Multichannel WAVE support over HDMI out


#1

What WAVE file formats are supported from USB to HDMI? Since the support claims HDMI 1.3 one expects support for most HD audio formats over HDMI (I’m not interested in SPDIF).

For example is 24 bit/96 kHz stereo wave file supported over HDMI (using a HDMI 1.3 receiver) ?

What about 5.1 LPCM (uncompressed)  24 bit/48 kHz wave?

What about iso images of DVD-Audio discs ? Do these play back properly over USB --> HDMI output?


#2

5.1 LPCM is supported.  The Live will also play True-HD (but only in an M2TS container).  It passes through 5.1 DTS (NOT DTS-HD) and 5.1 AC3.


#3

Thanks for that. I’ll give it a try. Do you know the support includes 24bit/96 kHz 5.1 LPCM?

What about  24 bit/192 kHz stereo? (over HDMI)?

I’ll create an iso image of a DVD-Audio disc containing these types of PCM audio and see if these iso images play back and carry the full quality audio over the HDMI.


#4

I tried a 5.1  24bit/96 kHz and also 5.1 24bit/48kHz.

In both cases, over HDMI, I only get Stereo at 48 kHz!

These are simple LPCM wave files and the HDMI receiver definitely supports 5.1 surround.

I don’t have a HDMI TV (only a HDMI 1.3 input receiver) so I have to first select the track on the USB using the composite video output view and then switch the input to the HDMI cable (which I gather the WD Live automatically switches modes to HD out).

I gather the WD Live doesn’t support outputing composite video out at the same time as when the HDMI output is active (which would be useful).


#5

Did you change the Live output from “Stereo” to “Digital” (in Audio/Video settings)?

You need to do this in order to get 5.1 surround passthrough (note that you will need to decode the sound yourself – the Live does not output surround sound).  It will passthrough 5.1 on both HDMI as well as optical (despite what the manual says).


#6

Yes the setting was set to digital.

The source file on the USB was an uncompressed 5.1 wav file (i.e. not AC3). I expected the HDMI to pass through this to my Pioneer receiver but it in fact receives the HDMI stream with just 2 channel at 48 kHz. I know the receiver can receive 5.1 as my BlueRay player outputs 5.1 LPCM via playback of an DVD-Audio disc, for example. 

I’m using a WD TV (not the Live unit) but I believe it is identical to the Live in terms of claimed surround sound support.


#7

If it’s not the Live you should post on the other forum – while it *might* be the same in many respects the firmware is definitely different and only those folks will know the right answer.


#8

OK thanks. I had initially did a search on the forums for this and didn’t notice this posting was for Live.

Anyway, here is a new posting in the correct section:

  Audio issues over HDMI


#9

Have you actually tried a 5.1 LPCM wave file?  I posted a link to a file here to see if anyone can get this to transmit as 5.1 over HDMI:

   5.1 sample file (8 Mb)

The discussion I referenced in the WD Live TV page seems to imply only HDMI 1.2 support.


#10

Yes, I have blu-ray videos with PCM 5.1 that play just fine in surround sound via HDMI 1.3.


#11

then maybe it is the “container” that is the problem.

A LPCM 5.1 uncompressed WAV file as standalone versus the container for the audio via Blue-ray video (with 5.1 audio) ripped and put on USB ??


#12

The container makes a huge difference.

For example, an MKV with a 5.1 AC3 track will output the AC3 track as expected over optical / HDMI (encoded AC3 with 6 channel audio).

The same codecs with an MP4 will not output the full 5.1 surround track, instead downsampling to 2.0 PCM.

Just playing the WAV file, I expect it would also get downsampled to 2.0 PCM.

Try muxing your wav file into an MKV container and see if that makes any difference.  You can easily do so using MKVmerge GUI.  

Hope that helps.  :)


#13

Just tried MKVmerge.GUI on a 5.1 LPCM. Muxes ok, … put it on USB … played back over HDMI and still stereo.


#14

But, once again, you’re not talking about a Live unit.

Really no point in continuing this discussion here.


#15

forgot to mention that muxing creates a .mka file (not mkv) because there is no video/pic content.

So it plays back via USB as a music file. I wonder if that makes a difference over HDMI?


#16

True, this is for Live and I’m talking about the WD TV unit and therefore the content is played ONLY from a USB. I wonder if the support is different when playing back a media file over the network connection of Live?

Specs seem to claim the same HDMI 1.3 support for both Live and HD.


#17

The following approach should clarify my question:

 If someone could post a very short (say 5 to 10  Mb) mkv file with 5.1 lpcm audio which they have tested VIA USB PLAYBACK using the WD Live unit and successfully played back over HDMI 1.3 as multichannel, then I can do exactly the same with the WD TV unit and compare results. That will show definitely if there is a difference.


#18

Regarding mkvmerge GUI … and this refers to testing the .mka file directly with computer and 5.1 surround card (not with WD TV),

I noticed that when a 5.1 LPCM wave 24bit/48 kHz is muxed to .mka, the resultant file plays back properly using:

 Windows Media Player 11 with Matroska FullPack1.1.2 with all the channels properly position (the original wave file was a simple voice recording with each channel identified).

However, the same .mka file has a channel-swapping error when played back with VLC 1.0.5:

The SL and SR channels are incorrectly placed in the FC and LF channels and vice versa (easy to do if you don’t understand the correct order for LPCM channel packing).