Dolby Digital on VCD SVCD or XVCD

[pclark]

I currently convert my dvd's to vcd using DVDx which I've had no problems with up to now. But what i would like to know is-- is it possible to rip a dvd to vcd,svcd or xvcd and keep dolby digital (3/2)sound on CD-r.
And a further question if i may, what in your opinion is the best commercially available software for ripping dvd to svcd, lets say money was no object

I also notice a lot of users on this site prefer to convert to scvd, does this mean they are using 3 cd-r's for each movie?

Sorry for all the questions, but it saves me posting 3
Thx in advance
Paul

[bde]

Not really. Some people claim that they have been able to preserve the audio stream, but this seems clearly impossible, because when the audio is converted to mpeg format, it loses all the extra AC3 information. Any audio that is put into a Mpeg will be in MP1 or MP2 format at the end. This means that the audio will be in either MPEG-1 format (8-256kbps), or MPEG-2 format (16-320kbps). In either instances, it will no longer contain any of the Dolby audio data, and thus, render further audio processing useless.

The few people that claim they've made a VCD/SVCD/XCD with all the audio data intact, usually can't say how they made it work, or haven't a clue as to the difference between a VCD and a divx file. With divx, yes, it is possible to put an AC3 file into the AVI file, but with MPEG, there isn't an option of using AC3. You cannot do what you have intended.

[hwoodwar]

DVD2SVCD has a MPEG 5.1 setting, which I assume is a Dolby 5.1 setting. However, I haven't gotten around to trying it yet.

I use DVD2SVCD to write to two CDs (SVCD standard) using TMPGenc, 2-Pass VBR and High Quality motion search precision. I am extremely pleased with the resulting quality. I am using a Celeron 1.1gig, 384meg ram and it takes 18-24hours for the entire process. The ripping is generally finished within the first half hour.

By the way DVD2SVCD can also write to VCD, CVD and DVD formats.

[pclark]

Thx for the speedy replies guys,

I have dvd2svcd and Tmpgenc 2.57 which i find unbelievably complicated! But the more i trawl through this site, the more savvy i become.
Thanks again
Great site
Paul

[Krabbenhuhn]

With DVD2SVCD it is possible to create 6-Channel sound. But that only works with mpeg2-audio, so no chance with VCD I think. But the problem with MPEG MC (Mpeg Multichannel or Mpeg 5.1) is, that many DVD-Standaloneplayers doesn't support it.

[Nelson37]

MPEG 5.1 is NOT Dolby Digital.

VERY FEW DVD players support MPEG 5.1, fewer amps. Basically, forget it.

You're more likely to have mini-DVD support.

You CAN maintain Dolby Prologic or Prologic 2, which is technically Dolby Digital, on SVCD and VCD.

Using CVD resolution, 352x480, which is a subset of SVCD, most movies will fit on 2 disks.

[Cornucopia]

While it IS possible to create an (X)VCD-Yes that means Non-standard VCD- muxed with AC3 stream audio (I have successfully done this myself), it will barely play on a computer (stuttering, etc) and NOT AT ALL on any settop player I've tried! (Better computer results with MP3, yet same on settop)

Also, UIAM (my new acronym, meaning=Unless I Am Mistaken), you will never be able to get MPG2Layer2 aka MPEG2 5.1 audio, to work either. Why? Because standard MPEG1 muxing (and their VCD subset) only allow 1 audio stream to be muxed with the video. SVCD, OTOH, is able to do this because it's MPEG2 and MPEG2 allows multiple streams. SVCD, specifically, supports 2 streams of audio. MPEG2 5.1 is supported by splitting up/spreading across both streams. And yes you should also be able to do this with XSVCD.

And remember Dolby Digital (DD)=AC3...but
AC3 can be Mono/1CH, Stereo/2CH, 3CH, 5CH, 5.1CH...
Don't get that mixed up w/ MPEG1layer2, which can be 1CH or 2CH, or with MPEG2layer2, which can be 1 CH, 2CH or 5.1CH.
Also remember, surround can be 5.1CH discreet or 2CH matrixed (Dolby surround).
As 2CH, it can exist as AC3, MPG1L2,MP3,MPG2L2,WAV-PCM--DTS even.
5.1CH can only exist as AC3 or DTS, or MPG2L2v5.1. (Not counting 6 separate WAV files, since that only works on harddrive workstations with pro sound out.)

Happy encoding,

Scott

[pclark]

Right, ahem!!!! eh? thanks I think!

Paul

[Cornucopia]

What I was trying to say was that you've got some options and I wanted to let you know what they were, but I wasn't gonna hold your hand and tell you what to do. Do you really want that?...

Are you married to "AC-3" or do you just want to preserve "surround"?

/TUT on:
If you're going only for standards-compatible VCD, the standard Mpeg1L2 stereo audio is really the only option. Re-encode the AC-3 to the mpeg, while doing a 5.1->Dolby surround downmix. (BeSweet is a tool for this).

If you go non-standard or if you go SVCD-type, you have more leeway.
/TUT off:

Said enough, won't say more unless asked.

Scott

[pclark]

Thanks,
the reason I was trying to preserve AC3 is I have recently bought a widescreen dts/digital/pro-logic TV. Playing a DVD with DTS is very close to a sexual experience(well in my opinion ) whereas VCD/SVCD is quite dull in comparison. If these are my options, then I will just have to bite the bullet and buy a DVD burner!

Thanks for your comments and time
Paul

[2573]

nelson wrote> You CAN maintain Dolby Prologic or Prologic 2, which is technically Dolby Digital, on SVCD and VCD.


dolby digital or ac3 is a surround mode , two frontals, TWO back chanels, one front central chanel and low frecuency chanel. Dolby digital is pure digital encoding, the signal is digital. The most DVD have this system

Dolby pro logic is an Analog surround system. The best thing of dolby prologic is can tranforn any stereo signal to hear it in surround. It has two frontal chanel, one back chanel ( with two spekers), one centran front chanel and low frecuency chanel.

I you have a TV, home cinema or anything has an Dolby prologic amplifier, you can hear your stereo vcd or svcds or video tape in surround, the result never will be as good as dolby Digital, but it will be great.

[Martyn1980]

Where do i start with my point.

The best your gonna get on SVCD for compatibility and quality is Dolby Pro Logic 2, which your Amp might support, if it doesn't then its plain old Dolby Pro.

I havn't come across a DVD player that can play AC-3 files on VCD/SVCD so forget about that.

Mpeg 5.1 is a good option if you have a Phillips DVD player which support the format, there are a few other makes of DVD player which do it, but they are quite rare and an amp which will decode the signal is even rarer, but they are out there, i have saw 2 amps that can do it, but i doubt you want to go out and buy more equipment.

If your amp supports Dolby Pro Logic 2 then encode the audio as Dolby surround 2 and use that option on your amp.

2573, yes you are right that Dolby Pro is an analogue system, and Dolby DIgital and DTS are pure digital, but Dolby Pro-Logic 2 is a very good in between, it can produce some very good results, and uses all 5 speakers and the sub very well at times, and is a lot better than plain old Pro-Logic.

[2573]

yes i know, i have dolby pro logic and i am very happy.

[pclark]

Thanks Guys,
So what software could I use for converting the audio to pro logic2? I presume this still means that the rear channel will be mono?

Paul

[Cornucopia]

There is floating around here a LOT of misinformation and half truths.

Here's what I know (and I've been working with it for 12 years), but if you aren't sure of my info, just check out The Dolby website...

Dolby Digital (aka AC3) is an ALL-DIGITAL encoding/decoding system (obviously!-hence the name "Digital"). It can take the shape of 1 channel (Mono/Center), 2 channels (L+R Stereo/Dual mono-for karaoke), 3 channels (L, C, R), 5 channels (Lfront, C, Rfront, Lrear/surround, Rrear/surround), and 5.1 channels (above + Low Freq. Effects--not specifically subwoofer though). There can be additional options, but these are the common configurations. All channels are "discreet", that is separate, independant, unmixed channels.

Dolby Surround is a 4 channel-->2 channel matrixing system. "Matrix" here means that the channels are mixed and interrelated-with specific proportions, such that they can later be "unmixed" and played out just as if they were discreet. Of course, there is always a compromise and loss of some separation when doing matrix downmixing.

Here's the part everybody needs to pay attention to:
*Dolby Surround can be ANALOG or DIGITAL. Witness dolby surround on old optical film soundtracks or on VHS stereo audio tracks (analog) or on CD's, VCD's, SVCD's, DVD's, etc. (digital) or LaserDisc (either).
*Dolby Surround information can reside on ANY 2 channel medium. Therefore, it is possible to have a "Dolby Surround" soundtrack encoded using the 2 channel AC3 digital stream format. Or mp2, Linear PCM/wav, aiff, even RealMedia!
*Dolby Surround's encoding matrix algorithm makes use of Phase and Delay and relative Volumes, and decoding will be compromised alot if compressed to a digital file with a LOW bitrate.

And importantly:
*Dolby Surround originally had 1 encoding matrix and 1 decoding matrix. Now there is still ONLY 1 encoding matrix, but there are 3 decoding matrices:
1. Dolby Surround decoding (normal)
2. Dolby Pro Logic decoding (includes "steering" and separation enhancement")
3. Dolby Pro Logic II decoding (more intelligent enhancement)
Once again, these can be ANALOG or DIGITAL.

So, nothing gets converted to "Pro Logic" or "Pro Logic 2"

*Decoding can be done with ANY 2 channel signal (analog or digital). It "should" be just decoding Dolby Surround info, but because it's an accessible system, you can "Decode" a signal that actually originally had NO encoding done to it--such as a regular stereo signal. RESULTS WILL BE UNPREDICTABLE, and any of the 3 decoding systems could be used.

*There are other types of 5.1 channel DISCREET surround signals--Mpeg2Layer2, DTS, which might be usable in a particular disc authoring situation. These probablywouldn't be using the 2 channel Dolby Surround Encoding, though.

I think that if the facts get conveyed, instead of anecdote, solutions will be more quickly forthcoming to those that need it.

Merry Christmas,

Scott

[pclark]

Eureka, I have seen the light, but the difference between pro logic and dts is vast in my opinion and consequently leaves me no option but to go dowm the dvd-r route and hence ultimately signals the demise of (s)vcd's once the general population experience dts for themselves [60p for a dvd-r and £149 for a dvd burner](controversial im sure).

Paul

[ryanreko]

Is Dolby Pro logic 2 the same thing as pro logic enhanced... my amp is a yamaha rx-v592

[Cornucopia]

ryanreko--Haven't compared the two, but it seems they are the same. (RE: Dolby Pro 2 = Dolby Pro Enhanced ?)

pclark--I agree that the difference between any Discreet multichannel format is lightyears ahead of any Matrixed one. DTS does seem to hold the higher ground with quality. However, in some respects this is comparing apples to oranges. Talking about 5.1 channels--If AC3 had as high a bitrate as DTS (~384kbps vs. ~1500kbps respectively--although figures could be off using memory), it's likely that AC3 would then sound as good as DTS. The question of choice for soundtrack usually boils down to "How much can be allocated to fit". I believe that is why AC3 is most often used. It is flexible bitratewise and channelwise, it's got better quality than MP2, and oh yeah, it is a primary acceptable choice when it comes to valid audio streams for DVD. That makes it more ubiquitous and that then feeds upon itself for further choices.

I'm glad you like the quality. It's hard to go back once you're spoiled by the Good Stuff. Hey, have you checked out mp4/AAC yet? That might make future choices moot...
8)
Scott

[vitualis]

Great post Cornucopia!

Just to summarise the facts for beginners:

• Dolby Surround encoding can be put into any stereo audio (including FM radio, audio CD and S/VCD)
• Dolby Digital AC3 is something else -- and cannot be put on a VCD or SVCD
• Dolby Pro Logic and Dolby Pro Logic II refer to the decoding method ONLY. You cannot encode audio to these specifications. These decoding methods all decode Dolby Surround matrixed audio.
• All the common DVD ripping techniques and programs support downmixing the Dolby Digital/AC3 5.1 audio into Dolby Surround compatible stereo audio
• Go to the Dolby website for more technical details. They've got some great information over there!

Regards.

[The Maynard]

Is Dolby Pro logic 2 the same thing as pro logic enhanced... my amp is a yamaha rx-v592

I had a Yamaha that had the same thing and all the ENHANCED does is make it more spacious sounding, like it's in a theater room. It doesn't do anything as far as the seperation of the sound and driving it to certain speakers. It's just a fuller sounding pro-logic.

[Martyn1980]

Just a few things

Dolby Pro Logic 2 has a stereo rear signal similar to Dolby Digital/DTS, and can sound quite similar to Dolby Digital at times, Blade sounds particularly good this way if u use the Dolby Surround soundtrack and use Dolby Pro2.

Virtualis i value your opinion so i believe you that Dolby Pro2 is only the decoding and not the encoding, but when encoding an AC3 file to an MP2 file i always used the surround2 option on whatever software i was using, usually HeAC3che, and got very good results this way, though i did notice if you encoded to Dual Channel you lost the centre speaker, so i recommend plain old stereo, rather than Joint stereo or Dual Channel

Im guessing the reason for this is with Dual Channel its 2 seperate channels so there is no mono channel, which the centre speaker takes the signal from, and Joint stereo can sound very confused and compressed at times, especially with complex scenes.

Im not to sure about whats new recently as ive been working a lot and havn't encoded a film since October, so im a bit rusty, so anyone feel free to correct me on any mistakes.

[vitualis]

Virtualis i value your opinion so i believe you that Dolby Pro2 is only the decoding and not the encoding, but when encoding an AC3 file to an MP2 file i always used the surround2 option on whatever software i was using, usually HeAC3che, and got very good results...

That software claims to downmix the audio in such a way that it apparently sounds better under Pro Logic II. I can't find any info if what it is doing is "Dolby sanctioned" or they simply discovered some clever tricks. In any case, it does mean that the result of the audio may be not as good for standard stereo listening or with a Dolby Pro Logic (not II) decoder.

... this way, though i did notice if you encoded to Dual Channel you lost the centre speaker, so i recommend plain old stereo, rather than Joint stereo or Dual Channel

This could be a bug in the software rather than it reflecting any MPEG encoding mode. The reason I say this is that in terms of data separation between channels, Dual Channel is the same as standard stereo. One channel encodes (L) and one channel encodes (R). The only difference is that in standard stereo, the bitrate can be dynamically allocated during encoding to whichever channel has more "need" (e.g., if L is silent and R has audio, most of the bitrate can go to R). This should have no effect on the actual Dolby Surround encoded info.

Regards.