libavfilter/vf_transpose.c:94: error: Null Dereference
  pointer `desc_in` last assigned on line 92 could be null and is dereferenced at line 94, column 19.

libavfilter/vf_transpose.c:86:1: start of procedure config_props_output()
84. }
85. 
86. static int config_props_output(AVFilterLink *outlink)
    ^
87. {
88.     AVFilterContext *ctx = outlink->src;

libavfilter/vf_transpose.c:88:5: 
86. static int config_props_output(AVFilterLink *outlink)
87. {
88.     AVFilterContext *ctx = outlink->src;
        ^
89.     TransContext *trans = ctx->priv;
90.     AVFilterLink *inlink = ctx->inputs[0];

libavfilter/vf_transpose.c:89:5: 
87. {
88.     AVFilterContext *ctx = outlink->src;
89.     TransContext *trans = ctx->priv;
        ^
90.     AVFilterLink *inlink = ctx->inputs[0];
91.     const AVPixFmtDescriptor *desc_out = av_pix_fmt_desc_get(outlink->format);

libavfilter/vf_transpose.c:90:5: 
88.     AVFilterContext *ctx = outlink->src;
89.     TransContext *trans = ctx->priv;
90.     AVFilterLink *inlink = ctx->inputs[0];
        ^
91.     const AVPixFmtDescriptor *desc_out = av_pix_fmt_desc_get(outlink->format);
92.     const AVPixFmtDescriptor *desc_in  = av_pix_fmt_desc_get(inlink->format);

libavfilter/vf_transpose.c:91:5: 
89.     TransContext *trans = ctx->priv;
90.     AVFilterLink *inlink = ctx->inputs[0];
91.     const AVPixFmtDescriptor *desc_out = av_pix_fmt_desc_get(outlink->format);
        ^
92.     const AVPixFmtDescriptor *desc_in  = av_pix_fmt_desc_get(inlink->format);
93. 

libavutil/pixdesc.c:1559:1: start of procedure av_pix_fmt_desc_get()
  1557. }
  1558. 
  1559. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1560. {
  1561.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1561:9: Taking false branch
  1559. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1560. {
  1561.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1562.         return NULL;
  1563.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1561:24: Taking false branch
  1559. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1560. {
  1561.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1562.         return NULL;
  1563.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1563:5: 
  1561.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1562.         return NULL;
  1563.     return &av_pix_fmt_descriptors[pix_fmt];
            ^
  1564. }
  1565. 

libavutil/pixdesc.c:1564:1: return from a call to av_pix_fmt_desc_get
  1562.         return NULL;
  1563.     return &av_pix_fmt_descriptors[pix_fmt];
  1564. }
        ^
  1565. 
  1566. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libavfilter/vf_transpose.c:92:5: 
90.     AVFilterLink *inlink = ctx->inputs[0];
91.     const AVPixFmtDescriptor *desc_out = av_pix_fmt_desc_get(outlink->format);
92.     const AVPixFmtDescriptor *desc_in  = av_pix_fmt_desc_get(inlink->format);
        ^
93. 
94.     trans->hsub = desc_in->log2_chroma_w;

libavutil/pixdesc.c:1559:1: start of procedure av_pix_fmt_desc_get()
  1557. }
  1558. 
  1559. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1560. {
  1561.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1561:9: Taking false branch
  1559. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1560. {
  1561.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1562.         return NULL;
  1563.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1561:24: Taking true branch
  1559. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1560. {
  1561.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1562.         return NULL;
  1563.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1562:9: 
  1560. {
  1561.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1562.         return NULL;
                ^
  1563.     return &av_pix_fmt_descriptors[pix_fmt];
  1564. }

libavutil/pixdesc.c:1564:1: return from a call to av_pix_fmt_desc_get
  1562.         return NULL;
  1563.     return &av_pix_fmt_descriptors[pix_fmt];
  1564. }
        ^
  1565. 
  1566. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libavfilter/vf_transpose.c:94:5: 
92.     const AVPixFmtDescriptor *desc_in  = av_pix_fmt_desc_get(inlink->format);
93. 
94.     trans->hsub = desc_in->log2_chroma_w;
        ^
95.     trans->vsub = desc_in->log2_chroma_h;
96. 
