libswscale/output.c:1280: error: Null Dereference
  pointer `desc` last assigned on line 1278 could be null and is dereferenced at line 1280, column 21.

libswscale/output.c:1270:1: start of procedure yuv2gbrp_full_X_c()
1268. YUV2RGBWRAPPERX(yuv2, rgb_full, rgb24_full,  AV_PIX_FMT_RGB24, 0)
1269. 
1270. static void
      ^
1271. yuv2gbrp_full_X_c(SwsContext *c, const int16_t *lumFilter,
1272.                   const int16_t **lumSrc, int lumFilterSize,

libswscale/output.c:1278:5: 
1276.                   int dstW, int y)
1277. {
1278.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(c->dstFormat);
          ^
1279.     int i;
1280.     int hasAlpha = (desc->flags & AV_PIX_FMT_FLAG_ALPHA) && alpSrc;

libavutil/pixdesc.c:1665:1: start of procedure av_pix_fmt_desc_get()
  1663. }
  1664. 
  1665. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1666. {
  1667.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1667:9: Taking false branch
  1665. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1666. {
  1667.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1668.         return NULL;
  1669.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1667:24: Taking true branch
  1665. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1666. {
  1667.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1668.         return NULL;
  1669.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1668:9: 
  1666. {
  1667.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1668.         return NULL;
                ^
  1669.     return &av_pix_fmt_descriptors[pix_fmt];
  1670. }

libavutil/pixdesc.c:1670:1: return from a call to av_pix_fmt_desc_get
  1668.         return NULL;
  1669.     return &av_pix_fmt_descriptors[pix_fmt];
  1670. }
        ^
  1671. 
  1672. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libswscale/output.c:1280:21: 
1278.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(c->dstFormat);
1279.     int i;
1280.     int hasAlpha = (desc->flags & AV_PIX_FMT_FLAG_ALPHA) && alpSrc;
                          ^
1281.     uint16_t **dest16 = (uint16_t**)dest;
1282.     int SH = 22 + 7 - desc->comp[0].depth_minus1;
