From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anssi Hannula Subject: Re: DSD over HDMI: audio data packetization Date: Mon, 05 Jan 2015 05:46:28 +0200 Message-ID: <54AA0914.4000109@iki.fi> References: <1420032720.2102.14.camel@gmail.com> <54A3FCD7.2010902@iki.fi> <96A12704CE18D347B625EE2D4A099D195C438E@SHSMSX103.ccr.corp.intel.com> <54A4185E.5010900@gmail.com> <54A41A18.3070005@iki.fi> <96A12704CE18D347B625EE2D4A099D195C4443@SHSMSX103.ccr.corp.intel.com> <54A4CF03.5030709@iki.fi> <1420341058.1981.6.camel@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail3.ippnet.fi (mail3.ippnet.fi [62.197.168.3]) by alsa0.perex.cz (Postfix) with ESMTP id 2E16B2606A5 for ; Mon, 5 Jan 2015 04:46:30 +0100 (CET) In-Reply-To: <1420341058.1981.6.camel@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Xuebing Wang Cc: "Yang, Libin" , "alsa-devel@alsa-project.org" , "; Takashi Iwai" , "Lin, Mengdong" , "; Wu Fengguang" , Andrej Falout List-Id: alsa-devel@alsa-project.org 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@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). > > -- Anssi Hannula