libswscale/swscale_unscaled.c:1199: error: Null Dereference
  pointer `desc` last assigned on line 1195 could be null and is dereferenced at line 1199, column 21.

libswscale/swscale_unscaled.c:1192:1: start of procedure check_image_pointers()
1190. }
1191. 
1192. static int check_image_pointers(uint8_t *data[4], enum AVPixelFormat pix_fmt,
      ^
1193.                                 const int linesizes[4])
1194. {

libswscale/swscale_unscaled.c:1195:5: 
1193.                                 const int linesizes[4])
1194. {
1195.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
          ^
1196.     int i;
1197. 

libavutil/pixdesc.c:1892:1: start of procedure av_pix_fmt_desc_get()
  1890. }
  1891. 
  1892. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1893. {
  1894.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1894:9: Taking false branch
  1892. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1893. {
  1894.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1895.         return NULL;
  1896.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1894:24: Taking true branch
  1892. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1893. {
  1894.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1895.         return NULL;
  1896.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1895:9: 
  1893. {
  1894.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1895.         return NULL;
                ^
  1896.     return &av_pix_fmt_descriptors[pix_fmt];
  1897. }

libavutil/pixdesc.c:1897:1: return from a call to av_pix_fmt_desc_get
  1895.         return NULL;
  1896.     return &av_pix_fmt_descriptors[pix_fmt];
  1897. }
        ^
  1898. 
  1899. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libswscale/swscale_unscaled.c:1198:10: 
1196.     int i;
1197. 
1198.     for (i = 0; i < 4; i++) {
               ^
1199.         int plane = desc->comp[i].plane;
1200.         if (!data[plane] || !linesizes[plane])

libswscale/swscale_unscaled.c:1198:17: Loop condition is true. Entering loop body
1196.     int i;
1197. 
1198.     for (i = 0; i < 4; i++) {
                      ^
1199.         int plane = desc->comp[i].plane;
1200.         if (!data[plane] || !linesizes[plane])

libswscale/swscale_unscaled.c:1199:9: 
1197. 
1198.     for (i = 0; i < 4; i++) {
1199.         int plane = desc->comp[i].plane;
              ^
1200.         if (!data[plane] || !linesizes[plane])
1201.             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}']