Problem with aac digital audio


#1

Hi… I am using my wd tv live with denon avr 1911 and sony lcd. me having problem with mp4 movies aac digital audio.video is coming up nice and clean, but no audio output… aac audio other formats have no problem. dts and dolby d also works fine… anybody with same problem? plse help… hope wd takes note of it in next firmware…


#2

KUTTU wrote:

Hi… I am using my wd tv live with denon avr 1911 and sony lcd. me having problem with mp4 movies aac digital audio.video is coming up nice and clean, but no audio output… aac audio other formats have no problem. dts and dolby d also works fine… anybody with same problem? plse help… hope wd takes note of it in next firmware…

This is no WD problem.  Reason is that the audio stream is 5.1 AAC.  So your Denon (and every other AVR) can not decode it.  Switch Audio on your unit to Stereo to listen to Audio with 5.1 AAC.  Or if you have the right tools, convert the audio stream into 5.1 AC3 dolby or another format that the Denon undertands.


#3

I have a very simialr setup (WDTV Live, Denon 2310, Sony LCD, etc…) and the exact same problem. AAC 5.1 audio tracks on mp4 files will not play 5.1 audio when the WDTV Live audio setting is set to digital. However, I also have an Astone 110D media player and it plays the video and 5.1 audio on mp4 files perfectly.

So at the very least this issue is a limitation of the WDTV Live and possibly a real problem that needs to be fixed with a future firmware update.


#4

shift8 wrote:

I have a very simialr setup (WDTV Live, Denon 2310, Sony LCD, etc…) and the exact same problem. AAC 5.1 audio tracks on mp4 files will not play 5.1 audio when the WDTV Live audio setting is set to digital. However, I also have an Astone 110D media player and it plays the video and 5.1 audio on mp4 files perfectly.

 

So at the very least this issue is a limitation of the WDTV Live and possibly a real problem that needs to be fixed with a future firmware update.

I do not know anything about the Astone 110D.  But are you sure you are listening to 5.1 AAC through the Denon or a downmixed stereo audio of the 5.1 signal?  I bet you it is downmixing it to stereo.  ****WD should allow users to switch Audio between stereo and digital via Options menu.****  This should resolve it.  But 5.1 AAC via the AVR?  I do not think so unless the Astone is downmixing it to stereo OR transcoding it to some other 5.1 audio signal.


#5

The Astone 110D is definitely playing 5.1 audio from AAC mp4 files through the Denon 2310 AVR. I tried 3 different files and all played 5.1 just fine – voice thru the center speaker, music on the fronts, effects in the rear, plus the subwoofer. The Denon automatically displays “Multi Ch In” when playing these files. A HDMI cable connects the 110D and the AVR.

Here’s some info re the 110D:  http://www.astone.com.au/index.php?productID=25

Anyhow, it bugs me that the WDTV Live cannot do this.


#6

shift8 wrote:

The Astone 110D is definitely playing 5.1 audio from AAC mp4 files through the Denon 2310 AVR. I tried 3 different files and all played 5.1 just fine – voice thru the center speaker, music on the fronts, effects in the rear, plus the subwoofer. The Denon automatically displays “Multi Ch In” when playing these files. A HDMI cable connects the 110D and the AVR.

 

Here’s some info re the 110D:  http://www.astone.com.au/index.php?productID=25

 

Anyhow, it bugs me that the WDTV Live cannot do this.

Interesting?  How is the Astone doing this?  Can you check the Denon AVR docs (manual) to see if it decodes AAC 5.1?  I doubt it, but I am curious to know.  Does anyone know how the AAC 5.1 is working fine with the Astone?

I am curious about this because the AAC stereo is WAY much better than an MP3.  I like the AAC format.  5.1 AAC offers Great sound quality at a compression ratio that beats AC3 (and of course DTS) while keeping an excellent quality.


#7

That player is probably converting them to 5.1ch LPCM data.


#8

shift8 wrote:

Here’s some info re the 110D:  http://www.astone.com.au/index.php?productID=25

 

Anyhow, it bugs me that the WDTV Live cannot do this.

Different media player, different chipset, different capabilities.

The Astone is using a Realtek chip; the WD TV range use Sigma chips.

It would be a VERY nice feature but I’m not sure if the hardware supports it…


#9

Too bad.

So it means that WD TV Live would never play AAC 5.1 Digital through Digital Output (Optical) ?

So it means that we should change into “Stereo” option for audio output?

:cry:


#10

apradz wrote:

Too bad.

So it means that WD TV Live would never play AAC 5.1 Digital through Digital Output (Optical) ?

So it means that we should change into “Stereo” option for audio output?

:cry:

I believe that the WD TV Live has a license for 2.0 AAC but not for 5.1 AAC, so it can’t convert the 5.1 AAC to PCM.  

It is probably trying to bitstream the 5.1 AAC.  Hard to tell for sure because my AVR (Pioneer VSX-1020) won’t decode AAC; I just get silence when playing it.  

The Live also bitstreams 5.1 WMA Pro due to a similar lack of a license for converting to PCM.  Fortunately, my amp DOES decode WMA, so I can hear that.  Before I got this amp, I heard nothing and assumed the Live couldn’t play 5.1 WMA at all!

The problem with wishing for conversion of 5.1 AAC to 5.1 PCM is that, even if WD did do it, many people still wouldn’t hear it; you can’t transfer 5.1 PCM over Optical due to limitations in the S/PDIF spec.

You’d need an HDMI connection to your amp to hear 5.1 PCM.

Stereo output is probably the only solution for now, unless you convert the 5.1 AAC to AC3 with Popcorn MKV Audio Converter (I did that with all my AAC 5.1 files and it doesn’t take long).


#11

“Stereo output is probably the only solution for now, unless you convert the 5.1 AAC to AC3 with Popcorn MKV Audio Converter (I did that with all my AAC 5.1 files and it doesn’t take long).”

This kind of thing can be done with free open-source software (at least, with Linux or OS X). The software in question is mkvextract (part of MKVToolnix) to extract the AAC track  from the container; then FAAD2 to decode the AAC into PCM; then Aften to to encode that to AC3 (and most important, to remap the channels correctly); and finally mkvmerge (MKVToolnix again) to put it back in the container. 

I know this sounds like a lot of work, but it can be scripted and a script exists, and you’ll be surprised at how quickly a 90 minute audio track can be converted.

http://www.videohelp.com/tools/mkvtoolnix

http://www.audiocoding.com/faad2.html

http://aften.sourceforge.net/

And the script, which has no license or even authorship included, so I’m assuming public domain (read through the whole thread):

http://forum.xbmc.org/showthread.php?t=62652


#12

Popcorn MKV Audio Converter is free and does everything you describe in one easy utility. It can also convert DTS or FLAC to AC3.

http://audioconverter.heartware.dk/Tutorial/


#13

“Popcorn MKV Audio Converter is free and does everything you describe in one easy utility. It can also convert DTS or FLAC to AC3.”

It looks like a good application; unfortunately, it’s a Winders application, and won’t help those of us with OS X or Linux.

We have Ffmpeg as well, which sadly fails to map the 6 channel audio properly when converting from AAC to AC3.