libavfilter/vf_transpose.c:93: error: Null Dereference
  pointer `desc_in` last assigned on line 91 could be null and is dereferenced at line 93, column 19.

libavfilter/vf_transpose.c:85:1: start of procedure config_props_output()
83. }
84. 
85. static int config_props_output(AVFilterLink *outlink)
    ^
86. {
87.     AVFilterContext *ctx = outlink->src;

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

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

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

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

libavutil/pixdesc.c:1464:1: start of procedure av_pix_fmt_desc_get()
  1462. }
  1463. 
  1464. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1465. {
  1466.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1466:9: Taking false branch
  1464. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1465. {
  1466.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1467.         return NULL;
  1468.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1466:24: Taking false branch
  1464. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1465. {
  1466.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1467.         return NULL;
  1468.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1468:5: 
  1466.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1467.         return NULL;
  1468.     return &av_pix_fmt_descriptors[pix_fmt];
            ^
  1469. }
  1470. 

libavutil/pixdesc.c:1469:1: return from a call to av_pix_fmt_desc_get
  1467.         return NULL;
  1468.     return &av_pix_fmt_descriptors[pix_fmt];
  1469. }
        ^
  1470. 
  1471. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

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

libavutil/pixdesc.c:1464:1: start of procedure av_pix_fmt_desc_get()
  1462. }
  1463. 
  1464. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1465. {
  1466.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1466:9: Taking false branch
  1464. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1465. {
  1466.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1467.         return NULL;
  1468.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1466:24: Taking true branch
  1464. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1465. {
  1466.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1467.         return NULL;
  1468.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1467:9: 
  1465. {
  1466.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1467.         return NULL;
                ^
  1468.     return &av_pix_fmt_descriptors[pix_fmt];
  1469. }

libavutil/pixdesc.c:1469:1: return from a call to av_pix_fmt_desc_get
  1467.         return NULL;
  1468.     return &av_pix_fmt_descriptors[pix_fmt];
  1469. }
        ^
  1470. 
  1471. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

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