Failed to add message : Failed to convert WAV file :
Sorry, this WAV file is in Microsoft ADPCM format.
This form allows you to upload an additional greeting message WAV file, which will be converted to the chosen format for use by your modem. The sample rate of the uploaded WAV should be the same as the sample rate of received messages, as should the selected format.
Sorry, this WAV file is in Microsoft ADPCM format.
-s/-u/-U/-A/-a/-i/-g/-f
The sample data encoding is signed linear (2's complement),
unsigned linear, u-law (logarithmic), A-law (logarithmic),
ADPCM, IMA_ADPCM, GSM, or Floating-point.
U-law (actually shorthand for mu-law) and A-law are the U.S.
and international standards for logarithmic telephone sound
compression. When uncompressed u-law has roughly the preci-
sion of 14-bit PCM audio and A-law has roughly the precision
of 13-bit PCM audio.
A-law and u-law data is sometimes encoded using a reversed
bit-ordering (ie. MSB becomes LSB). Internally, SoX under-
stands how to work with this encoding but there is currently
no command line option to specify it. If you need this sup-
port then you can use the psuedo file types of ".la" and
".lu" to inform sox of the encoding. See supported file
types for more information.
ADPCM is a form of sound compression that has a good compro-
mise between good sound quality and fast encoding/decoding
time. It is used for telephone sound compression and places
were full fidelity is not as important. When uncompressed it
has roughly the precision of 16-bit PCM audio. Popular ver-
sion of ADPCM include G.726, MS ADPCM, and IMA ADPCM. The -a
flag has different meanings in different file handlers. In
.wav files it represents MS ADPCM files, in all others it
means G.726 ADPCM. IMA ADPCM is a specific form of ADPCM
compression, slightly simpler and slightly lower fidelity
than Microsoft's flavor of ADPCM. IMA ADPCM is also called
DVI ADPCM.
GSM is a standard used for telephone sound compression in
European countries and its gaining popularity because of its
quality. It usually is CPU intensive to work with GSM audio
data.
sox ab.wav -r 7200 -A outabA.wav