Dolby Surround 2.1 software?

[Disco Makberto]

Hello, my friends!

As the title suggest, I am trying to find out if there is a software that allows me to create Dolby Surround 2.1 audio to be placed on a DVDR disc as part of DVD-compliant MPEG2 files. It appears that this set up is not something common, but the reason why I am interested in Dolby Surround 2.1 (two front speakers and one sub-woofer) is because of size constraints on DVDR discs when using better set ups like Dolby Digital 5.1. With the latter, and high quality video, I can only record up to 1 hour on a 4.3GB or so DVDR. Conversely, by using Dolby Surround 2.1, I think I can go up close to the 2 hours of DVD-compliant MPEG2 files I need to record on DVDR without sacrificing too much noticeable quality.

Of course, and I know that some of you are thinking this, why I don't just use Dolby Stereo 2.0? Yes, that is one course of action, but I think that Dolby Surround 2.1 is a step up.

Best to all,

Carlos "Shale" Disco Mak
discomakberto at megamixers dot co dot uk

[guns1inger]

The difference between 2.0 and 2.1 is there only if you are going to mix a LFE channel. Given the ability of most home theater rigs to redirect low frequencies to the LFE automatically, often there is little to be gained by doing this unless you really know what you are doing.

That said, Soft Encode and Vegas can easily do this, and I suspect that anything capable of doing a 5.1 encoding will also do lesser channel encodes. This would include Surcode, Nuendo, and probably ffmpeg.

If you set up your encoding properly, and depending on the source material, there is no reason why you cannot have 90 - 120 minutes of video with quality 5.1 AC3 audio.

[Disco Makberto]

Hello again, Gus1inger!

Yes, I was reading that some decks can "re-create" the sub-woofer channel based on Dolby 2.0. Still, I can see that some original factory-pressed DVD's include a Dolby 2.1 channel option, so I suppose there is (or there was) something to be gained with Dolby 2.1. Please take a look at the DVD "The 40-Year Old Virgin":

http://www.imdb.com/title/tt0405422/dvd

Of course, there are some instances by which a 2-hour movie and Dolby 5.1 can be incorporated into a 4.3GB DVDR. One of those instances is when transfering from VHS to DVDR. However, I think that I cannot back up that "40-Year Old Virgin" DVD with the same video quality and with Dolby 5.1 audio. I think I would need to sacrifice on video. Whether that is noticeable or not is not what I am addressing here; the point is that I think (though I could be wrong), based on some research I've done, that a "clone copy" of the video plus a "clone copy" of one of the Dolby 5.1 streams cannot be allocated to a 4.3GB DVDR. If am wrong, I would love to hear how to achive it.

One way or another, there is a middle ground that is more than sufficient for me, and that is Dolby 3.1. But again, is it possible to back up "The 40-Year Old Virgin" DVD with a "clone copy" of the video and a downmix to Dolby 3.1 on a 4.3GB DVDR, assuming that the DVD is a two-hour movie?

Thank you for your information about the softwares. I will try Vegas. And by the way, not all softwares capable of Dolby 5.1 can do many other combinations. Super, for instance, can only do 5.1 and 2.0, leaving out 2.1, 3.1, etc.

Take care,

Carlos "Shale" Disco Mak

[guns1inger]

Before you get too far down the track, have a look at the actual file size savings between a 5.1 and 2.1 channels. Most 5.1 AC3 audio tracks are encoded as 384 kbps, the better ones at 448 kbps.

What are you planning to encode your 2.1 channel mix at ?

The savings will be only a 200 - 300 MBs at the most. Not a lot to spread around the video if you expect huge improvments.

Most DVDs boast a 5.1 AC3 audio track nowadays, yet many of these have very little or in fact nothing in the LFE channel. It is there for completeness, but does not actually drive the sub-woofer. Instead this is left to the cut-over on the amplifier itself.

I should have been clearer - I was refering to dedicated multi-channel encoders. SUPER and it's kind do not fall into this category. SUPER uses ffmpeg for it's AC3 encoding, but keeps it simple at the front end. I suspect that if you scripted ffmpeg encoding yourself, you could get 2.1 out of the same engine.

How do you intend to actually re-mix the audio to get your three mono channels ? Or are you hoping the encoder will do this for you ?

Again, I don't believe the you will get enough in the way of savings to justify the effort, but good luck anyway.

/edit :

Quick example using the Videohelp online bitrate calculator

90 minute movie with 5.1 audio @ 384 kbps will have a video bitrate of 6384 kbps
90 minute movie with 2.1 audio @ 256 kbps will have a video bitrate of 6515 kbps

It's a slight improvement (about 2%) in the bitrate, but IMO not worth the drop in audio quality.

[Disco Makberto]

Hey, Gus1inger!

Thank you for your detailed response.

I didn't know that many of today's DVD's left the sub-woofer channel out on the DVD's themselves so that the amplifier works around it. Thank you for the information.

About Dolby, I am still undecided between 2.1 or 3.1, but I am leaning towards 3.1. Anyway, based on the fact that encoding a sub-woofer channel is not always necessary, I can even go Dolby 3.0. I am willing to sacrifice the rear speakers. Yes, I know, with this set up I won't enjoy full Dolby Surround, but that's okay.

Thank you very much for your calculations. I understand that with a 90 minutes video, Dolby 5.1 is not an issue, but I am not talking about any 90 minutes video. In fact, I am not talking about creating any custom-made videos. I am talking about backing up already existing factory-pressed DVD's when almost reaching 2 hours. For instance, I have this Rockamerica DVD of 1 hour 55 minutes and 15 seconds, video bitrate 10080 kbps variable, AC3 audio 48000hz 224kbps. Is it possible to upgrade this DVD to a DVDR with Dolby 5.1 while keeping the same video bitrate? I doubt it. I can probably upgrade it to Dolby 2.1, and maybe, just maybe, to Dolby 3.1, but I'd be hard pressed to think I can upgrade it to Dolby 5.1. But again, who I am to say so? I would love to be proved wrong.

Kindest regards,

Carlos "Shale" Disco Mak

[guns1inger]

You are only talking about a couple of hundred MB at most. Personally, I wouldn't drop anything bigger than 2.1 below 256kbps.

If you currently have a source with less that 5.1 you should not realistically expect to upgrade it to 5.1, regardless of space. The video you use as an example, if your numbers are correct, is using all the available bitrate. I suspect that you could easily run this through DVD Rebuilder with CCE or ProCoder, and fit it on a single layer disc with very little noticeable degradation of the image quality.

There is certainly no automatic way to add channels to your audio mix.

[Disco Makberto]

Hi, there!

Exactly, Gus1inger, that is my point. I cannot accomodate my video and audio settings on a DVDR 4.3GB if I use Dolby 5.1. I would need to reduce either the video quality or the audio quality.

Thank you for your information about DVD Rebuilder, et. al. I will check it out.

One final question, please. What is your audio bitrate reccomendation for Dolby 2.1 when the audio source is perfect DVD quality and when the audio source is VHS or vinyl?

Best,

Carlos "Shale" Disco Mak

[manono]

Personally I think you're wasting your time with this audio reencoding idea. As mentioned, the filesize savings are miniscule relative to the size of a DVD5, and the quality hit you'll take by reencoding the audio, especially if using something like BeSweet, is significant. If I were you, I'd spend my time learning how to reencode the video in order to maximize the quality, at the same time leaving the audio alone. Have you even said yet how you're shrinking the video? As you don't seem to have heard of DVD-Rebuilder, I can only believe that you don't know how to reencode video (as opposed to transcoding with something like DVD Shrink).

I cannot accomodate my video and audio settings on a DVDR 4.3GB if I use Dolby 5.1.

Do you have any idea what you're talking about? Just what's so special about your video settings that they can't accomodate DD 5.1 AC3 audio on a 4.37GB DVDR? The fact that you may have to lower the video bitrate by 4-5 percent? Maybe, if the original retail DVD with DD 5.1 audio was the tiniest bit over the size of a DVD5, but often in those cases you can reencode a menu, drop or reencode an extra, reencode just a chapter (like the credits, maybe), rather than mess up perfectly good audio by reencoding it.

For instance, I have this Rockamerica DVD of 1 hour 55 minutes and 15 seconds, video bitrate 10080 kbps variable, AC3 audio 48000hz 224kbps. Is it possible to upgrade this DVD to a DVDR with Dolby 5.1 while keeping the same video bitrate?

See, this is the kind of thing that makes me wonder about you. The average video bitrate is nowhere near 10080 kbps. The max video bitrate isn't even near 10080 kbps. I can't find Rockamerica in any database, so I can't check on the audio, but there is such a thing as DD 2.1 Surround. In any event, making it DD 5.1 sure isn't going to improve it.

[guns1inger]

Assuming you are correct with your bitrate (and be warned, some encoders just put the maximum bitrate into the headers, regardless of what it might really be), you will have to halve the bitrate to get it to fit on a DVD5. On top of that, 10080 is the absolute maximum allowable bitrate for video + audio combined.

Taking one of my personal favourites as an example. The Lawrence of Arabia Director's Cut is a two disc set. The full movie running time is 218 minutes, however the first disc has 134 minutes of the movie, with 5.1 AC3. The video takes up 6087MBs, the audio 449MBs (448 kbps). If you cut the audio down to say, 2.1 @224 kbps, you save about 200 MB. Compare to the 2000MB you have to save off the video, and it isn't really worth the effort.

[Disco Makberto]

Hello, Manono!

Thank you very much for your reply.

There is nothing special in "my settings". In fact, that is a little bit incorrect, strictly speaking. I should have said "the original DVD settings". Again, what I was/I am trying to achieve is a clone copy of the video part, using the same video quality by ripping it, while upgrading the audio part which is Dolby 2.0.

Yes, my DVD is a factory-pressed Rockamerica DVD. It is Videopool from April 2002. If you cannot find it, please E-mail me, and I can point you to a source.

The information I gave before came from GSpot and one VOB file from my Rockamerica DVD. The whole container reads:

DVD "VOB" format
MPEG-2 Program Stream << 1 vid, 1 aud
Sys Bitrate 10080 kb/s VBR

Oh, okay! So this is the container, so this is both video and audio, I suppose. Please excuse me my lack of knowledge here.

At the right, wher it says video, it reads kbps 4699.

In short, if I stated this wrongly before, please accept my apologies.

As for approaches, I respectfully disagree with you. If possible within the 4.3GB limitation of DVDR's, I don't see anything wrong with upgrading (not adding but upgrading) a Dolby 2.0 stream to Dolby 2.1 or Dolby 3.1 or Dolby 5.1 or what have you while keeping the same original video part, and placing everything on a DVDR. Of course, I understand that the ".1" is somewhat redundant, as Gus1Inger was kindly explaining to me, but that's okay.

In short, I appreciate any advice that you or any other reader can provide me.

At this very moment, I am trying to find a tool that can display in numbers the space used in a DVD. This way, if X DVD is very near 4.3GB, it would be pointless to upgrade the audio (unless I use Blue-Ray DVDR or HD-DVDR).

Most cordially,

Carlos "Shale" Disco Mak
discomakberto at megamixers dot co dot uk

[guns1inger]

How do you plan to "upgrade" 2.0 to 5.1 audio track ?

DVD Shrink can show you this information.

Again, using the VideoHelp Bitrate Calculator, and the bitrate you have provided from your original, you could put the whole 116 minutes of video, with a 384kbps 5.1 audio track on a DVD5 without using all the available space. The video you have is already very heavily compressed and does not use more than one layer of a disc.

[Disco Makberto]

Dear Gus1Inger,

Thank you kindly for giving the benefit of the doubt, but it appears that my calculations using GSpot were wrong. As a matter of fact, I don't like this GSpot because it doesn't give me infomation about space used on the whole DVD, so I have to use individual VOB's. If you know a better program, please let me know. Anyway, returning to the original point, video bitrate is 4699 kbps and audio bitrate AC3 224 kbps. The total runtime for the whole DVD is 1 hour 55 minutes and 15 seconds (I got this information from Windows Media Player, not from GSpot).

Upgrading the Dolby 2.0 stream or not would be dependant on space, total space on original DVD and substracting that amount from 4.3GB wich is the total space of DVDR's. You told me that I would need about 200MB available on the DVDR, so thank you for that information. In the meantime, let me see if I can find out the total space used on my Rockamerica DVD.

Until soon,

Carlos "Shale" Lacaye

[guns1inger]

I can tell you, using a bitrate calculator, that you can fit it all on a single layer DVD with room to spare, based on the two bitrates you have given me.

I am not questioning the space requirements for using 5.1 instead of 2.0 or 2.1 AC3. I am asking how you would in fact create all the missing data that you don't have when you start with a 2.0 AC3.

[Disco Makberto]

Greetings Guns1Linger!

I have heard, though I am not sure why, that the trick is going from surround to surround. So, if I have a Dolby Stereo 2.0, I would make Dolby Surround 2.1, and from there I can move to either Dolby 3.1 or Dolby 5.1, etc.

Apparently, if one goes from Dolby Stereo 2.0 directly to Dolby Surround 5.1, all that is created are identical 6 channels, not five channels plus a sub-woofer channel as in Dolby Surround 5.1.

Al the best,

CAL Disco Mak

[guns1inger]

I don't know where you heard this, but it is not true. You can't simply move from 2.0 to 2.1 then to 5.1 To get there you need to create all the missing channels in such a way that you get correct separation.

You will get much better surround from a clean stereo source and a good Dolby ProLogic II amplifier than from the method you are proposing.

[Disco Makberto]

Guns1Inger,

I read it somewhere on the Internet. I think it was a tutorial.

Okay, so I will follow your advice and disregard Dolby Surround on the DVDR's, but I can actually encode the DVDR's with Dolby Prologic II using SurCode from Minnetonka Audio. If their literature is correct, it is indeed possible to encode to Dolby 5.1 Prologic II based on a stereo source by using their software. Will this be a better approach?

Bye for now,

Carlos DM

[Disco Makberto]

Guns1Inger,

Another approach would be to upgrade from Dolby Stereo 2.0 to Dolby Surround 2.1 and use a Dolby ProLogic IIx amplifier. Apparently, this amplifier can upgrade to 5.1 on the fly if the source is Dolby Surround 2.1.

Please let me research more into this. If indeed these facts can be corroborated, I really think that Dolby Surround 2.1 is not a bad idea at all.

Goodwill to you,

Carlos Albert "Shale" Lacaye
Disco Mak

[guns1inger]

You don't need to do anything to your audio at all. A good Prologic II amp will do the work for you. I really think you are heading up the garden path for no good reason.

[Disco Makberto]

Gus1Inger,

I agree with you. But a good Pro Logic IIx amplifier can also upgrade from Dolby 2.1. So while using Dolby 2.0 doesn't hurt, the same can be said of Dolby 2.1, except that Dolby 2.1 could require a bit more of space, though minimal. Then again, if I use the bitrate of 256 kbps for both Dolby 2.0 and Dolby 2.1, the space would be the same. At any rate, I see a "phychological advantage" in having the ".1" already on the DVDR as opposed to having it "naked" and wait for the deck to work on it. And, yes, anyway you or I see it, I would still need the amplifier...that is why I said "pyschological advantage".

As for the Minnetonka tool, when is it advisable to use it? When one has the master tapes, perhaps?

Good day or night,

Carlos Albert "Shale" Lacaye

[guns1inger]

Your source needs to be mono wav files - one for each channel. Any mixing and directionality needs to be done in a multi-channel editor before creating the final wavs (unless your editor have native multi-channel output (e.g. Vegas does 5.1 AC3 from the timeline mix). You load the mono wavs into the correct channels of the encoder, and let it pull it all together for you.

The work is in creating the wav files. Have a read of this guide I wrote. You can skip the rear channels if you just want to create an LFE to go with your fronts

https://forum.videohelp.com/viewtopic.php?t=292142

[lacywest]

Here is some info >> http://en.wikipedia.org/wiki/Dolby_Digital

You've been asking us alot about encoding. What Dolby Digital ... Decoder are you using ??

Is it in a Home Theater Sound System ... like JVC ... Kenwood ... Pioneer ??

They will create sound fields with normal stereo.

My Pioneer VSX-1015TXK 7.1 Channels Receiver ... has a setting ... 7.1 Stereo. I use it quite often.

And I do have amplifiers and speakers for all 7 channels and ... I use Carver Amps and Acoustic Research speakers.

What about the .... .1 .... it is a Powered Sub Woofer ... the SW-30 Acoustic Research Subwoofer.

The Flight of the Phoenix ... in DTS .... sounds fantastic.

[Disco Makberto]

Good day, Guns1Inger!

Thank you for sharing with us your 5.1 guide. I find it really interesting.

Gus1Inger, you know, Minnetonka Dolby Digital Encoder version 2 can work from stereo wav files, so in this case like in Vegas, there is no need to go to mono wav first. As a matter of fact, I am no so convinced about starting out with mono wav files. If the end product is supposed to be Dolby 2.1 and the source is Dolby 2.0, and I go via mono wav files, how do I know that the new stereo mix is exactly the same as that on the source mix? I mean, it could be a slightly different mix, right? My goal is to preserve the original front stero mix while just adding a single channel sub-woofer mix.

Best to you,

Carlos "Shale" Lacaye

[guns1inger]

You can use the stereo mix if your encoder accepts it - some do, some don't. However if you take the left and right channels separately and encode them as 2.0 AC3 you will get exactly the same mix as if you had fed int he original stereo signal. Nothing has changed.

You also need to understand that the .1 is not bass. You can't just direct the bass from the stereo mix to the LFE and call it done. LFE is for Low Frequency Effects, not bass. Just be aware of this when you are trying to create on.

Anyway, it sounds like you have little idea of what is really involved, so go ahead and do what you think will work. I'm sure you will be happy with the outcome regardless.

[Disco Makberto]

Good day, Lacywest!

Thank you kindly for your contribution.

As for the decoders, in the meantime, I will be using my computer. As soon as possible, though, I will buy a Dolby ProLogic IIx standalone amplifier.

As you and Guns1Inger are correctly pointing out, Dolby Prologic IIx amplifiers can upgrade the audio of Dolby 2.0 to Dolby 5.1, etc. But this amplifier can also do the same with Dolby 2.1. Still, why do I then prefer Dolby 2.1 over Dolby 2.0 if the results are the same? Well, my "personal reasons" are (and I stress they are "personal reasons"):

1) Psychological advantages, and up to an extend, the wow factor. Ask anybody who is not very familiar with this stuff, "what name sounds better to you, Dolby 2.0 or Dolby 2.1?"

2) Sense of approaching a regular DVD or improving what one has. Some (or more than some) factory-pressed DVD's have a Dolby 2.1 stream, so why not doing the same with a DVDR? Whether that's advantegeous in measurable terms or not is a different issue.

3) Having a better DVDR. Most or even all DVDR's that can be found in the market are either Dolby 2.0 or Dolby 5.1. I have never seen a Dolby 2.1 DVDR (yes, of course, a Dolby 5.1 DVDR is better than a Dolby 2.1 DVDR).

4) Smoother downmixing. As you know, some decks dowmix a Dolby 5.1 stream to make it a Dolby 2.0 for compatability purposes. Logic tells me that it is easier to go from Dolby 2.1 to Dolby 2.0 as opposed to going from Dolby 5.1 to Dolby 2.0.

And they are more or less my reasons.

Please, if anybody of you finds my way of thinking faulty, I still respect you, but you have got to acknowledge that at least I am trying to back up my ideas.

Before I forget, something that I like about Dolby ProLogic IIx amplifiers is the "Music Mode" selector. As most of my DVD's are music videos, I find that feature very useful.

OK, that's all for now.

Greetings to all,

Carlos Albert "Shale" Lacaye
Disco Mak

[Disco Makberto]

Hi, Guns1Inger!

It is great news to know that mono wav files will produce the same stero mix. I didn't know that.

Of course, I have little idea or lack of experience in the audio field. And I am very proud to say so. But I am also very proud to say that I am trying to learn, so if you correct my mistakes, I thank you very much. You see, I bet that at one time you were also not knowledgeable about it. Everybody has to learn at one point or another.

I still don't know what my end product will be. Again, as I have said more than one time, there is no real measurable improvement in going from Dolby 2.0 to Dolby 2.1. But that doesn't mean it's not worth it. There are other reasons that I explained before. For some people, I am sure that they will say that my reasons are faulty. Well, I sincerely respect that point of view. But what have I got to lose? If my end product is not what I expected, well, that would mean that I would lost some hours in the making of them, and nothing more. Spending some hours is not critical for me, for I will learn something in the end.

As for the actual process, please read about the Minnetonka SurCode Dolby Ditigal here:

http://www.surcode.com/manuals/Dolby%20Digital%20V2.pdf

If I follow this manual, the process would be to throw in identical stereo wav files as Left Front, Right Front, and SubBase LFE, and encode. This will give me Dolby Surround 2.1.

In closing, I thank everybody fo your time and attention in helping me to achive my goals, or should I say "pseudo-goals"? (:

Cordialest regards,

Carlos "Shale" Lacaye
discomakberto at megamixers dot co dot uk

[raquete]

adobe audition multichannel encoder can do 2,2.1,3.1,4.1..etc easily.

edit: guns1inger is one "guide man",posting cool lessons!

[Disco Makberto]

Hello, Raquete!

Thank you for your information.

I find SurCode a little bit easier than Adobe, though I am sure that Adobe gives great results. I think there is a SurCode plug-in for Abobe as well; so, we can have the best of both.

Take care,

Carlos "Shale" Lacaye

P.S.: Yes, Guns1Inger talks with the "voice of experience". Yeah!

[guns1inger]

Surcode's ac3 encoder is just that, an encoder. It doesn't magically create missing channels or upgrade you from 2.0 to 2.1. You can feed it a stereo wav and tell it to output a 2.1 or even 5.1 audio track, however if you open that track up you will just find that you have front left and right, and the rest are empty. You have to create the missing channels for surcode to encode.

[raquete]

was tested and works:
extract .1 channel from L&R(source)using equalizer or fft filter.
audition have one preset "only the subwoofer" and is very good.

sonicfoundrysoftencode have option to 2.1 in "audio coding mode",
load the L&R,load the .1 channel...encode!

i think that vegas have the same option!

[Cornucopia]

Disco Mak,

Before you go any further, I think you ought to look at this thread: https://forum.videohelp.com/viewtopic.php?t=292947, specifically my 2 posts dealing with the DIFFERENCE between Bass Management and LFE channel use.

After seeing it, you'll probably agree that you wasting ALOT of effort which will just end up with your audio track giving an equivalent (if not identical) sonic experience (although possibly degraded).

Scott