libavfilter/vf_lut.c:205: error: Null Dereference
  pointer `desc` last assigned on line 201 could be null and is dereferenced at line 205, column 15.

libavfilter/vf_lut.c:197:1: start of procedure config_props()
195. };
196. 
197. static int config_props(AVFilterLink *inlink)
     ^
198. {
199.     AVFilterContext *ctx = inlink->dst;

libavfilter/vf_lut.c:199:5: 
197. static int config_props(AVFilterLink *inlink)
198. {
199.     AVFilterContext *ctx = inlink->dst;
         ^
200.     LutContext *s = ctx->priv;
201.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);

libavfilter/vf_lut.c:200:5: 
198. {
199.     AVFilterContext *ctx = inlink->dst;
200.     LutContext *s = ctx->priv;
         ^
201.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
202.     int min[4], max[4];

libavfilter/vf_lut.c:201:5: 
199.     AVFilterContext *ctx = inlink->dst;
200.     LutContext *s = ctx->priv;
201.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
         ^
202.     int min[4], max[4];
203.     int val, comp, ret;

libavutil/pixdesc.c:1468:1: start of procedure av_pix_fmt_desc_get()
  1466. }
  1467. 
  1468. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1469. {
  1470.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1470:9: Taking false branch
  1468. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1469. {
  1470.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1471.         return NULL;
  1472.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1470:24: Taking true branch
  1468. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1469. {
  1470.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1471.         return NULL;
  1472.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1471:9: 
  1469. {
  1470.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1471.         return NULL;
                ^
  1472.     return &av_pix_fmt_descriptors[pix_fmt];
  1473. }

libavutil/pixdesc.c:1473:1: return from a call to av_pix_fmt_desc_get
  1471.         return NULL;
  1472.     return &av_pix_fmt_descriptors[pix_fmt];
  1473. }
        ^
  1474. 
  1475. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libavfilter/vf_lut.c:205:5: 
203.     int val, comp, ret;
204. 
205.     s->hsub = desc->log2_chroma_w;
         ^
206.     s->vsub = desc->log2_chroma_h;
207. 
