现在很多平台对iOS太不友好了，iOS连个demo都没有...

截屏2021-06-30 上午10.34.23.png

只能自己摸索了，比较费事的就是这个接口鉴权,注意如果鉴权一直不通过就要检查下signature签名的base64长度是否是44个字节。

#import <CommonCrypto/CommonHMAC.h>
#import <CommonCrypto/CommonDigest.h>
#import <xlocale.h>
static NSString *const url = @"wss://ws-api.xfyun.cn/v2/igr";//webscoket地址

- (NSString *)host {
    NSURL *r = [NSURL URLWithString:url];
    NSString *date = [self lg_rfc1123String];
    NSString *signature_origin = [NSString stringWithFormat:@"host: %@\ndate: %@\nGET %@ HTTP/1.1",r.host,date,r.path];
    NSString *signature = [self hmacSHA256WithSecret:kXfyunApiSecret content:signature_origin];//hmac-sha256算法结合apiSecret对signature_origin签名 并BASE64编码
    NSString *authorization_origin = [NSString stringWithFormat:@"api_key=\"%@\", algorithm=\"hmac-sha256\", headers=\"host date request-line\", signature=\"%@\"",kXfyunApiKey,signature];
    NSData *dataAuthorization = [authorization_origin dataUsingEncoding:NSUTF8StringEncoding];
    NSString *authorization = [dataAuthorization base64EncodedStringWithOptions:0];//将加密结果进行一次BASE64编码。
    return [self lg_safeUrlWithFormat:[NSString stringWithFormat:@"%@?authorization=%@&date=%@&host=%@",url,authorization,date,r.host]];
}

- (NSString*)lg_rfc1123String {//当前时间戳，RFC1123格式(Mon, 02 Jan 2006 15:04:05 GMT)
    time_t date = (time_t)[[NSDate date] timeIntervalSince1970];
    struct tm timeinfo;
    gmtime_r(&date, &timeinfo);
    char buffer[32];
    size_t ret = strftime_l(buffer, sizeof(buffer), "%a, %d %b %Y %H:%M:%S UTC", &timeinfo, NULL);
    if (ret) {
        return @(buffer);
    } else {
        return nil;
    }
}

/**
 *  加密方式,MAC算法: HmacSHA256
 *
 *  @param secret       秘钥
 *  @param content 要加密的文本
 *
 *  @return 加密后的字符串
 */
- (NSString *)hmacSHA256WithSecret:(NSString *)secret content:(NSString *)content {
    const char *cKey  = [secret cStringUsingEncoding:NSASCIIStringEncoding];
    const char *cData = [content cStringUsingEncoding:NSASCIIStringEncoding];
    //Sha256:
     unsigned char cHMAC[CC_SHA256_DIGEST_LENGTH];
    CCHmac(kCCHmacAlgSHA256, cKey, strlen(cKey), cData, strlen(cData), cHMAC);
    NSData *HMAC = [[NSData alloc] initWithBytes:cHMAC
                                          length:sizeof(cHMAC)];
    NSString *hash = [HMAC base64EncodedStringWithOptions:0];//将加密结果进行一次BASE64编码。
    return hash;
}

- (NSString *)lg_safeUrlWithFormat:(id)object {
    NSString *cover = [NSString stringWithFormat:@"%@",cover];
    cover = [cover stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];
    return cover;
}

socket用的三方的 pod 'SocketRocket'#websoket。
SocketRocket集成

采集音频

#import "LGAudioRecordManager.h"
#import <AVFoundation/AVFoundation.h>
#import "LGRecordFileManager.h"

static Float64 const LGSampleRate = 8000;//采样率
static UInt32 const LGChannelsPerFrame = 1;//声道数量
static UInt32 const LGBitsPerChannel = 16;//每个采样数据的位数
static NSInteger const LGBufferCount = 3;//缓存区个数
static CGFloat const LGBufferDurationSeconds = 0.2;

@interface LGAudioRecordManager () {
    AudioQueueRef audioRef;//音频队列对象指针
    AudioStreamBasicDescription recordConfiguration;//音频流配置
    AudioQueueBufferRef audioBuffers[LGBufferCount];//音频流缓冲区对象
}

@property (nonatomic, copy) NSString *recordFilePath;//音频沙盒路径
@property (nonatomic,assign) AudioFileID recordFileID;//音频文件标识  用于关联音频文件
@property (nonatomic,assign) SInt64 recordPacket;//录音文件的当前包

@end

@implementation LGAudioRecordManager

+ (instancetype)sharedManager {
    static LGAudioRecordManager *manager = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        manager = [[LGAudioRecordManager alloc]init];
    });
    return manager;
}

- (instancetype)init {
    if (self == [super init]) {
        //采集路径
        self.recordFilePath = [LGRecordFileManager cacheFileWithFolder:@"LGAudioRecord" FileName:@"audioRecord.wav"];
        NSLog(@"recordFile:%@",_recordFilePath);
        
        recordConfiguration.mSampleRate =  LGSampleRate;
        recordConfiguration.mChannelsPerFrame = LGChannelsPerFrame;
        //编码格式
        recordConfiguration.mFormatID = kAudioFormatLinearPCM;
        recordConfiguration.mFormatFlags = kLinearPCMFormatFlagIsSignedInteger | kLinearPCMFormatFlagIsPacked;
        //每采样点占用位数
        recordConfiguration.mBitsPerChannel = LGBitsPerChannel;
        //每帧的字节数
        recordConfiguration.mBytesPerFrame = (recordConfiguration.mBitsPerChannel / 8) * recordConfiguration.mChannelsPerFrame;
        //每包的字节数
        recordConfiguration.mBytesPerPacket = recordConfiguration.mBytesPerFrame;
        //每帧的字节数
        recordConfiguration.mFramesPerPacket = 1;
    }
    return self;
}

- (void)initAudio {
    //设置音频输入信息和回调
    OSStatus status = AudioQueueNewInput(&recordConfiguration, inputBufferHandler, (__bridge void *)(self), NULL, NULL, 0, &audioRef);
    if( status != kAudioSessionNoError ) {
        NSLog(@"初始化出错");
        return ;
    }
    //计算估算的缓存区大小
    int frames = [self computeRecordBufferSize:&recordConfiguration seconds:LGBufferDurationSeconds];
    int bufferByteSize = frames * recordConfiguration.mBytesPerFrame;
    NSLog(@"缓存区大小%d",bufferByteSize);
    //创建缓冲器
    for (int i = 0; i < LGBufferCount; i++) {
        AudioQueueAllocateBuffer(audioRef, bufferByteSize, &audioBuffers[i]);
        AudioQueueEnqueueBuffer(audioRef, audioBuffers[i], 0, NULL);
    }
}

//回调
void inputBufferHandler(void *inUserData, AudioQueueRef inAQ, AudioQueueBufferRef inBuffer, const AudioTimeStamp *inStartTime,UInt32 inNumPackets, const AudioStreamPacketDescription *inPacketDesc) {
    LGAudioRecordManager *audioManager = [LGAudioRecordManager sharedManager];
    if (inNumPackets > 0) {
        //写入文件
        AudioFileWritePackets(audioManager.recordFileID, FALSE, inBuffer->mAudioDataByteSize,inPacketDesc, audioManager.recordPacket, &inNumPackets, inBuffer->mAudioData);
           audioManager.recordPacket += inNumPackets;
    }
    if (audioManager.isRecording) {
       //将缓冲器重新放入缓冲队列，以便重复使用该缓冲器
        AudioQueueEnqueueBuffer(inAQ, inBuffer, 0, NULL);
    }
}

- (int)computeRecordBufferSize:(const AudioStreamBasicDescription*)format seconds:(float)seconds {
    int packets, frames, bytes = 0;
    frames = (int)ceil(seconds * format->mSampleRate);
    
    if (format->mBytesPerFrame > 0) {
        bytes = frames * format->mBytesPerFrame;
    }else {
        UInt32 maxPacketSize = 0;
        if (format->mBytesPerPacket > 0) {
            maxPacketSize = format->mBytesPerPacket;
        }
        if (format->mFramesPerPacket > 0) {
            packets = frames / format->mFramesPerPacket;
        }else {
            packets = frames;
        }
        if (packets == 0) {
            packets = 1;
        }
        bytes = packets * maxPacketSize;
    }
    return bytes;
}

- (void)startRecord {
    [LGRecordFileManager removeFileAtPath:self.recordFilePath];
    [self initAudio];
    CFURLRef url = CFURLCreateWithString(kCFAllocatorDefault, (CFStringRef)self.recordFilePath, NULL);
    //创建音频文件夹
    AudioFileCreateWithURL(url, kAudioFileCAFType, &recordConfiguration, kAudioFileFlags_EraseFile,&_recordFileID);
    CFRelease(url);
    
    self.recordPacket = 0;
   
    //当有音频设备（比如播放音乐）导致改变时 需要配置
    [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];
    [[AVAudioSession sharedInstance] setActive:YES error:nil];
    OSStatus status = AudioQueueStart(audioRef, NULL);
    if( status != kAudioSessionNoError ) {
        NSLog(@"开始出错");
        return;
    }
    self.isRecording = true;
    NSLog(@"开始录音");
    // 设置可以更新声道的power信息
    [self performSelectorOnMainThread:@selector(enableUpdateLevelMetering) withObject:nil waitUntilDone:NO];
}

- (CGFloat)getCurrentVolume {
    UInt32 dataSize = sizeof(AudioQueueLevelMeterState) * recordConfiguration.mChannelsPerFrame;
    AudioQueueLevelMeterState *levels = (AudioQueueLevelMeterState*)malloc(dataSize);
    OSStatus rc = AudioQueueGetProperty(audioRef, kAudioQueueProperty_CurrentLevelMeter, levels, &dataSize);
    if (rc) {
        NSLog(@"OSStatus %d", (int)rc);
    }
    float channelAvg = 0;
    for (int i = 0; i < recordConfiguration.mChannelsPerFrame; i++) {
        channelAvg += levels[i].mPeakPower;
    }
    free(levels);
    return channelAvg;
}

- (BOOL)enableUpdateLevelMetering {
    UInt32 val = 1;
    OSStatus status = AudioQueueSetProperty(audioRef, kAudioQueueProperty_EnableLevelMetering, &val, sizeof(UInt32));
    if( status == kAudioSessionNoError ) {
        return YES;
    }
    return NO;
}

- (void)stopRecord {
    if (self.isRecording) {
        self.isRecording = NO;
        //停止录音队列和移，这里无需考虑成功与否
        OSStatus status = AudioQueueStop(audioRef, true);
        OSStatus status1 = AudioFileClose(_recordFileID);
        OSStatus status2 = AudioQueueDispose(audioRef, TRUE);
        NSLog(@"销毁录音%d%d%d",(int)status,(int)status1,(int)status2);
    }
}

- (void)dealloc {
    AudioQueueDispose(audioRef, TRUE);
    AudioFileClose(_recordFileID);
}

@end

上传音频

static char *const record_upload_queue = "com.soma.recordUploadQueue";//录音上传队列
static NSInteger const maxLength = 1280;//每次发送音频字节数
static NSInteger const minInterval = 40;//每次发送音频间隔40ms
    dispatch_queue_t recordQ =  dispatch_queue_create(record_upload_queue,
                                                      DISPATCH_QUEUE_SERIAL);
    dispatch_async(recordQ, ^{
        NSString *path = [LGRecordFileManager cacheFileWithFolder:@"LGAudioRecord" FileName:@"audioRecord.wav"];
        NSData *data = [[NSData alloc] initWithContentsOfFile:path];
        NSLog(@"文件大小%@ %f",data,(CGFloat)data.length/(CGFloat)maxLength);
        
        NSInputStream *inputStream = [[NSInputStream alloc] initWithFileAtPath:path];
        [inputStream open];
        NSInteger index = 0;
        int64_t addBytes = 0;//累计读取字节
        int64_t allBytes = data.length;//总字节
        uint8_t readBuffer [maxLength];
        
        BOOL endOfStreamReached = NO;//是否已经到结尾标识
        BOOL isError = NO;//是否出错

        while (!endOfStreamReached) {
//            if ([LGAudioUploadManager sharedManager].uploadStatus == AudioUploadStatusFailure) {
//                break;
//            }
           addBytes += maxLength;
           NSInteger bytesRead = [inputStream read:readBuffer maxLength:maxLength];
           if (bytesRead == 0) {
               //文件读取到最后
               endOfStreamReached = YES;
           } else if (bytesRead == -1) {
               //文件读取错误
               endOfStreamReached = YES;
               isError = YES;
           } else {
               //将字符不断的加载到视图
               NSData *data = [NSData dataWithBytesNoCopy:readBuffer length:bytesRead freeWhenDone:NO];
               NSString *audio = [data base64EncodedStringWithOptions:0];//BASE64编码。
               NSInteger status = 0;//第一帧
               if (addBytes < allBytes) {
                   status = 1;//中间帧
               }else {
                   status = 2;//最后一帧
               }
               if (index == 0) {
                   status = 0;//第一帧
               }
               NSMutableDictionary *dict = [NSMutableDictionary dictionary];
               if (status == 0) {//第一帧
                   NSDictionary *business = @{@"ent":@"igr",@"aue":@"raw",@"rate":@(8000)};
                   NSDictionary *common = @{@"app_id":kXfyunAppId};
                   dict[@"business"] = business;
                   dict[@"common"] = common;
               }
               NSDictionary *dataDict = @{@"status":@(status),@"audio":audio};
               dict[@"data"] = dataDict;
               [[SocketRocketUtility instance] sendData:dict withRequestURI:nil];
               index++;
               NSLog(@"NSInputStream %ld %ld",status,index);
               [NSThread sleepForTimeInterval:minInterval/1000.f];
           }
        }
        if (isError) {//读取出错 上传结束标识
            NSLog(@"录音文件读取出错，请重新录制");
        }
        [inputStream close];
    });