ffmpeg.c:3635: error: Null Dereference
  pointer `p` last assigned on line 3635 could be null and is dereferenced at line 3635, column 5.

ffmpeg.c:3620:1: start of procedure opt_streamid()
3618. 
3619. /* arg format is "output-stream-index:streamid-value". */
3620. static int opt_streamid(const char *opt, const char *arg)
      ^
3621. {
3622.     int idx;

ffmpeg.c:3626:5: 
3624.     char idx_str[16];
3625. 
3626.     strncpy(idx_str, arg, sizeof(idx_str));
          ^
3627.     idx_str[sizeof(idx_str)-1] = '\0';
3628.     p = strchr(idx_str, ':');

ffmpeg.c:3627:5: 
3625. 
3626.     strncpy(idx_str, arg, sizeof(idx_str));
3627.     idx_str[sizeof(idx_str)-1] = '\0';
          ^
3628.     p = strchr(idx_str, ':');
3629.     if (!p) {

ffmpeg.c:3628:5: 
3626.     strncpy(idx_str, arg, sizeof(idx_str));
3627.     idx_str[sizeof(idx_str)-1] = '\0';
3628.     p = strchr(idx_str, ':');
          ^
3629.     if (!p) {
3630.         fprintf(stderr,

ffmpeg.c:3629:10: Taking true branch
3627.     idx_str[sizeof(idx_str)-1] = '\0';
3628.     p = strchr(idx_str, ':');
3629.     if (!p) {
               ^
3630.         fprintf(stderr,
3631.                 "Invalid value '%s' for option '%s', required syntax is 'index:value'\n",

ffmpeg.c:3630:9: 
3628.     p = strchr(idx_str, ':');
3629.     if (!p) {
3630.         fprintf(stderr,
              ^
3631.                 "Invalid value '%s' for option '%s', required syntax is 'index:value'\n",
3632.                 arg, opt);

ffmpeg.c:3633:9: Skipping ffmpeg_exit(): empty list of specs
3631.                 "Invalid value '%s' for option '%s', required syntax is 'index:value'\n",
3632.                 arg, opt);
3633.         ffmpeg_exit(1);
              ^
3634.     }
3635.     *p++ = '\0';

ffmpeg.c:3635:5: 
3633.         ffmpeg_exit(1);
3634.     }
3635.     *p++ = '\0';
          ^
3636.     idx = parse_number_or_die(opt, idx_str, OPT_INT, 0, MAX_STREAMS-1);
3637.     streamid_map = grow_array(streamid_map, sizeof(*streamid_map), &nb_streamid_map, idx+1);
