libavcodec/imgconvert.c:88: error: Integer Overflow L2
  ([1, 129] - [0, 128]):unsigned64 by call to `is_gray`.

libavcodec/imgconvert.c:84:44: Call
82.         loss |= FF_LOSS_ALPHA;
83. 
84.     if (dst_pix_fmt == AV_PIX_FMT_PAL8 && !is_gray(src_desc))
                                               ^
85.         return loss | FF_LOSS_COLORQUANT;
86. 

libavcodec/imgconvert.c:49:1: Parameter `desc->flags`
  47. }
  48. 
  49. static int is_gray(const AVPixFmtDescriptor *desc)
      ^
  50. {
  51.     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;

libavcodec/imgconvert.c:88:13: Call
86. 
87.     if (src_desc->nb_components > dst_desc->nb_components)
88.         if (is_gray(dst_desc))
                ^
89.             loss |= FF_LOSS_CHROMA;
90. 

libavcodec/imgconvert.c:49:1: <LHS trace>
47. }
48. 
49. static int is_gray(const AVPixFmtDescriptor *desc)
    ^
50. {
51.     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;

libavcodec/imgconvert.c:49:1: Parameter `desc->nb_components`
  47. }
  48. 
  49. static int is_gray(const AVPixFmtDescriptor *desc)
      ^
  50. {
  51.     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;

libavcodec/imgconvert.c:49:1: <RHS trace>
47. }
48. 
49. static int is_gray(const AVPixFmtDescriptor *desc)
    ^
50. {
51.     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;

libavcodec/imgconvert.c:49:1: Parameter `desc->flags`
  47. }
  48. 
  49. static int is_gray(const AVPixFmtDescriptor *desc)
      ^
  50. {
  51.     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;

libavcodec/imgconvert.c:51:12: Binary operation: ([1, 129] - [0, 128]):unsigned64 by call to `is_gray` 
  49. static int is_gray(const AVPixFmtDescriptor *desc)
  50. {
  51.     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;
                 ^
  52. }
  53. 
