Question

我正在尝试对音频信号的部分进行一些测量（读作std::vector<double>），这涉及使用Aquila进行一些信号处理。我正在使用与their example中相同的函数计算MFCC常数，但我没有Aquila::SineGenerator而是从向量using this constructor创建Aquila::SignalSource。

我的功能，删除了不相关的代码，是：

void measure(std::vector<double> &output_vector, std::vector<double> &audio, int start_index, int end_index) {
    // Copy the raw note over.
    std::vector<double> note_audio(end_index - start_index);
    std::copy(audio.begin() + start_index, audio.begin() + end_index, note_audio.begin());

    // Calculate the MFCC constants.
    Aquila::SignalSource input(note_audio, 44100);
    Aquila::Mfcc mfcc(input.getSamplesCount());
    auto mfccValues = mfcc.calculate(input);

    // Copy them over to the output vector.
    for (int i = 0; i < mfccValues.size(); i++) {
        output_vector.push_back(mfccValues[i]);
    }
}

当它运行时 - 通常但不总是，第二次或第三次被调用 - 它崩溃并输出：

prog(15384,0x7fff7cafb310) malloc: *** error for object 0x7f8781863208: incorrect checksum for freed object - object was probably modified after being freed.
*** set a breakpoint in malloc_error_break to debug
Abort trap: 6

所以，我启动lldb并调试，在malloc_error_break设置一个断点，并得到这个堆栈跟踪：

(lldb) bt
* thread #1: tid = 0x23c194, 0x00007fff8f487bc0 libsystem_malloc.dylib`malloc_error_break, queue = 'com.apple.main-thread', stop reason = breakpoint 1.2
  * frame #0: 0x00007fff8f487bc0 libsystem_malloc.dylib`malloc_error_break
    frame #1: 0x00007fff8f4815c7 libsystem_malloc.dylib`szone_error + 386
    frame #2: 0x00007fff8f482e1a libsystem_malloc.dylib`small_free_list_remove_ptr + 291
    frame #3: 0x00007fff8f47f737 libsystem_malloc.dylib`szone_free_definite_size + 3429
    frame #4: 0x00000001000029a5 prog-debug`std::__1::__vector_base<double, std::__1::allocator<double> >::~__vector_base() [inlined] std::__1::__deallocate(__ptr=0x00000001008f3800) + 421 at new:164
    frame #5: 0x000000010000299c prog-debug`std::__1::__vector_base<double, std::__1::allocator<double> >::~__vector_base() [inlined] std::__1::allocator<double>::deallocate(this=0x0000000100307888, __p=0x00000001008f3800, (null)=6300) + 8 at memory:1636
    frame #6: 0x0000000100002994 prog-debug`std::__1::__vector_base<double, std::__1::allocator<double> >::~__vector_base() [inlined] std::__1::allocator_traits<std::__1::allocator<double> >::deallocate(__a=0x0000000100307888, __p=0x00000001008f3800, __n=6300) + 24 at memory:1447
    frame #7: 0x000000010000297c prog-debug`std::__1::__vector_base<double, std::__1::allocator<double> >::~__vector_base(this=0x0000000100307878) + 380 at vector:476
    frame #8: 0x0000000100002e25 prog-debug`std::__1::vector<double, std::__1::allocator<double> >::~vector(this=0x0000000100307878) + 21 at vector:481
    frame #9: 0x0000000100002355 prog-debug`std::__1::vector<double, std::__1::allocator<double> >::~vector(this=0x0000000100307878) + 21 at vector:481
    frame #10: 0x000000010004b99c prog-debug`Aquila::MelFilter::~MelFilter() + 28
    frame #11: 0x000000010004b975 prog-debug`Aquila::MelFilter::~MelFilter() + 21
    frame #12: 0x000000010004b8b7 prog-debug`std::__1::__vector_base<Aquila::MelFilter, std::__1::allocator<Aquila::MelFilter> >::~__vector_base() + 279
    frame #13: 0x000000010004b795 prog-debug`std::__1::vector<Aquila::MelFilter, std::__1::allocator<Aquila::MelFilter> >::~vector() + 21
    frame #14: 0x000000010004b775 prog-debug`std::__1::vector<Aquila::MelFilter, std::__1::allocator<Aquila::MelFilter> >::~vector() + 21
    frame #15: 0x000000010004b755 prog-debug`Aquila::MelFilterBank::~MelFilterBank() + 21
    frame #16: 0x000000010004b545 prog-debug`Aquila::MelFilterBank::~MelFilterBank() + 21
    frame #17: 0x000000010004b463 prog-debug`Aquila::Mfcc::calculate(Aquila::SignalSource const&, unsigned long) + 323
    frame #18: 0x00000001000203b6 prog-debug`measure(the_vector=0x00007fff5fbfd8c8, audio=0x00007fff5fbfe478, start_index=7078, end_index=13378) + 1270 at measureVector.cpp:62
    frame #19: 0x0000000100018eb2 prog-debug`extractVectors(vectors=0x00007fff5fbfe4e0, audio=vector<double, std::__1::allocator<double> > at 0x00007fff5fbfe478, sample_rate=44100, bg_audio=vector<double, std::__1::allocator<double> > at 0x00007fff5fbfe460, bg_sample_rate=44100, notes=0x00007fff5fbfe490) + 3234 at extractVectors.cpp:74
    frame #20: 0x000000010002b915 prog-debug`train(results=0x00007fff5fbff620, training_path=std::__1::string at 0x00007fff5fbff608, bg_audio=vector<double, std::__1::allocator<double> > at 0x00007fff5fbff5f0, bg_sample_rate=44100, classes=0x00007fff5fbff638) + 5733 at train.cpp:44
    frame #21: 0x00000001000211d3 prog-debug`MUSE(input_path=std::__1::string at 0x00007fff5fbff948, training_path=std::__1::string at 0x00007fff5fbff930, noise_profile_path=std::__1::string at 0x00007fff5fbff908, output_path=std::__1::string at 0x00007fff5fbff8f0) + 995 at muse.cpp:44
    frame #22: 0x00000001000217fd prog-debug`main(argc=5, argv=0x00007fff5fbffab8) + 717 at muse.cpp:55

有时候我会得到它，有时我会在内部（you can see them here）中得到其他错误，但它们都从Aquila::Mfcc::calculate()开始，通常似乎涉及析构函数。我遇到了类似的错误，并且是由于尝试返回基于堆栈的变量（oops - 这就是为什么我传递了我的output_vector并在函数中修改它），但我没有看到这里 - 我使用它，然后将double值复制到我的输出向量。我尝试创建note_audio作为new的指针，我尝试在堆栈和堆上创建它作为数组而不是std::vector，但无济于事。< / p>

使用CMake和LLVM在OS X Mavericks上构建C ++ 11。根据评论中的建议，我保存了the first ~300 lines of a Valgrind output的要点（尽管它一直持续到> 100个错误）。我在这里缺少什么？

Answer 1

我将这个问题发布到了Aquila GitHub问题页面和got back an answer来自图书馆的创建者。 Credit goes to another issue发现（好时机）。

简而言之：Aquila使用的FFT库OouraFFT要求矢量大小为2的幂，但如果情况并非如此，则不会抱怨它只会写入解除分配的内存第一次拨打OouraFFT::fft()。外卖课程总是断言你需要检查的条件才能在堆上疯狂。

＆＃34;释放对象的校验和错误＆＃34;在图书馆的破坏者中

1 个答案: