libavfilter/vf_transpose.c:104: error: Null Dereference
  pointer `desc_in` last assigned on line 102 could be null and is dereferenced at line 104, column 19.

libavfilter/vf_transpose.c:96:1: start of procedure config_props_output()
94. }
95. 
96. static int config_props_output(AVFilterLink *outlink)
    ^
97. {
98.     AVFilterContext *ctx = outlink->src;

libavfilter/vf_transpose.c:98:5: 
 96. static int config_props_output(AVFilterLink *outlink)
 97. {
 98.     AVFilterContext *ctx = outlink->src;
         ^
 99.     TransContext *trans = ctx->priv;
100.     AVFilterLink *inlink = ctx->inputs[0];

libavfilter/vf_transpose.c:99:5: 
 97. {
 98.     AVFilterContext *ctx = outlink->src;
 99.     TransContext *trans = ctx->priv;
         ^
100.     AVFilterLink *inlink = ctx->inputs[0];
101.     const AVPixFmtDescriptor *desc_out = av_pix_fmt_desc_get(outlink->format);

libavfilter/vf_transpose.c:100:5: 
 98.     AVFilterContext *ctx = outlink->src;
 99.     TransContext *trans = ctx->priv;
100.     AVFilterLink *inlink = ctx->inputs[0];
         ^
101.     const AVPixFmtDescriptor *desc_out = av_pix_fmt_desc_get(outlink->format);
102.     const AVPixFmtDescriptor *desc_in  = av_pix_fmt_desc_get(inlink->format);

libavfilter/vf_transpose.c:101:5: 
 99.     TransContext *trans = ctx->priv;
100.     AVFilterLink *inlink = ctx->inputs[0];
101.     const AVPixFmtDescriptor *desc_out = av_pix_fmt_desc_get(outlink->format);
         ^
102.     const AVPixFmtDescriptor *desc_in  = av_pix_fmt_desc_get(inlink->format);
103. 

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 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:1203:5: 
  1201.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1202.         return NULL;
  1203.     return &av_pix_fmt_descriptors[pix_fmt];
            ^
  1204. }
  1205. 

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_transpose.c:102:5: 
100.     AVFilterLink *inlink = ctx->inputs[0];
101.     const AVPixFmtDescriptor *desc_out = av_pix_fmt_desc_get(outlink->format);
102.     const AVPixFmtDescriptor *desc_in  = av_pix_fmt_desc_get(inlink->format);
         ^
103. 
104.     trans->hsub = desc_in->log2_chroma_w;

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_transpose.c:104:5: 
102.     const AVPixFmtDescriptor *desc_in  = av_pix_fmt_desc_get(inlink->format);
103. 
104.     trans->hsub = desc_in->log2_chroma_w;
         ^
105.     trans->vsub = desc_in->log2_chroma_h;
106. 
