Normalizing with FFdshow

[varunb]

Whenever I play any wave file encoded using ffdshow decoder, in graphedit, I have noticed that for 1-2 secs from the start of the playback, the sound level do not rises but after that interval, the sound level rises abruptly. This happens even if I play any audio in MPC. Whats the reason for this ? Can't I normalize those portions ?

If u want I can upload a sample for u guyz.

[tebasuna51]

Whenever I play any wave file encoded using ffdshow decoder, in graphedit, I have noticed that for 1-2 secs from the start of the playback, the sound level do not rises but after that interval, the sound level rises abruptly. This happens even if I play any audio in MPC. Whats the reason for this ? Can't I normalize those portions ?

If you check in ffdshow Audio decoder Configuration -> Volume -> Normalize, and put, for instance, 'Max. amplification: 500 %' here is how work with a test:

http://img524.imageshack.us/img524/7748/ffdshownormalizegi6.gif (http://imageshack.us)

1) After 0.5 sec. ffdshow decide the volume is too low (-45 dB) and apply the max amplification allowed 500%.

2) The volume remain low and the max amplification is applied.

3) The original volume grow and ffdshow reduce the amplification.

4) The original volume reach the max (0 dB) and the first samples are clipped until ffdshow decide attenuate a little the signal (-1.3 dB)

5) Light attenuation

6) Now the levels are like the input

This is how a dynamic Normalize work, until the max level in input signal are reached the gain applied can vary. This behavior can be accepted for play but not for conversion.

To convert a sound with normalization you need a two step soft, in first step search the max gain can be applied without clipping and in second step aply the same gain to the complete sound.

You can use Belight-BeSweet or BeHappy-Avysinth to do this work.

[varunb]

Thanx Tebasuna51 ! I didn't know that it was dynamic normalization. Anyways, I have tried BeHappy & its great but what if I want to perform normalization > 200% for conversion ? BeHappy has max limit of 200% only. I don't want use besweet as it hasn't been updated for a long time.

To convert a sound with normalization you need a two step soft.

Can u suggest me a better one ?

[tebasuna51]

Anyways, I have tried BeHappy & its great but what if I want to perform normalization > 200% for conversion ?
You can't Normalize more than 100%, or your signal become clipped (distorted). Other question is apply some range compression or boost, with less quality.

BeHappy has max limit of 200% only.
Maybe the next version we need limit that to 100% :rolleyes:

I don't want use besweet as it hasn't been updated for a long time.
BeLight-0.22_RC1 (http://kurtnoise.free.fr/index.php?dir=BeLight/&file=BeLight-0.22_RC1.exe)
2007-Feb-25 use the last BeSweet version with support for the new encoders Aften, NeroAacEnc, CT AacPlus and recent versions of lame, ogg, ...

[varunb]

You can't Normalize more than 100%, or your signal become clipped

But what about ffdshow, I mean, u must have noticed it many times in the Volume tab that the amplification levels > 100%. This means that it is possible to normalize the audio more than 100% without introducing any clipping. Isn't it ?

[tebasuna51]

A two pass normalize 100% means amplify the max. peak until the 100% value without clip and aply the same gain to all the audio. The gain can be 200% if the max peak reached have -6 dB (50%)

You can amplify without clip more than 100% with low signal (1) and (2) in the figure, but when reach high values (4) the signal is distorted.

After the max peak are reached ffdshow don't try amplify the signal anymore (6). If the max peak reached is at -6 dB (50%) ffdshow can maintain a gain of +6 dB (200%) along all the audio.
After the max peak ffdshow work like 2 pass, but before can aply different gain with changes in (1) and (3)