iPad アプリで kAudioFormatMPEG4AAC 形式を録音しようとしましたが、録音は iPad2 と iPad3 では正常に機能しますが、iPad1 では機能しません。ここで iPad1 と iPad3 には iOS 5.1 があり、iPad2 には iOS 5.0.1 があります。
記録用のコードは次のようになります。
if(recordEncoding == ENC_PCM)
{
[recordSettings setObject:[NSNumber numberWithInt: kAudioFormatLinearPCM] forKey: AVFormatIDKey];
[recordSettings setObject:[NSNumber numberWithFloat:44100.0] forKey: AVSampleRateKey];
[recordSettings setObject:[NSNumber numberWithInt:2] forKey:AVNumberOfChannelsKey];
[recordSettings setObject:[NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey];
[recordSettings setObject:[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsBigEndianKey];
[recordSettings setObject:[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsFloatKey];
}
else
{
NSNumber *formatObject;
switch (recordEncoding) {
case (ENC_AAC):
formatObject = [NSNumber numberWithInt: kAudioFormatMPEG4AAC];
break;
case (ENC_ALAC):
formatObject = [NSNumber numberWithInt: kAudioFormatAppleLossless];
break;
case (ENC_IMA4):
formatObject = [NSNumber numberWithInt: kAudioFormatAppleIMA4];
break;
case (ENC_ILBC):
formatObject = [NSNumber numberWithInt: kAudioFormatiLBC];
break;
case (ENC_ULAW):
formatObject = [NSNumber numberWithInt: kAudioFormatULaw];
break;
default:
formatObject = [NSNumber numberWithInt: kAudioFormatAppleIMA4];
}
[recordSettings setObject:formatObject forKey: AVFormatIDKey];
[recordSettings setObject:[NSNumber numberWithFloat:44100.0] forKey: AVSampleRateKey];
[recordSettings setObject:[NSNumber numberWithInt:2] forKey:AVNumberOfChannelsKey];
[recordSettings setObject:[NSNumber numberWithInt:12800] forKey:AVEncoderBitRateKey];
[recordSettings setObject:[NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey];
[recordSettings setObject:[NSNumber numberWithInt: AVAudioQualityHigh] forKey: AVEncoderAudioQualityKey];
}
誰でもこの問題を解決できますか。この記事が示唆するように、MPEG4AAC は iPAD 1 で動作します。