Need advice for ac3 playback

[sLiMpAuLy]

I have been trying to encode mpeg 2 video with ac3 audio for DVD authoring purposes ( sat captures ect...) I used TMPGEnc Plus to "simple de-multiplex" the files to the vid only and audio only formats. Next I used besweet to convert the mp2 to 5.1 wav, next I used ac3 machine to convert the wav to dobly ac3 5.1. After I "simple multiplex" the ac3 back to the m2v file I end up with my finshed mpeg 2 file.

I the try to preview it before I burn a disc and nothing will play the audio.

Not media player , not winDVD, nothing!

I have the ac3 filter installed and I think thats all I need right?

[txpharoah]

You cannot multiplex an AC3 with a M2V in an MPEG. You'd need a DVD VOB file. I suggest you read the guides some more.

[sLiMpAuLy]

I saved this post from this forum from a while back,

Did a little experimenting with the DVDMF.INI file. There are three lines in it:

playac3=0
decodeac3=0
uleadencodeac3=0

I changed the play and decode options to 1 and fired DVDMF up. Went to import an ac-3 mpeg (specifically, a Mystery Science Theater 3000 episode that I demuxed with TMPGEnc, converted the audio to ac3 with BeSweet, and remuxed with TMPGEnc). Still got that same error message. "Please convert to mpeg or pcm before continuing." Damn.

Went back to the DVDMF.INI file.

All three values were all zero again.

So I changed the play and decode lines BACK to 1 and made the file read-only.

Fired up DVDMF. Went to import the ac3 mpeg again. Same error message popped up. "Please convert to mpeg or pcm before continuing." I let out a few curse words and clicked OK. The file imported anyway! The ac3 audio would NOT play in the edit window, though.

Since this was just a quick experiment, I skipped making a menu and went straight to burning the disc, a DVD-RW just in case it turned out to be a coaster.

Guess what! The disc plays just fine on my Toshiba SD-K710! Hitting the Audio button on the remote tells me the sound is 2-channel Dolby Digital! It even plays on my Stone-Age Sony DVP-S7000, which normally pukes and says "disc error" on DVD-R's and RW's!

Now I'm curious whether I could have authored with the ac3 even without changing the ini file. After all, even with the change, I got the error message telling me ac3 isn't supported before going on to author the ac3 mpeg anyway.

In hindsight, maybe the "please convert to mpeg or pcm before continuing" message having a "do not show this message again" checkbox might have been a dead giveaway?

I'm going to uncheck the read-only box in the DVDMF.INI properties and see if I can still do ac3. Then I'm going to add a chapter menu and see the results.

Meanwhile I'll be interested in hearing other people's results?
_________________
Bob Simandl ... somewhere near St. Louis






Also, I was wondering if you could tell me exactly how you encoded with TMPGenc for the ac3 sound. I get as far as making the file, then am confused on what else I need to do. Do I then need to re-encode using TMPGenc to get the audio and video in the same file? Or do i need to use another program like virtual dub or something?


What I do is fire up TMPGEnc, but instead of opening the mpeg, I click File, then Mpeg Tools, then Simple De-Multiplex. For the Input, I browse to the mpeg file I want to split, say, whatever.mpg.

Once I select it, the output files, whatever.m2v and whatever.mp2 are filled in automatically. I click Run and go get a cup of coffee.

When it's done, I close TMPGEnc and fire up the BeSweet GUI. I choose AC3 as my output format, click the button to browse for an input file, select mp2 as my input format, pick my whatever.mp2 as my input file, click the button to browse for the output file, type in whatever.ac3 for the file name, click OK, click the SSRC button, make sure the sampling rate is set to 48000, click the BeSweet button, click the "mp2 to ac3" button, and go get another cup of coffee.

When that's done, I close BeSweet and fire up TMPGEnc again. I click File, then Mpeg Tools, then Simple Multiplex this time. I make the format MPEG-2 VBR, choose whatever.m2v for the video input and whatever.ac3 for the audio input, type in "whatever.ac3.mpg" for the output file name so it doesn't overwrite the original mpeg file, click Run, then go for a third cup of coffee.

When it's done two things will have taken place:

1. I have an mpeg file with ac3 sound that DVD MovieFactory 2 (and DVD Workshop 1.3) is apparently able to work with, despite the warning message saying otherwise, provided you've made the above changes to your DVDMF.INI file.

2. I'm wide awake.

The BeSweet part above is a bit simplified but there's a guide here on vcdhelp somewhere that explains how to use BeSweet better than I ever could.

Hope that helps....

I tried EXACALLY what it says and the file seems to encode fine but I can't play it on my pc

PLEASE HELP!!!!

*also I am using Ulead DVDWS 1.3 full version to author my dvd's*

[K2]

I do not agree with txpharoah, You can multiplex a AC3 into a MPEG.

I find the sound quality of the AC3 2.0 is the same in play back as AC3 5.1
my player can output AC3 2.0 to all five speakers fine. MPA to AC3 2.0 is one step with BeSweet GUI. Since you are starting with stereo you can only gain so much.

I can only play the AC3 audio with PowerDVD, but crashes on single files over 4 gig. You should be able to play after you make the VOBs and IFOs but before you burn to DVD.

[sLiMpAuLy]

So I can't play it as a mpeg then?

I must create the DVD files first before testing?

well that kinda sucks.....

[sLiMpAuLy]

Please if anyone has a better "recipe" for creating 5.1 ac3 files that can be mux'd to mpeg 1 or 2 Please post, as I'm sure that I'm not the only one struggling with this.

[Quigonsean]

Well, I dunno if this will work better, or even help, but I have a recipe for making 5.1AC3 files from PL1, or PL2. Well it doesn't have to be PLI,or II but there is no real reason to go about this or even all you already gop trough if the source is only stereo. Whats cool is PL I gives 4 discreet channels Frt L&R Centre, and 1 Rear, adn PL II does 6 discreet channels the same as DD only analog. If your source is PL I you will get a 5.1 file with 4 discreet channels and 2 emulated well really 5discrete, it gives you discrete Frt R&L, Centre, but splits the Single rear to play in the RS and LS, but it is mono rear through 2 speakers so that channel is sorta discreet, then the LFE is Emulated. I use the following 4 apps.
1)Tmpegenc
2)BeSweet and it's GUI
3)Hypercube Transcoder http://hypercube.is.dreaming.org/
4)Softencode 5.1

First demux your mpeg with Tmpegenc. (It is a good idea if you plan on doing this to cap your audio at 384kbs for quality and to be in DVD spec in the end)

Now, fire up BeSweet GUI and load in you .mpa/.mp2 file and convert to 2.0 channel AC#. Don't bother using the 5.1 setting because A) you will lose your Pro-Logig info embeded in the audio which will result in all 6 channels being emulated in the end, and B) If your source is not 6 channel it won't make it 5.1 even with it checked of just watch the dos box even with "Create 5.1 File" ticked the dos box will show it's converting in 2.0 channel mode.

After that fire up Hypercube Transcoder and set it to PCM Engine. Then load up your AC3 file that you made with BeSweet and run Hypercube. When it is done you will have 6 pcm files in the output directory you chose. Be sure you have plenty -o- Hard drive space Hypercube kicks out 6 PCM files you know uncompressed so you will basically have in used space the equivilant of 6 copies of the audio uncompressed.

Now, open up Softencode 5.1 Make sure when you set the prefaces and options etc...That under "Encoding" You choose to have it embed Time Code and that it is set to 00:00:00:00 Also there are some profile type settings choose "Standard Film", or "Standard Movie Industry" (I can't remember the exact wording but it is the only one refering to movies/films) Now load your pcm files.Note- you will have to set the "File Type" to *.* all files. And also be sure to load them 1 at a time. DO NOT hold Ctrl and click all of them it will freak out when it gets to the second file.
As you load each pcm, make sure to assign it to the correct channel. Hypercube names each file with the channel it belongs to in the name. ie EmpireStrikesBackAudioDemux_LFE.PCM So make sure to either click the speaker that corrosponds with the file in that tracks track listing. (It has a little 5.1 diagram 3 square in front 2 on rear corners and one in the middle for lfe) or use the pulldown menu, either works.
Make sure that "Lock Tracks" is checked of, and hit "Encode"

Go get a coffe or watch some tv, mabe goto the toilet cause this will take awhile, a little slower than realtime on my XP1700 with 512 MegRam

When it is done you will have a 5.1 Dolby Digital AC3 sound file for your listening enjoyment. Author, or ReMux then author so long as your Authoring App. supports AC3 DVDWorkshop does with ediding its ini file but you get no sound in the preview window.You only need their AC3 Power Pack to transcode to ac3. I've not done this though as now I no longer use DVD WS but Maestro.

Now in all fairness I have not done a whole lot of these conversions, and it is not worth the time IMHO if your not starting out with a Pro-Logic I, or II file becuase it will be psudo surround in that the channels are all emulated by sopftware, where as a PL I, or PL II has 4, or 6 descrete channels and will produce a real nice surround track, especially if the source is PL-II. This conversion is great when capping VHS tapes that either are not available on DVD, or are flicks you like but not enogh to re purchase it now on DVD.Well great on VHS tapes that have PL-I,II sound.

Also in all fairness, the latest one I've been working on is fighting me and winning. It's Empire Strikes Back SpecEd. The problem is my org mpeg audio track is the same length as my m2v, but the AC3 BeSweet kicks out is 7 or 8 minutes shorter. I hope I can figure this out, or get a proggie that converts my mpa to ac3 without shortening it, or that a future release of Hypercube accepts mpeg1 layer2 audio. Incedently if you DVD player supports multi-channel mpeg audio Hypercube transcodes to that as well as 6 raw pcm's.

This is not meant to be a guide just an experience that I hope may produce an ac3 file that might work for the org poster. BTW I have found numerous times I've had to run ac3 files made by BeSweet throough "ACEFix" for some programs to accept them, so this may fix your problems then and there. Actually it was AC3Delay Corrector not ac3fix ran on them. Just but this also was when the mpa was demuxed with DVD2AVI then converted with BeSweet.

Well I hope this helps ya, if not sorry to waste your time reading this novel of a post.

Sean Ward aka QuiGonSean

[sLiMpAuLy]

Thank you!

I will give that a try and if I have success I'll be sure to report my final methods here. If anyone else would like to add something I'm always open to sugestions.

[Quigonsean]

No Sweat. Yeah, that'd be great, please do post it here. I'd like to know if it works out for ya. Or if you have any trouble.

Sean

[Heartless Angel]

Please if anyone has a better "recipe" for creating 5.1 ac3 files that can be mux'd to mpeg 1 or 2 Please post, as I'm sure that I'm not the only one struggling with this.

I'm not sure if I'm gonna answer this right, but this is what I do for .mpg2 for DVD output...

I use VirtualDub to extract my .wav file and AC3Machine to create an .ac3 file(DEPENDANT on source audio), then I mux the audio/video in BBMpg/Avi2Mpg2.

If that sounds like something that you're interested in, I can give you the settings I use.

You should also be aware of various DVD authoring progs that do/don't accept .ac3 audio, and their respective ways to get around the problem, e.g., DVDWS.ini file.

"Titles are the shield that weak men hide behind..."

[Heartless Angel]

I've started using Sonic Foundry's Vegas 4 to create true 5.1 Dolby Digital/6 channel .ac3 audio streams. I'm still learning so the way I do it is probably a long way...

VirtualDub to extract audio .wav file, open in Vegas 4, and render as Dolby Digital 5.1 .ac3.

"Tell me, I will forget, show me, I may remember, but involve me and I'll understand."

[Cornucopia]

Quigonsean:

Your info on methods is basically very sound and helpful, but don't tell anybody that PL1 or PL2 has discreet channels cuz it's not true. Only PCM, DD(AC3) or MP2 audio has discreet channels. Dolby Surround (decoded to ANY form) is by definition Matrixed sound. While PL2 and to a lesser extent PL1 are better at increasing the apparent separation, it's still just trying to UN-Mix a Mix--with varying degrees of success.

I giving advice, we all have to be careful not to supply additional information that would mislead (myself included).

Scott