ffmpeg.c:3652: error: Null Dereference
  pointer `p` last assigned on line 3652 could be null and is dereferenced at line 3652, column 5.

ffmpeg.c:3637:1: start of procedure opt_streamid()
3635. 
3636. /* arg format is "output-stream-index:streamid-value". */
3637. static void opt_streamid(const char *opt, const char *arg)
      ^
3638. {
3639.     int idx;

ffmpeg.c:3643:5: 
3641.     char idx_str[16];
3642. 
3643.     strncpy(idx_str, arg, sizeof(idx_str));
          ^
3644.     idx_str[sizeof(idx_str)-1] = '\0';
3645.     p = strchr(idx_str, ':');

ffmpeg.c:3644:5: 
3642. 
3643.     strncpy(idx_str, arg, sizeof(idx_str));
3644.     idx_str[sizeof(idx_str)-1] = '\0';
          ^
3645.     p = strchr(idx_str, ':');
3646.     if (!p) {

ffmpeg.c:3645:5: 
3643.     strncpy(idx_str, arg, sizeof(idx_str));
3644.     idx_str[sizeof(idx_str)-1] = '\0';
3645.     p = strchr(idx_str, ':');
          ^
3646.     if (!p) {
3647.         fprintf(stderr,

ffmpeg.c:3646:10: Taking true branch
3644.     idx_str[sizeof(idx_str)-1] = '\0';
3645.     p = strchr(idx_str, ':');
3646.     if (!p) {
               ^
3647.         fprintf(stderr,
3648.                 "Invalid value '%s' for option '%s', required syntax is 'index:value'\n",

ffmpeg.c:3647:9: 
3645.     p = strchr(idx_str, ':');
3646.     if (!p) {
3647.         fprintf(stderr,
              ^
3648.                 "Invalid value '%s' for option '%s', required syntax is 'index:value'\n",
3649.                 arg, opt);

ffmpeg.c:3650:9: Skipping av_exit(): empty list of specs
3648.                 "Invalid value '%s' for option '%s', required syntax is 'index:value'\n",
3649.                 arg, opt);
3650.         av_exit(1);
              ^
3651.     }
3652.     *p++ = '\0';

ffmpeg.c:3652:5: 
3650.         av_exit(1);
3651.     }
3652.     *p++ = '\0';
          ^
3653.     idx = parse_number_or_die(opt, idx_str, OPT_INT, 0, MAX_STREAMS-1);
3654.     streamid_map[idx] = parse_number_or_die(opt, p, OPT_INT, 0, INT_MAX);

static void opt_streamid(const char *opt, const char *arg)
{
    int idx;
    char *p;
    char idx_str[16];
    strncpy(idx_str, arg, sizeof(idx_str));
    idx_str[sizeof(idx_str)-1] = '\0';
    p = strchr(idx_str, ':');
    if (!p) {
        fprintf(stderr,
                "Invalid value '%s' for option '%s', required syntax is 'index:value'\n",
                arg, opt);
        av_exit(1);
    }
    *p++ = '\0';
    idx = parse_number_or_die(opt, idx_str, OPT_INT, 0, MAX_STREAMS-1);
    streamid_map[idx] = parse_number_or_die(opt, p, OPT_INT, 0, INT_MAX);
}
['static void opt_streamid(const char *opt, const char *arg)\n{\n    int idx;\n    char *p;\n    char idx_str[16];\n    strncpy(idx_str, arg, sizeof(idx_str));\n    idx_str[sizeof(idx_str)-1] = \'\\0\';\n    p = strchr(idx_str, \':\');\n    if (!p) {\n        fprintf(stderr,\n                "Invalid value \'%s\' for option \'%s\', required syntax is \'index:value\'\\n",\n                arg, opt);\n        av_exit(1);\n    }\n    *p++ = \'\\0\';\n    idx = parse_number_or_die(opt, idx_str, OPT_INT, 0, MAX_STREAMS-1);\n    streamid_map[idx] = parse_number_or_die(opt, p, OPT_INT, 0, INT_MAX);\n}']