libavcodec/imgconvert.c:68: error: Null Dereference
  pointer `dst_desc` last assigned on line 67 could be null and is dereferenced at line 68, column 34.

libavcodec/imgconvert.c:62:1: start of procedure avcodec_get_pix_fmt_loss()
60. }
61. 
62. int avcodec_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt,
    ^
63.                              enum AVPixelFormat src_pix_fmt,
64.                              int has_alpha)

libavcodec/imgconvert.c:66:5: 
64.                              int has_alpha)
65. {
66.     const AVPixFmtDescriptor *src_desc = av_pix_fmt_desc_get(src_pix_fmt);
        ^
67.     const AVPixFmtDescriptor *dst_desc = av_pix_fmt_desc_get(dst_pix_fmt);
68.     int loss, i, nb_components = FFMIN(src_desc->nb_components,

libavutil/pixdesc.c:1559:1: start of procedure av_pix_fmt_desc_get()
  1557. }
  1558. 
  1559. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1560. {
  1561.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1561:9: Taking false branch
  1559. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1560. {
  1561.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1562.         return NULL;
  1563.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1561:24: Taking false branch
  1559. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1560. {
  1561.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1562.         return NULL;
  1563.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1563:5: 
  1561.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1562.         return NULL;
  1563.     return &av_pix_fmt_descriptors[pix_fmt];
            ^
  1564. }
  1565. 

libavutil/pixdesc.c:1564:1: return from a call to av_pix_fmt_desc_get
  1562.         return NULL;
  1563.     return &av_pix_fmt_descriptors[pix_fmt];
  1564. }
        ^
  1565. 
  1566. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libavcodec/imgconvert.c:67:5: 
65. {
66.     const AVPixFmtDescriptor *src_desc = av_pix_fmt_desc_get(src_pix_fmt);
67.     const AVPixFmtDescriptor *dst_desc = av_pix_fmt_desc_get(dst_pix_fmt);
        ^
68.     int loss, i, nb_components = FFMIN(src_desc->nb_components,
69.                                        dst_desc->nb_components);

libavutil/pixdesc.c:1559:1: start of procedure av_pix_fmt_desc_get()
  1557. }
  1558. 
  1559. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1560. {
  1561.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1561:9: Taking false branch
  1559. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1560. {
  1561.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1562.         return NULL;
  1563.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1561:24: Taking true branch
  1559. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1560. {
  1561.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1562.         return NULL;
  1563.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1562:9: 
  1560. {
  1561.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1562.         return NULL;
                ^
  1563.     return &av_pix_fmt_descriptors[pix_fmt];
  1564. }

libavutil/pixdesc.c:1564:1: return from a call to av_pix_fmt_desc_get
  1562.         return NULL;
  1563.     return &av_pix_fmt_descriptors[pix_fmt];
  1564. }
        ^
  1565. 
  1566. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libavcodec/imgconvert.c:68:34: 
66.     const AVPixFmtDescriptor *src_desc = av_pix_fmt_desc_get(src_pix_fmt);
67.     const AVPixFmtDescriptor *dst_desc = av_pix_fmt_desc_get(dst_pix_fmt);
68.     int loss, i, nb_components = FFMIN(src_desc->nb_components,
                                     ^
69.                                        dst_desc->nb_components);
70. 
