Re; Recording Sound on the Mac

[Dan Soneson]

Sivakatirwami,

You've gotten some good feedback already. We use the iMic with
Plantronics A-90 headsets to do audio recording. The quality is fine.

Once you have set the audio input in System Preferences, you don't
need Rev to do that any more. It becomes troublesome anyway, since
your users may not all have the same USB device, which the system would
list, and I have not found a way in Rev to go out and poll for the 
options.

There are three things I would suggest looking into:

set the recordSampleSize to 16 -- 8 just sounds scratchier and tinnier

As Tom said, "mp4a" may not be the best (or even any) choice for 
compression.
Although QuickTime Pro can compress files with that codec, I am not sure
it is available for other applications (like Rev) to use. I have 
realistically only
been able to compress audio from within Rev with IMA 4:1. The two MACE 
options are scratchy,
and Qualcomm sounds hollow, but it's usable. Perhaps you can just save 
the files
with no compression and use QuickTime to compress them as mp4a files...

BTW, the recordFormat property only deals with file types. From the 
docs:

> Value:
> The recordFormat is one of the following:
>
> 	aiff	records a file in AIFF format
> 	wave	records a file in WAV format
> 	ulaw	records a file in AU format
> 	movie	records a file in QuickTime format
>
So, that would not be where you set the compression. Use the 
recordCompression property instead.

Finally, if you use any compression at all, you cannot use the "play" 
command in Rev to play it back. You just get screeches. Use a QuickTime 
player instead. Set the filename of the player to your tSoundFile and 
play it pack through the player.


>   set the recordRate to 22.050 --the uSampleRate of me
>    set the recordChannels to 1 --the uRecordChannels of me
>    set the recordSamplesize to 8 --the uSampleSize of me
>    set the recordFormat to "mp4a" --the uRecordFormat of me
>
>    if fld  "soundFileName" is empty then
>      answer "You need to set a sound file name." with "OK"
>      exit  mouseup
>    end  if
>
>    if the short name of me = "Record" then
>      set the recordInput to "dflt"


HTH,
Dan

Daniel B. Soneson
Director, Language Lab
Southern CT State University