[alsa-devel] MCP7A HDMI passthrough audio Linux/ALSA
tiwai at suse.de
Fri Jul 3 21:27:36 CEST 2009
At Fri, 03 Jul 2009 20:07:09 +0200,
Stéphane BERTHELOT wrote:
> Takashi Iwai a écrit :
> > At Wed, 01 Jul 2009 11:18:15 +0200,
> > Stéphane BERTHELOT wrote:
> >> Takashi Iwai a écrit :
> >> At Tue, 30 Jun 2009 22:51:03 +0200,
> >> Stephane BERTHELOT wrote:
> >> Hm, so apparently your TV doesn't accept non-audio format?
> >> But TV accepted the ac3dec output with -R option, right?
> >> (Make sure this -- otherwise ac3dec might have decoded by itself.)
> >> Basically, -R means to send the encoded an AC3 stream (packed in the
> >> SPDIF format) without setting non-audio bit. Whether non-audio bit is
> >> 1 or 0 is the only difference between -C and -R. So, if -R really
> >> works but not -C, it means that the non-audio bit must be off no
> >> matter what you send. Weird.
> >> I'm sure the TV only accepted -R and not -C (or -P) with the same ac3 file.
> >> But I'm confused since I was quite sure -R would *decode* ac3 to PCM and then
> >> send it in LPCM format.
> > Ah, yes, of course. That's logical, then, that -R works.
> > Hm, then it's an issue of receiver side?
> > Can Windows send the raw AC3 and TV decodes it properly?
> > Takashi
> Thanks you Takashi,
> After investigating on the Windows side (damn!) I finally found that
> with the latest Nvidia official HDMI audio out drivers I was also
> receiving only stereo PCM.
> I'm very angry against Sharp since their TV set outputs AC3 when
> switched on DVB tuner mode, it even offer "digital audio out settings"
> on analog inputs (scart / component /...) but strangely this menu is no
> more available when on an HDMI channel.
> I'm very upset about this, since this TV set is about 6 months old seems
> already deprecated.
> I'm trying to get someone at Sharp service to make an upgrade to get
> digital audio through HDMI to the optical output but I have little hope
> about this. I still can't figure why they do that, is it a digital
> entertainment system or not ? My old frist-gen dvd player does better ...
> Thanks anyway for your help and if you can give me some hints about how
> to convince Sharp to make an upgrade for this I will be welcome. I'm
> pretty sure some other users have had the same kind of problems...
> I now need either to buy an USB audio card with SPDIF out (or in/out) or
> an HDMI switch (some have spdif out) or even a real new HD Audio Amp,
> but this is getting more and more expensive ...
Hm, but you can basically decode on PC and send multi-channel LPCM
over HDMI. Isn't it enough? Or, maybe not, depending on the setup...
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