Anssi, Libin,
Thanks for your help.
After a little bit of research, I do think it is possible to stream DSD over HDMI (the mechanism is as Anssi mentioned, similar way as HBR).
Please see HDA spec: 3.7.1 Stream Format Structure (If the TYPE is set to Non-PCM, the controller just pushes data over the link and is not concerned with formatting. The base rate, data type, and number of Words (MULT) to send each valid frame are specified to control the rate at which the non-PCM data is sent.)
7.3.3.8 Converter Format
What do you think? In order to implement this similiar mechanism (similar to HBR), I still have some detailed questions that I will write in another email. Thanks.
On Thu, 2015-01-01 at 06:37 +0200, Anssi Hannula wrote:
01.01.2015, 04:07, Yang, Libin kirjoitti:
Hi,
-----Original Message----- From: Anssi Hannula [mailto:anssi.hannula@iki.fi] Sent: Wednesday, December 31, 2014 11:45 PM To: Xuebing Wang Cc: Yang, Libin; alsa-devel@alsa-project.org; Lin, Mengdong; ; Takashi Iwai; ; Wu Fengguang Subject: Re: [alsa-devel] DSD over HDMI: audio data packetization
31.12.2014, 17:38, Xuebing Wang kirjoitti:
Anssi, Libin,
Thank you very much for your help.
If L-PCM audio data packetization is done by hardware, is it possible to implement DSD over HDMI on Intel integrated graphics? Thanks again.
I don't think so, unless:
(a) It is possible to somehow encapsulate the stream in Audio Sample Packets and be accepted by the receiver (like e.g. AC3, DTS). I'm not aware of such a way.
or: (b) There is some undocumented feature in the Intel HDMI codecs allowing the driver to switch to DSD or driver-constructed packets (instead of ASP) in similar way as there is a way to switch to HBR packets.
Yes, I agree. And I'm not sure whether HDMI spec supports DSD.
It does, via the "One Bit Audio" and "DST" formats (spec 5.3.9, 5.3.10 in 1.3a/1.4a).