ffmpeg-avutil-fifo

/* src must NOT be const as it can be a context for func that may need
 * updating (like a pointer or byte counter) */
int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size,
                          int (*func)(void *, void *, int))
{
    int total = size;
    uint32_t wndx= f->wndx;
    uint8_t *wptr= f->wptr;

    do {
        int len = FFMIN(f->end - wptr, size);
        if (func) {
            len = func(src, wptr, len);
            if (len <= 0)
                break;
        } else {
            memcpy(wptr, src, len);
            src = (uint8_t *)src + len;
        }
// Write memory barrier needed for SMP here in theory
        wptr += len;
        if (wptr >= f->end)
            wptr = f->buffer;
        wndx    += len;
        size    -= len;
    } while (size > 0);
    f->wndx= wndx;
    f->wptr= wptr;
    return total - size;
}

先看看快樂路徑，就是把數據庫複製到緩衝區。更新wptr指針。

memcpy(wptr, src, len);

有寫爆的可能。

C:\project\bin>test_ffmpeg.exe turbojpeg.dll
adler32_code is:ef270018
space is :1024
write 556032 data to fifo
space is :-555008