Subject:Help with filesize reduction & freq filtering

Posted by: elshintman

Date:11/8/2000 7:13:00 PM

I am involved in a high-end Web project produced entirely
in Flash 4. This Web site contains multiple types of
audio, mixed multitrack music, voiceover clips, and SFX
clips. My original approach was to resample all my 44.1kHz
audio files to 11.025kHz 16-bit mono setting, then import
those files into Flash using MP3 compression set to Best.
The end result of that was good quality audio across the
board with a mid-band wait on the download. This site is
quite media-rich, and a decent portion of that is audio,
but I want to decrease the overall weight that the audio
inserts to the download.

My next approach is to evaulate my voiceover and SFX clips
for possible conversion to 8-bit. The mixed multitrack
music would certainly not survive the conversion, so I'm
holding off on that. Flash 4 doesn't import audio clips
lower than an 11.025kHz sampling rate without time
expanding and lowering the pitch of the clip. I know that
Flash 5 allows the user to import precompressed MP3 files,
but before I do that I would like to rolloff unused
frequencies in the voiceover and SFX clips.

Does anyone know if it's possible to reduce the file size
of a clip by rolling off unused frequencies? For example,
the human voice sounds anywhere from 200-250Hz
(male/female) to around 12kHz, with sweet spots at 750Hz-
1kHz and 5kHz-6kHz (s's and t's). If I rolloff frequencies
less than 200Hz and greater than 12kHz, will I be able to
produce a smaller file?

Thanks,

-mark

Subject:Re: Help with filesize reduction & freq filtering

Reply by: Jeff_Lowes

Date:11/14/2000 11:41:00 PM

Filesize is determined by the number of samples in an audio file. A
sample is basically a "slice of time". Hence, one sample at a rate of
44.1kHz is 1/44100 seconds long. Adjusting the EQ of an audio file
does not adjust the length of the file.
I don't know alot about Flash and web audio; however, I have been
using the MusicMatchJukeBox to convert .wav files to .MP3 files and
it does an incredible job with great flexibility of conversion
settings. The MMJB is a FREE download from www.musicmatch.com. If you
don't have it already, I suggest that you get a copy and see if it
can help you out.
Good Luck.

Jeff Lowes
On-Track Recording

Mark DeCheser wrote:
>>I am involved in a high-end Web project produced entirely
>>in Flash 4. This Web site contains multiple types of
>>audio, mixed multitrack music, voiceover clips, and SFX
>>clips. My original approach was to resample all my 44.1kHz
>>audio files to 11.025kHz 16-bit mono setting, then import
>>those files into Flash using MP3 compression set to Best.
>>The end result of that was good quality audio across the
>>board with a mid-band wait on the download. This site is
>>quite media-rich, and a decent portion of that is audio,
>>but I want to decrease the overall weight that the audio
>>inserts to the download.
>>
>>My next approach is to evaulate my voiceover and SFX clips
>>for possible conversion to 8-bit. The mixed multitrack
>>music would certainly not survive the conversion, so I'm
>>holding off on that. Flash 4 doesn't import audio clips
>>lower than an 11.025kHz sampling rate without time
>>expanding and lowering the pitch of the clip. I know that
>>Flash 5 allows the user to import precompressed MP3 files,
>>but before I do that I would like to rolloff unused
>>frequencies in the voiceover and SFX clips.
>>
>>Does anyone know if it's possible to reduce the file size
>>of a clip by rolling off unused frequencies? For example,
>>the human voice sounds anywhere from 200-250Hz
>>(male/female) to around 12kHz, with sweet spots at 750Hz-
>>1kHz and 5kHz-6kHz (s's and t's). If I rolloff frequencies
>>less than 200Hz and greater than 12kHz, will I be able to
>>produce a smaller file?
>>
>>Thanks,
>>
>>-mark

Subject:Re: Help with filesize reduction & freq filtering

Reply by: elshintman

Date:11/15/2000 2:07:00 PM

Jeff -

Thanks for the tips. I was actually able to come to the same
conclusion thru some extensive testing of that theory. We decided to
dither some of the tracks from 16-bit to 8-bit, then encode the .wav
files to MP3 for import into Flash 5. 2 months ago, this wasn't even
a possibility.

As far as MMJB is concerned...yes it is free but not the best tool
out there for compressing MP3s. Everything from Audiograbber to
Audioactive Production Studio - Pro offer the user a wider selection
of sampling/compression/kbit rates. As far as Web work goes, one
needs to have as many compression options as possible, CD-produced
music is a completely different ballgame.

Thanks again,

-mark

On-Track Recording wrote:
>>Filesize is determined by the number of samples in an audio file. A
>>sample is basically a "slice of time". Hence, one sample at a rate
of
>>44.1kHz is 1/44100 seconds long. Adjusting the EQ of an audio file
>>does not adjust the length of the file.
>>I don't know alot about Flash and web audio; however, I have been
>>using the MusicMatchJukeBox to convert .wav files to .MP3 files and
>>it does an incredible job with great flexibility of conversion
>>settings. The MMJB is a FREE download from www.musicmatch.com. If
you
>>don't have it already, I suggest that you get a copy and see if it
>>can help you out.
>>Good Luck.
>>
>>Jeff Lowes
>>On-Track Recording
>>
>>Mark DeCheser wrote:
>>>>I am involved in a high-end Web project produced entirely
>>>>in Flash 4. This Web site contains multiple types of
>>>>audio, mixed multitrack music, voiceover clips, and SFX
>>>>clips. My original approach was to resample all my 44.1kHz
>>>>audio files to 11.025kHz 16-bit mono setting, then import
>>>>those files into Flash using MP3 compression set to Best.
>>>>The end result of that was good quality audio across the
>>>>board with a mid-band wait on the download. This site is
>>>>quite media-rich, and a decent portion of that is audio,
>>>>but I want to decrease the overall weight that the audio
>>>>inserts to the download.
>>>>
>>>>My next approach is to evaulate my voiceover and SFX clips
>>>>for possible conversion to 8-bit. The mixed multitrack
>>>>music would certainly not survive the conversion, so I'm
>>>>holding off on that. Flash 4 doesn't import audio clips
>>>>lower than an 11.025kHz sampling rate without time
>>>>expanding and lowering the pitch of the clip. I know that
>>>>Flash 5 allows the user to import precompressed MP3 files,
>>>>but before I do that I would like to rolloff unused
>>>>frequencies in the voiceover and SFX clips.
>>>>
>>>>Does anyone know if it's possible to reduce the file size
>>>>of a clip by rolling off unused frequencies? For example,
>>>>the human voice sounds anywhere from 200-250Hz
>>>>(male/female) to around 12kHz, with sweet spots at 750Hz-
>>>>1kHz and 5kHz-6kHz (s's and t's). If I rolloff frequencies
>>>>less than 200Hz and greater than 12kHz, will I be able to
>>>>produce a smaller file?
>>>>
>>>>Thanks,
>>>>
>>>>-mark