libswscale/swscale_unscaled.c:1190: error: Null Dereference
  pointer `desc` last assigned on line 1186 could be null and is dereferenced at line 1190, column 21.

libswscale/swscale_unscaled.c:1183:1: start of procedure check_image_pointers()
1181. }
1182. 
1183. static int check_image_pointers(uint8_t *data[4], enum AVPixelFormat pix_fmt,
      ^
1184.                                 const int linesizes[4])
1185. {

libswscale/swscale_unscaled.c:1186:5: 
1184.                                 const int linesizes[4])
1185. {
1186.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
          ^
1187.     int i;
1188. 

libavutil/pixdesc.c:1665:1: start of procedure av_pix_fmt_desc_get()
  1663. }
  1664. 
  1665. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1666. {
  1667.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1667:9: Taking false branch
  1665. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1666. {
  1667.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1668.         return NULL;
  1669.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1667:24: Taking true branch
  1665. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1666. {
  1667.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1668.         return NULL;
  1669.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1668:9: 
  1666. {
  1667.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1668.         return NULL;
                ^
  1669.     return &av_pix_fmt_descriptors[pix_fmt];
  1670. }

libavutil/pixdesc.c:1670:1: return from a call to av_pix_fmt_desc_get
  1668.         return NULL;
  1669.     return &av_pix_fmt_descriptors[pix_fmt];
  1670. }
        ^
  1671. 
  1672. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libswscale/swscale_unscaled.c:1189:10: 
1187.     int i;
1188. 
1189.     for (i = 0; i < 4; i++) {
               ^
1190.         int plane = desc->comp[i].plane;
1191.         if (!data[plane] || !linesizes[plane])

libswscale/swscale_unscaled.c:1189:17: Loop condition is true. Entering loop body
1187.     int i;
1188. 
1189.     for (i = 0; i < 4; i++) {
                      ^
1190.         int plane = desc->comp[i].plane;
1191.         if (!data[plane] || !linesizes[plane])

libswscale/swscale_unscaled.c:1190:9: 
1188. 
1189.     for (i = 0; i < 4; i++) {
1190.         int plane = desc->comp[i].plane;
              ^
1191.         if (!data[plane] || !linesizes[plane])
1192.             return 0;

static int check_image_pointers(uint8_t *data[4], enum AVPixelFormat pix_fmt,
                                const int linesizes[4])
{
    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
    int i;
    for (i = 0; i < 4; i++) {
        int plane = desc->comp[i].plane;
        if (!data[plane] || !linesizes[plane])
            return 0;
    }
    return 1;
}
['static int check_image_pointers(uint8_t *data[4], enum AVPixelFormat pix_fmt,\n                                const int linesizes[4])\n{\n    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);\n    int i;\n    for (i = 0; i < 4; i++) {\n        int plane = desc->comp[i].plane;\n        if (!data[plane] || !linesizes[plane])\n            return 0;\n    }\n    return 1;\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}']