bitrate conversion

[Phil rr]

i have long mp3s (dj sets) that have been recorded from an FM radio, at 192.

if i convert to 128 (given that fm radio might be only the equivalent of 112) is the only loss in quality down to the lower bitrate, or are there other things which will cause me to loose quality and will cause the mp3 to sound different?

thanks

[ChristinaS]

Re: bitrate conversion

i have long mp3s (dj sets) that have been recorded from an FM radio, at 192.

if i convert to 128 (given that fm radio might be only the equivalent of 112) is the only loss in quality down to the lower bitrate, or are there other things which will cause me to loose quality and will cause the mp3 to sound different?

thanks

I think that if all you're changing is the bitrate and you current files are acceptable, you'll probably hardly notice the slight drop in audio quality, but your files will be 33% smaller. If you were to go down to 64kbps that will make a much bigger difference in audio quality.

[xoas]

Re: bitrate conversion

Yes, there are other considerations. Consider lossy codecs to be like a copy machine which has various degrees of accuracy (comparable to bitrates). You have already made a copy at a given accuracy (192 kbs) and now you want to make a copy of that copy at a lower resolution (128 kbs). Your first copy was not a perfect copy of the original and the second copy will be a less perfect copy of your first copy.
Now that is part of the reality. The other part is that it may not make any difference to a listener. Only your ears would be able to tell you that. So give it a try if you wish. Keep in mind (if you run into this situation again) that if the original sets were copied at 128 kbs to start out with you would have a better copy than if you copied first to 192 kbs and then copied to 128. But that may not be your choice anyway.
Hope this helps.
Best wishes,
Bill Mikkelsen

[Phil rr]

Re: bitrate conversion

Hi, thank you for the info.

i've converted one file, i *think* it sounds about the same....!!

could anyone tell me, does the mp3 get re-encoded when the bitrate is lowered, or is it purely a case of removing some of the information?

ie, is the conversion, an mp3 of an mp3 of a radio recording, or is it just an mp3, with some information removed?

thanks again.

[Phil rr]

Re: bitrate conversion

taking it a bit further (just for the sake of)

if i converted 192 > 160, thgen 160 > 128, do you know if this would give an identical file as a 192 > 128? (ignoring hard drive write errors etc)

[ChristinaS]

Re: bitrate conversion

taking it a bit further (just for the sake of)

if i converted 192 > 160, thgen 160 > 128, do you know if this would give an identical file as a 192 > 128? (ignoring hard drive write errors etc)

Probably not.

Every conversion to lossy formats involves some loss or modification of quality.

I suspect conversions between formats are done internally in 2 steps:
one step converts the source file to a uniform standard internal format (maybe .wav or .au) and a second step converts that to your desired target format.

Whether or not your ears can detect the differences is debatable. But a bit by bit analysis of the resulting files will most likely reveal that they are not identical.

[Phil rr]

Re: bitrate conversion

fair enuff

so would it become an mp3 of an mp3, or just a converted mp3?

[ChristinaS]

Re: bitrate conversion

fair enuff

so would it become an mp3 of an mp3, or just a converted mp3?

Let's just say another mp3 of the same original audio file.

Or, if you'd rather an analogy, a photo print from a negative made from another photo print.

[xoas]

Re: bitrate conversion

if you'd rather an analogy, a photo print from a negative made from another photo print.

Ooooohhhh!!!!! Great analogy!

[ChristinaS]

Re: bitrate conversion

Ooooohhhh!!!!! Great analogy!

:lustig1:

[Phil rr]

Re: bitrate conversion

ok

[Phil rr]

Re: bitrate conversion

by the way, ChristinaS, my friend likes your avatar pic