void av_log(AVCodecContext* avctx, int level, const char *fmt, ...)
void av_log(void* avcl, int level, const char *fmt, ...)
void av_log(AVCodecContext* avctx, int level, const char *fmt, ...){    va_list vl;    va_start(vl, fmt);    av_vlog(avctx, level, fmt, vl);    va_end(vl);}