libavcodec/decode.c:622: error: Null Dereference
  pointer `desc` last assigned on line 621 could be null and is dereferenced at line 622, column 12.

libavcodec/decode.c:619:1: start of procedure is_hwaccel_pix_fmt()
617. }
618. 
619. static int is_hwaccel_pix_fmt(enum AVPixelFormat pix_fmt)
     ^
620. {
621.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);

libavcodec/decode.c:621:5: 
619. static int is_hwaccel_pix_fmt(enum AVPixelFormat pix_fmt)
620. {
621.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
         ^
622.     return desc->flags & AV_PIX_FMT_FLAG_HWACCEL;
623. }

libavutil/pixdesc.c:1898:1: start of procedure av_pix_fmt_desc_get()
  1896. }
  1897. 
  1898. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1899. {
  1900.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1900:9: Taking false branch
  1898. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1899. {
  1900.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1901.         return NULL;
  1902.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1900:24: Taking true branch
  1898. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1899. {
  1900.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1901.         return NULL;
  1902.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1901:9: 
  1899. {
  1900.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1901.         return NULL;
                ^
  1902.     return &av_pix_fmt_descriptors[pix_fmt];
  1903. }

libavutil/pixdesc.c:1903:1: return from a call to av_pix_fmt_desc_get
  1901.         return NULL;
  1902.     return &av_pix_fmt_descriptors[pix_fmt];
  1903. }
        ^
  1904. 
  1905. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libavcodec/decode.c:622:5: 
620. {
621.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
622.     return desc->flags & AV_PIX_FMT_FLAG_HWACCEL;
         ^
623. }
624. 

static int is_hwaccel_pix_fmt(enum AVPixelFormat pix_fmt)
{
    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
    return desc->flags & AV_PIX_FMT_FLAG_HWACCEL;
}
['static int is_hwaccel_pix_fmt(enum AVPixelFormat pix_fmt)\n{\n    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);\n    return desc->flags & AV_PIX_FMT_FLAG_HWACCEL;\n}', 'const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)\n{\n    if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)\n        return NULL;\n    return &av_pix_fmt_descriptors[pix_fmt];\n}']