ffmpeg.c:3581: error: Uninitialized Value
  The value read from codec_id was never initialized.

ffmpeg.c:3581:9: 
3579.         audio_enc->sample_rate = audio_sample_rate;
3580.     } else {
3581.         audio_enc->codec_id = codec_id;
              ^
3582.         set_context_opts(audio_enc, avcodec_opts[AVMEDIA_TYPE_AUDIO], AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM, codec);
3583. 
