[mythtv-users] Dolby Digital Signal indicator on Receiver(SOLVED)

dexter sl dexterslmul at hotmail.com
Sat Mar 29 18:29:28 UTC 2008


Update - Problem Solved

While checking out the "Configuring Digital Sound" page I looked at the section called "Bit Perfect Audio" and used the following settings in conjunction with Bas' recommendation:
On Mythfrontend Utilities/Setup->Setup-General  
go to the Audio page and set your audio device as

 Audio output device        = ALSA:cards.pcm.iec958
 Passthrough outputdevice   = Alsa:iec958:{AES0 0x02}
 Enable AC3 to SPDIF passthrough   check
 Enable DTS to SPDIF passthrough   checkNow everything works fine.  I mentioned earlier that I thought I would have to convert the sampling rate for the recordings and music but then realized after  reading "ALSA by default will upsample all of your audio to 48Khz" on the website, that the sample rate conversion was not my problem.  Setting the above parameters was the solution.

I went ahead and added the iecset command to rc.local to make sure it gets set whenever the system starts up:

/etc/rc.local


iecset audio 0

Thanks to everyone for there input on this.  Especially Bas, since I do not believe any of the above settings from the "Configuring Digital Sound" page would have worked without the knowledge of the "iecset" parameter 

Thanks again,
-dex
From: dexterslmul at hotmail.com
To: mythtv-users at mythtv.org
Date: Fri, 28 Mar 2008 12:24:05 -0400
Subject: Re: [mythtv-users] Dolby Digital Signal indicator on Receiver








Thanks for the info guys.  I guess I really was not receiving DD 5.1 surround like I thought.  I followed Bas' suggestion, and sure enough the DD signal lit up on my receiver when playing Movies via mythvideo.  Below are the settings that worked:

Default audio device: /dev/dsp

Passthrough device: ALSA:iec958{AES0 0x02}

Checked: "AC3 to SPDIF passthrough"

Exited mythfrontend and ran: iecset audio 0

Restarted mythfrontend and successfully played movies with true DD 5.1 output.

Ok, now DD 5.1 is working for my movies, but I get no sound once "AC3 to SPDIF passthrough" is checked and/or "iecset audio 0" is set.  Undoing these settings gives me sound back for my recordings and music but obviously no DD.  So basically I am now in a similar situation where I have to manually change it back to get stereo sound for my music and recordings just like Bas.

I am going to follow the "Configuring Digital Sound" procedures in the mythtv wiki "http://www.mythtv.org/wiki/index.php/Configuring_Digital_Sound."  They apparently have a section called:"5.2 But I want to have all my sound go to the S/PDIF connector, how do I do that?" Hopefully it will resolve this last issue by converting all sound to a 48KHz sampling rate.  This way with all my new settings in place above, I should be able to get sound for all sources successfully plus DD whenever it is detected.  Let me know if my logic is flawed here or if someone has any other suggestions.  I will report back on how this works out.

-dex

> Date: Wed, 26 Mar 2008 16:01:25 +0100
> From: bas.wielens at arcor.de
> To: mythtv-users at mythtv.org
> Subject: Re: [mythtv-users] Dolby Digital Signal indicator on Receiver
> 
> I had (and still have) similar problem, I solved it by typing 
> 
> iecset audio 0
> 
> inside a shell.
> 
> This way it will set the non-audio bit in the header of the SPDIF package. The only disadvantage is that you should do this manually inside a shell and that you have to set it back when listing to stereo music. Let me know if this works for you. Normally you could specify this inside the frontend settings for video in the pass-through output device like:
> 
> ALSA:iec958{AES0 0x06} or ALSA:iec958{AES0 0x02}
> 
> In my case however this does not work (Latest alsa driver for the nForce4 snd_intel…), so I am stuck to the manual workaround, unfortunately. 
> 
> Let me know if setting of the non-audio bit worked for you and if the pass-through devices specified above are working. 
> 
> 
> 
> ----- Original Nachricht ----
> Von:     Darryl Hirschler <Darryl.Hirschler at practiceworks.com>
> An:      Discussion about mythtv <mythtv-users at mythtv.org>
> Datum:   26.03.2008 15:19
> Betreff: Re: [mythtv-users] Dolby Digital Signal indicator on Receiver
> 
> > Just a guess, but is it possible Myth is down-grading the audio to
> > 2-channel Dolby Pro Logic?  That's a sort of pseudo-surround and might
> > be enough to fool you into thinking that you are getting true surround.
> > Check and make sure each of your back speakers are independent of each
> > other and not playing the same sound.
> > 
> >  
> > 
> >  
> > 
> > Darryl
> > 
> >  
> > 
> > ________________________________
> > 
> > From: mythtv-users-bounces at mythtv.org
> > [mailto:mythtv-users-bounces at mythtv.org] On Behalf Of dexter sl
> > Sent: Wednesday, March 26, 2008 10:05 AM
> > To: mythtv-users at mythtv.org
> > Subject: [mythtv-users] Dolby Digital Signal indicator on Receiver
> > 
> >  
> > 
> > Hi everyone, I have a Denon AVR-2700.  Right now my mythfrontend is
> > hooked up via the optical connection from my Turtle Beach Riviera.  I
> > get sound for my recordings, mythvideo, and mythdvd all through the
> > SPDIF including 5.1 apparently, and I get sound from my receiver just
> > fine.  
> > 
> > Whats interesing is now that I am getting 5.1 to my surround sound
> > system I see the Dolby "Pro Logic" indicator light up, I see the
> > "DIGITAL" indicator light up and the "LOCK" green indicator light up,
> > but I don't actually see the "Dolby Digital" red indicator light up.
> > 
> > Now when the THX intro plays on movies from my mythfrontend, I here the
> > sound moving through the speakers like I normally would when playing
> > from a regular DVD player outputting Dolby Digital 5.1, with the
> > exception that the "Dolby Digital" red indicator lights up when the 5.1
> > comes from a regular DVD player, but not when it comes from the
> > mythfrontend.
> > 
> > So, Dolby Digital appears to by working fine from my mythfrontend, I am
> > just curious if anyone can explain why my "Dolby Digital" indicator
> > might not light up even though I am hearing the 5.1 audio through my
> > surround sound system.
> > 
> >  
> > 
> > ________________________________
> > 
> > Windows Live Hotmail is giving away Zunes. Enter for your chance to win.
> > <http://www.windowslive-hotmail.com/ZuneADay/?locale=en-US&ocid=TXT_TAGL
> > M_Mobile_Zune_V1> 
> > 
> > 
> > 
> > --------------------------------
> > 
> > _______________________________________________
> > mythtv-users mailing list
> > mythtv-users at mythtv.org
> > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
> > 
> 
> Jetzt komfortabel bei Arcor-Digital TV einsteigen: Mehr Happy Ends, mehr Herzschmerz, mehr Fernsehen! Erleben Sie 50 digitale TV Programme und optional 60 Pay TV Sender, einen elektronischen Programmführer mit Movie Star Bewertungen von TV Movie. Außerdem, aktuelle Filmhits und prickelnde Erotik in der Arcor-Videothek. Infos unter www.arcor.de/tv
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users

Watch “Cause Effect,” a show about real people making a real difference. Learn more.

_________________________________________________________________
Watch “Cause Effect,” a show about real people making a real difference.  Learn more.
http://im.live.com/Messenger/IM/MTV/?source=text_watchcause
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mythtv.org/pipermail/mythtv-users/attachments/20080329/20da34a8/attachment.htm 


More information about the mythtv-users mailing list