無法初始化類型爲'void *'的類型爲'void * const *'的變量

Question

我試圖在iOS的核心音頻中部分文件緩衝區，爲了做到這一點，我需要更改開始我傳遞給memcpy的地址。我的代碼看起來像這樣...

UInt32 bytesToRead = inBuffer->mAudioDataBytesCapacity; 
int srcOffset = 0; 
while (bytesToRead > 0) { 
    UInt32 maxBytesFromCurrentPiece = self.currentAudioPiece.audioData.length - self.currentAudioPieceIndex; 
    //Take the min of what the current piece can provide OR what is needed to be read 
    UInt32 bytesToReadNow = MIN(maxBytesFromCurrentPiece, bytesToRead); 

    NSData *subRange = [self.currentAudioPiece.audioData subdataWithRange:NSMakeRange(self.currentAudioPieceIndex, bytesToReadNow)]; 
    //Copy what you can before continuing loop 

    void *srcStart = (&inBuffer->mAudioData + srcOffset); 
    memcpy(srcStart, subRange.bytes, subRange.length); 
    srcOffset += subRange.length; 
    bytesToRead -= bytesToReadNow; 

Appcode顯示沒有錯誤，但編譯器顯示了這個：

「語義問題」 - 無法 右值初始化類型「無效*」的變量類型'void * const *'

在「* srcStart」的行上。

Answer 1

嘗試改變

void *srcStart = (&inBuffer->mAudioData + srcOffset); 

到

char *srcStart = ((char *)inBuffer->mAudioData) + srcOffset; 

這將跳過字節的適當數量。