Dear all,

I have a recently started experimenting with wavegain (replaygain for wave
files). It looks to be a very useful tool but there are some things that I
am comfused about.

I understand that it uses psychoacoustic analysis to measure the perceived
loudness and adjust the gain on that basis. My questions: does it apply a
single gain factor across the entire file or does it analyse the file on a
frame-by-frame basis and apply different amounts of gain in different parts
of the track. Secondly, does it apply the same gain across all frequencies
or does it take into account the differing perceived loudness of different
frequencies.

Furthermore, I tested wavegain on a sample files that I have (a frequency
sweep from 20Hz to 20KHz, all at equal amplitude). I noticed that it reduced
the overall amplitude of the audio track quite significantly even though
there was no chance of clipping. My question: is it possible to apply
wavegain on a music file so that it uses the full range of possible values,
i.e. performs some kind of normalization.

I would appreciate any help on these issues.

Many Thanks

RG

"rg" wrote in message

Dear all,

I have a recently started experimenting with wavegain (replaygain for
wave files). It looks to be a very useful tool but there are some
things that I am comfused about.

Have you read:

http://www.hydrogenaudio.org/forums/...opic=24527&hl=

????

I understand that it uses psychoacoustic analysis to measure the
perceived loudness and adjust the gain on that basis. My questions:
does it apply a single gain factor across the entire file or does it
analyse the file on a frame-by-frame basis and apply different
amounts of gain in different parts of the track. Secondly, does it
apply the same gain across all frequencies or does it take into
account the differing perceived loudness of different frequencies.

Reference says:

"MP3Gain then writes to the global gain header of every block, adjusting
them all up or down by the same amount in order to achieve those Replaygain
values."

Applying different amounts of gain would be compression, which is not what
the software does.


Furthermore, I tested wavegain on a sample files that I have (a
frequency sweep from 20Hz to 20KHz, all at equal amplitude). I
noticed that it reduced the overall amplitude of the audio track
quite significantly even though there was no chance of clipping. My
question: is it possible to apply wavegain on a music file so that it
uses the full range of possible values, i.e. performs some kind of
normalization.

Normalization would undo what the software does. You can have one or the
other but not both at the same time.

Hi,

Thanks very much for your reply and thank you for the link.

With respect to applying gain across differing frequency ranges, my
understanding is that since perceived loudness is different for different
frequency ranges (as shown in the Fletcher-Munson curve), by applying the
same gain across all frequencies the actual perceived gain will be different
for different frequency ranges. I was just curious how it works in practice.

The reason I asked about the normalization is because I was really surprised
at how much reduction in amplitude there actually was. The wavegained track
had an amplitude about 1/5th of the original, and the original was already
half of maximum (on a linear scale).

Many Thanks,

RG

"Arny Krueger" wrote in message
...
"rg" wrote in message

Dear all,

I have a recently started experimenting with wavegain (replaygain for
wave files). It looks to be a very useful tool but there are some
things that I am comfused about.

Have you read:

http://www.hydrogenaudio.org/forums/...opic=24527&hl=

????

I understand that it uses psychoacoustic analysis to measure the
perceived loudness and adjust the gain on that basis. My questions:
does it apply a single gain factor across the entire file or does it
analyse the file on a frame-by-frame basis and apply different
amounts of gain in different parts of the track. Secondly, does it
apply the same gain across all frequencies or does it take into
account the differing perceived loudness of different frequencies.

Reference says:

"MP3Gain then writes to the global gain header of every block, adjusting
them all up or down by the same amount in order to achieve those
Replaygain
values."

Applying different amounts of gain would be compression, which is not what
the software does.


Furthermore, I tested wavegain on a sample files that I have (a
frequency sweep from 20Hz to 20KHz, all at equal amplitude). I
noticed that it reduced the overall amplitude of the audio track
quite significantly even though there was no chance of clipping. My
question: is it possible to apply wavegain on a music file so that it
uses the full range of possible values, i.e. performs some kind of
normalization.

Normalization would undo what the software does. You can have one or the
other but not both at the same time.

rg wrote:
Hi,

Thanks very much for your reply and thank you for the link.

With respect to applying gain across differing frequency ranges, my
understanding is that since perceived loudness is different for different
frequency ranges (as shown in the Fletcher-Munson curve), by applying the
same gain across all frequencies the actual perceived gain will be different
for different frequency ranges. I was just curious how it works in practice.

The reason I asked about the normalization is because I was really surprised
at how much reduction in amplitude there actually was. The wavegained track
had an amplitude about 1/5th of the original, and the original was already
half of maximum (on a linear scale).

Many Thanks,

RG

"Arny Krueger" wrote in message
...

"rg" wrote in message


Dear all,

I have a recently started experimenting with wavegain (replaygain for
wave files). It looks to be a very useful tool but there are some
things that I am comfused about.

Have you read:

http://www.hydrogenaudio.org/forums/...opic=24527&hl=

????


I understand that it uses psychoacoustic analysis to measure the
perceived loudness and adjust the gain on that basis. My questions:
does it apply a single gain factor across the entire file or does it
analyse the file on a frame-by-frame basis and apply different
amounts of gain in different parts of the track. Secondly, does it
apply the same gain across all frequencies or does it take into
account the differing perceived loudness of different frequencies.

Reference says:

"MP3Gain then writes to the global gain header of every block, adjusting
them all up or down by the same amount in order to achieve those

Replaygain

values."

Applying different amounts of gain would be compression, which is not what
the software does.



Furthermore, I tested wavegain on a sample files that I have (a
frequency sweep from 20Hz to 20KHz, all at equal amplitude). I
noticed that it reduced the overall amplitude of the audio track
quite significantly even though there was no chance of clipping. My
question: is it possible to apply wavegain on a music file so that it
uses the full range of possible values, i.e. performs some kind of
normalization.

Normalization would undo what the software does. You can have one or the
other but not both at the same time.





foobar has wavegain