[alsa-devel] MCP7A HDMI passthrough audio Linux/ALSA

Takashi Iwai tiwai at suse.de
Wed Jul 1 12:01:16 CEST 2009

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?


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