[alsa-devel] DSD over HDMI: audio data packetization

[Anssi Hannula]

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