4 seperate mono WAV @48000Hz to 2.1 AC3?

[mumbles]

Hey there,

I'm kinda stuck here... I've been trying to take a stereo audio source and add an LFE track to it to create a 2.1 AC-3 file. Anyway, I'm using Sonic Foundry Sonic Encode 1.0 to create an AC-3 file using 4 seperate mono WAVs @ 48000Hz, 16 Bits. I've tried many different combinations and none seem to work--as the program just crashes. I've tried eliminating the LFE channel and it still won't work. It gets no further than 5% before crashing.

I've had this issue in the past with Soft Encode and I can't figure it out (I originally had 44,100Hz, 16-bit files--but it didn't work so i'm trying 48000Hz). All files are the same length, I don't care if I have to get rid of the center channel as I don't feel it's that necessary--but if I need it to comply with SoftEncode I'm using it. I've thought about tricking it by placing blank files for the surround channels--not sure about this. I've considered other programs such as BeSweet GUI & WaveWizard (have no idea what i'm doing with that).

Any ideas?

[aedipuss]

softencode was dropped from sonic foundry what...7 years ago? as far as i remember even when it did manage to finished encoding an ac3 file they were all non-compliant anyway. 2, 3, or 5ch. it didn't matter, it's useless.

[guns1inger]

Why add an LFE to a stereo source ? Most LFE channels have very little if anything in them, and rely of the amp themselves to switch the low frequencies across.

[Cornucopia]

softencode was dropped from sonic foundry what...7 years ago? as far as i remember even when it did manage to finished encoding an ac3 file they were all non-compliant anyway. 2, 3, or 5ch. it didn't matter, it's useless.

What are you talking about?!

Have used SFSE for years, 2-ch or 5.1 ch. ALL compliant files output (as long as you choose the right settings). Most of the time now I use the AC3 encoder in Vegas (as it's likely an updated version of SFSE incorporated as a plugin), but still no problems either way. Sounds like a case of GIGO.

Scott

[mumbles]

What are you talking about?!

Have used SFSE for years, 2-ch or 5.1 ch. ALL compliant files output (as long as you choose the right settings). Most of the time now I use the AC3 encoder in Vegas (as it's likely an updated version of SFSE incorporated as a plugin), but still no problems either way. Sounds like a case of GIGO.

Scott

yeah I'm quite sure that's it. I bet if I just went with a normal 5.1 mix with surround channels it would work, but then again I don't know what could be wrong with it. I've tried numerous options and none seem to work. I recall having this issue with a previous, much larger & complex file but I changed one option and it worked--or at least that's what I remember. I thought I had used a different program (freeware?) to do it but, like I said, I can't remember.

[aedipuss]

never had softencode make an ac3 that was the proper length. give it 6 48khz mono wavs and it always ended up with adding seconds if not minutes to the ac3 audio it made. at some point the movies would always go out of sync.
if you still want to try and get it to work - in encode options uncheck everything to start and set the drop down compression box to "none".

[Cornucopia]

Couple of rules to follow with SFSE:

1. DVD's are all 48kHz, so ALWAYS give it 48kHz source files. (This is a big bugaboo for lots of apps). UNCHECK [Auto] unless you have consistent and reliable sources.

2. Make sure that [Intel byte order] is UNCHECKED. DVD's all expect Motorola byte ordering.

3. Many modes are available 1.0, 2.0 3.0...5.1, and LFE is available as an option in all but 1.0 and 2.0. But don't use LFE unless you actually have Low Frequency Effects that aren't meant to be folded into the mains. Many, many people mix up Bass Management with LFE assignment.

4. Bitrates can be anywhere from 96kbps to 640kbps, but most common is 192 or 224 for 2.0ch and 384 or 448 for 5.1ch.

5. Bitstream mode/type should ALMOST ALWAYS be [Main Audio Service:Complete Main]

6. All channels/tracks should be EXACTLY the same length, down to sample, otherwise this will cause the app to pad.

7. These are the rest of the settings that are commonly used:
Dialog Normalization: -27dB
Audio Bandwidth: 20.30kHz
Dolby Surround: Not Indicated or NOT Dolby Surround encoded
Digital DeEmphasis: Unchecked
DC Highpass Filter: Checked
Bandwidth Lowpass Filter: Checked
Dynamic Range Compression: Film Standard (a better place to start)
RF overmodulation protection: Checked
Timecode: UNCHECKED<--Important!

The other stuff can go either way, doesn't matter too much from an authoring standpoint (copyrighted, audio prod. info).

That should get you started on the right track...

HTH,
Scott

[Noahtuck]

never had softencode make an ac3 that was the proper length. give it 6 48khz mono wavs and it always ended up with adding seconds if not minutes to the ac3 audio it made. at some point the movies would always go out of sync.

Must have been U.E.
I just made a 5.1 track saturday and it ended up being the exact same length as the other audio tracks and the dvd never went out of sync, like every other time i have used it.
Although i must admit i do like using Vegas more than Soft Encode.

[Cornucopia]

I concur.

[mikiem]

"I'm using Sonic Foundry Sonic Encode 1.0 to create an AC-3 file using 4 seperate mono WAVs @ 48000Hz, 16 Bits. I've tried many different combinations and none seem to work--as the program just crashes. "

Probably stupid question on my part, but why 4 files? I mean that's one stereo & one mono track, or 3 mono. In the Vegas ac3 stuff I know it'd just be stereo ac3 with LFE enabled, but have never played with softencode so don't know if that means anything.

Edit: if it helps, in the vegas dialogs anyway, have separate settings off stereo for 3.1 etc. Also if it helps, if you do give up on softencode, check the forums here on using other then besweet for ac3 encoding.

[guns1inger]

I have had Soft Encode do strange things from time to time, but the reason I stopped using it is simple. It is so slow compared to Vegas, and Vegas has so many more options, as Mikiem pointed out.

I can understand why you might want to put a mono surround into, instead of using Dolby PL to do it, but I still can see the point to putting an LFE channel on a stereo mix.

[mumbles]

thanks for all the help so far everyone! to break it down a bit, i have 3 channels for the front (left, center & right) and one for the LFE. I'm likely to take out the center channel in the end if possible.

now one of the problems is that the LFE channel is a fake that i made by just lowering the EQ of everything but the bass down to Infinite db... i knew from listening to it that it wasn't a true LFE channel and i have my doubts that the project will sound good at all after doing this... infact, the LFE channel is louder than the other files itself so i need to work some stuff out. i wish there was a program that would generate a true LFE channel--but i bet that's impossible as i've seen real LFE channels' and there's little soundwave activity at all.

i've tried some of your suggestions (went thru your list Scott) but so far nothing has worked. at this point i'm going to assume that there's an issue with my source files. i'll re-convert everything and try it over. another thing is that i do have Sony Vegas but i don't have the AC-3 encoder plugin and have no idea to activate it if i did--from what i've found out it only comes with Sony's Vegas+DVD package. i would love to try that route instead. the freeware app method is a little out there, i've pretty much fried my brain with this authoring stuff.

another detail is that my C drive has less than 700MB free, so i set the temp directory on my D drive with over 15GB free. does that matter with SFSE? i'm assuming the C drive wouldn't need free space if the temp files aren't even going on it but at this point it wouldn't surprise me.

[Cornucopia]

Couple of things:

Don't use LFE for that--that's kind of what I mentioned in my point #3 above about people mixing up Bass Management & LFE assignment.

All of the Full (meaning non-LFE) tracks in a surround configuration are just that--FULL. This means they can (and probably ought to) include 0Hz (20Hz realisticly)...20+kHz response (not even counting higher sample rate stuff).
When you put bass in one of these main channels, it will get played out on your playback system depending on how you've set it up. This includes Bass Management (Subwoofer Included/Not, Level, Delay, Crossover Freq., etc). On playback systems with subwoofers (and suggested Bass Mgmt setups), ALL material below, say 80Hz, is rerouted to the mono or stereo subwoofer--whether it's coming from the Full or LFE channels.

You also SPECIFICALLY do NOT want to re-route your main bass material into the LFE channel only, because when systems which are Stereo/DolbySurround/PL do a downmix (automatically), they throw out the LFE channel altogether! This is the recommended and intended procedure direct from Dolby Labs, I kid you not. So don't get caught with missing bass...

There is no app from automatically generating a completely synthetic LFE, but honestly, it's overrated and rarely needed.

I know the upgrade from Vegas to Vegas+DVDA (which is the one that includes the AC3 encoder) is $299US, and that's a little steep, but that's partly 'cuz of Dolby's licensing demands. If you do enough of this kind of stuff, it's probably worth it.

But get out your wallet anyway, 'cuz it sure sounds like you need more drive space...


Scott

[raquete]

from soft encode help file:
"LFE low-pass filter
This parameter will apply a low-pass filter to the encoded LFE channel when checked. The low-pass cutoff frequency will be at 120 Hz. It is recommended that this option be checked for best results."

but wait please.
all day long my hobby is extract channels from stereo sources to do AC3 5.1,i really like it.
LFE (stomach effects as i call) always had my special atention.
i did many scripts in audition for fft filter,equalizers to test.
doing "thousands tests for long months,my conclusion is:
don't encode LFE,let the decoder do the job for you!!

best regards all!