短视频平台源码，iOS 仿微信语音输入动画

短视频平台源码，iOS 仿微信语音输入动画实现的相关代码

```handlebars
//
// PBSpeechRecognizer.h
// ParkBest
//
// Created by summerxx27 on 2018/10/30.
// Copyright © 2018年 summerxx27. All rights reserved.
//
#import <Foundation/Foundation.h>

NS_ASSUME_NONNULL_BEGIN
@protocol PBSpeechRecognizerProtocol <NSObject>
@optional
- (void)recognitionSuccess:(NSString *)result;
- (void)recognitionFail:(NSString *)result;
- (void)level:(float)value;
@end
@interface PBSpeechRecognizer : NSObject
@property(nonatomic,weak) id<PBSpeechRecognizerProtocol> delegate;
- (void)startR;
- (void)stopR;
@end

NS_ASSUME_NONNULL_END
```

```handlebars
//
// PBSpeechRecognizer.m
// ParkBest
//
// Created by summerxx27 on 2018/10/30.
// Copyright © 2018年 summerxx27. All rights reserved.
//

#import "PBSpeechRecognizer.h"
#import <Speech/Speech.h>
API_AVAILABLE(ios(10.0))
@interface PBSpeechRecognizer()
@property (nonatomic, strong) AVAudioEngine *audioEngine;
@property (nonatomic, strong) SFSpeechRecognizer *speechRecognizer;
@property (nonatomic, strong) SFSpeechAudioBufferRecognitionRequest *recognitionRequest;
@property (nonatomic, strong) AVAudioRecorder *recorder;
@property (nonatomic, strong) NSTimer *levelTimer;
@end
@implementation PBSpeechRecognizer

- (void)startR {
if (!self.speechRecognizer) {
// 设置语言
NSLocale *locale = [NSLocale localeWithLocaleIdentifier:@"zh-CN"];
if (@available(iOS 10.0, *)) {
self.speechRecognizer = [[SFSpeechRecognizer alloc] initWithLocale:locale];
} else {
// Fallback on earlier versions
}
}
if (!self.audioEngine) {
self.audioEngine = [[AVAudioEngine alloc] init];
}
AVAudioSession *audioSession = [AVAudioSession sharedInstance];
if (@available(iOS 10.0, *)) {
[audioSession setCategory:AVAudioSessionCategoryRecord mode:AVAudioSessionModeMeasurement options:AVAudioSessionCategoryOptionDuckOthers error:nil];
} else {
// Fallback on earlier versions
}
[audioSession setActive:YES withOptions:AVAudioSessionSetActiveOptionNotifyOthersOnDeactivation error:nil];
if (self.recognitionRequest) {
[self.recognitionRequest endAudio];
self.recognitionRequest = nil;
}
if (@available(iOS 10.0, *)) {
self.recognitionRequest = [[SFSpeechAudioBufferRecognitionRequest alloc] init];
} else {
// Fallback on earlier versions
}
self.recognitionRequest.shouldReportPartialResults = YES; // 实时翻译
if (@available(iOS 10.0, *)) {
[self.speechRecognizer recognitionTaskWithRequest:self.recognitionRequest resultHandler:^(SFSpeechRecognitionResult * _Nullable result, NSError * _Nullable error) {
if (result.isFinal) {
NSLog(@"is final: %d result: %@", result.isFinal, result.bestTranscription.formattedString);
if ([self.delegate respondsToSelector:@selector(recognitionSuccess:)]) {
[self.delegate recognitionSuccess:result.bestTranscription.formattedString];
}
}else {
if ([self.delegate respondsToSelector:@selector(recognitionFail:)]) {
// [self.delegate recognitionFail:error.domain];
}
}
}];
} else {
// Fallback on earlier versions
}
AVAudioFormat *recordingFormat = [[self.audioEngine inputNode] outputFormatForBus:0];
[[self.audioEngine inputNode] installTapOnBus:0 bufferSize:1024 format:recordingFormat block:^(AVAudioPCMBuffer * _Nonnull buffer, AVAudioTime * _Nonnull when) {
[self.recognitionRequest appendAudioPCMBuffer:buffer];
}];
[self.audioEngine prepare];
[self.audioEngine startAndReturnError:nil];


/// 检测声音
[[AVAudioSession sharedInstance]
setCategory: AVAudioSessionCategoryPlayAndRecord error: nil];

/// 不需要保存录音文件
NSURL *url = [NSURL fileURLWithPath:@"/dev/null"];

NSDictionary *settings = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithFloat: 44100.0], AVSampleRateKey,
[NSNumber numberWithInt: kAudioFormatAppleLossless], AVFormatIDKey,
[NSNumber numberWithInt: 2], AVNumberOfChannelsKey,
[NSNumber numberWithInt: AVAudioQualityMax], AVEncoderAudioQualityKey,
nil];

NSError *error;
_recorder = [[AVAudioRecorder alloc] initWithURL:url settings:settings error:&error];
if (_recorder)
{
[_recorder prepareToRecord];
_recorder.meteringEnabled = YES;
[_recorder record];
_levelTimer = [NSTimer scheduledTimerWithTimeInterval: 1 target: self selector: @selector(levelTimerCallback:) userInfo: nil repeats: YES];
}
else
{
NSLog(@"%@", [error description]);
}


}
/// 开始语音输入后, 开启一个定时器, 来检测声音的大小
- (void)levelTimerCallback:(NSTimer *)timer {
[_recorder updateMeters];

float level; // The linear 0.0 .. 1.0 value we need.
float minDecibels = -80.0f; // Or use -60dB, which I measured in a silent room.
float decibels = [_recorder averagePowerForChannel:0];

if (decibels < minDecibels)
{
level = 0.0f;
}
else if (decibels >= 0.0f)
{
level = 1.0f;
}
else
{
float root = 2.0f;
float minAmp = powf(10.0f, 0.05f * minDecibels);
float inverseAmpRange = 1.0f / (1.0f - minAmp);
float amp = powf(10.0f, 0.05f * decibels);
float adjAmp = (amp - minAmp) * inverseAmpRange;

level = powf(adjAmp, 1.0f / root);
}

/// level 范围[0 ~ 1], 转为[0 ~120] 之间
/// 通过这个delegate来回调到使用的类中
if ([self.delegate respondsToSelector:@selector(level:)]) {
[self.delegate level:120 * level];
}
}

- (void)stopR {
[_levelTimer invalidate];
[[self.audioEngine inputNode] removeTapOnBus:0];
[self.audioEngine stop];
[self.recognitionRequest endAudio];
self.recognitionRequest = nil;
}
@end
```

通过Value的值来动态切换图片就可以了, 或者不使用图片而自己绘制话筒旁边的小横线.

```handlebars
- (void)level:(float)value {
if (0 < value && value < 10) {
_voiceView.image = [UIImage imageNamed:@"v_1"];
}else if (value > 10 && value < 20) {
_voiceView.image = [UIImage imageNamed:@"v_2"];

}else if (value > 20 && value < 25) {
_voiceView.image = [UIImage imageNamed:@"v_3"];

}else if (value > 25 && value < 35) {
_voiceView.image = [UIImage imageNamed:@"v_4"];

}else if (value > 35 && value < 45) {
_voiceView.image = [UIImage imageNamed:@"v_5"];

}else if (value > 45 ) {
_voiceView.image = [UIImage imageNamed:@"v_6"];
}
}
```

这里是长按方法

```handlebars
- (void)longPress:(UILongPressGestureRecognizer *)gestureRecognizer{
CGPoint point = [gestureRecognizer locationInView:self.view];
if(gestureRecognizer.state == UIGestureRecognizerStateBegan) {
[self startRecording];
} else if(gestureRecognizer.state == UIGestureRecognizerStateEnded) {
[self stopRecording];

} else if(gestureRecognizer.state == UIGestureRecognizerStateChanged) {
NSLog(@"y ========== %f", point.y);
/// 判断y滑动到一定的值, 且取消语音的识别, 这里可以通过逻辑简单控制下
if (point.y < 513) {
_cancel = @"yes";
NSLog(@"voice cencel");
}
} else if (gestureRecognizer.state == UIGestureRecognizerStateFailed) {

} else if (gestureRecognizer.state == UIGestureRecognizerStateCancelled) {

}
}
```