What _exactly_ does it mean to "normalize" an audio stream?

JimmyBarnes · 8th January 2002, 05:17

Does it simply mean to make the softer sounds louder and the louder ones softer? If so, to what "common" level?

thanx
JB

wmansir · 8th January 2002, 08:06

Actually, what your talking about is called dynamic compression. It compresses the difference between the soft and loud parts, so entire dynamic range of the soundtrack is reduced.

Normalization on the other hand, does not change the dynamic range. So the difference between the loud and soft parts are the same. Instead, it increases the volume until the loudest part is as loud as the soundtrack can handle without causing errors. This increase in volume is applied equally to the entire soundtrack, so that all parts are louder.

There is a 'normal' amount of dynamic compression performed when a DVD is played in a standalone, which often can be adjusted by the player. Some software decoders, like Azid, also allow you to adjust this compression when decoding the soundtrack to a .wav file.

pacohaas · 8th January 2002, 08:33

how about reading the FAQ's before posting?

8th January 2002, 09:17

I always use a 'DRC light' for my DivX movies. If Dynamic range is still too high for the speakers i use for playback i activate 'DeDynamic' audio DirectShowFilter in PowerDivX 3.12 and compress a few dB of dynamics more ( max. 15 dB or sound sill start pumping due to AGC, very annoying, but 15 dB compression is a lot ).

For SVCD i always apply 'DRC normal' in Azid ...

JimmyBarnes · 8th January 2002, 14:08

Quote:

Originally posted by wmansir
Actually, what your talking about is called dynamic compression. It compresses the difference between the soft and loud parts, so entire dynamic range of the soundtrack is reduced.

That could be what I need rather than normalisation.

When I ran Normalize v0.241 on the PCM wav soundtrack file, it did a peak scan and reported that peaks were at allowable min and max respectively => no amplification required.

Can you suggest a program which can do dynamic compression? The movie soundtrack is from Pearl Harbor - speech is very soft and often inaudible unless TV playback volume is set to near maximum, but on that setting, volume level from the bombing sequences is deafening.

thanx
JB

8th January 2002, 17:25

If its a WAV you may try Dedynamic.exe from http://www.divx-digest.com .

It will perform AGC on the WAV and amplify the silent scenes only. I recommend to use 4 - 6 dB compression, never use more than 15 dB ( sound strange ).

If its an AC3 still than use Besweet and Besweet GUI from Doom9 download to transcode this AC3 to MP3 and set a DRC setting in Azid like 'DRC ligth' or 'DRC normal'.

In case its a final AVI already download PowerDivX 3.12 player from Doom9 or http://www.powerdivx.com and activate the 'DeDynamic' audio DirectShowFilter for playback .... it will allow you to perform AGC on playback, plus in addition to that + 6 dB amplification ( free of clipping ).

I this is still not enough and the silent scenes still not loud enough you may try the excellent tool 'WaveBooster' from LigH to amplify your sound by up to +12 dB without the danger to run into clipping . It comes as part of BeSweet and BeSweet GUI should allow you to process the WAV into another WAV, or to transcode it to Lame VBR/ABR MP3 same go. The final MP3 ( very high quality ) can be muxed to your AVI using nandub RC2 ( Doom9 again ).

JimmyBarnes · 8th January 2002, 23:36

Quote:

Originally posted by ChristianHJW
If its a WAV you may try Dedynamic.exe from http://www.divx-digest.com.

I presume that's Nicky Pages (site down or URL not found). I found his Fixinf Bad Audio page however.
http://nickyguides.digital-digest.com/fix-audio.htm

He shows how to use dedynamic.exe but his audio software page doesn't have dedynamic.exe strangely enough.

Did an FTP search for "dedynamic.exe" - no hits.

Anywhere you know I can download it for sure?

thanx
JB

9th January 2002, 00:12

Attaching it here .... only 30 kb ..... Matthias is an excellent coder !

8th January 2002, 05:17	#1 \| Link
JimmyBarnes the Interrogator Join Date: Oct 2001 Location: DownUnder Posts: 664	What _exactly_ does it mean to "normalize" an audio stream? Does it simply mean to make the softer sounds louder and the louder ones softer? If so, to what "common" level? thanx JB Last edited by JimmyBarnes; 8th January 2002 at 05:20.

8th January 2002, 08:33	#3 \| Link
pacohaas Audio Moderator Join Date: Oct 2001 Posts: 697	how about reading the FAQ's before posting? __________________ {-n24-} The Old Fair Use Homepage

8th January 2002, 08:06	#2 \| Link
wmansir Moderator Join Date: Oct 2001 Location: USA Posts: 1,919	Actually, what your talking about is called dynamic compression. It compresses the difference between the soft and loud parts, so entire dynamic range of the soundtrack is reduced. Normalization on the other hand, does not change the dynamic range. So the difference between the loud and soft parts are the same. Instead, it increases the volume until the loudest part is as loud as the soundtrack can handle without causing errors. This increase in volume is applied equally to the entire soundtrack, so that all parts are louder. There is a 'normal' amount of dynamic compression performed when a DVD is played in a standalone, which often can be adjusted by the player. Some software decoders, like Azid, also allow you to adjust this compression when decoding the soundtrack to a .wav file.

8th January 2002, 09:17	#4 \| Link
ChristianHJW Guest Posts: n/a	I always use a 'DRC light' for my DivX movies. If Dynamic range is still too high for the speakers i use for playback i activate 'DeDynamic' audio DirectShowFilter in PowerDivX 3.12 and compress a few dB of dynamics more ( max. 15 dB or sound sill start pumping due to AGC, very annoying, but 15 dB compression is a lot ). For SVCD i always apply 'DRC normal' in Azid ...

8th January 2002, 17:25	#6 \| Link
ChristianHJW Guest Posts: n/a	If its a WAV you may try Dedynamic.exe from http://www.divx-digest.com . It will perform AGC on the WAV and amplify the silent scenes only. I recommend to use 4 - 6 dB compression, never use more than 15 dB ( sound strange ). If its an AC3 still than use Besweet and Besweet GUI from Doom9 download to transcode this AC3 to MP3 and set a DRC setting in Azid like 'DRC ligth' or 'DRC normal'. In case its a final AVI already download PowerDivX 3.12 player from Doom9 or http://www.powerdivx.com and activate the 'DeDynamic' audio DirectShowFilter for playback .... it will allow you to perform AGC on playback, plus in addition to that + 6 dB amplification ( free of clipping ). I this is still not enough and the silent scenes still not loud enough you may try the excellent tool 'WaveBooster' from LigH to amplify your sound by up to +12 dB without the danger to run into clipping . It comes as part of BeSweet and BeSweet GUI should allow you to process the WAV into another WAV, or to transcode it to Lame VBR/ABR MP3 same go. The final MP3 ( very high quality ) can be muxed to your AVI using nandub RC2 ( Doom9 again ).

9th January 2002, 00:12	#8 \| Link
ChristianHJW Guest Posts: n/a	Attaching it here .... only 30 kb ..... Matthias is an excellent coder !