libavcodec/imgconvert.c:80: error: Integer Overflow L2
  ([0, +oo] - [0, 128]):unsigned64 by call to `is_gray`.

libavcodec/imgconvert.c:80:44: Call
78.         loss |= FF_LOSS_ALPHA;
79. 
80.     if (dst_pix_fmt == AV_PIX_FMT_PAL8 && !is_gray(src_desc))
                                               ^
81.         return loss | FF_LOSS_COLORQUANT;
82. 

libavcodec/imgconvert.c:45:1: <LHS trace>
43. #endif
44. 
45. static int is_gray(const AVPixFmtDescriptor *desc)
    ^
46. {
47.     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;

libavcodec/imgconvert.c:45:1: Parameter `desc->nb_components`
  43. #endif
  44. 
  45. static int is_gray(const AVPixFmtDescriptor *desc)
      ^
  46. {
  47.     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;

libavcodec/imgconvert.c:45:1: <RHS trace>
43. #endif
44. 
45. static int is_gray(const AVPixFmtDescriptor *desc)
    ^
46. {
47.     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;

libavcodec/imgconvert.c:45:1: Parameter `desc->flags`
  43. #endif
  44. 
  45. static int is_gray(const AVPixFmtDescriptor *desc)
      ^
  46. {
  47.     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;

libavcodec/imgconvert.c:47:12: Binary operation: ([0, +oo] - [0, 128]):unsigned64 by call to `is_gray` 
  45. static int is_gray(const AVPixFmtDescriptor *desc)
  46. {
  47.     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;
                 ^
  48. }
  49. 
