Converting WAV to AC3 - sound loss

[MackemX]

I've used ffmpeggui03c which was simple to use but there is a significant loss in sound volume

is this normal?

I was going to use Besweet but apparently it doesn't make compliant AC3 streams so I'd rather not use it

any suggestions?

[drewzor]

Hi MackemX, what was the original biterate for the wav? and the biterate of the ac3.. if it is significantly different that would be where the loss of detail/volume has gone. Also in Besweet there is a advanced area that allows you to change the DB, maybe its set negative dropping the total volume over-all.

Hope this helps

[Soopafresh]

Try the latest version of Aften with the AftenGUI . You'll see a dropdown box called DRC profile. That'll add dynamic range compression, which will increase the volume of the soft parts.

http://kurtnoise.free.fr/index.php?dir=Aften/

Choose DRC Profile -- FilmStd or Speech

[FulciLives]

The problem is that none of the freeware AC-3 encoders allow you to set the "special" parameters that can control the "volume".

For instance you should first normalize your WAV file to -3.0db (to be safe) although technically you can normalize to 0.0db if you wanted (although cheap speakers like those built-in to a TV may not handle 0.0db audio well without distortion).

Then in your AC-3 encoder you set it up to -31db for the Dialog Normalization setting and you set the Dynamic Range compression to NONE (also no RF Modulation compression).

That will give you an AC-3 audio file that has the same "volume level" as the WAV file.

Unfortunately like I said none of the freeware AC-3 encoding programs have those options available (at least to the best of my knowledge).

You need something like the old "Soft Encode" program or the AC-3 encoder plug-in for SoundForge or Vegas etc.

- John "FulciLives" Coleman

[MackemX]

thanks for the reply guys as I'm not so clever in the audio area when it comes to DVD's. The WAV file is from a DVD with LPCM but I don't know the bit rate as I never really looked. The DVD is 2 hours long and the audio is 1330MB with the video being 2788MB

I asked earlier in this thread below how to convert LPCM to AC3 but while I was waiting I tried Besweet and the ffmpeggui03c. I'd rather not use Besweet for the compatibility issue someone has mentioned

https://forum.videohelp.com/viewtopic.php?t=316092

I've just paid some good money for these DVD's and whoever created them didn't do a great job . That's why I'm remaking them again creating a menu/adding chapters/resynchronizing some audio etc. Seeing as 1 DVD had LPCM audio I thought I'd convert it as I can probably put 2 DVD's onto 1

it doesn't have to specifically be AC3 as the 2nd DVD is MPEG-1 audio so anything will do really as this isn't a movie nor does it have lots of sound effects, it's mainly speech . It does have varying levels of audio in different scenes with the speech as sometimes the mic hasn't been in the same place. Would 'normalizing' improve the audio?

there are also quite a few pops n crackles on one DVD as I think it's a bad recording (the kind when recording levels set high if you know what I mean). I'm just playing around as I don't really need to do it but I thought I'd give it a try as I know my mate wants me to put a few of his home videos onto DVD so this will be good practice

I see SoundFourge have a 30 day trial so I may give that a go

thanks again (but no doubt I'll be back )

p.s. I've made it sound like a porno movie

[FulciLives]

Try the latest version of Aften with the AftenGUI . You'll see a dropdown box called DRC profile. That'll add dynamic range compression, which will increase the volume of the soft parts.

http://kurtnoise.free.fr/index.php?dir=Aften/

Choose DRC Profile -- FilmStd or Speech

I've never heard of this Aften program so I downloaded AftenGUI 1.3 (which appears to be the newest version) and unzipped it ... I also downloaded Aften 0.05 rev216 (which appears to be the newest version of the "core" program) and put it it in the same folder as the GUI files.

This FREEWARE AC-3 encoder does have options like the more professional encoders ... I've never seen these options in other FREEWARE AC-3 encoders.

Here is how I did it:









The input was a 16-bit 48k 2 channel Stereo PCM WAV audio file that had normalization applied to -3.0db using GOLDWAVE ... one could do the same thing with Audacity which I mention since Audacity is FREEWARE whereas GOLDWAVE is not FREEWARE.

I have to admit I am not "positive" as to the setting on the MISC. TAB so I left all that at the default settings but I'm pretty sure that for 2.0 AC-3 that all the other settings are correct.

These settings I picked in Aften are based on my AC-3 encoding experience with the "Soft Encode" AC-3 encoder as well as the AC-3 encoder from Sony Vegas/SoundForge.

For more info on AC-3 encoding there is an excellent guide in the AUDIO ENCODING FORUM over at the doom9 forums.

- John "FulciLives" Coleman

[MackemX]

why am I converting it to AC3 in the first place?

I'd be happy with basic stereo or even mono as it's just someone talking

[FulciLives]

why am I converting it to AC3 in the first place?

I'd be happy with basic stereo or even mono as it's just someone talking

Well the DVD Video format calls for either LPCM WAV audio or MP2 audio or AC-3 audio and AC-3 audio doesn't mean Surround Sound per se ... you can have normal 2 channel mono or 2 channel stereo AC-3 which is called 2.0 AC-3

As for why to go with AC-3 ... LPCM WAV takes up a lot of room whereas AC-3 is compressed in such a way that it offers excellent sound quality yet takes up only a fraction of the space of LPCM WAV audio. MP2 audio (also called MPEG-1 LAYER II audio) is not considered to be very compatible when it comes to NTSC regions and really should be avoided for a professional level DVD Video disc.

- John "FulciLives" Coleman

[MackemX]

keep it coming as I'm learning new stuff here . It was DVDShrink that said the other DVD was MPEG-1 audio but now I realise what it is and you've just confirmed it (MP2/Layer II)

the original quality isn't the best to begin with plus it's only speech so I'm not looking for anything special just as long as it's OK

I will try a MP2 version just to see what it's like

[Soopafresh]

Glad to see you found that little app, FulciLives. It is a good one, and it is being actively developed. There's supposed to be a plugin to make it work with Besweet/Belight as well.

[jan.t]

Hello

I want to use AftenGui_1.4 on my new Vista laptop but cant unzip it. I get "access denied" and "cant find path" for all files (in swedish). I dont want to change since I know it works well when I burn my dvds. Any Ideas`?

I solved it. I had the program elsewhere and copied it!

Thank you