avconv.c:2811: error: Null Dereference
  pointer `codec` last assigned on line 2804 could be null and is dereferenced at line 2811, column 8.

avconv.c:2799:1: start of procedure find_codec_or_die()
2797. }
2798. 
2799. static AVCodec *find_codec_or_die(const char *name, enum AVMediaType type, int encoder)
      ^
2800. {
2801.     const char *codec_string = encoder ? "encoder" : "decoder";

avconv.c:2801:32: Condition is true
2799. static AVCodec *find_codec_or_die(const char *name, enum AVMediaType type, int encoder)
2800. {
2801.     const char *codec_string = encoder ? "encoder" : "decoder";
                                     ^
2802.     AVCodec *codec;
2803. 

avconv.c:2801:5: 
2799. static AVCodec *find_codec_or_die(const char *name, enum AVMediaType type, int encoder)
2800. {
2801.     const char *codec_string = encoder ? "encoder" : "decoder";
          ^
2802.     AVCodec *codec;
2803. 

avconv.c:2804:13: Condition is true
2802.     AVCodec *codec;
2803. 
2804.     codec = encoder ?
                  ^
2805.         avcodec_find_encoder_by_name(name) :
2806.         avcodec_find_decoder_by_name(name);

avconv.c:2804:5: 
2802.     AVCodec *codec;
2803. 
2804.     codec = encoder ?
          ^
2805.         avcodec_find_encoder_by_name(name) :
2806.         avcodec_find_decoder_by_name(name);

avconv.c:2807:9: Taking true branch
2805.         avcodec_find_encoder_by_name(name) :
2806.         avcodec_find_decoder_by_name(name);
2807.     if(!codec) {
              ^
2808.         av_log(NULL, AV_LOG_FATAL, "Unknown %s '%s'\n", codec_string, name);
2809.         exit_program(1);

avconv.c:2808:9: Skipping av_log(): empty list of specs
2806.         avcodec_find_decoder_by_name(name);
2807.     if(!codec) {
2808.         av_log(NULL, AV_LOG_FATAL, "Unknown %s '%s'\n", codec_string, name);
              ^
2809.         exit_program(1);
2810.     }

avconv.c:2809:9: Skipping exit_program(): empty list of specs
2807.     if(!codec) {
2808.         av_log(NULL, AV_LOG_FATAL, "Unknown %s '%s'\n", codec_string, name);
2809.         exit_program(1);
              ^
2810.     }
2811.     if(codec->type != type) {

avconv.c:2811:8: 
2809.         exit_program(1);
2810.     }
2811.     if(codec->type != type) {
             ^
2812.         av_log(NULL, AV_LOG_FATAL, "Invalid %s type '%s'\n", codec_string, name);
2813.         exit_program(1);

static AVCodec *find_codec_or_die(const char *name, enum AVMediaType type, int encoder)
{
    const char *codec_string = encoder ? "encoder" : "decoder";
    AVCodec *codec;
    codec = encoder ?
        avcodec_find_encoder_by_name(name) :
        avcodec_find_decoder_by_name(name);
    if(!codec) {
        av_log(NULL, AV_LOG_FATAL, "Unknown %s '%s'\n", codec_string, name);
        exit_program(1);
    }
    if(codec->type != type) {
        av_log(NULL, AV_LOG_FATAL, "Invalid %s type '%s'\n", codec_string, name);
        exit_program(1);
    }
    return codec;
}
['static AVCodec *find_codec_or_die(const char *name, enum AVMediaType type, int encoder)\n{\n    const char *codec_string = encoder ? "encoder" : "decoder";\n    AVCodec *codec;\n    codec = encoder ?\n        avcodec_find_encoder_by_name(name) :\n        avcodec_find_decoder_by_name(name);\n    if(!codec) {\n        av_log(NULL, AV_LOG_FATAL, "Unknown %s \'%s\'\\n", codec_string, name);\n        exit_program(1);\n    }\n    if(codec->type != type) {\n        av_log(NULL, AV_LOG_FATAL, "Invalid %s type \'%s\'\\n", codec_string, name);\n        exit_program(1);\n    }\n    return codec;\n}']