libavfilter/vsrc_color.c:155: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_buffer`.

libavfilter/vsrc_color.c:154:5: Call
152.                       0, 0, color->w, color->h);
153.     ff_draw_slice(link, 0, color->h, 1);
154.     ff_end_frame(link);
         ^
155.     avfilter_unref_buffer(picref);
156. 

libavfilter/video.c:251:5: Call
  249.         link->src_buf = NULL;
  250.     }
  251.     avfilter_unref_bufferp(&link->cur_buf);
           ^
  252. }
  253. 

libavfilter/buffer.c:89:5: Call
    87. void avfilter_unref_bufferp(AVFilterBufferRef **ref)
    88. {
    89.     avfilter_unref_buffer(*ref);
            ^
    90.     *ref = NULL;
    91. }

libavfilter/buffer.c:74:1: Parameter `ref->buf->refcount`
      72. }
      73. 
      74. void avfilter_unref_buffer(AVFilterBufferRef *ref)
          ^
      75. {
      76.     if (!ref)

libavfilter/vsrc_color.c:155:5: Call
153.     ff_draw_slice(link, 0, color->h, 1);
154.     ff_end_frame(link);
155.     avfilter_unref_buffer(picref);
         ^
156. 
157.     return 0;

libavfilter/buffer.c:74:1: <LHS trace>
72. }
73. 
74. void avfilter_unref_buffer(AVFilterBufferRef *ref)
    ^
75. {
76.     if (!ref)

libavfilter/buffer.c:74:1: Parameter `ref->buf->refcount`
  72. }
  73. 
  74. void avfilter_unref_buffer(AVFilterBufferRef *ref)
      ^
  75. {
  76.     if (!ref)

libavfilter/buffer.c:78:11: Binary operation: ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_buffer` 
  76.     if (!ref)
  77.         return;
  78.     if (!(--ref->buf->refcount))
                ^
  79.         ref->buf->free(ref->buf);
  80.     if (ref->extended_data != ref->data)

void avfilter_unref_buffer(AVFilterBufferRef *ref)
{
    if (!ref)
        return;
    if (!(--ref->buf->refcount))
        ref->buf->free(ref->buf);
    if (ref->extended_data != ref->data)
        av_freep(&ref->extended_data);
    av_free(ref->video);
    av_free(ref->audio);
    av_free(ref);
}
['static int color_request_frame(AVFilterLink *link)\n{\n    ColorContext *color = link->src->priv;\n    AVFilterBufferRef *picref = ff_get_video_buffer(link, AV_PERM_WRITE, color->w, color->h);\n    picref->video->pixel_aspect = (AVRational) {1, 1};\n    picref->pts                 = color->pts++;\n    picref->pos                 = -1;\n    ff_start_frame(link, avfilter_ref_buffer(picref, ~0));\n    ff_draw_rectangle(picref->data, picref->linesize,\n                      color->line, color->line_step, color->hsub, color->vsub,\n                      0, 0, color->w, color->h);\n    ff_draw_slice(link, 0, color->h, 1);\n    ff_end_frame(link);\n    avfilter_unref_buffer(picref);\n    return 0;\n}', 'void ff_end_frame(AVFilterLink *link)\n{\n    void (*end_frame)(AVFilterLink *);\n    if (!(end_frame = link->dstpad->end_frame))\n        end_frame = default_end_frame;\n    end_frame(link);\n    if (link->src_buf) {\n        avfilter_unref_buffer(link->src_buf);\n        link->src_buf = NULL;\n    }\n    avfilter_unref_bufferp(&link->cur_buf);\n}', 'void avfilter_unref_bufferp(AVFilterBufferRef **ref)\n{\n    avfilter_unref_buffer(*ref);\n    *ref = NULL;\n}', 'void avfilter_unref_buffer(AVFilterBufferRef *ref)\n{\n    if (!ref)\n        return;\n    if (!(--ref->buf->refcount))\n        ref->buf->free(ref->buf);\n    if (ref->extended_data != ref->data)\n        av_freep(&ref->extended_data);\n    av_free(ref->video);\n    av_free(ref->audio);\n    av_free(ref);\n}']