TRTC 接入实时语音识别

//1.TRTCAudioFrameDelegate 协议是 TRTC 获取音频源的协议，由于 ASR 识别16k或8k采样率的音频数据，所以需要设置 setAudioQuality 为 TRTCCloudDef#TRTC_AUDIO_QUALITY_SPEECH (流畅:采样率:16k;单声道;音频裸码率:16kbps)

- (void) onCapturedRawAudioFrame:(TRTCAudioFrame *)frame {//此方法为 TRTC 本地麦克风采集到的原始音频数据回调：

  NSUInteger readLength = [frame.data length];
  void *pcmBytes = (void *)frame.data.bytes;
  [dataSource didRecordAudioData:pcmBytes length:readLength];
}

#import<QCloudSDK/QCloudSDK.h>

//1.使用第三方外部数据源传入语音数据，自定义 data source 需要实现 QCloudAudioDataSource 协议
QDAudioDataSource *dataSource = [[QDAudioDataSource alloc] init];

//2.创建 QCloudRealTimeRecognizer 识别实例
QCloudRealTimeRecognizer *realTimeRecognizer = [[QCloudRealTimeRecognizer alloc] initWithConfig:config dataSource:dataSource];

@interface QDAudioDataSource : NSObject<QCloudAudioDataSource>
@end

@implementation QDAudioDataSource
@synthesize running = _running;

//SDK 会调用此方法获取当前状态
- (BOOL)running{
    return _recording;
}

//SDK 会调用 start 方法，实现此协议的类需要初始化数据源
- (void)start:(void(^)(BOOL didStart, NSError *error))completion{
  _data = [[NSMutableData alloc] init];
}

//SDK 会调用 stop 方法，实现此协议的类需要停止提供数据
- (void)stop{
  _recording = NO;
  _data = nil;
}

//SDK 会调用实现此协议的对象的此方法读取语音数据
- (nullable NSData *)readData:(NSInteger)expectLength{
  NSData *data = nil;
  if ([_data length] >= _offset + expectLength) {
      data = [_data subdataWithRange:NSMakeRange(_offset, expectLength)];
      [_data replaceBytesInRange:NSMakeRange(_offset, expectLength) withBytes:NULL length:0];
  }
  return data;
}

//此处仅为演示，需用户自行完善音频数据源填充
- (void)didRecordAudioData:(void * const )bytes length:(NSInteger)length{
  [_data appendBytes:bytes length:length];
}
@end