libavcodec/hevc.c:2725: error: Null Dereference
  pointer `desc` last assigned on line 2724 could be null and is dereferenced at line 2725, column 23.

libavcodec/hevc.c:2722:1: start of procedure verify_md5()
2720. }
2721. 
2722. static int verify_md5(HEVCContext *s, AVFrame *frame)
      ^
2723. {
2724.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(frame->format);

libavcodec/hevc.c:2724:5: 
2722. static int verify_md5(HEVCContext *s, AVFrame *frame)
2723. {
2724.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(frame->format);
          ^
2725.     int pixel_shift = desc->comp[0].depth_minus1 > 7;
2726.     int i, j;

libavutil/pixdesc.c:1504:1: start of procedure av_pix_fmt_desc_get()
  1502. }
  1503. 
  1504. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1505. {
  1506.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1506:9: Taking false branch
  1504. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1505. {
  1506.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1507.         return NULL;
  1508.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1506:24: Taking true branch
  1504. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1505. {
  1506.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1507.         return NULL;
  1508.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1507:9: 
  1505. {
  1506.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1507.         return NULL;
                ^
  1508.     return &av_pix_fmt_descriptors[pix_fmt];
  1509. }

libavutil/pixdesc.c:1509:1: return from a call to av_pix_fmt_desc_get
  1507.         return NULL;
  1508.     return &av_pix_fmt_descriptors[pix_fmt];
  1509. }
        ^
  1510. 
  1511. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libavcodec/hevc.c:2725:23: 
2723. {
2724.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(frame->format);
2725.     int pixel_shift = desc->comp[0].depth_minus1 > 7;
                            ^
2726.     int i, j;
2727. 
