libswscale/swscale_unscaled.c:1144: error: Null Dereference
  pointer `desc` last assigned on line 1140 could be null and is dereferenced at line 1144, column 21.

libswscale/swscale_unscaled.c:1137:1: start of procedure check_image_pointers()
1135. }
1136. 
1137. static int check_image_pointers(uint8_t *data[4], enum AVPixelFormat pix_fmt,
      ^
1138.                                 const int linesizes[4])
1139. {

libswscale/swscale_unscaled.c:1140:5: 
1138.                                 const int linesizes[4])
1139. {
1140.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
          ^
1141.     int i;
1142. 

libavutil/pixdesc.c:1599:1: start of procedure av_pix_fmt_desc_get()
  1597. }
  1598. 
  1599. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1600. {
  1601.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1601:9: Taking false branch
  1599. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1600. {
  1601.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1602.         return NULL;
  1603.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1601:24: Taking true branch
  1599. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1600. {
  1601.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1602.         return NULL;
  1603.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1602:9: 
  1600. {
  1601.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1602.         return NULL;
                ^
  1603.     return &av_pix_fmt_descriptors[pix_fmt];
  1604. }

libavutil/pixdesc.c:1604:1: return from a call to av_pix_fmt_desc_get
  1602.         return NULL;
  1603.     return &av_pix_fmt_descriptors[pix_fmt];
  1604. }
        ^
  1605. 
  1606. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libswscale/swscale_unscaled.c:1143:10: 
1141.     int i;
1142. 
1143.     for (i = 0; i < 4; i++) {
               ^
1144.         int plane = desc->comp[i].plane;
1145.         if (!data[plane] || !linesizes[plane])

libswscale/swscale_unscaled.c:1143:17: Loop condition is true. Entering loop body
1141.     int i;
1142. 
1143.     for (i = 0; i < 4; i++) {
                      ^
1144.         int plane = desc->comp[i].plane;
1145.         if (!data[plane] || !linesizes[plane])

libswscale/swscale_unscaled.c:1144:9: 
1142. 
1143.     for (i = 0; i < 4; i++) {
1144.         int plane = desc->comp[i].plane;
              ^
1145.         if (!data[plane] || !linesizes[plane])
1146.             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}']