ffmpeg.c:3342: error: Null Dereference
  pointer `oc` last assigned on line 3331 could be null and is dereferenced at line 3342, column 5.

ffmpeg.c:3321:1: start of procedure opt_output_file()
3319. }
3320. 
3321. static void opt_output_file(const char *filename)
      ^
3322. {
3323.     AVFormatContext *oc;

ffmpeg.c:3326:5: 
3324.     int use_video, use_audio, use_subtitle;
3325.     int input_has_video, input_has_audio, input_has_subtitle;
3326.     AVFormatParameters params, *ap = &params;
          ^
3327. 
3328.     if (!strcmp(filename, "-"))

ffmpeg.c:3328:10: Taking false branch
3326.     AVFormatParameters params, *ap = &params;
3327. 
3328.     if (!strcmp(filename, "-"))
               ^
3329.         filename = "pipe:";
3330. 

ffmpeg.c:3331:5: 
3329.         filename = "pipe:";
3330. 
3331.     oc = avformat_alloc_context();
          ^
3332. 
3333.     if (!file_oformat) {

libavformat/options.c:77:1: start of procedure avformat_alloc_context()
  75. }
  76. 
  77. AVFormatContext *avformat_alloc_context(void)
      ^
  78. {
  79.     AVFormatContext *ic;

libavformat/options.c:80:5: 
  78. {
  79.     AVFormatContext *ic;
  80.     ic = av_malloc(sizeof(AVFormatContext));
          ^
  81.     if (!ic) return ic;
  82.     avformat_get_context_defaults(ic);

libavutil/mem.c:47:1: start of procedure av_malloc()
    45.    linker will do it automatically. */
    46. 
    47. void *av_malloc(unsigned int size)
        ^
    48. {
    49.     void *ptr = NULL;

libavutil/mem.c:49:5: 
    47. void *av_malloc(unsigned int size)
    48. {
    49.     void *ptr = NULL;
            ^
    50. #if CONFIG_MEMALIGN_HACK
    51.     long diff;

libavutil/mem.c:55:8: Taking false branch
    53. 
    54.     /* let's disallow possible ambiguous cases */
    55.     if(size > (INT_MAX-16) )
               ^
    56.         return NULL;
    57. 

libavutil/mem.c:66:9: Taking false branch
    64.     ((char*)ptr)[-1]= diff;
    65. #elif HAVE_POSIX_MEMALIGN
    66.     if (posix_memalign(&ptr,16,size))
                ^
    67.         ptr = NULL;
    68. #elif HAVE_MEMALIGN

libavutil/mem.c:99:5: 
     97.     ptr = malloc(size);
     98. #endif
     99.     return ptr;
             ^
    100. }
    101. 

libavutil/mem.c:100:1: return from a call to av_malloc
     98. #endif
     99.     return ptr;
    100. }
         ^
    101. 
    102. void *av_realloc(void *ptr, unsigned int size)

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

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

libavformat/options.c:85:1: return from a call to avformat_alloc_context
  83.     ic->av_class = &av_format_context_class;
  84.     return ic;
  85. }
      ^
  86. 
  87. #if LIBAVFORMAT_VERSION_MAJOR < 53

ffmpeg.c:3333:10: Taking true branch
3331.     oc = avformat_alloc_context();
3332. 
3333.     if (!file_oformat) {
               ^
3334.         file_oformat = guess_format(NULL, filename, NULL);
3335.         if (!file_oformat) {

ffmpeg.c:3334:9: Skipping guess_format(): empty list of specs
3332. 
3333.     if (!file_oformat) {
3334.         file_oformat = guess_format(NULL, filename, NULL);
              ^
3335.         if (!file_oformat) {
3336.             fprintf(stderr, "Unable to find a suitable output format for '%s'\n",

ffmpeg.c:3335:14: Taking true branch
3333.     if (!file_oformat) {
3334.         file_oformat = guess_format(NULL, filename, NULL);
3335.         if (!file_oformat) {
                   ^
3336.             fprintf(stderr, "Unable to find a suitable output format for '%s'\n",
3337.                     filename);

ffmpeg.c:3336:13: 
3334.         file_oformat = guess_format(NULL, filename, NULL);
3335.         if (!file_oformat) {
3336.             fprintf(stderr, "Unable to find a suitable output format for '%s'\n",
                  ^
3337.                     filename);
3338.             av_exit(1);

ffmpeg.c:3338:13: Skipping av_exit(): empty list of specs
3336.             fprintf(stderr, "Unable to find a suitable output format for '%s'\n",
3337.                     filename);
3338.             av_exit(1);
                  ^
3339.         }
3340.     }

ffmpeg.c:3342:5: 
3340.     }
3341. 
3342.     oc->oformat = file_oformat;
          ^
3343.     av_strlcpy(oc->filename, filename, sizeof(oc->filename));
3344. 

static void opt_output_file(const char *filename)
{
    AVFormatContext *oc;
    int use_video, use_audio, use_subtitle;
    int input_has_video, input_has_audio, input_has_subtitle;
    AVFormatParameters params, *ap = &params;
    if (!strcmp(filename, "-"))
        filename = "pipe:";
    oc = avformat_alloc_context();
    if (!file_oformat) {
        file_oformat = guess_format(NULL, filename, NULL);
        if (!file_oformat) {
            fprintf(stderr, "Unable to find a suitable output format for '%s'\n",
                    filename);
            av_exit(1);
        }
    }
    oc->oformat = file_oformat;
    av_strlcpy(oc->filename, filename, sizeof(oc->filename));
    if (!strcmp(file_oformat->name, "ffm") &&
        av_strstart(filename, "http:", NULL)) {
        int err = read_ffserver_streams(oc, filename);
        if (err < 0) {
            print_error(filename, err);
            av_exit(1);
        }
    } else {
        use_video = file_oformat->video_codec != CODEC_ID_NONE || video_stream_copy || video_codec_name;
        use_audio = file_oformat->audio_codec != CODEC_ID_NONE || audio_stream_copy || audio_codec_name;
        use_subtitle = file_oformat->subtitle_codec != CODEC_ID_NONE || subtitle_stream_copy || subtitle_codec_name;
        if (nb_input_files > 0) {
            check_audio_video_sub_inputs(&input_has_video, &input_has_audio,
                                         &input_has_subtitle);
            if (!input_has_video)
                use_video = 0;
            if (!input_has_audio)
                use_audio = 0;
            if (!input_has_subtitle)
                use_subtitle = 0;
        }
        if (audio_disable) {
            use_audio = 0;
        }
        if (video_disable) {
            use_video = 0;
        }
        if (subtitle_disable) {
            use_subtitle = 0;
        }
        if (use_video) {
            new_video_stream(oc);
        }
        if (use_audio) {
            new_audio_stream(oc);
        }
        if (use_subtitle) {
            new_subtitle_stream(oc);
        }
        oc->timestamp = rec_timestamp;
        for(; metadata_count>0; metadata_count--){
            av_metadata_set(&oc->metadata, metadata[metadata_count-1].key,
                                           metadata[metadata_count-1].value);
        }
        av_metadata_conv(oc, oc->oformat->metadata_conv, NULL);
    }
    output_files[nb_output_files++] = oc;
    if (oc->oformat->flags & AVFMT_NEEDNUMBER) {
        if (!av_filename_number_test(oc->filename)) {
            print_error(oc->filename, AVERROR_NUMEXPECTED);
            av_exit(1);
        }
    }
    if (!(oc->oformat->flags & AVFMT_NOFILE)) {
        if (!file_overwrite &&
            (strchr(filename, ':') == NULL ||
             filename[1] == ':' ||
             av_strstart(filename, "file:", NULL))) {
            if (url_exist(filename)) {
                if (!using_stdin) {
                    fprintf(stderr,"File '%s' already exists. Overwrite ? [y/N] ", filename);
                    fflush(stderr);
                    if (!read_yesno()) {
                        fprintf(stderr, "Not overwriting - exiting\n");
                        av_exit(1);
                    }
                }
                else {
                    fprintf(stderr,"File '%s' already exists. Exiting.\n", filename);
                    av_exit(1);
                }
            }
        }
        if (url_fopen(&oc->pb, filename, URL_WRONLY) < 0) {
            fprintf(stderr, "Could not open '%s'\n", filename);
            av_exit(1);
        }
    }
    memset(ap, 0, sizeof(*ap));
    if (av_set_parameters(oc, ap) < 0) {
        fprintf(stderr, "%s: Invalid encoding parameters\n",
                oc->filename);
        av_exit(1);
    }
    oc->preload= (int)(mux_preload*AV_TIME_BASE);
    oc->max_delay= (int)(mux_max_delay*AV_TIME_BASE);
    oc->loop_output = loop_output;
    oc->flags |= AVFMT_FLAG_NONBLOCK;
    set_context_opts(oc, avformat_opts, AV_OPT_FLAG_ENCODING_PARAM);
    file_oformat = NULL;
    file_iformat = NULL;
}
['static void opt_output_file(const char *filename)\n{\n    AVFormatContext *oc;\n    int use_video, use_audio, use_subtitle;\n    int input_has_video, input_has_audio, input_has_subtitle;\n    AVFormatParameters params, *ap = &params;\n    if (!strcmp(filename, "-"))\n        filename = "pipe:";\n    oc = avformat_alloc_context();\n    if (!file_oformat) {\n        file_oformat = guess_format(NULL, filename, NULL);\n        if (!file_oformat) {\n            fprintf(stderr, "Unable to find a suitable output format for \'%s\'\\n",\n                    filename);\n            av_exit(1);\n        }\n    }\n    oc->oformat = file_oformat;\n    av_strlcpy(oc->filename, filename, sizeof(oc->filename));\n    if (!strcmp(file_oformat->name, "ffm") &&\n        av_strstart(filename, "http:", NULL)) {\n        int err = read_ffserver_streams(oc, filename);\n        if (err < 0) {\n            print_error(filename, err);\n            av_exit(1);\n        }\n    } else {\n        use_video = file_oformat->video_codec != CODEC_ID_NONE || video_stream_copy || video_codec_name;\n        use_audio = file_oformat->audio_codec != CODEC_ID_NONE || audio_stream_copy || audio_codec_name;\n        use_subtitle = file_oformat->subtitle_codec != CODEC_ID_NONE || subtitle_stream_copy || subtitle_codec_name;\n        if (nb_input_files > 0) {\n            check_audio_video_sub_inputs(&input_has_video, &input_has_audio,\n                                         &input_has_subtitle);\n            if (!input_has_video)\n                use_video = 0;\n            if (!input_has_audio)\n                use_audio = 0;\n            if (!input_has_subtitle)\n                use_subtitle = 0;\n        }\n        if (audio_disable) {\n            use_audio = 0;\n        }\n        if (video_disable) {\n            use_video = 0;\n        }\n        if (subtitle_disable) {\n            use_subtitle = 0;\n        }\n        if (use_video) {\n            new_video_stream(oc);\n        }\n        if (use_audio) {\n            new_audio_stream(oc);\n        }\n        if (use_subtitle) {\n            new_subtitle_stream(oc);\n        }\n        oc->timestamp = rec_timestamp;\n        for(; metadata_count>0; metadata_count--){\n            av_metadata_set(&oc->metadata, metadata[metadata_count-1].key,\n                                           metadata[metadata_count-1].value);\n        }\n        av_metadata_conv(oc, oc->oformat->metadata_conv, NULL);\n    }\n    output_files[nb_output_files++] = oc;\n    if (oc->oformat->flags & AVFMT_NEEDNUMBER) {\n        if (!av_filename_number_test(oc->filename)) {\n            print_error(oc->filename, AVERROR_NUMEXPECTED);\n            av_exit(1);\n        }\n    }\n    if (!(oc->oformat->flags & AVFMT_NOFILE)) {\n        if (!file_overwrite &&\n            (strchr(filename, \':\') == NULL ||\n             filename[1] == \':\' ||\n             av_strstart(filename, "file:", NULL))) {\n            if (url_exist(filename)) {\n                if (!using_stdin) {\n                    fprintf(stderr,"File \'%s\' already exists. Overwrite ? [y/N] ", filename);\n                    fflush(stderr);\n                    if (!read_yesno()) {\n                        fprintf(stderr, "Not overwriting - exiting\\n");\n                        av_exit(1);\n                    }\n                }\n                else {\n                    fprintf(stderr,"File \'%s\' already exists. Exiting.\\n", filename);\n                    av_exit(1);\n                }\n            }\n        }\n        if (url_fopen(&oc->pb, filename, URL_WRONLY) < 0) {\n            fprintf(stderr, "Could not open \'%s\'\\n", filename);\n            av_exit(1);\n        }\n    }\n    memset(ap, 0, sizeof(*ap));\n    if (av_set_parameters(oc, ap) < 0) {\n        fprintf(stderr, "%s: Invalid encoding parameters\\n",\n                oc->filename);\n        av_exit(1);\n    }\n    oc->preload= (int)(mux_preload*AV_TIME_BASE);\n    oc->max_delay= (int)(mux_max_delay*AV_TIME_BASE);\n    oc->loop_output = loop_output;\n    oc->flags |= AVFMT_FLAG_NONBLOCK;\n    set_context_opts(oc, avformat_opts, AV_OPT_FLAG_ENCODING_PARAM);\n    file_oformat = NULL;\n    file_iformat = NULL;\n}', 'AVFormatContext *avformat_alloc_context(void)\n{\n    AVFormatContext *ic;\n    ic = av_malloc(sizeof(AVFormatContext));\n    if (!ic) return ic;\n    avformat_get_context_defaults(ic);\n    ic->av_class = &av_format_context_class;\n    return ic;\n}', 'void *av_malloc(unsigned int size)\n{\n    void *ptr = NULL;\n#if CONFIG_MEMALIGN_HACK\n    long diff;\n#endif\n    if(size > (INT_MAX-16) )\n        return NULL;\n#if CONFIG_MEMALIGN_HACK\n    ptr = malloc(size+16);\n    if(!ptr)\n        return ptr;\n    diff= ((-(long)ptr - 1)&15) + 1;\n    ptr = (char*)ptr + diff;\n    ((char*)ptr)[-1]= diff;\n#elif HAVE_POSIX_MEMALIGN\n    if (posix_memalign(&ptr,16,size))\n        ptr = NULL;\n#elif HAVE_MEMALIGN\n    ptr = memalign(16,size);\n#else\n    ptr = malloc(size);\n#endif\n    return ptr;\n}']