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

[Xuebing Wang]

Andrej,

I have a slight doubt about
"KSDATAFORMAT_SUBTYPE_IEC61937_ONE_BIT_AUDIO".

To be concise "IEC61937_ONE_BIT_AUDIO"

I do not have all IEC 61937 specs, I can not find
"IEC61937_ONE_BIT_AUDIO" in the list below.

Part 1: General
Part 2: Burst-info
Part 3: Non-linear PCM bitstreams according to the AC-3 format
Part 4: Non-linear PCM bitstreams according to the MPEG audio format
Part 5: Non-linear PCM bitstreams according to the DTS (Digital Theater
Systems) format(s)
Part 6: Non-linear PCM bitstreams according to the MPEG-2 AAC and MPEG-4
AAC audio formats
Part 7: Non-linear PCM bitstreams according to the ATRAC, ATRAC2/3 and
ATRAC-X formats
Part 8: Non-linear PCM bitstreams according to the Windows Media Audio
(WMA) Professional format
Part 9: Non-linear PCM bitstreams according to the MAT format
Part 10: Non-linear PCM bitstreams according to the MPEG-4 audio
lossless coding (ALS) format - Edition 1.0
Part 11: MPEG-4 AAC and its extensions in LATM/LOAS
Part 12: Non-linear PCM bitstreams according to the DRA formats

Thanks.


On Tue, 2015-01-06 at 17:33 +1300, Andrej Falout wrote:
> Hi Anssi,
> 
> 
> Just wondering how Microsoft documentation fits into this discussion:
> 
> "Representing Formats for IEC 61937 Transmissions"
> 
> http://msdn.microsoft.com/en-us/library/windows/desktop/dd316761%
> 28v=vs.85%29.aspx
> 
> 
> "Microsoft-provided HD Audio class driver supports PCM, AC3, DTS, AAC,
> Dolby Digital Plus, WMA Pro, MAT(MLP) formats. The GUIDs for the
> compressed audio formats that are not supported by the HD audio class
> driver and can be implemented by third-party solutions are listed in
> the following table. "
> 
>      CEA 861 Type
>     SubFormat GUID
>       Description
> 0x08
> 00000008-0cea-0010-8000-00aa00389b71
> 
> KSDATAFORMAT_SUBTYPE_IEC61937_ATRAC
> 
> 
> Adaptive Transform
> Acoustic Coding (ATRAC)
> 0x09
> 00000009-0cea-0010-8000-00aa00389b71
> 
> KSDATAFORMAT_SUBTYPE_IEC61937_ONE_BIT_AUDIO
> 
> 
> One-Bit Audio
> 0x0d
> 0000000d-0cea-0010-8000-00aa00389b71
> 
> KSDATAFORMAT_SUBTYPE_IEC61937_DST
> 
> 
> Direct Stream Transport
> (DST)—lossless
> compressed DSD (Direct
> Stream Digital).
> 
> 
> And knowing that IEC 61937 from HDMI 1.3 also supports above 6.144
> Mbps...
> 
> 
> Is there a doubt that above information is correct, and that DST/DST
> can be carried over 61937 in Microsoft HDA class driver, in this
> example, by "implementing a third-party solution" as described in this
> table?
> 
> 
> Thanks,
> 
> Andrej Falout
> 
> 
> On Mon, Jan 5, 2015 at 4:46 PM, Anssi Hannula <anssi.hannula at iki.fi>
> wrote:
>         04.01.2015, 05:10, Xuebing Wang kirjoitti:
>         > 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.
>         
>         That setting will still not allow you to send One-bit audio or
>         DST
>         packets. The stream will still be encapsulated in either ASP
>         or HBR
>         packets, depending on the value of the EPT field (Encoded
>         Packet Type,
>         7.3.3.13).
>         
>         
>         >
>         > 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 at iki.fi]
>         >>>> Sent: Wednesday, December 31, 2014 11:45 PM
>         >>>> To: Xuebing Wang
>         >>>> Cc: Yang, Libin; alsa-devel at 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).
>         >
>         >
>         
>         
>         
>         --
>         Anssi Hannula
> 
>