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View Full Version : Downmix 5.1 EX to normal 5.1 ???????


tincek01
26th November 2002, 09:49
I want to do a Divx5 of the Lord of the Rings, which has a 5.1 EX soundtrack. Unfortunately , my Denon receiver doesn't support 5.1 EX mode ( but it does 5.1 ). So , now i want to downmix the audio to normal 5.1 , without the EX flag ( which was set by NewLine by mistake ). What do i need ????

tincek

ps : I have all the usual ripping tools...

jimbokoz
26th November 2002, 13:09
Why would you want to do that?

Dolby Digital EX is a "6.1" channel system - but the centre rear channel is matrixed into the surround left and right channels in similar fashion to the way Dolby Pro-Logic matrixes a surround channel into a stereo soundtrack... as a result, the soundtrack is truly only 5.1 discrete channels.

If your amp isn't EX compatible, it simply means it doesn't have the extra decoding algorithms to process a centre rear channel out of the two surround channels present.

At the fundamental level, EX will play back on a non-EX amp normally. It contains only 5.1 discrete channels.

Unless of course you are confused by the soundtracks available - as I recall the LOTR also has a 6.1 DTS ES soundtrack. Not many amplifiers do support that at the low end. If so, there are no tools I know of that can decode DTS to a file... I'd suggest you stick with the AC3 soundtrack...

tincek01
26th November 2002, 17:24
here's the thing >>>
NewLine has put out a 2 disc LOTR with Dolby EX 5.1 soundtrack, which
i haven't been able to play on my Denon receiver. After searching on the internet i found out, that NewLine has set the EX flag in the Dolby EX track, which causes quite a few receivers to go numb ( at least in the European edition ) if you don-t have a proper EX receiver. They have done that, although the Dolby Laboratories have adviced to NOT SET the EX flag
( you can set it up manually ) as it was done in the StarWars Episode 1 ( which plays perfect and is also EX ). So, that's why i am asking...

Tincek

rjamorim
26th November 2002, 20:42
Then maybe you should contact NewLine, demanding a replacement?

I think that's the best thing to do.

The Belgain
26th November 2002, 23:25
Hello rjamorin, I didn't know you posted in doom9 as well as HA. Fancy seeing you here. Are you here to try'n push AAC through on the sly :) ?

rjamorim
27th November 2002, 01:45
Originally posted by The Belgain
Hello rjamorin, I didn't know you posted in doom9 as well as HA. Fancy seeing you here. Are you here to try'n push AAC through on the sly :) ?

No, I'm here because I left HA. :)

The Belgain
27th November 2002, 01:57
Oh yeah, I forgot about that, sorry.

How does it feel being a 'noob'?

rjamorim
27th November 2002, 02:41
Hehe. Well, I don't really feel like a noob, because lots of people recognize me. I'm a "famous noob" :D

Besides, I'm not a noob anymore at audiocoding.com forum. (Although I am at my other "new homes": Doom9, Everwicked and CD-rw.org) :)


-----
OK, enough off-topic. Let's go back to Dolby downmixing discussion.

tincek01
27th November 2002, 09:09
Yeah , please help me with that....

tincek

wakebrder
27th November 2002, 10:30
I wonder if there is a way to set these "EX/ES" flags in scenarist? I've had some DTS-ES titles where I lost the ES flag somewhere in the encoding/reauthoring process. The resulting soundtrack was reduced to 5.1 DTS.:( Seems I'm trying to accomplish the same thing, only in reverse since my amp does support EX/ES. :D Maybe some of the scenarist pros could inform us if there is such an option? I assume you're authoring DVD's here.

tincek01
24th January 2003, 15:12
:confused:

Just want to know, if it is possible to downsample the 5.1 EX track to
normal 5.1 ??? my receiver supports 5.1 & dts , but no 5.1 EX...
What tools do i need ???

Thanx for the answers !

tincek

S_O
2nd February 2003, 20:16
Finally I can post! Five endless days...

I read about the problem and wrote a program which will set the EX-Flag, if it exists, to "Not Indicated". Unfortunately I donīt have any AC3 with this flag, so I couldnīt test it, it will most likely not work yet. Please post a little bit of the ac3 (100KB is enough), that I can check my program and my receiver if it is also affected with this incompatible-problem. The flag is not out of the standard, every decoder should be able to decode that ac3, because it is stored in the additional bitstream information, which can just be skipped if the decoder doesnīt know what to do with it.

I forgot, the attachments need to be approved before they are shown. Uploaded file here is a link: ac3ex (22,3KB) (http://l.b.oltmanns.bei.t-online.de/ac3ex.zip)

wakebrder
4th February 2003, 00:59
DD & DD-EX are backwards compatible. If you have an EX title, your DD receiver will just matrix the center surround info between your left and right surrounds. No need to mess with the flag. BTW, some EX titles are not even MARKED correctly on the box. An EX title would even play through a PRO LOGIC or even stereo receiver for that matter.:eek:

frank
4th February 2003, 02:38
@tincek01
That is a known bug in DENON's firmware!
Please contact DENON service.

S_O
4th February 2003, 11:16
It is backward-compatible, but some recivers with a special decoder chip (for example some Denon receiver) have problems with that.
Also the firmware is not upgradeable, you have to send your receiver to Denon and wait (Iīve read up to half a year) until you get it fixed back (with anew decoder chip). Also Denon said the chips of this series are very rare and Denon will not be able to fix all receivers directly when they get them.
The EX-Signal is simply encoded in the rear channels, like in Pro Logic where the additional channels are encoded in the stereo signal. There is just a flag in the aditional bitstream information, that says the file is EX encoded. This additional bitstream information are within the standards, ATSC A/52a says you can do whatever you want with it, you define the size of it (up to 64Byte), and the decoder skips that block. Dolby defined now what to do with that additional bitstream information. In Annex C of ATSC A/52a you can read exactly what.
My tool simply sets the flag to "Not indicated". Could someone please send me a ac3 with the EX-Flag set? I would like to test my program.

pKurmannCH
14th November 2005, 14:21
Hi S_O

Could you send me your EX-Tool by PM or upload it again.

I need it to set a flag!