callback

void ReadStreamClientCallBack(CFReadStreamRef   stream,
                          CFStreamEventType     type,
                          void*                 clientCallBackInfo) {
    BMHttpAudioStreamManager *manager = (__bridge BMHttpAudioStreamManager*) clientCallBackInfo;
    [manager readStreamClientCallBackWithData:stream withType:type];
}

- (void) readStreamClientCallBackWithData:(CFReadStreamRef) stream
                                 withType:(CFStreamEventType) type {

    if(type == kCFStreamEventHasBytesAvailable) {
        UInt8 buffer[2048];
        CFIndex bytesRead = CFReadStreamRead(stream, buffer, sizeof(buffer));

        if (bytesRead < 0) {
            //nothing
        }
        // If zero bytes were read, wait for the EOF to come.
        else if (bytesRead) {
            // parse the data. this will call MyPropertyListenerProc and MyPacketsProc
            // AudioFileStreamParseBytes function called when you have data to pass to the parser.
            // Send the data to the parser sequentially and, if possible, without gaps.
            OSStatus err = AudioFileStreamParseBytes(_audioData->audioFileStream, bytesRead, buffer, 0);
/*   This is what I had before, before I changed it to work 10.13.14
            OSStatus err = AudioFileStreamParseBytes(((AudioData *) audioData)->audioFileStream, bytesRead, buffer, 0);
*/
            if (err) PRINTERROR("AudioFileStreamParseBytes");
        }
    }
}



function that calls the above:
if (!CFReadStreamSetClient(stream8, kNetworkEvents, ReadStreamClientCallBack, &ctxt)) {...}