On Tue, Jan 24, 2012 at 5:39 PM, Alexander Motin <mav_at_freebsd.org> wrote: > On 25.01.2012 01:32, Mickaël Maillot wrote: >> >> 2012/1/24 Alexander Motin <mav_at_freebsd.org <mailto:mav_at_freebsd.org>> >> Number of channels should be set to 8 by application when it >> expects bit >> rate above 6Mbps. Sample rate, as I've described, just give more >> fine >> control. Increasing sample rate does not automatically increase >> channels. They are orthogonal: >> Rate 48 96 192 48 96 192 >> Channels 2 2 2 8 8 8 >> ------------------------------__---------------------------- >> >> Mbps 1.5 3 6 12 24 49 >> >> >> ok so set 8 channels is just to allow more bandwidth. >> i just looked at alsa hdmi code (because i never find oss code that can >> play hd audio), >> they set 192k and 8 channels for every DTS HD / TRUEHD / E-AC3 file, so >> i was thinking to do the same. > > > HBR mode (8 channels) is not always supported by hardware and not defined by > HDMI 1.1 spec (not sure about 1.2). So I think if possible, it would be nice > to differentiate them. > >> What I've forgot is to allow 8ch format. :) Add the patch below. >> Hope >> sound(4) has no other limitations for it. >> >> Hmm. Looks like there is some limitation. You may grep kernel for >> AFMT_PASSTHROUGH and find two "XXX force ..." comments and code, >> including forcing 2 channels for AC3. Luckily for not part for >> frequency is commented out. Further we may try to comment or modify >> part about number of channels. >> >> spotted and commented >> >> --- hdaa.c (revision 230511) >> +++ hdaa.c (working copy) >> _at__at_ -4979,6 +4979,8 _at__at_ >> } >> if (HDA_PARAM_SUPP_STREAM___FORMATS_AC3(fmtcap)) { >> >> ch->fmtlist[i++] = SND_FORMAT(AFMT_AC3, 2, 0); >> + if (channels >= 8) >> + ch->fmtlist[i++] = SND_FORMAT(AFMT_AC3, 8, 0); >> } >> ch->fmtlist[i] = 0; >> i = 0; >> >> But in your case I think it should be enough to just increase >> sample >> rate to 96 or 192KHz. >> >> so if my problem persist after settings 8 channels, i'll blame xbmc oss >> part. > > > Can't wait to know result. :) > > -- > Alexander Motin > > _______________________________________________ > freebsd-multimedia_at_freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-multimedia > To unsubscribe, send any mail to > "freebsd-multimedia-unsubscribe_at_freebsd.org" Oops, device_delete_children is not available on 8_RELENG. -- Zhihao Yuan, nickname lichray The best way to predict the future is to invent it. ___________________________________________________ 4BSD -- http://4bsd.biz/Received on Wed Jan 25 2012 - 03:47:52 UTC
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