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pjcactus
08-10-2004, 02:59 AM
Hi,
Just started with dBpowerAMP Music Converter....so have L's up!
Something I don't understand - advice welcome.
I have a small spoken word voice file in wav format and have converted this into mp3 format.
The original wav file size was 697KB and the new mp3 file is 274KB - I expected a greater reduction in size - AND the details of the mp3 file shows compression ration of 7:1 and a reduction in size to 274KB from an uncompressed size of 1937KB!!...
...Where does the 1937KB come from?...my wav file was 697.
Thanks,
John
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ChristinaS
08-10-2004, 03:12 AM
What are the attributes of your original wav file?

It must have been mono, probably 22KHz or less. The mp3 file is probably stereo, 44.1KHz, likely 96kbps or so.

I think the compression ratio is in relation to a regular 44.1KHz stereo wav file.

pjcactus
08-10-2004, 05:19 AM
Thanks Christina,
REf attributes...
wav - 697KB
Yes, sample rate 22kHz, bit rate 176kbps and mono

mp3 - 274KB (and quoted uncompressed size 1937KB)
Frequency (I presume thats the same as sample rate) 32k, Variable bit rate average 72, and also mono.

...But what I still don't understand is where the uncompressed size of 1937KB comes from?

Thanks,

John

ChristinaS
08-10-2004, 10:19 AM
Thanks Christina,
REf attributes...
wav - 697KB
Yes, sample rate 22kHz, bit rate 176kbps and mono

mp3 - 274KB (and quoted uncompressed size 1937KB)
Frequency (I presume thats the same as sample rate) 32k, Variable bit rate average 72, and also mono.

...But what I still don't understand is where the uncompressed size of 1937KB comes from?

Thanks,

John
Ok, just do an experiment. Take your wav file and run it through dMC an convert it to WAV 44.1KHz 16-bit stereo (2) . I am sure it will end up as about 1937KB.

I believe the compression rate for your final mp3 is expressed based on an uncompressed wav file of "regular" specs, i.e. as above.