I've observed that Android devices differ (sometimes radically!) in
what audio rates and encodings they support, as well as the number of
channels (mono/stereo). In my freeware app "SoundForm" (a signal
generator) I have gone to some lengths to try to set the audio system
up with a combination of parameter settings that the phone actually
works with (my initial release of SoundForm always tried to use
44100/16/1 and worked fine on e.g. Droid, G1, and many others, but
failed on several phones - it turned out that they only supported
44100/16/2 or different rates).
The code I use for discovering which audio settings work is as follows
int rates[] = {8000,11025,22050,44100,48000};
int configs[] =
{AudioFormat.CHANNEL_CONFIGURATION_MONO,AudioFormat.CHANNEL_CONFIGURATION_STEREO};
int encodings[] =
{AudioFormat.ENCODING_PCM_8BIT,AudioFormat.ENCODING_PCM_16BIT};
int minBuffer,sampleRate,encoding,config;
AudioRecord audio = null;
for(int i=0;i<rates.length;i++) {
for(int j=0;j<configs.length;j++) {
for(int k=0;k<encodings.length;k++) {
sampleRate = rates[i];
config = configs[j];
encoding = encodings[k];
try {
minBuffer =
AudioRecord.getMinBufferSize(sampleRate,config,encoding);
if(minBuffer != AudioRecord.ERROR_BAD_VALUE &&
minBuffer != AudioRecord.ERROR) {
boolean bGood = true;
try {
audio = new AudioRecord(
MediaRecorder.AudioSource.MIC,
sampleRate,config,encoding,
minBuffer);
int istate = audio.getState();
if(istate !=
AudioRecord.STATE_INITIALIZED)
bGood = false;
} catch (Exception e) {
bGood = false;
}
if(bGood) .... (add settings
combination to list of working settings)
if(audio != null) audio.release();
audio = null;
}
} catch (Exception e) {System.err.println("Bad
"+e);}
}
}
}
It's worth noting that, based on observations, even if
getMinBufferSize() returns a positive result, the audio system on some
devices can still fail on initialisation, hence the code to create a
new AudioRecord object and check its state. (The minBufferSize for
playback is more reliable in this regard.)
The above set of checks is available as a standalone app in Market
called "AudioCaps" - it simply shows a list of the working rates
supported on the 'phone, for play and record.
Now to my question :-)
Users of the Samsung Galaxy S report that SoundForm doesn't work for
them - and causes a force close :-(
Does anyone here have a Galaxy S they would be kind enough to try
SoundForm on, and let me have the logcat from when it fails?
Also, any tips on aspects of setting up rates/encodings/channels in
Android would be most welcome.
Thanks!
--
You received this message because you are subscribed to the Google
Groups "Android Developers" group.
To post to this group, send email to android-developers@googlegroups.com
To unsubscribe from this group, send email to
android-developers+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/android-developers?hl=en
