ffmpeg.c:3688: error: Null Dereference
  pointer `oc` last assigned on line 3666 could be null and is dereferenced at line 3688, column 5.

ffmpeg.c:3655:1: start of procedure opt_output_file()
3653. }
3654. 
3655. static void opt_output_file(const char *filename)
      ^
3656. {
3657.     AVFormatContext *oc;

ffmpeg.c:3660:5: 
3658.     int err, use_video, use_audio, use_subtitle;
3659.     int input_has_video, input_has_audio, input_has_subtitle;
3660.     AVFormatParameters params, *ap = &params;
          ^
3661.     AVOutputFormat *file_oformat;
3662. 

ffmpeg.c:3663:10: Taking false branch
3661.     AVOutputFormat *file_oformat;
3662. 
3663.     if (!strcmp(filename, "-"))
               ^
3664.         filename = "pipe:";
3665. 

ffmpeg.c:3666:5: 
3664.         filename = "pipe:";
3665. 
3666.     oc = avformat_alloc_context();
          ^
3667.     if (!oc) {
3668.         print_error(filename, AVERROR(ENOMEM));

libavformat/options.c:78:1: start of procedure avformat_alloc_context()
  76. }
  77. 
  78. AVFormatContext *avformat_alloc_context(void)
      ^
  79. {
  80.     AVFormatContext *ic;

libavformat/options.c:81:5: 
  79. {
  80.     AVFormatContext *ic;
  81.     ic = av_malloc(sizeof(AVFormatContext));
          ^
  82.     if (!ic) return ic;
  83.     avformat_get_context_defaults(ic);

libavutil/mem.c:64:1: start of procedure av_malloc()
    62.    linker will do it automatically. */
    63. 
    64. void *av_malloc(size_t size)
        ^
    65. {
    66.     void *ptr = NULL;

libavutil/mem.c:66:5: 
    64. void *av_malloc(size_t size)
    65. {
    66.     void *ptr = NULL;
            ^
    67. #if CONFIG_MEMALIGN_HACK
    68.     long diff;

libavutil/mem.c:72:8: Taking false branch
    70. 
    71.     /* let's disallow possible ambiguous cases */
    72.     if(size > (INT_MAX-32) )
               ^
    73.         return NULL;
    74. 

libavutil/mem.c:83:9: Taking false branch
    81.     ((char*)ptr)[-1]= diff;
    82. #elif HAVE_POSIX_MEMALIGN
    83.     if (posix_memalign(&ptr,32,size))
                ^
    84.         ptr = NULL;
    85. #elif HAVE_MEMALIGN

libavutil/mem.c:114:5: 
    112.     ptr = malloc(size);
    113. #endif
    114.     return ptr;
             ^
    115. }
    116. 

libavutil/mem.c:115:1: return from a call to av_malloc
    113. #endif
    114.     return ptr;
    115. }
         ^
    116. 
    117. void *av_realloc(void *ptr, size_t size)

libavformat/options.c:82:10: Taking true branch
  80.     AVFormatContext *ic;
  81.     ic = av_malloc(sizeof(AVFormatContext));
  82.     if (!ic) return ic;
               ^
  83.     avformat_get_context_defaults(ic);
  84.     ic->av_class = &av_format_context_class;

libavformat/options.c:82:14: 
  80.     AVFormatContext *ic;
  81.     ic = av_malloc(sizeof(AVFormatContext));
  82.     if (!ic) return ic;
                   ^
  83.     avformat_get_context_defaults(ic);
  84.     ic->av_class = &av_format_context_class;

libavformat/options.c:86:1: return from a call to avformat_alloc_context
  84.     ic->av_class = &av_format_context_class;
  85.     return ic;
  86. }
      ^

ffmpeg.c:3667:10: Taking true branch
3665. 
3666.     oc = avformat_alloc_context();
3667.     if (!oc) {
               ^
3668.         print_error(filename, AVERROR(ENOMEM));
3669.         ffmpeg_exit(1);

ffmpeg.c:3668:9: 
3666.     oc = avformat_alloc_context();
3667.     if (!oc) {
3668.         print_error(filename, AVERROR(ENOMEM));
              ^
3669.         ffmpeg_exit(1);
3670.     }

cmdutils.c:434:1: start of procedure print_error()
  432. }
  433. 
  434. void print_error(const char *filename, int err)
       ^
  435. {
  436.     char errbuf[128];

cmdutils.c:437:5: 
  435. {
  436.     char errbuf[128];
  437.     const char *errbuf_ptr = errbuf;
           ^
  438. 
  439.     if (av_strerror(err, errbuf, sizeof(errbuf)) < 0)

cmdutils.c:439:9: Taking true branch
  437.     const char *errbuf_ptr = errbuf;
  438. 
  439.     if (av_strerror(err, errbuf, sizeof(errbuf)) < 0)
               ^
  440.         errbuf_ptr = strerror(AVUNERROR(err));
  441.     fprintf(stderr, "%s: %s\n", filename, errbuf_ptr);

cmdutils.c:440:9: Skipping strerror(): method has no implementation
  438. 
  439.     if (av_strerror(err, errbuf, sizeof(errbuf)) < 0)
  440.         errbuf_ptr = strerror(AVUNERROR(err));
               ^
  441.     fprintf(stderr, "%s: %s\n", filename, errbuf_ptr);
  442. }

cmdutils.c:441:5: 
  439.     if (av_strerror(err, errbuf, sizeof(errbuf)) < 0)
  440.         errbuf_ptr = strerror(AVUNERROR(err));
  441.     fprintf(stderr, "%s: %s\n", filename, errbuf_ptr);
           ^
  442. }
  443. 

cmdutils.c:442:1: return from a call to print_error
  440.         errbuf_ptr = strerror(AVUNERROR(err));
  441.     fprintf(stderr, "%s: %s\n", filename, errbuf_ptr);
  442. }
       ^
  443. 
  444. static int warned_cfg = 0;

ffmpeg.c:3669:9: Skipping ffmpeg_exit(): empty list of specs
3667.     if (!oc) {
3668.         print_error(filename, AVERROR(ENOMEM));
3669.         ffmpeg_exit(1);
              ^
3670.     }
3671. 

ffmpeg.c:3672:9: Taking true branch
3670.     }
3671. 
3672.     if (last_asked_format) {
              ^
3673.         file_oformat = av_guess_format(last_asked_format, NULL, NULL);
3674.         if (!file_oformat) {

ffmpeg.c:3673:9: Skipping av_guess_format(): empty list of specs
3671. 
3672.     if (last_asked_format) {
3673.         file_oformat = av_guess_format(last_asked_format, NULL, NULL);
              ^
3674.         if (!file_oformat) {
3675.             fprintf(stderr, "Requested output format '%s' is not a suitable output format\n", last_asked_format);

ffmpeg.c:3674:14: Taking false branch
3672.     if (last_asked_format) {
3673.         file_oformat = av_guess_format(last_asked_format, NULL, NULL);
3674.         if (!file_oformat) {
                   ^
3675.             fprintf(stderr, "Requested output format '%s' is not a suitable output format\n", last_asked_format);
3676.             ffmpeg_exit(1);

ffmpeg.c:3678:9: 
3676.             ffmpeg_exit(1);
3677.         }
3678.         last_asked_format = NULL;
              ^
3679.     } else {
3680.         file_oformat = av_guess_format(NULL, filename, NULL);

ffmpeg.c:3688:5: 
3686.     }
3687. 
3688.     oc->oformat = file_oformat;
          ^
3689.     av_strlcpy(oc->filename, filename, sizeof(oc->filename));
3690. 
