After years of discussions, several patch series and two different proposedapproaches, LinuxTV developers finally decided that S2API is the bettertechnical proposal and should be accepted as the way to allow supporting newerDTV standards, starting with DVB-S2. As previously announced at http://linuxtv.org/news.php?entry=2008-09-19.mchehab,a representative group of active developers at LinuxTV community attended thefirst V4L/DVB Summit, that started with the V4L/DVB miniconf at LinuxPlumbers/2008. Several other additional formal (BOF's) and informal meetingshappened there, in the benefit of the improvement of the development ofmultimedia drivers and core. During the miniconf, both Multiproto API (proposed by Manu) and S2API (proposedby Steven), were presented. A technical discussion was made during the DVB BOFsession in order to compare the two proposals and check for theneed/convenience of other core internal changes to draw an evolution timelinefor DVB. The DVB BOF had the presence of the following LinuxTV members: Douglas Schilling Landgraf Hans Verkuil Mauro Carvalho Chehab Michael Krufky Patrick Boettcher Steven Toth Thierry Merle Manjunath Hadlii We had also a presence of an end-user listening to the BOF (Brandon Fouts). During the BOF, the LinuxTV members carefully analyzed the pros and cons forboth proposals. At the end, all people present there agreed that S2API istechnically more reliable in time than Multiproto proposal. So it was decidedthat S2API will be merged upstream. The main arguments in favor of S2API over Multiproto are: - Future proof – the proposal for S2API is more flexible, easily allowing the addition of newer features and new standard support; - Simplicity – S2API patches are very simple, while Multiproto presented a very complex series of changes. Simpler approaches reduces the time for maintaining the source code; - Capability of allowing improvements even on the existing standards, like allowing diversity control that starts to appear on newer DVB devices. Some improvements were proposed by the LinuxTV developers, in order to improvethe S2API, including: - Adding an API command for querying DVB version, to allow an easier detection by userspace applications; - Name the DVB API with S2API as DVB version 5; - Update DVB API documentation to reflect the API changes; - Remove from DVB API the unused API ioctls, to match the API with the existing implementations. The author of S2API got the task of adding those suggestions at the proposedstandard and send a pull request to the subsystem maintainer, together withpatches for his drivers that use the newer API. It was also discussed that some of the internal Multiproto API changes may beneeded in other to support some of the other existing DVB-S2 drivers that weredeveloped considering Multiproto API. Internal changes can be added at any timewithout producing problems in the user API. The group aims to have a unified in-kernel DVB-S2 HVR4000 / TT-3200 tree (thatalso supports all of the derivative CX24116 / STB0899 known products) within 4weeks from the announcement, hopefully in time for kernel 2.6.28. For that, wewould like to ask Manu to port his drivers to the new API. The end goal is to add proper support for all devices that would have beensupported by multiproto and S2API alike available. There are already volunteers working or that have offered to work on Kaffeineand MythTV S2API support. We still need volunteers to work on dvb-apps support. If you feel that you likecontribute, please be our guest! We would like to thank you all that contributed for those discussions andimprovements to happen, Mauro Carvalho ChehabV4L/DVB Maintainer _______________________________________________linux-dvb mailing listlinux-dvb@xxxxxxxxxxxxxxx://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
