void av_vlog(AVCodecContext* avctx, int level, const char *fmt, va_list vl)
void av_vlog(void* avcl, int level, const char *fmt, va_list vl)
void av_vlog(AVCodecContext* avctx, int level, const char *fmt, va_list vl){    av_log_callback(avctx, level, fmt, vl);}