blocks|key|2849839|text|如果sigbuf的类型为(void+*)，则您的代码行|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2849840|sigbuf=(complex_float+*)malloc(bitsPerBlk*sigLen*sizeof(complex_float));|code-block|syntax|javascript|2849841|应该能够更改为|2849842|sigbuf=(void+*)malloc(bitsPerBlk*sigLen*sizeof(complex_float));|2849843|因为malloc的左边是一个简单的铸型！|2849844|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

if sigbuf is of type (void *) then your line

<pre><code>sigbuf=(complex_float *)malloc(bitsPerBlk*sigLen*sizeof(complex_float));
</code></pre>

should be able to be changed to 

<pre><code>sigbuf=(void *)malloc(bitsPerBlk*sigLen*sizeof(complex_float));
</code></pre>

as left of the malloc is simply a cast!

blocks|key|2937476|text|很抱歉，我的错是我没能清楚地解释我的观点。声明如下|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2937477|void+*sigbuf;
complex_float+*comSig;|code-block|syntax|javascript|2937478|2937479|+complex_float|blockquote|2937480|2937481|2937482|是一个由两个浮动元素组成的结构。|2937483|2937484|+sigbuf|2937485|2937486|2937487|将存储调制后的数据，然后将其进一步传递给传输系统。|2937488|2937489|+comSig|2937490|2937491|2937492|是一个complex_float数组(基本上是正弦和余弦函数输出的数组)。|2937493|DSP基础设施需要调制输出在|2937494|2937495|+sigbuf|2937496|2937497|2937498|已计算并保存在|2937499|2937500|+comSig|2937501|2937502|2937503|。somSig和sigbuf都是在数字信号处理基础设施中预先定义的。|2937504|我的问题是，我可以将整个comSig复制到sigbuf数组中，但不能访问sigbuf数组的各个元素。|2937505|我能够通过全局指针传递comSig数组本身的地址来绕过这个问题的任何方法variable.The+DSP基础设施都提供了这样做的自由。所以，现在这个问题似乎已经解决了。再次感谢，安舒。|2937506|entityMap^0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|1O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|1P|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|1Q|8|@]|9|@]|A|$]]|$1|H|3|I|5|J|7|1R|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|1S|8|@]|9|@]|A|$]]|$1|L|3|-4|5|6|7|1T|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|1U|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|1V|8|@]|9|@]|A|$]]|$1|P|3|Q|5|J|7|1W|8|@]|9|@]|A|$]]|$1|R|3|-4|5|6|7|1X|8|@]|9|@]|A|$]]|$1|S|3|-4|5|6|7|1Y|8|@]|9|@]|A|$]]|$1|T|3|U|5|6|7|1Z|8|@]|9|@]|A|$]]|$1|V|3|-4|5|6|7|20|8|@]|9|@]|A|$]]|$1|W|3|X|5|J|7|21|8|@]|9|@]|A|$]]|$1|Y|3|-4|5|6|7|22|8|@]|9|@]|A|$]]|$1|Z|3|-4|5|6|7|23|8|@]|9|@]|A|$]]|$1|10|3|11|5|6|7|24|8|@]|9|@]|A|$]]|$1|12|3|13|5|6|7|25|8|@]|9|@]|A|$]]|$1|14|3|-4|5|6|7|26|8|@]|9|@]|A|$]]|$1|15|3|16|5|J|7|27|8|@]|9|@]|A|$]]|$1|17|3|-4|5|6|7|28|8|@]|9|@]|A|$]]|$1|18|3|-4|5|6|7|29|8|@]|9|@]|A|$]]|$1|19|3|1A|5|6|7|2A|8|@]|9|@]|A|$]]|$1|1B|3|-4|5|6|7|2B|8|@]|9|@]|A|$]]|$1|1C|3|1D|5|J|7|2C|8|@]|9|@]|A|$]]|$1|1E|3|-4|5|6|7|2D|8|@]|9|@]|A|$]]|$1|1F|3|-4|5|6|7|2E|8|@]|9|@]|A|$]]|$1|1G|3|1H|5|6|7|2F|8|@]|9|@]|A|$]]|$1|1I|3|1J|5|6|7|2G|8|@]|9|@]|A|$]]|$1|1K|3|1L|5|6|7|2H|8|@]|9|@]|A|$]]|$1|1M|3|-4|5|6|7|2I|8|@]|9|@]|A|$]]]|1N|$]]

sorry for that, my bad that i was not able to explain my point clearly. The declarations are as follows

<pre><code>void *sigbuf;
complex_float *comSig;
</code></pre>

<blockquote>
 complex_float
</blockquote>

is a struct consisting of two float elements.

<blockquote>
 sigbuf
</blockquote>

will store the modulated data which is then passed further for transmission system. 

<blockquote>
 comSig
</blockquote>

is a complex_float array (basically an array of sin and cosine function ouputs).

The DSP infrastructure needs the modulated output in 

<blockquote>
 sigbuf
</blockquote>

which has been calculated and saved in 

<blockquote>
 comSig
</blockquote>

.
Both somSig and sigbuf are predefined in the DSP infrastructure.

My problem was that I was able to copy the entire comSig aaray to sigbuf array, but was not able to access the individual elements 
of the sigbuf array.

Any ways I was able to circumvent the problem by passing the address of the comSig array itself via a global pointer variable.The DSP infrastructure
gives the freedom to do so. So, for now the problem seems to have been fixed.
Thanks again, Anshu.

blocks|key|2849923|text|确保目标地址sigbuf正确对齐。例如，DSP可能要求4字节浮点值必须在4字节边界上对齐。memcpy()很可能不会检查对齐，并且会毫无错误地复制单个字节。但是，如果sigbuf没有正确的对齐方式，那么您将无法以浮点型的形式访问内容(即，当数据从内存读取到寄存器中时，数据将被损坏)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2849924|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Ensure that the destination address, sigbuf, is properly aligned. For example, the DSP may require that 4-byte float values must be aligned on 4-byte boundaries. memcpy() likely does not check alignment and will copy the individual bytes without complaint. But if sigbuf does not have the proper alignment then you will not be able to access the contents as a float (i.e., the data will be corrupted when it is read from memory into a register).

blocks|key|1212786|text|我将在这里进行猜测。为什么不将comSig复制到sigBuf，然后将其传递给您的API呢？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1212787|complex_float+*sigBuf+=+malloc(TOTAL_SIZE_OF_COMSIG);
memcpy(sigBuf,+comSig,+TOTAL_SIZE_OF_COMSIG);|code-block|syntax|javascript|1212788|我不知道你的函数的文档，但听起来你的API接受了一个空指针，指向某个数据缓冲区，可能还有它的长度或元素的数量。|1212789|dsp_api(sigBuf,+sigBufSize);|1212790|我认为你误解了什么是空指针，以及你的函数想要什么。空指针只是指向某些数据的通用指针。它是函数接收任何数据的方式，然后可能将其转换为complex_float结构以对数据进行操作。|1212791|作为未来的参考，为什么你不能取消引用一个空指针是因为它没有大小。你必须将它转换为一个类型，然后你才能取消对它的引用。|1212792|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

I'm going to take a guess here. Why don't you just make a copy of comSig to sigBuf then pass it to your API?

<pre><code>complex_float *sigBuf = malloc(TOTAL_SIZE_OF_COMSIG);
memcpy(sigBuf, comSig, TOTAL_SIZE_OF_COMSIG);
</code></pre>

I don't know the docs on your function but it sounds like your API takes a void pointer to some buffer of data and perhaps its length or number of elements.

<pre><code>dsp_api(sigBuf, sigBufSize);
</code></pre>

I think you are misunderstanding what a void pointer is and what your function wants. A void pointer is just a generic pointer to some data. It's the functions way of taking in any data, then probably casting it to your complex_float structure to operate on the data.

As a future reference to why you weren't able to dereference a void pointer is because it has no size. You'd have to cast it to a type then you'd be able to dereference it.

I am working on implementing BFSK algorithm on a DSP processor and need to simulate the implementation on LINUX using predefined DSP infra files. The input data in coming in the the form of a float array. The individual bits are extracted from the input one by one. The modulated output is generated in the fprm of a typdef struct, which is a consists of two float variables (real and imaginary parts since the modulated data is a complex baseband signal). But the DSP simulation needs the output to be saved into a void pointer array. This cant be changed as the DSP APIs need it in the form of a void pointer. The definition of the struct is as follows :

<pre><code>typedef struct {
float re;
float im;
}complex_float;
</code></pre>

I am able to copy the data into the void pointer using memcpy : 

<pre><code>sigbuf=(float *)malloc(bitsPerBlk*sigLen*sizeof(complex_float));

memcpy(sigbuf, comSig, (bitsPerBlk*sigLen*sizeof(complex_float)));
</code></pre>

sigbuf is the void pointer array where the ouput would be saved and comSig is the complex_float array where the modulated output is saved. The thing is I am not able to access the invidual values of the sigbuf array. I tried this as well

<pre><code>sigbuf=(complex_float *)malloc(bitsPerBlk*sigLen*sizeof(complex_float));
</code></pre>

But still it doesnot work.

If someone can help me out it would be very helpful for me.

Thanks,
Anshu

Saving struct data to a void* variable

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我的工作是在DSP处理器上实现BFSK算法，需要在LINUX上使用预定义的DSP底层文件来模拟实现。输入数据以浮点数组的形式出现。从输入中逐个提取各个比特。在typdef结构的fprm中生成调制输出，该结构由两个浮点变量(实部和虚部，因为调制数据是复数基带信号)组成。但DSP仿真需要将输出保存到空指针数组中。这不能改变...

问将结构数据保存到void*变量
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