From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from web38804.mail.mud.yahoo.com ([209.191.125.95]) by www.linuxtv.org with smtp (Exim 4.63) (envelope-from ) id 1Kdn4t-00019L-Js for linux-dvb@linuxtv.org; Thu, 11 Sep 2008 16:23:25 +0200 Date: Thu, 11 Sep 2008 07:22:48 -0700 (PDT) From: Uri Shkolnik To: linux-dvb@linuxtv.org, Christophe Thommeret In-Reply-To: <200809111535.19315.hftom@free.fr> MIME-Version: 1.0 Message-ID: <740897.54819.qm@web38804.mail.mud.yahoo.com> Subject: Re: [linux-dvb] Multiple frontends on a single adapter support Reply-To: urishk@yahoo.com List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: linux-dvb-bounces@linuxtv.org Errors-To: linux-dvb-bounces+mchehab=infradead.org@linuxtv.org List-ID: --- On Thu, 9/11/08, Christophe Thommeret wrote: > From: Christophe Thommeret > Subject: [linux-dvb] Multiple frontends on a single adapter support > To: linux-dvb@linuxtv.org > Date: Thursday, September 11, 2008, 4:35 PM > Hi all, > = > ( Please don't mix this thread with the "DVB-S2 / > Multiproto and future = > modulation support" thread. ) > = > Summary: > = > Some devices provide several tuners, even of different > types. > So called "Dual" or "Twin" tuners can > be used at the same time. > Some others (like HVR4000) can't be used at the same > time. > = > My initial question was: How could an application know that > 2 (or more) tuners = > are exclusive (when one is used the other(s) is(are) not > free.) > = > I suggested the following: > Since actually all multiple tuners drivers expose several > fontend0 in separate = > adapters, maybe a solution for exclusive tuners could be to > have : > - adapter0/frontend0 -> S/S2 tuner > - adapter0/frontend1 -> T tuner > so, an application could assume that these tuners are > exclusive. > = > Janne Grunau acked the idea and said that an experimental > driver for HVR4000 = > is already doing this. > = > This was confirmed by Steven Toth: > "Correct, frontend1, demux1, dvr1 etc. All on the same > adapter. The = > driver and multi-frontend patches manage exclusive access > to the single = > internal resource." > = > Andreas Oberritter said: > "This way is used on dual and quad tuner Dreambox > models." (non exclusive = > tuners). > "How about dropping demux1 and dvr1 for this adapter > (exclusive tuners), since = > they don't create any benefit? IMHO the number of demux > devices should always = > equal the number of simultaneously usable transport stream > inputs." > = > Uri Shkolnik said: > "Some of the hardware devices which using our chipset > have two tuners per = > instance, and should expose 1-2 tuners with 0-2 demux (TS), > since not all DTV = > standard are TS based, and when they are (TS based), it > depends when you are = > using two given tuners together (diversity =A0mode, same > content) or each one = > is used separately (different frequency and modulation, > different content, = > etc.)." > = > = > = > So, here are my questions: > = > @Steven Toth: > What do you think of Andreas' suggestion? Do you think > it could be done that = > way for HVR4000 (and 3000?) ? > = > @Uri Shkolnik: > Do you mean that non-TS based standards don't make use > of multiplexing at all? > = Take CMMB for example, some standard's options are that the content is RTP = based, so the content path is via the IP stack, another CMMB mode is Mpeg4 = frames. = DAB (and DAB-IP) are other good examples. By demux.h ( http://www.linuxtv.org/cgi-bin/viewcvs.cgi/dvb-kernel-v4/linux= /include/linux/dvb/demux.h?view=3Dmarkup ) demux is "de-multiplexing of a t= ransport stream (TS)", since those standards are not TS based, they can not= be "demuxed". If its an IP-based DTV standard, you just create a pipe from= the device into the IP stack and pass all content. If it a frames based st= andards, you need other mechanism, anyway, you don't need a demux = > = > -- = > Christophe Thommeret > = > = > _______________________________________________ > linux-dvb mailing list > linux-dvb@linuxtv.org > http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb = _______________________________________________ linux-dvb mailing list linux-dvb@linuxtv.org http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb