avio_printf(s->pb, "#software: %s\n", LIBAVFORMAT_IDENT);
for (i = 0; i < s->nb_streams; i++) {
AVStream *st = s->streams[i];
avio_printf(s->pb, "#software: %s\n", LIBAVFORMAT_IDENT);
for (i = 0; i < s->nb_streams; i++) {
AVStream *st = s->streams[i];