libavcodec/decode.c:707: error: Null Dereference
  pointer `desc` last assigned on line 706 could be null and is dereferenced at line 707, column 12.

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

libavcodec/decode.c:706:5: 
704. static int is_hwaccel_pix_fmt(enum AVPixelFormat pix_fmt)
705. {
706.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
         ^
707.     return desc->flags & AV_PIX_FMT_FLAG_HWACCEL;
708. }

libavutil/pixdesc.c:1894:1: start of procedure av_pix_fmt_desc_get()
  1892. }
  1893. 
  1894. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1895. {
  1896.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1896:9: Taking false branch
  1894. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1895. {
  1896.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1897.         return NULL;
  1898.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1896:24: Taking true branch
  1894. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1895. {
  1896.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1897.         return NULL;
  1898.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1897:9: 
  1895. {
  1896.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1897.         return NULL;
                ^
  1898.     return &av_pix_fmt_descriptors[pix_fmt];
  1899. }

libavutil/pixdesc.c:1899:1: return from a call to av_pix_fmt_desc_get
  1897.         return NULL;
  1898.     return &av_pix_fmt_descriptors[pix_fmt];
  1899. }
        ^
  1900. 
  1901. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libavcodec/decode.c:707:5: 
705. {
706.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
707.     return desc->flags & AV_PIX_FMT_FLAG_HWACCEL;
         ^
708. }
709. 
