libswscale/swscale.c:2841: error: Null Dereference
  pointer `filter` last assigned on line 2835 could be null and is dereferenced at line 2841, column 9.

libswscale/swscale.c:2830:1: start of procedure sws_getDefaultFilter()
2828. #endif
2829. 
2830. SwsFilter *sws_getDefaultFilter(float lumaGBlur, float chromaGBlur,
      ^
2831.                                 float lumaSharpen, float chromaSharpen,
2832.                                 float chromaHShift, float chromaVShift,

libswscale/swscale.c:2835:5: 
2833.                                 int verbose)
2834. {
2835.     SwsFilter *filter= av_malloc(sizeof(SwsFilter));
          ^
2836. 
2837.     if (lumaGBlur!=0.0){

libavutil/mem.c:47:1: start of procedure av_malloc()
  45.    linker will do it automatically. */
  46. 
  47. void *av_malloc(unsigned int size)
      ^
  48. {
  49.     void *ptr = NULL;

libavutil/mem.c:49:5: 
  47. void *av_malloc(unsigned int size)
  48. {
  49.     void *ptr = NULL;
          ^
  50. #if CONFIG_MEMALIGN_HACK
  51.     long diff;

libavutil/mem.c:55:8: Taking false branch
  53. 
  54.     /* let's disallow possible ambiguous cases */
  55.     if(size > (INT_MAX-16) )
             ^
  56.         return NULL;
  57. 

libavutil/mem.c:66:9: Taking true branch
  64.     ((char*)ptr)[-1]= diff;
  65. #elif HAVE_POSIX_MEMALIGN
  66.     if (posix_memalign(&ptr,16,size))
              ^
  67.         ptr = NULL;
  68. #elif HAVE_MEMALIGN

libavutil/mem.c:67:9: 
  65. #elif HAVE_POSIX_MEMALIGN
  66.     if (posix_memalign(&ptr,16,size))
  67.         ptr = NULL;
              ^
  68. #elif HAVE_MEMALIGN
  69.     ptr = memalign(16,size);

libavutil/mem.c:99:5: 
   97.     ptr = malloc(size);
   98. #endif
   99.     return ptr;
           ^
  100. }
  101. 

libavutil/mem.c:100:1: return from a call to av_malloc
   98. #endif
   99.     return ptr;
  100. }
       ^
  101. 
  102. void *av_realloc(void *ptr, unsigned int size)

libswscale/swscale.c:2837:9: Taking false branch
2835.     SwsFilter *filter= av_malloc(sizeof(SwsFilter));
2836. 
2837.     if (lumaGBlur!=0.0){
              ^
2838.         filter->lumH= sws_getGaussianVec(lumaGBlur, 3.0);
2839.         filter->lumV= sws_getGaussianVec(lumaGBlur, 3.0);

libswscale/swscale.c:2841:9: 
2839.         filter->lumV= sws_getGaussianVec(lumaGBlur, 3.0);
2840.     }else{
2841.         filter->lumH= sws_getIdentityVec();
              ^
2842.         filter->lumV= sws_getIdentityVec();
2843.     }

libswscale/swscale.c:2924:1: start of procedure sws_getIdentityVec()
  2922. 
  2923. 
  2924. SwsVector *sws_getIdentityVec(void){
        ^
  2925.     return sws_getConstVec(1.0, 1);
  2926. }

libswscale/swscale.c:2925:5: Skipping sws_getConstVec(): empty list of specs
  2923. 
  2924. SwsVector *sws_getIdentityVec(void){
  2925.     return sws_getConstVec(1.0, 1);
            ^
  2926. }
  2927. 

libswscale/swscale.c:2926:1: return from a call to sws_getIdentityVec
  2924. SwsVector *sws_getIdentityVec(void){
  2925.     return sws_getConstVec(1.0, 1);
  2926. }
        ^
  2927. 
  2928. double sws_dcVec(SwsVector *a){
