libavcodec/decode.c:706: error: Null Dereference
  pointer `desc` last assigned on line 705 could be null and is dereferenced at line 706, column 12.

libavcodec/decode.c:703:1: start of procedure is_hwaccel_pix_fmt()
701. }
702. 
703. static int is_hwaccel_pix_fmt(enum AVPixelFormat pix_fmt)
     ^
704. {
705.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);

libavcodec/decode.c:705:5: 
703. static int is_hwaccel_pix_fmt(enum AVPixelFormat pix_fmt)
704. {
705.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
         ^
706.     return desc->flags & AV_PIX_FMT_FLAG_HWACCEL;
707. }

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:706:5: 
704. {
705.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
706.     return desc->flags & AV_PIX_FMT_FLAG_HWACCEL;
         ^
707. }
708. 
