ffmpeg.c:3707: error: Null Dereference
  pointer `p` last assigned on line 3707 could be null and is dereferenced at line 3707, column 5.

ffmpeg.c:3692:1: start of procedure opt_streamid()
3690. 
3691. /* arg format is "output-stream-index:streamid-value". */
3692. static int opt_streamid(const char *opt, const char *arg)
      ^
3693. {
3694.     int idx;

ffmpeg.c:3698:5: 
3696.     char idx_str[16];
3697. 
3698.     strncpy(idx_str, arg, sizeof(idx_str));
          ^
3699.     idx_str[sizeof(idx_str)-1] = '\0';
3700.     p = strchr(idx_str, ':');

ffmpeg.c:3699:5: 
3697. 
3698.     strncpy(idx_str, arg, sizeof(idx_str));
3699.     idx_str[sizeof(idx_str)-1] = '\0';
          ^
3700.     p = strchr(idx_str, ':');
3701.     if (!p) {

ffmpeg.c:3700:5: 
3698.     strncpy(idx_str, arg, sizeof(idx_str));
3699.     idx_str[sizeof(idx_str)-1] = '\0';
3700.     p = strchr(idx_str, ':');
          ^
3701.     if (!p) {
3702.         fprintf(stderr,

ffmpeg.c:3701:10: Taking true branch
3699.     idx_str[sizeof(idx_str)-1] = '\0';
3700.     p = strchr(idx_str, ':');
3701.     if (!p) {
               ^
3702.         fprintf(stderr,
3703.                 "Invalid value '%s' for option '%s', required syntax is 'index:value'\n",

ffmpeg.c:3702:9: 
3700.     p = strchr(idx_str, ':');
3701.     if (!p) {
3702.         fprintf(stderr,
              ^
3703.                 "Invalid value '%s' for option '%s', required syntax is 'index:value'\n",
3704.                 arg, opt);

ffmpeg.c:3705:9: Skipping ffmpeg_exit(): empty list of specs
3703.                 "Invalid value '%s' for option '%s', required syntax is 'index:value'\n",
3704.                 arg, opt);
3705.         ffmpeg_exit(1);
              ^
3706.     }
3707.     *p++ = '\0';

ffmpeg.c:3707:5: 
3705.         ffmpeg_exit(1);
3706.     }
3707.     *p++ = '\0';
          ^
3708.     idx = parse_number_or_die(opt, idx_str, OPT_INT, 0, MAX_STREAMS-1);
3709.     streamid_map = grow_array(streamid_map, sizeof(*streamid_map), &nb_streamid_map, idx+1);

static int 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);
        ffmpeg_exit(1);
    }
    *p++ = '\0';
    idx = parse_number_or_die(opt, idx_str, OPT_INT, 0, MAX_STREAMS-1);
    streamid_map = grow_array(streamid_map, sizeof(*streamid_map), &nb_streamid_map, idx+1);
    streamid_map[idx] = parse_number_or_die(opt, p, OPT_INT, 0, INT_MAX);
    return 0;
}
['static int 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        ffmpeg_exit(1);\n    }\n    *p++ = \'\\0\';\n    idx = parse_number_or_die(opt, idx_str, OPT_INT, 0, MAX_STREAMS-1);\n    streamid_map = grow_array(streamid_map, sizeof(*streamid_map), &nb_streamid_map, idx+1);\n    streamid_map[idx] = parse_number_or_die(opt, p, OPT_INT, 0, INT_MAX);\n    return 0;\n}']