Speech Recognition on iPhone 5

Question

I am using the iOS Speech Recognition API in the Objective-C iOS app. It works on iPhone 6, 7, but does not work on iPhone 5 (iOS, 10.2.1).

Also note that this works on iPhone 5, not iPhone 5.

Is iOS API to work on iPhone 5? Do you need to do something else to make it work, or does anyone know what the problem is?

Below is the base code. No errors occur, and a microphone volume is detected, but no speech is detected.

if (audioEngine != NULL) { [audioEngine stop]; [speechTask cancel]; AVAudioInputNode* inputNode = [audioEngine inputNode]; [inputNode removeTapOnBus: 0]; } recording = YES; micButton.selected = YES; //NSLog(@"Starting recording... SFSpeechRecognizer Available? %d", [speechRecognizer isAvailable]); NSError * outError; //NSLog(@"AUDIO SESSION CATEGORY0: %@", [[AVAudioSession sharedInstance] category]); AVAudioSession* audioSession = [AVAudioSession sharedInstance]; [audioSession setCategory: AVAudioSessionCategoryPlayAndRecord withOptions:AVAudioSessionCategoryOptionDefaultToSpeaker error:&outError]; [audioSession setMode: AVAudioSessionModeMeasurement error:&outError]; [audioSession setActive: true withOptions: AVAudioSessionSetActiveOptionNotifyOthersOnDeactivation error:&outError]; SFSpeechAudioBufferRecognitionRequest* speechRequest = [[SFSpeechAudioBufferRecognitionRequest alloc] init]; //NSLog(@"AUDIO SESSION CATEGORY1: %@", [[AVAudioSession sharedInstance] category]); if (speechRequest == nil) { NSLog(@"Unable to create SFSpeechAudioBufferRecognitionRequest."); return; } speechDetectionSamples = 0; // This some how fixes a crash on iPhone 7 // Seems like a bug in iOS ARC/lack of gc AVAudioEngine* temp = audioEngine; audioEngine = [[AVAudioEngine alloc] init]; AVAudioInputNode* inputNode = [audioEngine inputNode]; speechRequest.shouldReportPartialResults = true; // iOS speech does not detect end of speech, so must track silence. lastSpeechDetected = -1; speechTask = [speechRecognizer recognitionTaskWithRequest: speechRequest delegate: self]; [inputNode installTapOnBus:0 bufferSize: 4096 format: [inputNode outputFormatForBus:0] block:^(AVAudioPCMBuffer* buffer, AVAudioTime* when) { @try { long millis = [[NSDate date] timeIntervalSince1970] * 1000; if (lastSpeechDetected != -1 && ((millis - lastSpeechDetected) > 1000)) { lastSpeechDetected = -1; [speechTask finish]; return; } [speechRequest appendAudioPCMBuffer: buffer]; //Calculate volume level if ([buffer floatChannelData] != nil) { float volume = fabsf(*buffer.floatChannelData[0]); if (volume >= speechDetectionThreshold) { speechDetectionSamples++; if (speechDetectionSamples >= speechDetectionSamplesNeeded) { //Need to change mic button image in main thread [[NSOperationQueue mainQueue] addOperationWithBlock:^ { [micButton setImage: [UIImage imageNamed: @"micRecording"] forState: UIControlStateSelected]; }]; } } else { speechDetectionSamples = 0; } } } @catch (NSException * e) { NSLog(@"Exception: %@", e); } }]; [audioEngine prepare]; [audioEngine startAndReturnError: &outError]; NSLog(@"Error %@", outError); 

Answer 1

I think the error is here in this code:

 long millis = [[NSDate date] timeIntervalSince1970] * 1000; 

32-bit devices (iPhone 5 is a 32-bit device) can store a maximum number of up to 2 ^ 32-1, i.e. 2,147,483,647.

I checked the iPhone 5 sim, the millis value has a negative value. In the code snippet you posted, there is no mention of how lastSpeechDetected set after initial setting it to -1, but if somehow ((millis - lastSpeechDetected) > 1000) is true, then it will go into the if block and complete the speech task.