static int au_write_trailer(AVFormatContext *s) { AVIOContext *pb = s->pb; int64_t file_size; if (s->pb->seekable) { /* update file size */ file_size = avio_tell(pb); avio_seek(pb, 8, SEEK_SET); avio_wb32(pb, (uint32_t)(file_size - 24)); avio_seek(pb, file_size, SEEK_SET); avio_flush(pb); } return 0; }