ffmpeg.c:3721: error: Null Dereference
  pointer `file_oformat` last assigned on line 3710 could be null and is dereferenced at line 3721, column 17.

ffmpeg.c:3685:1: start of procedure opt_output_file()
3683. }
3684. 
3685. static void opt_output_file(const char *filename)
      ^
3686. {
3687.     AVFormatContext *oc;

ffmpeg.c:3690:5: 
3688.     int err, use_video, use_audio, use_subtitle, use_data;
3689.     int input_has_video, input_has_audio, input_has_subtitle, input_has_data;
3690.     AVFormatParameters params, *ap = &params;
          ^
3691.     AVOutputFormat *file_oformat;
3692. 

ffmpeg.c:3693:10: Taking false branch
3691.     AVOutputFormat *file_oformat;
3692. 
3693.     if (!strcmp(filename, "-"))
               ^
3694.         filename = "pipe:";
3695. 

ffmpeg.c:3696:5: 
3694.         filename = "pipe:";
3695. 
3696.     oc = avformat_alloc_context();
          ^
3697.     if (!oc) {
3698.         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 false 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:83:5: Skipping avformat_get_context_defaults(): empty list of specs
  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;
  85.     return ic;

libavformat/options.c:84:5: 
  82.     if (!ic) return ic;
  83.     avformat_get_context_defaults(ic);
  84.     ic->av_class = &av_format_context_class;
          ^
  85.     return ic;
  86. }

libavformat/options.c:85:5: 
  83.     avformat_get_context_defaults(ic);
  84.     ic->av_class = &av_format_context_class;
  85.     return ic;
          ^
  86. }

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:3697:10: Taking false branch
3695. 
3696.     oc = avformat_alloc_context();
3697.     if (!oc) {
               ^
3698.         print_error(filename, AVERROR(ENOMEM));
3699.         ffmpeg_exit(1);

ffmpeg.c:3702:9: Taking false branch
3700.     }
3701. 
3702.     if (last_asked_format) {
              ^
3703.         file_oformat = av_guess_format(last_asked_format, NULL, NULL);
3704.         if (!file_oformat) {

ffmpeg.c:3710:9: Skipping av_guess_format(): empty list of specs
3708.         last_asked_format = NULL;
3709.     } else {
3710.         file_oformat = av_guess_format(NULL, filename, NULL);
              ^
3711.         if (!file_oformat) {
3712.             fprintf(stderr, "Unable to find a suitable output format for '%s'\n",

ffmpeg.c:3711:14: Taking true branch
3709.     } else {
3710.         file_oformat = av_guess_format(NULL, filename, NULL);
3711.         if (!file_oformat) {
                   ^
3712.             fprintf(stderr, "Unable to find a suitable output format for '%s'\n",
3713.                     filename);

ffmpeg.c:3712:13: 
3710.         file_oformat = av_guess_format(NULL, filename, NULL);
3711.         if (!file_oformat) {
3712.             fprintf(stderr, "Unable to find a suitable output format for '%s'\n",
                  ^
3713.                     filename);
3714.             ffmpeg_exit(1);

ffmpeg.c:3714:13: Skipping ffmpeg_exit(): empty list of specs
3712.             fprintf(stderr, "Unable to find a suitable output format for '%s'\n",
3713.                     filename);
3714.             ffmpeg_exit(1);
                  ^
3715.         }
3716.     }

ffmpeg.c:3718:5: 
3716.     }
3717. 
3718.     oc->oformat = file_oformat;
          ^
3719.     av_strlcpy(oc->filename, filename, sizeof(oc->filename));
3720. 

ffmpeg.c:3719:5: 
3717. 
3718.     oc->oformat = file_oformat;
3719.     av_strlcpy(oc->filename, filename, sizeof(oc->filename));
          ^
3720. 
3721.     if (!strcmp(file_oformat->name, "ffm") &&

libavutil/avstring.c:64:1: start of procedure av_strlcpy()
  62. }
  63. 
  64. size_t av_strlcpy(char *dst, const char *src, size_t size)
      ^
  65. {
  66.     size_t len = 0;

libavutil/avstring.c:66:5: 
  64. size_t av_strlcpy(char *dst, const char *src, size_t size)
  65. {
  66.     size_t len = 0;
          ^
  67.     while (++len < size && *src)
  68.         *dst++ = *src++;

libavutil/avstring.c:67:12: Loop condition is true. Entering loop body
  65. {
  66.     size_t len = 0;
  67.     while (++len < size && *src)
                 ^
  68.         *dst++ = *src++;
  69.     if (len <= size)

libavutil/avstring.c:67:28: Loop condition is false. Leaving loop
  65. {
  66.     size_t len = 0;
  67.     while (++len < size && *src)
                                 ^
  68.         *dst++ = *src++;
  69.     if (len <= size)

libavutil/avstring.c:69:9: Taking true branch
  67.     while (++len < size && *src)
  68.         *dst++ = *src++;
  69.     if (len <= size)
              ^
  70.         *dst = 0;
  71.     return len + strlen(src) - 1;

libavutil/avstring.c:70:9: 
  68.         *dst++ = *src++;
  69.     if (len <= size)
  70.         *dst = 0;
              ^
  71.     return len + strlen(src) - 1;
  72. }

libavutil/avstring.c:71:5: 
  69.     if (len <= size)
  70.         *dst = 0;
  71.     return len + strlen(src) - 1;
          ^
  72. }
  73. 

libavutil/avstring.c:72:1: return from a call to av_strlcpy
  70.         *dst = 0;
  71.     return len + strlen(src) - 1;
  72. }
      ^
  73. 
  74. size_t av_strlcat(char *dst, const char *src, size_t size)

ffmpeg.c:3721:10: 
3719.     av_strlcpy(oc->filename, filename, sizeof(oc->filename));
3720. 
3721.     if (!strcmp(file_oformat->name, "ffm") &&
               ^
3722.         av_strstart(filename, "http:", NULL)) {
3723.         /* special case for files sent to ffserver: we get the stream

static void opt_output_file(const char *filename)
{
    AVFormatContext *oc;
    int err, use_video, use_audio, use_subtitle, use_data;
    int input_has_video, input_has_audio, input_has_subtitle, input_has_data;
    AVFormatParameters params, *ap = &params;
    AVOutputFormat *file_oformat;
    if (!strcmp(filename, "-"))
        filename = "pipe:";
    oc = avformat_alloc_context();
    if (!oc) {
        print_error(filename, AVERROR(ENOMEM));
        ffmpeg_exit(1);
    }
    if (last_asked_format) {
        file_oformat = av_guess_format(last_asked_format, NULL, NULL);
        if (!file_oformat) {
            fprintf(stderr, "Requested output format '%s' is not a suitable output format\n", last_asked_format);
            ffmpeg_exit(1);
        }
        last_asked_format = NULL;
    } else {
        file_oformat = av_guess_format(NULL, filename, NULL);
        if (!file_oformat) {
            fprintf(stderr, "Unable to find a suitable output format for '%s'\n",
                    filename);
            ffmpeg_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);
            ffmpeg_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;
        use_data = data_stream_copy ||  data_codec_name;
        if (nb_input_files > 0) {
            check_inputs(&input_has_video,
                         &input_has_audio,
                         &input_has_subtitle,
                         &input_has_data);
            if (!input_has_video)
                use_video = 0;
            if (!input_has_audio)
                use_audio = 0;
            if (!input_has_subtitle)
                use_subtitle = 0;
            if (!input_has_data)
                use_data = 0;
        }
        if (audio_disable)    use_audio    = 0;
        if (video_disable)    use_video    = 0;
        if (subtitle_disable) use_subtitle = 0;
        if (data_disable)     use_data     = 0;
        if (use_video)    new_video_stream(oc, nb_output_files);
        if (use_audio)    new_audio_stream(oc, nb_output_files);
        if (use_subtitle) new_subtitle_stream(oc, nb_output_files);
        if (use_data)     new_data_stream(oc, nb_output_files);
        oc->timestamp = recording_timestamp;
        av_metadata_copy(&oc->metadata, metadata, 0);
        av_metadata_free(&metadata);
    }
    output_files[nb_output_files++] = oc;
    if (oc->oformat->flags & AVFMT_NEEDNUMBER) {
        if (!av_filename_number_test(oc->filename)) {
            print_error(oc->filename, AVERROR(EINVAL));
            ffmpeg_exit(1);
        }
    }
    if (!(oc->oformat->flags & AVFMT_NOFILE)) {
        if (!file_overwrite &&
            (strchr(filename, ':') == NULL ||
             filename[1] == ':' ||
             av_strstart(filename, "file:", NULL))) {
            if (avio_check(filename, 0) == 0) {
                if (!using_stdin) {
                    fprintf(stderr,"File '%s' already exists. Overwrite ? [y/N] ", filename);
                    fflush(stderr);
                    if (!read_yesno()) {
                        fprintf(stderr, "Not overwriting - exiting\n");
                        ffmpeg_exit(1);
                    }
                }
                else {
                    fprintf(stderr,"File '%s' already exists. Exiting.\n", filename);
                    ffmpeg_exit(1);
                }
            }
        }
        if ((err = avio_open(&oc->pb, filename, AVIO_FLAG_WRITE)) < 0) {
            print_error(filename, err);
            ffmpeg_exit(1);
        }
    }
    memset(ap, 0, sizeof(*ap));
    if (av_set_parameters(oc, ap) < 0) {
        fprintf(stderr, "%s: Invalid encoding parameters\n",
                oc->filename);
        ffmpeg_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, NULL);
    av_freep(&forced_key_frames);
    uninit_opts();
    init_opts();
}
['static void opt_output_file(const char *filename)\n{\n    AVFormatContext *oc;\n    int err, use_video, use_audio, use_subtitle, use_data;\n    int input_has_video, input_has_audio, input_has_subtitle, input_has_data;\n    AVFormatParameters params, *ap = &params;\n    AVOutputFormat *file_oformat;\n    if (!strcmp(filename, "-"))\n        filename = "pipe:";\n    oc = avformat_alloc_context();\n    if (!oc) {\n        print_error(filename, AVERROR(ENOMEM));\n        ffmpeg_exit(1);\n    }\n    if (last_asked_format) {\n        file_oformat = av_guess_format(last_asked_format, NULL, NULL);\n        if (!file_oformat) {\n            fprintf(stderr, "Requested output format \'%s\' is not a suitable output format\\n", last_asked_format);\n            ffmpeg_exit(1);\n        }\n        last_asked_format = NULL;\n    } else {\n        file_oformat = av_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            ffmpeg_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            ffmpeg_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        use_data = data_stream_copy ||  data_codec_name;\n        if (nb_input_files > 0) {\n            check_inputs(&input_has_video,\n                         &input_has_audio,\n                         &input_has_subtitle,\n                         &input_has_data);\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            if (!input_has_data)\n                use_data = 0;\n        }\n        if (audio_disable)    use_audio    = 0;\n        if (video_disable)    use_video    = 0;\n        if (subtitle_disable) use_subtitle = 0;\n        if (data_disable)     use_data     = 0;\n        if (use_video)    new_video_stream(oc, nb_output_files);\n        if (use_audio)    new_audio_stream(oc, nb_output_files);\n        if (use_subtitle) new_subtitle_stream(oc, nb_output_files);\n        if (use_data)     new_data_stream(oc, nb_output_files);\n        oc->timestamp = recording_timestamp;\n        av_metadata_copy(&oc->metadata, metadata, 0);\n        av_metadata_free(&metadata);\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(EINVAL));\n            ffmpeg_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 (avio_check(filename, 0) == 0) {\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                        ffmpeg_exit(1);\n                    }\n                }\n                else {\n                    fprintf(stderr,"File \'%s\' already exists. Exiting.\\n", filename);\n                    ffmpeg_exit(1);\n                }\n            }\n        }\n        if ((err = avio_open(&oc->pb, filename, AVIO_FLAG_WRITE)) < 0) {\n            print_error(filename, err);\n            ffmpeg_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        ffmpeg_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, NULL);\n    av_freep(&forced_key_frames);\n    uninit_opts();\n    init_opts();\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(size_t size)\n{\n    void *ptr = NULL;\n#if CONFIG_MEMALIGN_HACK\n    long diff;\n#endif\n    if(size > (INT_MAX-32) )\n        return NULL;\n#if CONFIG_MEMALIGN_HACK\n    ptr = malloc(size+32);\n    if(!ptr)\n        return ptr;\n    diff= ((-(long)ptr - 1)&31) + 1;\n    ptr = (char*)ptr + diff;\n    ((char*)ptr)[-1]= diff;\n#elif HAVE_POSIX_MEMALIGN\n    if (posix_memalign(&ptr,32,size))\n        ptr = NULL;\n#elif HAVE_MEMALIGN\n    ptr = memalign(32,size);\n#else\n    ptr = malloc(size);\n#endif\n    return ptr;\n}', 'size_t av_strlcpy(char *dst, const char *src, size_t size)\n{\n    size_t len = 0;\n    while (++len < size && *src)\n        *dst++ = *src++;\n    if (len <= size)\n        *dst = 0;\n    return len + strlen(src) - 1;\n}']