[alsa-devel] [PATCH] ALSA: hda - Set channels count for HBR format

[Takashi Iwai]

At Tue, 7 Aug 2012 07:40:40 +0000,
Wang, Xingchao wrote:
> 
> Hi Takashi,
> 
> When test HBR feature, unless specify the channel number in command line(as below), alsa will be confused about the real channel number.
> 
> aplay -D hdmi:DEV=1,AES0=0x06 -c8 -fs16_le -r192000 testi.dtshd.20120730.ma-71-24.spdif

But is_hbr_format() assumes the channels must be 8.

#define is_hbr_format(format) \
	((format & AC_FMT_TYPE_NON_PCM) && (format & AC_FMT_CHAN_MASK) == 7)

where format value is computed from runtime->channels in
snd_hda_calc_stream_format().

So, passing anything else than 8 is simply invalid as HBR.

> If the HBR stream is gone through pulseaudio(regarded as passthrough), the channels number is faked. 

That is, this is simply a wrong operation.


Takashi

> 
> Thanks
> --xingchao
> 
> > -----Original Message-----
> > From: alsa-devel-bounces at alsa-project.org
> > [mailto:alsa-devel-bounces at alsa-project.org] On Behalf Of Wang Xingchao
> > Sent: Tuesday, August 07, 2012 3:20 PM
> > To: alsa-devel at alsa-project.org; tiwai at suse.de
> > Cc: Wang, Xingchao
> > Subject: [alsa-devel] [PATCH] ALSA: hda - Set channels count for HBR format
> > 
> > If it's HBR format, the channels count should be 8.
> > 
> > Signed-off-by: Wang Xingchao <xingchao.wang at intel.com>
> > ---
> >  sound/pci/hda/patch_hdmi.c |    7 +++++--
> >  1 file changed, 5 insertions(+), 2 deletions(-)
> > 
> > diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c index
> > ad319d4..ae4e67e 100644
> > --- a/sound/pci/hda/patch_hdmi.c
> > +++ b/sound/pci/hda/patch_hdmi.c
> > @@ -1153,8 +1153,11 @@ static int
> > generic_hdmi_playback_pcm_prepare(struct hda_pcm_stream *hinfo,
> >  	struct hdmi_spec *spec = codec->spec;
> >  	int pin_idx = hinfo_to_pin_index(spec, hinfo);
> >  	hda_nid_t pin_nid = spec->pins[pin_idx].pin_nid;
> > -
> > -	hdmi_set_channel_count(codec, cvt_nid, substream->runtime->channels);
> > +
> > +	if (is_hbr_format(format))
> > +		hdmi_set_channel_count(codec, cvt_nid, 8);
> > +	else
> > +		hdmi_set_channel_count(codec, cvt_nid,
> > substream->runtime->channels);
> > 
> >  	hdmi_setup_audio_infoframe(codec, pin_idx, substream);
> > 
> > --
> > 1.7.9.5
> > 
> > _______________________________________________
> > Alsa-devel mailing list
> > Alsa-devel at alsa-project.org
> > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
>