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6 channels eac3 detection ?

Posted: 25 Sep 2012 23:55
by plotzzz
Hi, usually when I played a video with a 6 channel track I could choose between stereo and 5.1 output in the audio menu. But until recently I only have the stereo option, both on VLC 1.1.11 and VLC 2.0.3.
(I have checked there are 6 channels with Mediainfo and Audacity)

Any idea ?
Thanks.

Re: 6 channels eac3 detection ?

Posted: 26 Sep 2012 12:27
by Jean-Baptiste Kempf
Can you try VLC 2.0.4 nightly builds, please?

Re: 6 channels eac3 detection ?

Posted: 26 Sep 2012 12:57
by plotzzz
Same Result with vlc-2.0.4-20120926-0203.

Sample of original .ts file (cut with tsmuxer):http://www.sendspace.com/file/5xtr68 (8Mb)
Muxed with Mkvmerge: http://www.sendspace.com/file/2k6h7o (8Mb)
Extracted audio track: http://www.sendspace.com/file/elxjlx (0.4Mb)

None of these would propose 5.1 output.

Re: 6 channels eac3 detection ?

Posted: 14 Dec 2012 13:30
by Theof
+1 , with VLC 2.0.4 Twoflower compiled by jb on villacia.jbkempf.com (Oct 15 2012 22:16:58)

... for all those of us who record french TNT TV ( and might prefer to use VLC rather than something else, MPC-HC, by instance)

Re: 6 channels eac3 detection ?

Posted: 14 Dec 2012 18:33
by Jean-Baptiste Kempf
We know about this issue, and we will fix for 2.1.0

Re: 6 channels eac3 detection ?

Posted: 15 Dec 2012 13:39
by Theof
Thanks !

Just to make things clear, I need a conversion from E-AC3 to AC3 5.1 for S/PDIF output (and probably also for more fancy input formats, like DTS-HD, True HD - although I do not ever seen them so far).

I also have an HDMI output linked to a TV, that seems accept AC3 but not E-AC3. Matter of initialisation protocol likely, however I would be reassured to force the output format...

Re: 6 channels eac3 detection ?

Posted: 15 Dec 2012 16:41
by Jean-Baptiste Kempf
This is a bit different though. Why not output PCM over your HDMI ?

Re: 6 channels eac3 detection ?

Posted: 16 Dec 2012 15:08
by Theof
This is a bit different though. Why not output PCM over your HDMI ?
... because I enjoy listening surround sounds, if the sound source holds several channels.

My digital AV receiver (amplifier) processes stereo PCM, AC3 and DTS encoded sounds through S/PDIF connection - and nothing else (like multichannel PCM, E-AC3, DTS-HD, or HDMI connection). In this configuration, where the PC audio ouput is directly transmitted to the AV receiver, it is the responsability of the PC audio filters to convert the sounds to the compatible encodings, with 5.1 channels in case of a surround sound source.

As I said, I can also use another configuration, where the main screen of the PC is a TV set connected through an HDMI cable. In this case, the audio is output through the HDMI link to the TV set, which transfer it to the amplifier through a S/PDIF connection. This work well for stereo PCM and AC3 streams. Currently, it seems that sending E-AC3 streams through HDMI output nothing, that surprises me because I'm sure the TV is able to convert external (HDMI) E-AC3 streams to AC3 (or extract it as additional audio stream of HDMI ?). It may be a matter of content protection (HDCP), a bug of initialisation protocol or a limitation of additional audio streams - I have no tools nor knowledge to go further. Doesn't work also for simple DTS streams.

You might wish to know my equipment :
  • MPC-HC with ffdshow audio (64 bits)
    Realtek High Definition Audio chip (embedded on motherboard)
    Sapphire Radeon HD6450 graphic card (with ATI HDMI audio)
    Sony KDL-46W5500 TV set
    Surround Sound Receiver NAD T761
    Tuner Enregistreur TNT HD AKIRA (HDMI-connected to the TV set, sending E-AC3 streams correctly converted to AC3 5.1 by the TV)
... it goes without saying that the TV set converts the broadcasted E-AC3 sound to AC3 over S/PDIF connection.

HDMI seems messy, isn't it ?

Re: 6 channels eac3 detection ?

Posted: 18 Dec 2012 02:09
by Jean-Baptiste Kempf
But conversion from E-AC3 to AC-3 will be a decoding anyway, so then, why not just output 6-channels PCM?

Re: 6 channels eac3 detection ?

Posted: 18 Dec 2012 12:51
by Theof
But conversion from E-AC3 to AC-3 will be a decoding anyway, so then, why not just output 6-channels PCM?
Because my AV Receiver has no input for 6-channels PCM
My digital AV receiver (amplifier) processes stereo PCM, AC3 and DTS encoded sounds through S/PDIF connection - and nothing else
It would be interesting to try the transmitting of the 6 channels through the HDMI link, but I have no guaranty of the result. Just for fun, let me quote
When using HDMI input with Super Audio CD or DVD-Audio, DIGITAL AUDIO OUT (OPTICAL) may not output audio signals.
with no more explanations...