From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anssi Hannula Subject: Re: DSD over HDMI: audio data packetization Date: Thu, 01 Jan 2015 06:37:23 +0200 Message-ID: <54A4CF03.5030709@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> 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 1C405260431 for ; Thu, 1 Jan 2015 05:37:26 +0100 (CET) In-Reply-To: <96A12704CE18D347B625EE2D4A099D195C4443@SHSMSX103.ccr.corp.intel.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: "Yang, Libin" Cc: "; Takashi Iwai" , "Lin, Mengdong" , "alsa-devel@alsa-project.org" , Xuebing Wang , "; Wu Fengguang" List-Id: alsa-devel@alsa-project.org 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). >> >> >>> >>> On 12/31/2014 10:28 PM, Yang, Libin wrote: >>>> Hi Xuebing, >>>> >>>> >>>>> -----Original Message----- >>>>> From: Anssi Hannula [mailto:anssi.hannula@iki.fi] >>>>> Sent: Wednesday, December 31, 2014 9:41 PM >>>>> To: Xuebing Wang >>>>> Cc: alsa-devel@alsa-project.org; Yang, Libin; Lin, Mengdong; ; >>>>> Takashi Iwai; ; Wu Fengguang >>>>> Subject: Re: [alsa-devel] DSD over HDMI: audio data packetization >>>>> >>>>> 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. >>>> As the N/CTS need fs and frequency of TMDS info, the hdmi driver does >>>> not implement this feature. >>>> >>>> We currently are designing an audio link between audio subsystem and >>>> other components, like video or USB. >>>> >>>> Maybe we will add the N/CTS information transmission. So we can >>>> calculate the N/CTS value in audio or gfx driver. >>>> >>>> >>>>>> Thanks. >>>>>> Xuebing Wang >>>>>> >>>>>> >>>>> >>>>> -- >>>>> Anssi Hannula >>> >> >> >> -- >> Anssi Hannula -- Anssi Hannula