libavfilter/vf_lut.c:219: error: Null Dereference
  pointer `desc` last assigned on line 215 could be null and is dereferenced at line 219, column 17.

libavfilter/vf_lut.c:211:1: start of procedure config_props()
209. };
210. 
211. static int config_props(AVFilterLink *inlink)
     ^
212. {
213.     AVFilterContext *ctx = inlink->dst;

libavfilter/vf_lut.c:213:5: 
211. static int config_props(AVFilterLink *inlink)
212. {
213.     AVFilterContext *ctx = inlink->dst;
         ^
214.     LutContext *lut = ctx->priv;
215.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);

libavfilter/vf_lut.c:214:5: 
212. {
213.     AVFilterContext *ctx = inlink->dst;
214.     LutContext *lut = ctx->priv;
         ^
215.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
216.     int min[4], max[4];

libavfilter/vf_lut.c:215:5: 
213.     AVFilterContext *ctx = inlink->dst;
214.     LutContext *lut = ctx->priv;
215.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
         ^
216.     int min[4], max[4];
217.     int val, comp, ret;

libavutil/pixdesc.c:1199:1: start of procedure av_pix_fmt_desc_get()
  1197. }
  1198. 
  1199. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1200. {
  1201.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1201:9: Taking false branch
  1199. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1200. {
  1201.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1202.         return NULL;
  1203.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1201:24: Taking true branch
  1199. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1200. {
  1201.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1202.         return NULL;
  1203.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1202:9: 
  1200. {
  1201.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1202.         return NULL;
                ^
  1203.     return &av_pix_fmt_descriptors[pix_fmt];
  1204. }

libavutil/pixdesc.c:1204:1: return from a call to av_pix_fmt_desc_get
  1202.         return NULL;
  1203.     return &av_pix_fmt_descriptors[pix_fmt];
  1204. }
        ^
  1205. 
  1206. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libavfilter/vf_lut.c:219:5: 
217.     int val, comp, ret;
218. 
219.     lut->hsub = desc->log2_chroma_w;
         ^
220.     lut->vsub = desc->log2_chroma_h;
221. 
