By the way, [tom@localhost ~]$ diff <(grep surround41.conf /usr/share/alsa/cards/*.conf | cut -d ":" -f 1) <(grep surround50.conf /usr/share/alsa/cards/*.conf | cut -d ":" -f 1) [tom@localhost ~]$ diff <(grep surround41.conf /usr/share/alsa/cards/*.conf | cut -d ":" -f 1) <(grep surround21.conf /usr/share/alsa/cards/*.conf | cut -d ":" -f 1) 12d11 < /usr/share/alsa/cards/Echo_Echo3G.conf [tom@localhost ~]$ On 16 January 2016 at 22:09, Tom Yan <tom.ty89@xxxxxxxxx> wrote: > What I mean is, should we really by default set up PCMs that provide a > SUBSET of POSSIBLE channel configurations that IS BUILT and RELYS ON > ttable? > > [tom@localhost ~]$ grep ttable /usr/share/alsa/pcm/surround* > /usr/share/alsa/pcm/surround21.conf: ttable.0.FL 1 > /usr/share/alsa/pcm/surround21.conf: ttable.1.FR 1 > /usr/share/alsa/pcm/surround21.conf: ttable.2.LFE 1 > /usr/share/alsa/pcm/surround41.conf: ttable.0.FL 1 > /usr/share/alsa/pcm/surround41.conf: ttable.1.FR 1 > /usr/share/alsa/pcm/surround41.conf: ttable.2.RL 1 > /usr/share/alsa/pcm/surround41.conf: ttable.3.RR 1 > /usr/share/alsa/pcm/surround41.conf: ttable.4.LFE 1 > /usr/share/alsa/pcm/surround50.conf: ttable.0.FL 1 > /usr/share/alsa/pcm/surround50.conf: ttable.1.FR 1 > /usr/share/alsa/pcm/surround50.conf: ttable.2.RL 1 > /usr/share/alsa/pcm/surround50.conf: ttable.3.RR 1 > /usr/share/alsa/pcm/surround50.conf: ttable.4.FC 1 > > If we are really gonna provide them, why only these 3? What about: > surround30 (surround51 - RL - RR - LFE) > surround31 (surround51 - RL - RR) > surround60 (surround71 - FC - LFE, corresponds to surround40) > surround61 (surround71 - FC, corresponds to surround41) > surround70 (surround71 - LFE, corresponds to surround 50) > > surround30 more or less corresponds to surround50 as well, and > surround31 doesn't even have the weirdness of using only either one > channel in the C/Sub port like the others. _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel