I found a way to change just the sample rate. It's a bit techy but straightforward.
So just did it and transposed an example exported audio file down by an octave by halving the sample rate, then imported it back into Viena - and it did change the pitch, and what's more, also preserved the original loop points.
So the method certainly works
TECHY DETAILS IF YOU WANT TO TRY IT YOURSELF
Here is how to do it if you want to give it a go.
You need to use a hex editor. I used WinHex. But it is pretty easy to do, so don't worry if you have never edited hex before.
Then open the .wav file. You will see its contents in hexadecimal.
Look for the sample rate. It is at the position 0x18, i.e. 24 bytes into the file, and is four bytes long, and all numbers in the header are recorded with the LOW BYTE FIRST (opposite of the order you'd expect)
So for instance if the original sample rate was 44100, then in hexadecimal this is AC44.
You can use google for decimal to hexadecimal conversions if you don't have a hexadecimal calculator:
44100 in hexadecimal = (google search)AC44 is two bytes (its two hexadecimal digits for each byte). As a 4 byte number its 0000AC44
Since it is low byte first order, you reverse those bytes to get.
44AC0000
So look for that sequence of bytes in the file.
To reduce the pitch by an octave, then you divide that by 2, so using google again:
44100/2 in hexadecimal = (google search)44100/2 in hexadecimal = 5622
Put this into low byte first order and you get
22560000
So edit the file in your hex editor and replace the 44AC0000 by 22560000
There's another field in the header you need to edit as well to make the header consistent - but no need to do that by hand, you can use Goldwave to do that.
Just open your edited file, and resave it in Goldwave. You can check that Goldwave does indeed play it an octave lower.
That works because Goldwave will happily open a file with just the sample rate changed - most programs will complain that it is "corrupted".
Now import it into Viena. Use the same file name you used when you exported it from Viena and Viena will replace the original sample, and play it an octave lower. Any the instruments in the soundfont that use that sample will play it an octave lower
This is basically what FTS would do if I program it to auto retune the samples in a soundfont.
For details of the .WAV file format in detail, with a nice diagram and an example,
WAVE PCM soundfile format Linkback: http://robertinventor.com/smf/index.php?topic=58.msg186#msg186
