ffmpeg.c:3748: error: Null Dereference
  pointer `oc` last assigned on line 3726 could be null and is dereferenced at line 3748, column 5.

ffmpeg.c:3715:1: start of procedure opt_output_file()
3713. }
3714. 
3715. static void opt_output_file(const char *filename)
      ^
3716. {
3717.     AVFormatContext *oc;

ffmpeg.c:3720:5: 
3718.     int err, use_video, use_audio, use_subtitle, use_data;
3719.     int input_has_video, input_has_audio, input_has_subtitle, input_has_data;
3720.     AVFormatParameters params, *ap = &params;
          ^
3721.     AVOutputFormat *file_oformat;
3722. 

ffmpeg.c:3723:10: Taking false branch
3721.     AVOutputFormat *file_oformat;
3722. 
3723.     if (!strcmp(filename, "-"))
               ^
3724.         filename = "pipe:";
3725. 

ffmpeg.c:3726:5: 
3724.         filename = "pipe:";
3725. 
3726.     oc = avformat_alloc_context();
          ^
3727.     if (!oc) {
3728.         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:3727:10: Taking true branch
3725. 
3726.     oc = avformat_alloc_context();
3727.     if (!oc) {
               ^
3728.         print_error(filename, AVERROR(ENOMEM));
3729.         ffmpeg_exit(1);

ffmpeg.c:3728:9: 
3726.     oc = avformat_alloc_context();
3727.     if (!oc) {
3728.         print_error(filename, AVERROR(ENOMEM));
              ^
3729.         ffmpeg_exit(1);
3730.     }

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

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

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

cmdutils.c:441:9: Skipping strerror(): method has no implementation
  439. 
  440.     if (av_strerror(err, errbuf, sizeof(errbuf)) < 0)
  441.         errbuf_ptr = strerror(AVUNERROR(err));
               ^
  442.     fprintf(stderr, "%s: %s\n", filename, errbuf_ptr);
  443. }

cmdutils.c:442:5: 
  440.     if (av_strerror(err, errbuf, sizeof(errbuf)) < 0)
  441.         errbuf_ptr = strerror(AVUNERROR(err));
  442.     fprintf(stderr, "%s: %s\n", filename, errbuf_ptr);
           ^
  443. }
  444. 

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

ffmpeg.c:3729:9: Skipping ffmpeg_exit(): empty list of specs
3727.     if (!oc) {
3728.         print_error(filename, AVERROR(ENOMEM));
3729.         ffmpeg_exit(1);
              ^
3730.     }
3731. 

ffmpeg.c:3732:9: Taking true branch
3730.     }
3731. 
3732.     if (last_asked_format) {
              ^
3733.         file_oformat = av_guess_format(last_asked_format, NULL, NULL);
3734.         if (!file_oformat) {

ffmpeg.c:3733:9: Skipping av_guess_format(): empty list of specs
3731. 
3732.     if (last_asked_format) {
3733.         file_oformat = av_guess_format(last_asked_format, NULL, NULL);
              ^
3734.         if (!file_oformat) {
3735.             fprintf(stderr, "Requested output format '%s' is not a suitable output format\n", last_asked_format);

ffmpeg.c:3734:14: Taking false branch
3732.     if (last_asked_format) {
3733.         file_oformat = av_guess_format(last_asked_format, NULL, NULL);
3734.         if (!file_oformat) {
                   ^
3735.             fprintf(stderr, "Requested output format '%s' is not a suitable output format\n", last_asked_format);
3736.             ffmpeg_exit(1);

ffmpeg.c:3738:9: 
3736.             ffmpeg_exit(1);
3737.         }
3738.         last_asked_format = NULL;
              ^
3739.     } else {
3740.         file_oformat = av_guess_format(NULL, filename, NULL);

ffmpeg.c:3748:5: 
3746.     }
3747. 
3748.     oc->oformat = file_oformat;
          ^
3749.     av_strlcpy(oc->filename, filename, sizeof(oc->filename));
3750. 
