problems converting mp3 -> ac3

[oahnve]

I have tried getting a 44100 mhz Fraunhofer mp3 -> 48000 ac3 by using BeSweet. The ac3 turned out silent and half the size it should have been, so I tried converting it to wav - same result.

Why is this?

[DJRumpy]

Make sure you have the latest version of BeSweet. Also, grab the latest version of BeSweet GUI (v6B6 I think). You will also need SSCR (you can find all of these in the TOOLS section on the left).

Open the Besweet GUI, and click on BeSweet on the right. It has three inputs that you must give it. The path to your BeSweet.EXE, the path to your input file, and the path and filename of your output file. Click the little floppy symbols at the top left of the GUI to define those. The setup is the same for SSRC. Convert your audio to WAV if it isn't already. You will need it to resample your WAV audio from 44.1 to 48 Khz using SSRC. Then back to BeSweet to convert your 48Khz WAV to AC3.

[oahnve]

Thank you for your tips, although I have the latest version and I have defined all of the settings in BeSweet. I try to tell it to convert directly from mp3 44100 to ac3 48000. Shouldn't that be possible? It ends up with a seemingly good file, that is... silent.

Now I converted the 44100 mp3 to a 48000 wav in winamp and shall try to convert it to ac3 in BeSweet just to see if the problem is that it can't convert 44.1 mp3 -> 48 ac3.

[DJRumpy]

I've tried the one click does all, but it doesn't seem to work very well. Just do the steps manually. Convert to WAV. Resample with SSRC if necessary. Convert to MP2/AC3.

[NightWing]

Had luck just converting the Mpeg audio into a PCM wave. IE raw audio. Then from there into a AC3.

[oahnve]

Ok, so that is the problem... Thanks!

I got it working after lots of pain (converted in Winamp to 48 and then in BeSweet to ac3), but the first time I got a file that was twice as long as the original file... what the heck is that??

Then in some way I got it the normal size and everything seems fine (I checked it in Winamp and all audio was present and perfect). What happens - When I try to author it in Spruce the audio stops after half the movie...

Oh, I should add that it is a mono 96 kb/s I am dealing with.

[DJRumpy]

I would suspect a corrupt audio file. What format was in to begin with, and what steps did you take to extract it? I think you said it was MP3?

[oahnve]

mp3 96 kb/s mono.

I extracted it with VirtualDub, converted from 44.1 -> 48 with Winamp (is there a better way - it seems to go too fast using WA somehow...) and finally from mp3 -> ac3 with BeSweet.

About the file being corrupt - how come it is fine in wav (I actually even burned it on a RW with wav and it worked, but I know the VOB's become too big for the DVD-R media I use), mp3 and even when listening to it in ac3 in Winamp?

[DJRumpy]

Use SSCR to convert it from 44.1 to 48Khz. When you extracted it from VirtualDub, did you use the 'Direct Stream Copy', or 'Full Processing Mode' under the audio menu (in other words, did you extract an MP3, or a WAV file)?

[oahnve]

Direct Stream Copy in VirtualDub.

How is SSRC used as standalone pgm? I guess it is used by BeSweet and also TMPGEnc, but I never used it on its own. Is it basically as a command line pgm?

Btw: Thanks for ur time!

[DJRumpy]

It can be used on it's own, but its DOS based. The BeSweet GUI (find it in the TOOLS section), comes with a built in plug-in for the dos executable (ssrc.exe). Much easier than typing the necessary LONG command line.

I would also suggest you extract your audio in virutal dub using the "Full Processing Mode". This will give you a WAV file instead of an MP3, which then has to be converted to WAV. It also removes any VBR encoding errors (if they exist).

[oahnve]

Ok, now I have all information at least... so just need to do the job.

THANKS again!!

[DJRumpy]

Just post if you have any problems/questions...

[oahnve]

Since you say it like that I feel I need to take advantage of the situation and ask you if you are an expert at Xvid-conversion to DVD. I tried several times converting a 25 fps Xvid -> DVD and it is smooth as silk on the PC, but on the standalone it is veeery jerky. I tried posting this question about a week ago without any luck.

I have converted lots of 23 fps -> DVD and also 25 fps DivX with sweet result.

When converting 25 fps I should NOT do 3:2 pulldown I take it from all the guides. But it feels like a logic reason for my problems since from what I understand the TV plays back media at a different frame rate than the PC monitor.

Sorry for trying to take advantage of you, but I'm kind of out of alternatives with this one...

[DJRumpy]

Are you NTSC, or PAL? If your NTSC, you should convert it back to 23.976 fps before encoding, and use pulldown to telecine it to 29.97 fps.

Also, what encoder are you using?

[oahnve]

I am PAL, but normally it handles both.

I frameserv with VirtualDub to TMPGEnc (tried CCE once, but got some strange purple borders on the output movie...) and it works perfect with all formats and codecs except for Xvid 25 fps. Xvid 23 works like a charm, Divx any fps works like a charm. That is why I am so confused...

[DJRumpy]

I haven't heard that one before. If your player supports both, then you can always try converting it back to 23.976 with AVISynth. Use:

AssumeFPS(23.976,False)

You need to extract your audio first with VirtualDub. Use BeSweet, and the PAL to FILM option to convert your audio It takes about 5 minutes extra work. I can't help you much on the encoder. I could never get the pulldown to work properly in TMPGenc. You could always convert back to 23.976, and use PULLDOWN.EXE to add the pulldown flags to your MPEG. I use CCE. You should give it another try, as it will trim hours off of your project.

[oahnve]

Because the codec doesn't have ANYthing to do with the framerate - right?! It should be a no-brainer from my side, but I have tried it three times with both CCE and TMPGEnc.

CCE seems like a better choice, but it hogs looots of memory (I think 3x more than TMPGEnc), which I can't do since I work on it while encoding. Would you know of any reason why I got the purple (actually the side borders were white and the top/bottom borders purple...) borders? I am pretty good at TMPGEnc, but CCE is new to me, so I just followed the guide at doom9.

[DJRumpy]

It would depend on the options that are selected (specifically under the Video options), and the resolution of your input file.

What resolution and type is your input file? You mentioned DivX. Are you frameserving that to CCE, or just dropping onto CCE as is? Also, what video options are you using?

[oahnve]

The only one I tried with CCE was a frameserved 25 fps 640x256 Xvid. I tried to follow the guide at doom9, so I am not really sure what video options I checked. DVD compliant, Add sequence end code I guess...

[DJRumpy]

Your getting black borders, because you checked 'DVD Compliant', and your AVI was not a standard DVD resolution. CCE corrects this by picture framing your movie, to fill out the resolution to standard. This is an easy fix. Just install AVISynth, and write the following script in Notepad for a 1.85:1 movie:

AVISource("c:\yourmoviepath\yourmovie.avi")
BicubicResize(720,576)

Save it as a .AVS file. If your movie's aspect ratio is 2.35:1:

AVISource("c:\yourmoviepath\yourmovie.avi")
BicubicResize(720,432)
AddBorders(0,72,0,72)

Try encoding a small piece of clip, and view it with a DVD software player. I've never encoded in PAL resolutions, so I don't know if the math for DVD 2.35:1 aspect ratio's is the same.

[oahnve]

Wow, thanks! I'll definitly try that. Thanks a lot!!!

[oahnve]

Ok, I'm back... with updates on the problem.

Now I have tried a few 23 fps-movies frame served with VirtualDub -> TMPEnc. Two of them I put on the same DVD - one was jerky one wasn't. Both of them were 23fps, had mp3 audio that I had converted to WAV and then to ac3. The only difference between them was that I had checked for bad frames in one of them - could that be a problem? When I do that I first check for bad frames and then save to a new avi-file.

I tried a third avi in exactly the same manner - jerky. I am going to try not checking for bad frames, but it sounds unbelievable.

[DJRumpy]

I never check for bad frames, unless I suspect them. The option doesn't perform any changes to your source avi, unless you save it as a new avi. I doubt that is why your output was jerky. I also frameserve everything using AVISynth.

Are you sure you had all of the same options selected for both runs? You should consider making a template, and running the same template on both AVI's, to ensure everything else is equal.

[oahnve]

Well, I guess I can't be 100% sure about it, but pretty darned sure at least.

Do you know if the sound could be the problem? I convert them with VirtualDub and Ac3Machine. I am going to see if a wav will make a difference. I need to try everything.

I'll try a template.

[oahnve]

BIG NEWS... Encoded the 23fps divx but this time changed the field order to see if that was the problem. Also made the file small enough to be able to hold the wav to see if that was the problem.

Authored the mpeg in Spruce with the WAV, worked perfectly on the standalone. Of course I think it is the field order that was the problem. Just to be sure I also author it with the ac3 encoded from WAV with ac3Machine. IT WAS JERKY. I found the problem!!!

It was the sound that did it. Why the heck is that and what should I do about that? I mean - I could try different encoders, but what is the difference between ac3 and ac3? I can't be stuck using WAV when converting do DVD...

[DJRumpy]

Use BeSweet and BeSweetGUI to create your AC3. I wonder what bitrate your AC3 is? You can use the MPEG Properties tool from the TOOLS section to the left to view it's bitrate.

[oahnve]

Update: I re-encoded the ac3 to 224 kb/s instead of the original 192, and all problems were solved... Is this maybe the standalone's fault?

[DJRumpy]

Shouldn't have mattered. This was for DVD right? SVCD doesn't technically support AC3. The bitrate for your audio is within specs though. Maybe something during the conversion process hosed the file. There are a lot of steps to complete, and any one of them could go wrong. That's why I like the BeSweet GUI. All in one place. Input..resample..output.

[oahnve]

The thing is I have always used BeSweet GUI. Maybe once or twice Ac3Machine - but it is using the same software... Anyway my encoding future looks better now - a lot thanks to you !