wav >>> ac3

[rdbello]

Is it possible to convert a WAV stereo in AC3 5.1 channels?

[mikecito]

Yes

You can use Besweet, but I prefer Sonic Foundry's Soft Encode.

You won't get surround sound out of it, but it will produce a compliant 5.1 stream. To get surround sound, you need the 5.1 source. Sure, you can duplicate the left and right front to the left and right back and add some LFE and center channel sound, but it won't change how it sounds, other than coming from all the speakers instead of 2. If you have a good receiver, you should be able to tell it to do that WITHOUT converting it to 5.1 first. Mine does it, and it's not too expensive.

[rdbello]

Could you explain to me how can I do this with Soft Encode?


Thanks

[mikecito]

Well - it depends on what you want to do. If you want the same music coming out of all 6 speakers, then just open multiple copies of the wave file and assign (on the left side there's a speaker diagram) each left and right to the places you want them. Usually channel 0 is left, and channel 1 is right (or channel 1 and 2 respectively if your program starts numbering at 1 instead of zero).

However - this won't sound very good because you will have to choose between left and right on the center channel, and on the LFE, which shouldn't have the original sample anyway.

So - to fix this, if you just want your music to sound like it's coming from all around you, I would leave the center channel and LFE blank, and just encode to the four speakers.

If you want all 6 speakers pumping, then open the original wave in CoolEdit and mix down to one channel for the center channel. Save that as a center channel wave to open in Soft Encode. THEN - for the center channel, pass that same down-mixed wave(In Cooledit) through a low pass filter set to about 120HZ or so. Save the processed wave for the LFE channel, as this is perfect for most subwoofer systems.

Also - don't forget to check your encode options to make sure you're encoding to 5 channels + LFE enabled.

Does that help?

[rdbello]

You help me very much, mikecito. I did not only understand very well the part of the Cool Edit. How can I make the "mix down you one channel I will be the to center channel" and about the filter that I'll use to set in 120 mhz: is in the Cool Edit or the Soft Encode?

Thanks

[mikecito]

To down mix two channels into one channel, just open your 2-channel (Stereo) wave in cool edit. Then click on edit --> convert sample type. Under the channels section of the pop up window, just click on the mono option. Leave everything else the same, and push ok. If it's a large file, then you might have to wait a few minutes while it does all the adjustments, but there will be a progress bar. Then save that file as a wave file labeled as center so you know which one it is.

Next - to do the 120 HZ lowpass filter, I found an easy way in Soft Encode. Under Encode Settings, on the right there is a tab that says "preprocessing." There is a checkbox there that says "LFE low-pass filter." Make sure that is checked. It is the default setting, but make sure anyway. That should filter any sound you put into the LFE for you. Make sure you use the combined Center channel wave for the LFE too.

In Soft Encode, I would leave all the other default settings like they are unless you really know what you're doing. The only setting I would change is the bitrate on the top left of encode settings. The higher the bitrate, the higher quality the output. 448 should be plenty for anyone's ear. Also - if the final output is dvd, you must have your audio encoded at 48000 HZ(before soft encode). DVD Authoring programs won't accept (neither will soft encode without changing some settings) 44100 HZ sound. If you started with a 44100 HZ wave, you can adjust it in the same place you mixed the two channel wave to mono.

I hope that helps!

[rdbello]

I understood. You use Cool Edit only to convert the audio file in 16 bits mono, correct?

See what I made:
I imported the audio file two times, this generated 4 channels. Later I imported audio_center.wav and it generated only one because it is mono, right? I must import it to place again as to subwoofer?

One more question:
I'll play this dvd in my home theather. If I'll listen this audio in a tv speaker, this sound will be good too playing in two channels?


Thanks so much for your help.

[mikecito]

That's right - you use cool edit to convert the audio file to 16 bit mono 48000 HZ audio.

Also - you're right on the second half too - importing it again is how you get the channel for the subwoofer, just like you reimported the original wave for the rear channels.

Also - your tv will reproduce the sound correctly, because it will be playing the original source file that you imported to the front R/L channels in the first place. You won't have the surround effect, of course, but the sound will be the original sample because all the extra ones you created will be lost in the stereo connection from your dvd player to the tv... unless your dvd forces all channels to the stereo speakers on the tv. But don't worry too much about that. It should be fine.

[rdbello]

Thanks again for all. If you'll need any help and if I can help you, let me know. I'm a novice in dvd authoring, but I understand something about scenarist/reel. I intend one day to develope some games in dvd and I'm studying to make it. This technique that you explained today can be used to also producing titles for karaoke, too?

[mikecito]

Not sure on the Karoake thing - sorry, I've never messed with it.

[megamax]

Dear Mikecito,

Hi !

I am using Video encoder Metrox & Dazle DVC II wich encode real time MPEG 2 streem for dvd encoding.(I dont have Dolby hardware encoder).
can I use audio streem direct with ACID PRO 4.0 or Vegas+DVD or any other software .

Coz audio encoded is not wave or I have to menualy encode audio to WAV or MP3 ?