Proper settings for 5.1 surround in DVD3SVCD ?

[LOBO_DK]

Well..
I tried this great proggy 2 times now... But - anyway - i actually check my marker for the audio stream that says 5.1 - but i still only get stereo in my rips....
Am i doing something wrong - or is it not possible to get 5.1 surround down to SVCD ??

Help me out here

[markrb]

5.1 is the source audio. SVCD is Dolby Stereo.

Read the newbie faq this will answer most of your questions.

Mark

[LOBO_DK]

Yeah . well read it...
And i was just wondering.... if there was any way to get surround on SVCD...

[markrb]

It is converted to Dolby Pro Logic surround.
My reciever plays it fine. You may have to make sure
that yours is setup to play pro logic. Most recievers
require a manual change.

Mark

[mrbass]

doom9 posted about this a couple of months ago. Short answer is NO even though 5.1 is in the SVCD spec. 0% of dvd players will decode it with SVCD. So don't waste your time.

[Doom9]

actually.. there's one philips model that can (search the audio forum.. there's a long thread about mpeg2 mutlichannel compatibility).. but to implement something that will work for 1 known player.. waste of time and effort if you ask me.

[LOBO_DK]

Okay..... so i can get surround - but no 5.1
Thats okay by me - better taht plain stereo :)

Is there any settings i should be aware of ??
(my first 2 reps with dvd2svcd sounds just like stereo - no surround)


Thx..

LOBO

[Buzzard]

"Short answer is NO even though 5.1 is in the SVCD spec. 0% of dvd players will decode it with SVCD. So don't waste your time."

But your RECEIVER may be capable of decodinging the digital pass through and automatically kick in to "Dolby Pro Logic" when it sees the PRO LOGIC carrier signal. My Onkyo 777 ( 130 watts X 5 ) does this all the time. I always grab the 5.1 surround signal on the source disk if it's there.

I feel your comment of "So don't waste your time." is not acceptable for everyone.

BUZZARD

[Mozart]

@buzzard

are you sure about this? mp2 means "mpeg1 layer 2" audio, while such 5.1 audio for SVCD is mpeg2. AFAIK, it is too difficult to make such audio file, which involves the use of linux tools. Even if the SVCD has 5.1 mpeg2 audio, most of built-in decoders cannot send such audio "as is" using the digital port. There are more informations about this issue here (http://208.189.26.162/vbb/showthread.php?threadid=9113)

[Buzzard]

I am telling you that the digital pass through from my DVD player to the receiver automatically kicks my receiver into Dolby Pro Logic ( It say so on the display screen ).The program IS playing in surround sound as I have checked the sound from the speakers carefully. In my DVD2SVCD COPY of Pearl Harbor I made you could hear the planes zooming overhead from back to front and diagonally across in the long "attack" scene ..

BUZZARD

[Mozart]

Using audio encoding under DVD2SVCD control you don't have 5.1 mpeg2 audio, which means 5+1 different audio streams. Period. Read that thread!

[Buzzard]

"Using audio encoding under DVD2SVCD control you don't have 5.1 mpeg2 audio, which means 5+1 different audio streams. Period. Read that thread!"

Ok - It may not be 5.1 mpeg 2 audio but it IS some form of surround sound that kicks on the PRO LOGIC decoder in my receiver - and it does give some form of auditory surround sound through my speakers.

BUZZARD

[Labersack]

Nobody sayd you can't encode with Dolby Prologic, where you can hear planes flying from back left to front right.
But the question was about dolby 5.1, this is a different kind of sound-format.

[markrb]

Dolby 5.1 is a digital format and cannot be reproduced by the analog output that SVCD's do. The closest you can get is using Dolby Pro Logic 2 in a newer reciever. Failing that the next closest thing is Dolby Pro-Logic and DVD2SVCD does encode the SVCD with this surround information, but to hear it your reciever must be able to decode it and also must be setup to use it.
I have an Onkto 898 and it does see and decode the Dolby Pro Logic stream as Dolby Pro Logic 2.
Make sure that both of your analog ouputs are connected to your reciever. Just like a VCR you need both to be able to decode Dolby Pro Logic Stereo.

Mark

[LOBO_DK]

Well - do i actually need that ? (analog signal) - or can i use my RCA-to-RCA (coaxial) ??...
And... If i want Dolby Sorround.. Is there ANY settings i should take notice of in dvd2svcd ?

[markrb]

DVD2SVCD put in everything you need to do Dolby Pro Logic Surround.
Much like A VHS tape.

Dolby Pro Logic cannot be sent out the Digital line whether it is coax(RCA) or fiber.

The analog signal outputs are the two that are typically marked as red and white. One for left channel one for right.

You need to have you reciever setup to decode the signal.
To get surround out of the SVCD's you need to make sure your reciever can do Dolby Pro Logic and make sure you have it turned on.

I suggest you read your owners manual of you DVD player if you still have questions.


This is becoming a home theater question and could be better answered by a site catering to that end.
I suggest you read this if you are still confused. http://www.dolby.com/company/is.ot.0011.TechOverview.05.html

Mark

[LOBO_DK]

Well... Thx for all the help... :)
I have everything i need to know now... Thx...

[SupaCoopa]

"Dolby Pro Logic cannot be sent out the Digital line whether it is coax (RCA) or fiber"

Markrb, I don't seem to get this one. I am not saying you're mistaken but I haven't heard such a comment before and my Pioneer DVD and Yamaha AV-Amp manuals don't say anything likewise too.
I'm quite curious why this might be happening, since digital connections are surely capable of delivering two seperate L-R channels and Dolby Pro-Logic information is encoded internally through these channels.
So, in theory, the player sends separate L-R channels, the amplifier receives separate L-R channels (through digital as well as analog) and decodes the present Pro-Logic information to deliver four channel output. Where exactly is the Pro-Logic information lost?

If you can give more info or a more specific source (dolby.com is a huge site) it will be most welcome as I'm quite interested in home theater in general.

Cheers

[markrb]

The reason for this is simple really.
Digital inputs on a reciever and other equipment have to see a digital signal correctly encoded and Dolby Pro Logic is an analog signal.

Once again and for the last time. An analog signal CANNOT be played on a digital input.
Dolby Digital and Dolby Pro Logic are two completly different things.
A Dolby Digital signal needs a Dolby Digital decoder to play it. The signal is brought over by one single cable.

Dolby Pro Logic needs a Pro Logic decoder to play it. Dolby Pro Logic needs an analog right and left channel, two cables.

Different software, different delivery methods.

Try this remove all you cables from you DVD player. Only put in the digital audio (single RCA and make sure the plug says digital output and is most likely black) and video cable. Attach to your reciever. Attempt to play a SVCD (not DVD). You will get no sound.

Remove the digital (single RCA)cable and install the two analog(Red and white RCA cables) and play an SVCD you will get sound.

Take a look at this Pioneer DVD player. Notice the words Analog and digital.
http://www.pioneerelectronics.com/Pioneer/Files/dv-343_BACKPANEL_20015291337194800.pdf

Last do not confuse a DVD's ability to play over an analog line as being digital. DVD's and Dolby Digital are backward compatible with Dolby Pro Logic. If you only use the Red and White cables to your reciever you are playing, in fact, Dolby Pro Logic from a Dolby Digital source. What is happening is that the Dolby Digital signal is being converted to analog inside the DVD player. You can do this as this is part of the Dolby Digital Spec.

Any more info needed head to a home theater website.

Mark

[Spawn]

Mmm where to start.

First of all you CAN'T ENCODE DOLBY PRO-LOGIC, so toss out that idea (Read the faqs on Dolby's site for more info). DOLBY PRO-LOGIC/PRO-LOGIC-2 ARE both DECODING ONLY algorithms, you CAN NOT ENCODE these, it doesn't work like that. You can only encode Dolby Surround information into your SVCDs (Or ANY STEREO source for that matter).

-Playing back a Dolby Surround encoded Stereo source through an old "Dolby Surround" capable amp will decode 3 channels: the left, right and rear channel (Rear channel bandwidth limited to ~7khz).

-Playing it back through a Dolby Pro Logic capable amp will decode 4 channels (I say that term lightly as there not independent channels like DD or DTS, there simply derived from the Dolby Surround information encoded into the stereo signal): Left, right, center, and rear (Again the rear is limited to 7khz)

-Playing it back through a Dolby Pro Logic-2 amp will decode 5.1 channels (Again these aren't 6 independent channels, but channels derived from the Dolby Surround encoding using mathematical formulas (Again read Dolby's site))



Secondly, when we make an SVCD with surround sound. Were encoding a Dolby Surround encoded Stereo wave file into an Mpeg-1 Layer 2 file .

When we play this back on our dvd players the dvd player will either:

-Decode the Mpeg-1 Layer 2 audio and send it through the the analog outputs AND/OR the digital outputs as a STEREO PCM AUDIO signal.

Or

-Pass through the Mpeg-1 Layer 2 audio data untouched through the digital outputs on the DVD player to the receiver (Where it will then be decoded)

(Note this is a generalization and applies to MOST, but probably not ALL dvd players)



Also markrb, Dolby Pro Logic isn't an analog signal, in fact its not anything that you imply with your context of it. Remember ITS A DECODING only algorithm in your receiver/decoder, not a sound format or signal as you might imply.

Secondly if you meant to say "Dolby Surround is an analog signal" your still wrong, cause SVCD is a digital medium, and all the audio and video on it are digital. The Dolby Surround information is encoded into PCM STEREO audio (wave file in our cases), then encoded into a MP2 file.

Hence digital, so markrb now I don't think I even need to mention everything else wrong in your last post. You get the picture.

**HOWEVER if you were referring to VHS or maybe LaserDisc (Using the analog sound channels not digital of course) then you might me more correct in your use of "Dolby ****" is an analog signal.



Also if your not getting an audio signal through your digi-outs on your dvd player while playing an SVCD, you have something setup wrong, or something is broken. Cause I've watched svcd's through my dvd player (And many others) connected to my amp through TOSLINK or COAX digital connections for well over two years now and never had a problem.

So basically markrb, your wrong in many ways (Not to offend you, just pointing out your errors, and I don't wanna see you get flamed)


NOTE on MPEG2-MC 5.1:

Since Philips heavenly backed the SVCD standard its obvious why they chose MPEG2-MC as the 5.1 audio format instead of Dolby Digital (In case you don't know what I'm talking about, when DVD's first came out Philips heavily backed MPEG2-MC as the 5.1 audio format for DVD. Although supported for a while in Europe, never took off and has since died to Dolby Digital/DTS).

So SVCD got stuck with a dead standard. Although SVCD supports MPEG2 5.1 Multi-Channel VERY LITTLE RECEIVERS SUPPORT THIS, NOTE THAT I SAID RECEIVERS NOT DVD PLAYERS. Many dvd players simply pass through the mpeg audio data untouched (Almost all Pioneer players have this option available on the setup menu), if your not getting true 5.1 audio on an MPEG2-MC encoded SVCD, its most likely your receiver's fault NOT your DVD player. I do know for fact some older models Philips receiver do support MPEG2-MC 5.1 decoding, although I haven't seen these for a while.

Anyways long enough first post, comment as needed.

-Spawn

[markrb]

There is often a line of confusion as to what is digital and what is analog and technically anyone can say that any source material on a Digital media is digital and in a sense they would be right. However as quoted from Dolby Labs, Dolby Stereo and Pro Logic are analog based schemes.
Again you are right saying you cannot encode Dolby Pro Logic. According to Dolby Labs, Pro Logic is a decoding scheme. It was a poor use of words on my part. I should have stayed with Stereo, but in trying and stay as simple as possible I was technically wrong.

According to Dolby Labs themselves Dolby Stereo, Pro Logic and Pro Logic 2 are analog schemes. I suggest you read the white papers or contact Dolby Labs directly. What makes Dolby Stereo and the others analog is how the signal is encoded and decoded not the way it is transmitted.

1. Dolby Surround is the consumer version of the original analog Dolby multichannel film sound format.


"Overview of Dolby Technologies

5. Consumer Surround Sound

Dolby Surround is the consumer version of the original analog Dolby multichannel film sound format. When a Dolby Surround soundtrack is produced, four channels of audio information—left, center, right, and surround—are matrix-encoded onto two audio tracks. These two tracks are then carried on stereo program sources such as videotapes and TV broadcasts into the home, where they can be decoded to recreate the original four channels and the surround sound experience. Thousands of feature films on home video, as well as many television shows, are encoded in Dolby Surround.



Here is another paragraph from another Dolby Stereo white paper.

Dolby analog movies and Dolby Surround video and television programs include an additional sonic dimension over conventional stereo productions. They are made using a Dolby MP (Motion Picture) Matrix encoder, which encodes four channels of audio into a standard two-channel format, suitable for recording and transmission in the same manner as regular stereo programs.


I suggest that if you wish to push the point of whether these Dolby Stereo types are analog or digital contact Dolby themselves. I have contacted them in the past when an argument came up about this very subject on laserdisks and their response to me was the Dolby stereo is an analog based system no matter the media. The only true Digital Dolby Stereo scheme in the home is Dolby Digital and EX(although not developed by Dolby Labs)


Now to your last point. Wow was I wrong on the signal being able to be carried over the digital line. I did some testing and it works with just the Digital connected. I know that I played a video that wouldn't work before and I based my line of thinking on that.


So to sum up.

1. You are right saying Dolby Pro Logic is only decoding.
2. You are right saying that Dolby Stereo will transmit across the digital line (man how could I have missed that one)
3. You are wrong calling Dolby Stereo/Pro Logic/Pro Logic 2 Digital


Mark

[Spawn]

Good post,

However I believe you miunderstand a tad bit. The stuff you quoted from Dolby's site is 100% true, they do refer to it as analog. HOWEVER the context they use refers to it SPECIFICALLY on analog mediums such as tv broadcasts, video tapes, etc.

Audio cd's can be encoded with Dolby Surround (In fact majority are), are you claiming these to be analog as well? The only difference between how audio cd's and VCD/SVCD's store audio is that audio cd's use uncompressed pcm where as VCD/SVCD's use MP2.

Furthermore some DVD's come with 2 channel Dolby Digital audio tracks, which can be Dolby Surround encoded. Are these analog as well, cause aside from the encoding scheme (DD instead of MP2) there no different audio wise from SVCD's.

A Dolby Surround encoded Stereo track an be represented using frequency modulation (Like on a cassette tape or VHS, where its stored analog) or pulse code modulation (Like on a cd, dvd or any other digital source, where its stored with 0 & 1's).

Dolby Surround encoded tracks can be played back from an 80's Stereo tape player or played back digitally through a DVD player through to an amp.

Lets just agree to simplify things, Dolby Surround/Pro-Logic/Pro-Logic2 are just mathematical models that can extract surround information from a Dolby Surround encoded STEREO source (Whether it be a DVD/SVCD/VHS/CD, analog or digital etc), calling them digital or analog is the wrong word, there mathematical formulas (In the simplest sense). Agreed?

Dolby Digital is an actual sound format supporting up to 5.1 discrete channels (DD EX matrix encodes a rear center channel into rear left & right, kinda like how Dolby Surround encoding works), each channel is independently encoded from the others. Dolby Digital is its own sound format, it can't be encoded into a stereo source then recreated on playback. However you could encode Dolby Surround information onto a 2 channel Dolby Digital track. Simply think of Dolby Digital as an audio compression standard similar to MP3 (Or MP2, Ogg Vorbis, etc ..)(Only Dolby Digital is alot better and supporting up to 6 channels)

I hope I clarified things, perhaps someone else might be to able explain it better, perhaps re-post in the audio encoding section. I'm only an amateur compared to some of those guys.

Looking forward to reply,

-SPaWN

[markrb]

I am leaving the first part of my post as is so you can see my thinking, but I really think I found the answer in the Dolby FAQ and it seems both of us are right. If you don't care how I was thinking skip to the last part.






I agree with most of your points you mentioned.
I wish to clarify that I do not say that the recorded medium is analog. I am saying the the decoding process of Dolby Stereo is analog. It may be recorded as digital, transported as digital, but the decoding is done in analog.

The only part I disagree with and I realize it is nit picking a little is that while most of the process might be digital in the areas you mention the actual decoding is done using an analog based formula and probably analog signals. Now whether that formula is done in digital mode using an analog emulation it is still done in analog.

Although I tend to believe, but have no proof, that it is easier and cheaper for a digital signal to be converted to analog and use one method to decode. If this did not happen then signals from TV, VCR's and other definate analog sources would need either to be converted to digital or decoded in a seperate process.

I will hopefully have a definate answer soon. I contacted Dolby Labs directly and asked them to comment on the points brought up here.

I am really not certain, but I believe that 2 channel Dolby Digital is just a subset of the 5.1 Dolby Digital and has it's own decoding scheme much the same as Dolby Stereo, but not Dolby Stereo. That is one I need to look into further.

I just keep coming back to the answer I got from Dolby about a very similar situation based on laserdisc material.
Their answer there was that Dolby Stereo and all formats based on it where analog regardless of the media it was recorded on and the transport.

I hope to know more soon. This is definately one of the areas that are starting to blur what is analog and what is digital.

Here is a question in the FAQ I missed and this might clear up a few things:
3. Can I hear Dolby Digital programs over a regular stereo or Dolby Surround Pro Logic system?

Yes, you can use most of the new Dolby Digital program sources with your current playback system, because they incorporate Dolby Digital decoders and provide conventional analog stereo outputs. However, with many DVD-Video players, digital cable set-top boxes, and other sources, you need a separate multichannel Dolby Digital decoder to experience the thrilling 5.1-channel surround sound used on many Dolby Digital programs.


Another qoute from the Dolby Digital FAQ. Here they say that Dolby Digital 2 channel has it's own decoder, but they don't explain further.

Many program sources, including all DVD players and digital cable set-top boxes, provide a built-in, two-channel Dolby Digital decoder with analog stereo outputs (see question 7). For 5.1-channel playback, most units have a separate digital output that provides the undecoded Dolby Digital signal (data stream) for connection to an external unit, such as an A/V receiver, that has its own 5.1-channel Dolby Digital decoder. See Figure 11-1.



There is more, but nothing, including what I posted, gives a 100% answer. If I do not hear back from Dolby I will let this post die and even though I don't have a 100% answer I will not be knocking my head against a wall. It is what it is and knowing the answer will not change this. It works and it seems to work well.

If nothing else I am very happy I found out that I can send the SVCD audio over my digital COAX line.



Wait!! I think I found the golden nugget hiding among the dust that is a FAQ. It confirms, at least in part, what you are saying, but it also seems to confirm my way of thinking as well. It seems to point to a Digital emulation of an analog scheme.


6. Does 5.1-channel Dolby Digital make Dolby Surround obsolete?

No, Dolby Surround will be with us for as long as stereo is with us. This is why all Dolby Digital decoder units also incorporate a digitally-implemented Dolby Surround Pro Logic decoder.


Mark

[Spawn]

Mmm reading Dolby's site right now, although they have alot on there site, its worded poorly, often referring to Dolby Surround as an analog film format (Pointing to its heritage), I believe this is so it doesn't confuse people.

Also check out this page, it clearly shows Dolby Surround can be encoded into a stereo (2 channel) Dolby Digital track.
http://www.thedigitalbits.com/officialfaq.html#1.28

It quotes:
"Some discs (many from Columbia TriStar) have 2-channel Dolby Surround audio (or plain stereo) on track one and 5.1-channel audio on track two. Since some studios create separate sound mixes optimized for Dolby Surround or stereo, and they feel the default track should match the majority of sound systems in use. Unless you specifically select the 5.1-channel track (with the audio button on the remote or with the on-screen menu) the player will play the default 2-channel track. (Note: Some players such as the Sony 3000 have a feature to automatically select the first 5.1 track.)"


Also you pointed out LaserDisc. Well LaserDisc is a weird special case, since it has BOTH digital AND analog audio channels, so its an exception. However almost all newer LD's use the digital channels for Dolby Surround encoded pcm stereo. To confuse everyone more, newer LD's usually use the analog tracks to store Dolby Digital 5.1 or DTS 5.1 (Its actually an interesting process, they store around ~1400kbit/sec in the ANALOG audio tracks)

Also in most newer amps the pro-logic/2 decoding is done in a digital asic or dsp, however this wouldn't increase or decrease the audio quality, as the decoding is simply a math equation (Ok, not simple, but relative to a computer it is).

Regardless of the interpretation of Dolby's site, the simplest fact remains. When watching an SVCD or playing back an audio cd on any home theater (With a digi connection between dvd player and amp) we get 100% pure digital surround sound, although its not 6 discrete channels, but 4 pseudo channels, its still surround sound, and its still digital sound.

-SPaWN