On Sun, 22 Feb 2009 18:39:33 +0100 wk <handygewinnspiel@xxxxxx> wrote: > Since dvb-api doc is still outdated by six years... > > > The following patch changes dvbapi.pdf as following: > _______________________________________________________________________________ > > - change from twosided book format to singlesided book format. > * By doing so, the readability is improved and on the right-hand side > is more space on every second page. > > - change copyright notice on first page by adding "2008, 2009 > www.linuxtv.org" > > - add "The Linux DVB Developers http://www.linuxtv.org"; to 'written by' > > - increase API Version number to 5 > > - change Version Number and date > -- 24/07/2003 V 1.0.0 > ++ 22/02/2009 Version 1.1.0 <- unstable version now, every time api > is changed version should be increased now > > - chapter 1 - What you need to know > * added goal: "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" > * added comment: odd api version numbers = unstable -> not to be used > for driver/app development > > - chapter 1 - history > * add History of DVB API v 4 > * add comment LinuxTV project beeing an independend and non-profit > community > * add reasons for DVB API v 5 and decision on Plumbers Conference 2008 > towards S2API > > - chapter 1 - Overview > * changed "DVB PCI card" wherever found, since API doesnt depend on > PCI bus > * changed "MPEG picture and sound decoding" to "MPEG video and audio > decoding", > since mpeg picture is misleading > > - fix some typos inside chapter 1 > - fix "Overfull \hbox" warnings from chapter 1 (*only* chapter 1 for now..) > > Signed-off-by: Winfried Koehler <handygewinnspiel@xxxxxx> > _______________________________________________________________________________ > > Please response, comment, improve, review, apply. Do not ignore silently, > having a new API doc should be hard requirement for next kernel versions. It follows a few comments. > > diff -Nrup v4l-dvb-359d95e1d541/dvb-spec/dvbapi/dvbapi.tex > v4l-dvb-a7ea3df69673/dvb-spec/dvbapi/dvbapi.tex > --- v4l-dvb-359d95e1d541/dvb-spec/dvbapi/dvbapi.tex 2009-02-22 > 17:07:48.123742503 +0100 > +++ v4l-dvb-a7ea3df69673/dvb-spec/dvbapi/dvbapi.tex 2009-02-21 > 17:33:29.557033066 +0100 > @@ -1,4 +1,4 @@ > -\documentclass[a4paper,10pt]{book} > +\documentclass[a4paper,10pt,oneside]{book} > \usepackage[dvips,colorlinks=true]{hyperref} > > \usepackage{times} > diff -Nrup v4l-dvb-359d95e1d541/dvb-spec/dvbapi/intro.tex > v4l-dvb-a7ea3df69673/dvb-spec/dvbapi/intro.tex > --- v4l-dvb-359d95e1d541/dvb-spec/dvbapi/intro.tex 2009-02-18 > 13:49:37.000000000 +0100 > +++ v4l-dvb-a7ea3df69673/dvb-spec/dvbapi/intro.tex 2009-02-22 > 16:03:12.610230293 +0100 > @@ -7,36 +7,73 @@ > 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. > + > +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. > +\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 > +The first API for DVB cards was used at Convergence in late 1999 > +as 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 > + > +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 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". > + > + > +Today, the LinuxTV project is an independend and non-profit community > project s/independend/independent/ > +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. > + > + > +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. > \newpage > \section{Overview} > > @@ -49,7 +86,7 @@ provides a first implementation of the L > \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 > @@ -85,10 +122,10 @@ 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''). > +On a DVB 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 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 card or STB provides conditional access hardware. > > \section{Linux DVB Devices} > @@ -117,12 +154,11 @@ 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 +173,13 @@ 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: > > > Cheers, Mauro -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
