libavfilter/vf_drawbox.c:82: error: Null Dereference
  pointer `desc` last assigned on line 80 could be null and is dereferenced at line 82, column 15.

libavfilter/vf_drawbox.c:77:1: start of procedure config_input()
75. }
76. 
77. static int config_input(AVFilterLink *inlink)
    ^
78. {
79.     DrawBoxContext *s = inlink->dst->priv;

libavfilter/vf_drawbox.c:79:5: 
77. static int config_input(AVFilterLink *inlink)
78. {
79.     DrawBoxContext *s = inlink->dst->priv;
        ^
80.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
81. 

libavfilter/vf_drawbox.c:80:5: 
78. {
79.     DrawBoxContext *s = inlink->dst->priv;
80.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
        ^
81. 
82.     s->hsub = desc->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_drawbox.c:82:5: 
80.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
81. 
82.     s->hsub = desc->log2_chroma_w;
        ^
83.     s->vsub = desc->log2_chroma_h;
84. 

static int config_input(AVFilterLink *inlink)
{
    DrawBoxContext *s = inlink->dst->priv;
    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
    s->hsub = desc->log2_chroma_w;
    s->vsub = desc->log2_chroma_h;
    if (s->w == 0) s->w = inlink->w;
    if (s->h == 0) s->h = inlink->h;
    av_log(inlink->dst, AV_LOG_VERBOSE, "x:%d y:%d w:%d h:%d color:0x%02X%02X%02X%02X\n",
           s->w, s->y, s->w, s->h,
           s->yuv_color[Y], s->yuv_color[U], s->yuv_color[V], s->yuv_color[A]);
    return 0;
}
['static int config_input(AVFilterLink *inlink)\n{\n    DrawBoxContext *s = inlink->dst->priv;\n    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);\n    s->hsub = desc->log2_chroma_w;\n    s->vsub = desc->log2_chroma_h;\n    if (s->w == 0) s->w = inlink->w;\n    if (s->h == 0) s->h = inlink->h;\n    av_log(inlink->dst, AV_LOG_VERBOSE, "x:%d y:%d w:%d h:%d color:0x%02X%02X%02X%02X\\n",\n           s->w, s->y, s->w, s->h,\n           s->yuv_color[Y], s->yuv_color[U], s->yuv_color[V], s->yuv_color[A]);\n    return 0;\n}', 'const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)\n{\n    if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)\n        return NULL;\n    return &av_pix_fmt_descriptors[pix_fmt];\n}']