libavcodec/decode.c:422: error: Null Dereference
  pointer `desc` last assigned on line 421 could be null and is dereferenced at line 422, column 12.

libavcodec/decode.c:419:1: start of procedure is_hwaccel_pix_fmt()
417. }
418. 
419. static int is_hwaccel_pix_fmt(enum AVPixelFormat pix_fmt)
     ^
420. {
421.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);

libavcodec/decode.c:421:5: 
419. static int is_hwaccel_pix_fmt(enum AVPixelFormat pix_fmt)
420. {
421.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
         ^
422.     return desc->flags & AV_PIX_FMT_FLAG_HWACCEL;
423. }

libavutil/pixdesc.c:1914:1: start of procedure av_pix_fmt_desc_get()
  1912. }
  1913. 
  1914. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1915. {
  1916.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1916:9: Taking false branch
  1914. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1915. {
  1916.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1917.         return NULL;
  1918.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1916:24: Taking true branch
  1914. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1915. {
  1916.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1917.         return NULL;
  1918.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1917:9: 
  1915. {
  1916.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1917.         return NULL;
                ^
  1918.     return &av_pix_fmt_descriptors[pix_fmt];
  1919. }

libavutil/pixdesc.c:1919:1: return from a call to av_pix_fmt_desc_get
  1917.         return NULL;
  1918.     return &av_pix_fmt_descriptors[pix_fmt];
  1919. }
        ^
  1920. 
  1921. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libavcodec/decode.c:422:5: 
420. {
421.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
422.     return desc->flags & AV_PIX_FMT_FLAG_HWACCEL;
         ^
423. }
424. 
