From mboxrd@z Thu Jan  1 00:00:00 1970
From: Anssi Hannula <anssi.hannula@iki.fi>
Subject: Re: DSD over HDMI: audio data packetization
Date: Wed, 31 Dec 2014 15:40:39 +0200
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To: Xuebing Wang <xbing6@gmail.com>
Cc: Libin Yang <libin.yang@intel.com>, ";
 Mengdong Lin" <mengdong.lin@intel.com>, "alsa-devel@alsa-project.org" <alsa-devel@alsa-project.org>, "; Wu Fengguang" <wfg@linux.intel.com>, ";
 Takashi Iwai" <tiwai@suse.de>
List-Id: alsa-devel@alsa-project.org

31.12.2014, 15:32, Xuebing Wang kirjoitti:
> Hi Community,

Hi,

> I am trying to implement DSD (one bit audio) over HDMI, for Intel
> integrated graphics. I am referencing HDMI specification 1.3a.
> 
> Regarding audio data packetization, I am referencing spec:
> 5.3.4 Audio Sample Packet
> 7.6 Audio Data Packetization
> 
> Q1) Would you please point to me where is the source code to handle
> L-PCM audio sample packetization (to implement 5.3.4 Audio Sample
> Packet)?

It is done by the hardware.

> Q2) I admit that I did not carefully read HD-Audio specification. Is
> this possible that this L-PCM audio data packetization is done by
> *hardware* (e.g HDMI related widgets/pins)?

Yes.

> Q3) Did we implement "7.2 Audio Sample Clock Capture and Regeneration"?

That is done by hardware. With some HDA codecs the video driver
calculates the N/CTS values "manually", but AFAIK not on Intel HW.

> Thanks.
> Xuebing Wang
> 
> 


-- 
Anssi Hannula