libswscale/output.c:1279: error: Null Dereference
  pointer `desc` last assigned on line 1277 could be null and is dereferenced at line 1279, column 21.

libswscale/output.c:1269:1: start of procedure yuv2gbrp_full_X_c()
1267. YUV2RGBWRAPPERX(yuv2, rgb_full, rgb24_full,  AV_PIX_FMT_RGB24, 0)
1268. 
1269. static void
      ^
1270. yuv2gbrp_full_X_c(SwsContext *c, const int16_t *lumFilter,
1271.                   const int16_t **lumSrc, int lumFilterSize,

libswscale/output.c:1277:5: 
1275.                   int dstW, int y)
1276. {
1277.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(c->dstFormat);
          ^
1278.     int i;
1279.     int hasAlpha = (desc->flags & AV_PIX_FMT_FLAG_ALPHA) && alpSrc;

libavutil/pixdesc.c:1703:1: start of procedure av_pix_fmt_desc_get()
  1701. }
  1702. 
  1703. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1704. {
  1705.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1705:9: Taking false branch
  1703. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1704. {
  1705.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1706.         return NULL;
  1707.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1705:24: Taking true branch
  1703. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1704. {
  1705.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1706.         return NULL;
  1707.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1706:9: 
  1704. {
  1705.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1706.         return NULL;
                ^
  1707.     return &av_pix_fmt_descriptors[pix_fmt];
  1708. }

libavutil/pixdesc.c:1708:1: return from a call to av_pix_fmt_desc_get
  1706.         return NULL;
  1707.     return &av_pix_fmt_descriptors[pix_fmt];
  1708. }
        ^
  1709. 
  1710. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libswscale/output.c:1279:21: 
1277.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(c->dstFormat);
1278.     int i;
1279.     int hasAlpha = (desc->flags & AV_PIX_FMT_FLAG_ALPHA) && alpSrc;
                          ^
1280.     uint16_t **dest16 = (uint16_t**)dest;
1281.     int SH = 22 + 8 - desc->comp[0].depth;
