libavcodec/imgconvert.c:75: error: Integer Overflow L2
  ([1, 129] - [0, 128]):unsigned64 by call to `is_gray`.

libavcodec/imgconvert.c:71:44: Call
69.         loss |= FF_LOSS_ALPHA;
70. 
71.     if (dst_pix_fmt == AV_PIX_FMT_PAL8 && !is_gray(src_desc))
                                               ^
72.         return loss | FF_LOSS_COLORQUANT;
73. 

libavcodec/imgconvert.c:36:1: Parameter `desc->flags`
  34. #include "libavutil/imgutils.h"
  35. 
  36. static int is_gray(const AVPixFmtDescriptor *desc)
      ^
  37. {
  38.     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;

libavcodec/imgconvert.c:75:13: Call
73. 
74.     if (src_desc->nb_components > dst_desc->nb_components)
75.         if (is_gray(dst_desc))
                ^
76.             loss |= FF_LOSS_CHROMA;
77. 

libavcodec/imgconvert.c:36:1: <LHS trace>
34. #include "libavutil/imgutils.h"
35. 
36. static int is_gray(const AVPixFmtDescriptor *desc)
    ^
37. {
38.     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;

libavcodec/imgconvert.c:36:1: Parameter `desc->nb_components`
  34. #include "libavutil/imgutils.h"
  35. 
  36. static int is_gray(const AVPixFmtDescriptor *desc)
      ^
  37. {
  38.     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;

libavcodec/imgconvert.c:36:1: <RHS trace>
34. #include "libavutil/imgutils.h"
35. 
36. static int is_gray(const AVPixFmtDescriptor *desc)
    ^
37. {
38.     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;

libavcodec/imgconvert.c:36:1: Parameter `desc->flags`
  34. #include "libavutil/imgutils.h"
  35. 
  36. static int is_gray(const AVPixFmtDescriptor *desc)
      ^
  37. {
  38.     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;

libavcodec/imgconvert.c:38:12: Binary operation: ([1, 129] - [0, 128]):unsigned64 by call to `is_gray` 
  36. static int is_gray(const AVPixFmtDescriptor *desc)
  37. {
  38.     return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;
                 ^
  39. }
  40. 
