ffmpeg.c:3449: error: Uninitialized Value
  The value read from codec_id was never initialized.

ffmpeg.c:3449:9: 
3447.         AVRational fps= frame_rate.num ? frame_rate : (AVRational){25,1};
3448. 
3449.         video_enc->codec_id = codec_id;
              ^
3450.         set_context_opts(video_enc, avcodec_opts[AVMEDIA_TYPE_VIDEO], AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM, codec);
3451. 
