libavcodec/imgconvert.c:441: error: Null Dereference
  pointer `buf` last assigned on line 438 could be null and is dereferenced by call to `memcpy()` at line 441, column 5.

libavcodec/imgconvert.c:432:1: start of procedure deinterlace_bottom_field_inplace()
430. }
431. 
432. static void deinterlace_bottom_field_inplace(uint8_t *src1, int src_wrap,
     ^
433.                                              int width, int height)
434. {

libavcodec/imgconvert.c:438:5: 
436.     int y;
437.     uint8_t *buf;
438.     buf = av_malloc(width);
         ^
439. 
440.     src_m1 = src1;

libavutil/mem.c:62:1: start of procedure av_malloc()
  60.  * linker will do it automatically. */
  61. 
  62. void *av_malloc(size_t size)
      ^
  63. {
  64.     void *ptr = NULL;

libavutil/mem.c:64:5: 
  62. void *av_malloc(size_t size)
  63. {
  64.     void *ptr = NULL;
          ^
  65. #if CONFIG_MEMALIGN_HACK
  66.     long diff;

libavutil/mem.c:70:9: Taking true branch
  68. 
  69.     /* let's disallow possibly ambiguous cases */
  70.     if (size > (INT_MAX - 32) || !size)
              ^
  71.         return NULL;
  72. 

libavutil/mem.c:71:9: 
  69.     /* let's disallow possibly ambiguous cases */
  70.     if (size > (INT_MAX - 32) || !size)
  71.         return NULL;
              ^
  72. 
  73. #if CONFIG_MEMALIGN_HACK

libavutil/mem.c:115:1: return from a call to av_malloc
  113. #endif
  114.     return ptr;
  115. }
       ^
  116. 
  117. void *av_realloc(void *ptr, size_t size)

libavcodec/imgconvert.c:440:5: 
438.     buf = av_malloc(width);
439. 
440.     src_m1 = src1;
         ^
441.     memcpy(buf,src_m1,width);
442.     src_0=&src_m1[src_wrap];

libavcodec/imgconvert.c:441:5: 
439. 
440.     src_m1 = src1;
441.     memcpy(buf,src_m1,width);
         ^
442.     src_0=&src_m1[src_wrap];
443.     src_p1=&src_0[src_wrap];

static void deinterlace_bottom_field_inplace(uint8_t *src1, int src_wrap,
                                             int width, int height)
{
    uint8_t *src_m1, *src_0, *src_p1, *src_p2;
    int y;
    uint8_t *buf;
    buf = av_malloc(width);
    src_m1 = src1;
    memcpy(buf,src_m1,width);
    src_0=&src_m1[src_wrap];
    src_p1=&src_0[src_wrap];
    src_p2=&src_p1[src_wrap];
    for(y=0;y<(height-2);y+=2) {
        deinterlace_line_inplace(buf,src_m1,src_0,src_p1,src_p2,width);
        src_m1 = src_p1;
        src_0 = src_p2;
        src_p1 += 2*src_wrap;
        src_p2 += 2*src_wrap;
    }
    deinterlace_line_inplace(buf,src_m1,src_0,src_0,src_0,width);
    av_free(buf);
}
['static void deinterlace_bottom_field_inplace(uint8_t *src1, int src_wrap,\n                                             int width, int height)\n{\n    uint8_t *src_m1, *src_0, *src_p1, *src_p2;\n    int y;\n    uint8_t *buf;\n    buf = av_malloc(width);\n    src_m1 = src1;\n    memcpy(buf,src_m1,width);\n    src_0=&src_m1[src_wrap];\n    src_p1=&src_0[src_wrap];\n    src_p2=&src_p1[src_wrap];\n    for(y=0;y<(height-2);y+=2) {\n        deinterlace_line_inplace(buf,src_m1,src_0,src_p1,src_p2,width);\n        src_m1 = src_p1;\n        src_0 = src_p2;\n        src_p1 += 2*src_wrap;\n        src_p2 += 2*src_wrap;\n    }\n    deinterlace_line_inplace(buf,src_m1,src_0,src_0,src_0,width);\n    av_free(buf);\n}', 'void *av_malloc(size_t size)\n{\n    void *ptr = NULL;\n#if CONFIG_MEMALIGN_HACK\n    long diff;\n#endif\n    if (size > (INT_MAX - 32) || !size)\n        return NULL;\n#if CONFIG_MEMALIGN_HACK\n    ptr = malloc(size + 32);\n    if (!ptr)\n        return ptr;\n    diff              = ((-(long)ptr - 1) & 31) + 1;\n    ptr               = (char *)ptr + diff;\n    ((char *)ptr)[-1] = diff;\n#elif HAVE_POSIX_MEMALIGN\n    if (posix_memalign(&ptr, 32, size))\n        ptr = NULL;\n#elif HAVE_ALIGNED_MALLOC\n    ptr = _aligned_malloc(size, 32);\n#elif HAVE_MEMALIGN\n    ptr = memalign(32, size);\n#else\n    ptr = malloc(size);\n#endif\n    return ptr;\n}']