuxtv.org website (so, adding the corresponding \href pointers), for those > > interested on getting the other API to know here both are available. > > > > > > Changed and linked to > http://www.linuxtv.org/downloads/video4linux/API/V4L2_API/v4l2spec/v4l2.pdf > > >> + > >> + > >> +With the further development of newer DTV standards, the existing version > >> +3 of the Linux DVB API was no longer able to support all DTV standards and > >> +newer hardware. Two concurrent approaches to overcome the problem where > >> +proposed, \texttt{Multiproto} and \texttt{S2API}. > >> + > >> +At > >> +\href {http://www.linuxtv.org/news.php?entry=2008-09-19.mchehab}{Linux > >> Plumbers Conference 2008} > >> +the decision was made towards to S2API, basically an extension to > >> +\texttt{DVB API Version 3} called \texttt{DVB API Version 5}. > >> + > >> + > >> +This Linux DVB API documentation will be extended to reflect these > >> additions. > >> > > > > While we don't finish adding the S2API parts, maybe we should say instead: > > > > This document is currently under review to reflect the S2API additions. > > > > > > Changed, but please answer the question above. > Also changed: "dvb card" -> "dvb device" as suggested by Derek. > > updated patch below. > > -- Winfried > > -------------------------------------------------------------------------------------------------------------------------------- > > diff -Nurp v4l-dvb-17554cc18063/dvb-spec/dvbapi/dvbapi.tex > v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/dvbapi.tex > --- v4l-dvb-17554cc18063/dvb-spec/dvbapi/dvbapi.tex 2009-02-23 > 16:26:38.000000000 +0100 > +++ v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/dvbapi.tex 2009-02-26 > 18:40:35.008186330 +0100 > @@ -1,4 +1,4 @@ > -\documentclass[a4paper,10pt]{book} > +\documentclass[a4paper,10pt,oneside]{book} > \usepackage[dvips,colorlinks=true]{hyperref} > > \usepackage{times} > diff -Nurp v4l-dvb-17554cc18063/dvb-spec/dvbapi/intro.tex > v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/intro.tex > --- v4l-dvb-17554cc18063/dvb-spec/dvbapi/intro.tex 2009-02-23 > 16:26:38.000000000 +0100 > +++ v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/intro.tex 2009-02-26 > 20:04:57.245819770 +0100 > @@ -7,49 +7,84 @@ > 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 > -\texttt{http://www.dvb.org/} and/or \texttt{http://www.etsi.org/}. > +i.e you should know what a program stream or 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 > \texttt{http://www.dvb.org/} > +and/or \texttt{http://www.etsi.org/}. > > 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++. > > +The goal of this API is to provide a consistent abstraction layer for > +different digital TV hardware, allowing software applications to be > +developed without hardware details as well as serving as driver > +developers reference. > + > +\newpage > \section{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 > +The first API for DVB devices was used at Convergence in late 1999 > +as an extension of the Video4Linux API which was primarily > +developed for frame grabber devices. > + > + > +As such it was not really well suited to be used for DVB devices 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 > + > +In early 2000, Convergence was 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 \texttt{http://www.linuxtv.org/} 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. > > > +In 2003 Convergence and Toshiba Electronics Europe GmbH started the > development > +of > +\href > {http://www.linuxtv.org/downloads/linux-dvb-api-v4/linux-dvb-api-v4-0-3.pdf}{DVB > API Version 4} > +with public discussion on the linux-dvb mailing list. The goal was a > complete > +new API, reflecting that PCs and embedded platforms are diverging. On a PC > +usually a budget device provides the full raw transport stream and > decoding > +and processing is main CPU's task. On embedded platforms, however, data is > +multiplexed by specialized hardware or firmware for direct application use > +which relieves the main CPU from these tasks. Therefore, Linux DVB > +API Version 4 was suggested but neither completed, nor implemented. > + > + > +Today, the LinuxTV project is an independent and non-profit community > project > +by DVB/V4L enthusiasts and developers interested in Digital TV and > Analog TV, > +sharing the same hg tree. > + > +This document describes the digital TV API. For Analog TV and radio, > please consult > +\href{http://www.linuxtv.org/downloads/video4linux/API/V4L2_API/v4l2spec/v4l2.pdf}{V4L2 > API}. > + > + > +With the further development of newer DTV standards, the existing version > +3 of the Linux DVB API was no longer able to support all DTV standards and > +newer hardware. Two concurrent approaches to overcome the problem where > +proposed, \texttt{Multiproto} and \texttt{S2API}. > + > +At > +\href {http://www.linuxtv.org/news.php?entry=2008-09-19.mchehab}{Linux > Plumbers Conference 2008} > +the decision was made towards to S2API, basically an extension to > +\texttt{DVB API Version 3} called \texttt{DVB API Version 5}. > + > + > +This document is currently under review to reflect the S2API additions. > \newpage > \section{Overview} > > \begin{figure}[htbp] > \begin{center} > \includegraphics{dvbstb.ps} > - \caption{Components of a DVB card/STB} > + \caption{Components of a DVB device/STB} > \label{fig:dvbstb} > \end{center} > \end{figure} > > > -A DVB PCI card or DVB set-top-box (STB) usually consists of the following > +A DVB device or DVB set-top-box (STB) usually consists of the following > main hardware components: > \begin{itemize} > \item Frontend consisting of tuner and DVB demodulator > @@ -85,11 +120,11 @@ a TV set. > Figure \ref{fig:dvbstb} 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. > +On a DVB device not all of these have to be present since some > +functionality can be provided by the main CPU of the PC (e.g. MPEG video > +and audio decoding) or is not needed (e.g. for data-only uses like > +``internet over satellite''). In fact, almost all new DTV devices use > the CPU for MPEG decoding. > +Also not every device or STB provides conditional access hardware. > > \section{Linux DVB Devices} > > @@ -117,12 +152,11 @@ All devices can be found in the \texttt{ > \item \texttt{/dev/dvb/adapterN/demuxM}, > \item \texttt{/dev/dvb/adapterN/caM}, > \end{itemize} > -where N enumerates the DVB PCI cards in a system starting from~0, > +where N enumerates the DVB adapters (pci cards, usb devices, ..) 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 ``\texttt{/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. > +these devices. > > More details about the data structures and function calls of > all the devices are described in the following chapters. > @@ -137,10 +171,13 @@ in application sources with a partial pa > #include <linux/dvb/frontend.h> > \end{verbatim} > > -To enable applications to support different API version, an additional > +To enable applications to support different API versions, an additional > include file \texttt{linux/dvb/version.h} exists, which defines the > constant \texttt{DVB\_API\_VERSION}. This document describes > -\texttt{DVB\_API\_VERSION~3}. > +\texttt{DVB\_API\_VERSION~5}. > + > +Since API version 5 an API command for quering API version also exists, > +allowing user space applications to detect API version during runtime. > > %%% Local Variables: > %%% mode: latex > diff -Nurp v4l-dvb-17554cc18063/dvb-spec/dvbapi/title.tex > v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/title.tex > --- v4l-dvb-17554cc18063/dvb-spec/dvbapi/title.tex 2009-02-23 > 16:26:38.000000000 +0100 > +++ v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/title.tex 2009-02-26 > 18:40:35.008186330 +0100 > @@ -1,16 +1,20 @@ > \pagenumbering{arabic} > \pagestyle{empty} > -\title{\huge\textbf{LINUX DVB API Version 3}} > +\title{\huge\textbf{LINUX DVB API Version 5}} > > \author{ > \includegraphics{cimlogo.psi}\\ > - Copyright 2002, 2003 Convergence GmbH\\\\ > + Copyright:\\ > + 2002, 2003 Convergence GmbH,\\ > + 2008, 2009 www.linuxtv.org\\\\ > Written by Dr. Ralph J.K. Metzler\\ > - \texttt{<rjkm@metzlerbros.de>}\\\\ > + \texttt{<rjkm@metzlerbros.de>}\\ > and Dr. Marcus O.C. Metzler\\ > - \texttt{<mocm@metzlerbros.de>}\\ > + \texttt{<mocm@metzlerbros.de>},\\ > + and The Linux DVB developers\\ > + \texttt{http://www.linuxtv.org}\\\\ > } > -\date{24/07/2003\\V 1.0.0} > +\date{22/02/2009\\Version 1.1.0} > > \maketitle > > > > Cheers, Mauro -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Mauro Carvalho Chehab schrieb: > Hi wk, > > Let's commit what we currently have. Could you please re-submit the patch > again, this time providing a proper description, and your SOB? > > Cheers, > Mauro. > The attached patch provides the following changes to DVB API: - files changed - dvbapi.tex - intro.tex - title.tex - change page format from "twosided book" to "onesided book" to improve readability - fix several latex compiling warnings "Overfull \hbox" due to too long lines. - replace in chapter 1 all occurrencies of "DVB PCI card" with "DVB device" - change First Page: - add "and The Linux DVB developers" to Copyright - add "2008, 2009 www.linuxtv.org" to Copyright - change version and date to "22/02/2009 Version 1.1.0" - change Chapter 1, Section 1.2 History: - remove line that Convergence is maintainer of doc, since in fact linuxtv.org is currently maintaining it. - remove line "Together with the LinuxTV community (i.e. you, the reader of this document), the Linux DVB API will be constantly reviewed and improved." - remove line "With the Linux driver for the Siemens/Hauppauge DVB PCI card Convergence provides a first implementation of the Linux DVB API" - add comment about neither completed, nor implemented DVB API v4 - add comment about being project independent and non-profit - add comment describing digital part only and cross-reference to V4L2 API on linuxtv - add comment about need for API extension for newer DTV standards - add comment about Multiproto and S2API and decision on plumbers conference 2k8 - add comment about version now called v5 - change Chapter 1, Section 1.3 Overview: - change "MPEG picture and sound decoding" to "MPEG video and audio decoding" - change Chapter 1, Section 1.4 Linux DVB Devices - remove reference to no longer used devfs - change Chapter 1, Section 1.5 API include files - fix typo: "to support different API version" -> "to support different API versions" - add "Since API version 5 an API command for quering API version also exists, allowing user space applications to detect API version during runtime" => see also: http://www.linuxtv.org/news.php?entry=2008-09-23.mchehab "Adding an API command for querying DVB version, to allow an easier detection by userspaceapplications" Signed-off-by: Winfried Koehler <handygew...@gmx.de> ---------------------------------------------------------------------------- diff -Nurp v4l-dvb-17554cc18063/dvb-spec/dvbapi/dvbapi.tex v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/dvbapi.tex --- v4l-dvb-17554cc18063/dvb-spec/dvbapi/dvbapi.tex 2009-02-23 16:26:38.000000000 +0100 +++ v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/dvbapi.tex 2009-02-26 18:40:35.008186330 +0100 @@ -1,4 +1,4 @@ -\documentclass[a4paper,10pt]{book} +\documentclass[a4paper,10pt,oneside]{book} \usepackage[dvips,colorlinks=true]{hyperref} \usepackage{times} diff -Nurp v4l-dvb-17554cc18063/dvb-spec/dvbapi/intro.tex v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/intro.tex --- v4l-dvb-17554cc18063/dvb-spec/dvbapi/intro.tex 2009-02-23 16:26:38.000000000 +0100 +++ v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/intro.tex 2009-02-26 20:04:57.245819770 +0100 @@ -7,49 +7,84 @@ 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 -\texttt{http://www.dvb.org/} and/or \texttt{http://www.etsi.org/}. +i.e you should know what a program stream or 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 \texttt{http://www.dvb.org/} +and/or \texttt{http://www.etsi.org/}. 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++. +The goal of this API is to provide a consistent abstraction layer for +different digital TV hardware, allowing software applications to be +developed without hardware details as well as serving as driver +developers reference. + +\newpage \section{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 +The first API for DVB devices was used at Convergence in late 1999 +as an extension of the Video4Linux API which was primarily +developed for frame grabber devices. + + +As such it was not really well suited to be used for DVB devices 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 + +In early 2000, Convergence was 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 \texttt{http://www.linuxtv.org/} 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. +In 2003 Convergence and Toshiba Electronics Europe GmbH started the development +of +\href {http://www.linuxtv.org/downloads/linux-dvb-api-v4/linux-dvb-api-v4-0-3.pdf}{DVB API Version 4} +with public discussion on the linux-dvb mailing list. The goal was a complete +new API, reflecting that PCs and embedded platforms are diverging. On a PC +usually a budget device provides the full raw transport stream and decoding +and processing is main CPU's task. On embedded platforms, however, data is +multiplexed by specialized hardware or firmware for direct application use +which relieves the main CPU from these tasks. Therefore, Linux DVB +API Version 4 was suggested but neither completed, nor implemented. + + +Today, the LinuxTV project is an independent and non-profit community project +by DVB/V4L enthusiasts and developers interested in Digital TV and Analog TV, +sharing the same hg tree. + +This document describes the digital TV API. For Analog TV and radio, please consult +\href{http://www.linuxtv.org/downloads/video4linux/API/V4L2_API/v4l2spec/v4l2.pdf}{V4L2 API}. + + +With the further development of newer DTV standards, the existing version +3 of the Linux DVB API was no longer able to support all DTV standards and +newer hardware. Two concurrent approaches to overcome the problem where +proposed, \texttt{Multiproto} and \texttt{S2API}. + +At +\href {http://www.linuxtv.org/news.php?entry=2008-09-19.mchehab}{Linux Plumbers Conference 2008} +the decision was made towards to S2API, basically an extension to +\texttt{DVB API Version 3} called \texttt{DVB API Version 5}. + + +This document is currently under review to reflect the S2API additions. \newpage \section{Overview} \begin{figure}[htbp] \begin{center} \includegraphics{dvbstb.ps} - \caption{Components of a DVB card/STB} + \caption{Components of a DVB device/STB} \label{fig:dvbstb} \end{center} \end{figure} -A DVB PCI card or DVB set-top-box (STB) usually consists of the following +A DVB device or DVB set-top-box (STB) usually consists of the following main hardware components: \begin{itemize} \item Frontend consisting of tuner and DVB demodulator @@ -85,11 +120,11 @@ a TV set. Figure \ref{fig:dvbstb} 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. +On a DVB device not all of these have to be present since some +functionality can be provided by the main CPU of the PC (e.g. MPEG video +and audio decoding) or is not needed (e.g. for data-only uses like +``internet over satellite''). In fact, almost all new DTV devices use the CPU for MPEG decoding. +Also not every device or STB provides conditional access hardware. \section{Linux DVB Devices} @@ -117,12 +152,11 @@ All devices can be found in the \texttt{ \item \texttt{/dev/dvb/adapterN/demuxM}, \item \texttt{/dev/dvb/adapterN/caM}, \end{itemize} -where N enumerates the DVB PCI cards in a system starting from~0, +where N enumerates the DVB adapters (pci cards, usb devices, ..) 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 ``\texttt{/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. +these devices. More details about the data structures and function calls of all the devices are described in the following chapters. @@ -137,10 +171,13 @@ in application sources with a partial pa #include <linux/dvb/frontend.h> \end{verbatim} -To enable applications to support different API version, an additional +To enable applications to support different API versions, an additional include file \texttt{linux/dvb/version.h} exists, which defines the constant \texttt{DVB\_API\_VERSION}. This document describes -\texttt{DVB\_API\_VERSION~3}. +\texttt{DVB\_API\_VERSION~5}. + +Since API version 5 an API command for quering API version also exists, +allowing user space applications to detect API version during runtime. %%% Local Variables: %%% mode: latex diff -Nurp v4l-dvb-17554cc18063/dvb-spec/dvbapi/title.tex v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/title.tex --- v4l-dvb-17554cc18063/dvb-spec/dvbapi/title.tex 2009-02-23 16:26:38.000000000 +0100 +++ v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/title.tex 2009-02-26 18:40:35.008186330 +0100 @@ -1,16 +1,20 @@ \pagenumbering{arabic} \pagestyle{empty} -\title{\huge\textbf{LINUX DVB API Version 3}} +\title{\huge\textbf{LINUX DVB API Version 5}} \author{ \includegraphics{cimlogo.psi}\\ - Copyright 2002, 2003 Convergence GmbH\\\\ + Copyright:\\ + 2002, 2003 Convergence GmbH,\\ + 2008, 2009 www.linuxtv.org\\\\ Written by Dr. Ralph J.K. Metzler\\ - \texttt{<rjkm@metzlerbros.de>}\\\\ + \texttt{<rjkm@metzlerbros.de>}\\ and Dr. Marcus O.C. Metzler\\ - \texttt{<mocm@metzlerbros.de>}\\ + \texttt{<mocm@metzlerbros.de>},\\ + and The Linux DVB developers\\ + \texttt{http://www.linuxtv.org}\\\\ } -\date{24/07/2003\\V 1.0.0} +\date{22/02/2009\\Version 1.1.0} \maketitle -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff -Nurp v4l-dvb-17554cc18063/dvb-spec/dvbapi/dvbapi.tex v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/dvbapi.tex --- v4l-dvb-17554cc18063/dvb-spec/dvbapi/dvbapi.tex 2009-02-23 16:26:38.000000000 +0100 +++ v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/dvbapi.tex 2009-02-26 18:40:35.008186330 +0100 @@ -1,4 +1,4 @@ -\documentclass[a4paper,10pt]{book} +\documentclass[a4paper,10pt,oneside]{book} \usepackage[dvips,colorlinks=true]{hyperref} \usepackage{times} diff -Nurp v4l-dvb-17554cc18063/dvb-spec/dvbapi/intro.tex v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/intro.tex --- v4l-dvb-17554cc18063/dvb-spec/dvbapi/intro.tex 2009-02-23 16:26:38.000000000 +0100 +++ v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/intro.tex 2009-02-26 20:04:57.245819770 +0100 @@ -7,49 +7,84 @@ 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 -\texttt{http://www.dvb.org/} and/or \texttt{http://www.etsi.org/}. +i.e you should know what a program stream or 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 \texttt{http://www.dvb.org/} +and/or \texttt{http://www.etsi.org/}. 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++. +The goal of this API is to provide a consistent abstraction layer for +different digital TV hardware, allowing software applications to be +developed without hardware details as well as serving as driver +developers reference. + +\newpage \section{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 +The first API for DVB devices was used at Convergence in late 1999 +as an extension of the Video4Linux API which was primarily +developed for frame grabber devices. + + +As such it was not really well suited to be used for DVB devices 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 + +In early 2000, Convergence was 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 \texttt{http://www.linuxtv.org/} 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. +In 2003 Convergence and Toshiba Electronics Europe GmbH started the development +of +\href {http://www.linuxtv.org/downloads/linux-dvb-api-v4/linux-dvb-api-v4-0-3.pdf}{DVB API Version 4} +with public discussion on the linux-dvb mailing list. The goal was a complete +new API, reflecting that PCs and embedded platforms are diverging. On a PC +usually a budget device provides the full raw transport stream and decoding +and processing is main CPU's task. On embedded platforms, however, data is +multiplexed by specialized hardware or firmware for direct application use +which relieves the main CPU from these tasks. Therefore, Linux DVB +API Version 4 was suggested but neither completed, nor implemented. + + +Today, the LinuxTV project is an independent and non-profit community project +by DVB/V4L enthusiasts and developers interested in Digital TV and Analog TV, +sharing the same hg tree. + +This document describes the digital TV API. For Analog TV and radio, please consult +\href{http://www.linuxtv.org/downloads/video4linux/API/V4L2_API/v4l2spec/v4l2.pdf}{V4L2 API}. + + +With the further development of newer DTV standards, the existing version +3 of the Linux DVB API was no longer able to support all DTV standards and +newer hardware. Two concurrent approaches to overcome the problem where +proposed, \texttt{Multiproto} and \texttt{S2API}. + +At +\href {http://www.linuxtv.org/news.php?entry=2008-09-19.mchehab}{Linux Plumbers Conference 2008} +the decision was made towards to S2API, basically an extension to +\texttt{DVB API Version 3} called \texttt{DVB API Version 5}. + + +This document is currently under review to reflect the S2API additions. \newpage \section{Overview} \begin{figure}[htbp] \begin{center} \includegraphics{dvbstb.ps} - \caption{Components of a DVB card/STB} + \caption{Components of a DVB device/STB} \label{fig:dvbstb} \end{center} \end{figure} -A DVB PCI card or DVB set-top-box (STB) usually consists of the following +A DVB device or DVB set-top-box (STB) usually consists of the following main hardware components: \begin{itemize} \item Frontend consisting of tuner and DVB demodulator @@ -85,11 +120,11 @@ a TV set. Figure \ref{fig:dvbstb} 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. +On a DVB device not all of these have to be present since some +functionality can be provided by the main CPU of the PC (e.g. MPEG video +and audio decoding) or is not needed (e.g. for data-only uses like +``internet over satellite''). In fact, almost all new DTV devices use the CPU for MPEG decoding. +Also not every device or STB provides conditional access hardware. \section{Linux DVB Devices} @@ -117,12 +152,11 @@ All devices can be found in the \texttt{ \item \texttt{/dev/dvb/adapterN/demuxM}, \item \texttt{/dev/dvb/adapterN/caM}, \end{itemize} -where N enumerates the DVB PCI cards in a system starting from~0, +where N enumerates the DVB adapters (pci cards, usb devices, ..) 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 ``\texttt{/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. +these devices. More details about the data structures and function calls of all the devices are described in the following chapters. @@ -137,10 +171,13 @@ in application sources with a partial pa #include <linux/dvb/frontend.h> \end{verbatim} -To enable applications to support different API version, an additional +To enable applications to support different API versions, an additional include file \texttt{linux/dvb/version.h} exists, which defines the constant \texttt{DVB\_API\_VERSION}. This document describes -\texttt{DVB\_API\_VERSION~3}. +\texttt{DVB\_API\_VERSION~5}. + +Since API version 5 an API command for quering API version also exists, +allowing user space applications to detect API version during runtime. %%% Local Variables: %%% mode: latex diff -Nurp v4l-dvb-17554cc18063/dvb-spec/dvbapi/title.tex v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/title.tex --- v4l-dvb-17554cc18063/dvb-spec/dvbapi/title.tex 2009-02-23 16:26:38.000000000 +0100 +++ v4l-dvb-17554cc18063_1/dvb-spec/dvbapi/title.tex 2009-02-26 18:40:35.008186330 +0100 @@ -1,16 +1,20 @@ \pagenumbering{arabic} \pagestyle{empty} -\title{\huge\textbf{LINUX DVB API Version 3}} +\title{\huge\textbf{LINUX DVB API Version 5}} \author{ \includegraphics{cimlogo.psi}\\ - Copyright 2002, 2003 Convergence GmbH\\\\ + Copyright:\\ + 2002, 2003 Convergence GmbH,\\ + 2008, 2009 www.linuxtv.org\\\\ Written by Dr. Ralph J.K. Metzler\\ - \texttt{<rjkm@metzlerbros.de>}\\\\ + \texttt{<rjkm@metzlerbros.de>}\\ and Dr. Marcus O.C. Metzler\\ - \texttt{<mocm@metzlerbros.de>}\\ + \texttt{<mocm@metzlerbros.de>},\\ + and The Linux DVB developers\\ + \texttt{http://www.linuxtv.org}\\\\ } -\date{24/07/2003\\V 1.0.0} +\date{22/02/2009\\Version 1.1.0} \maketitle