int ff_ape_write_tag(AVFormatContext *s) { AVDictionaryEntry *e = NULL; int64_t start, end; int size, count = 0; if (!s->pb->seekable) return 0; start = avio_tell(s->pb); // header avio_write(s->pb, "APETAGEX", 8); // id avio_wl32 (s->pb, APE_TAG_VERSION); // version avio_wl32(s->pb, 0); // reserve space for size avio_wl32(s->pb, 0); // reserve space for tag count // flags avio_wl32(s->pb, APE_TAG_FLAG_CONTAINS_HEADER | APE_TAG_FLAG_CONTAINS_FOOTER | APE_TAG_FLAG_IS_HEADER); ffio_fill(s->pb, 0, 8); // reserved while ((e = av_dict_get(s->metadata, "", e, AV_DICT_IGNORE_SUFFIX))) { int val_len = strlen(e->value); avio_wl32(s->pb, val_len); // value length avio_wl32(s->pb, 0); // item flags avio_put_str(s->pb, e->key); // key avio_write(s->pb, e->value, val_len); // value count++; } size = avio_tell(s->pb) - start; // footer avio_write(s->pb, "APETAGEX", 8); // id avio_wl32 (s->pb, APE_TAG_VERSION); // version avio_wl32(s->pb, size); // size avio_wl32(s->pb, count); // tag count // flags avio_wl32(s->pb, APE_TAG_FLAG_CONTAINS_HEADER | APE_TAG_FLAG_CONTAINS_FOOTER); ffio_fill(s->pb, 0, 8); // reserved // update values in the header end = avio_tell(s->pb); avio_seek(s->pb, start + 12, SEEK_SET); avio_wl32(s->pb, size); avio_wl32(s->pb, count); avio_seek(s->pb, end, SEEK_SET); return 0; }