static int64_t mkv_write_seekhead(AVIOContext *pb, MatroskaMuxContext *mkv) { AVIOContext *dyn_cp; mkv_seekhead *seekhead = mkv->main_seekhead; ebml_master metaseek, seekentry; int64_t currentpos; int i; currentpos = avio_tell(pb); if (seekhead->reserved_size > 0) { if (avio_seek(pb, seekhead->filepos, SEEK_SET) < 0) { currentpos = -1; goto fail; } } if (start_ebml_master_crc32(pb, &dyn_cp, &metaseek, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size) < 0) { currentpos = -1; goto fail; } for (i = 0; i < seekhead->num_entries; i++) { mkv_seekhead_entry *entry = &seekhead->entries[i]; seekentry = start_ebml_master(dyn_cp, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE); put_ebml_id(dyn_cp, MATROSKA_ID_SEEKID); put_ebml_num(dyn_cp, ebml_id_size(entry->elementid), 0); put_ebml_id(dyn_cp, entry->elementid); put_ebml_uint(dyn_cp, MATROSKA_ID_SEEKPOSITION, entry->segmentpos); end_ebml_master(dyn_cp, seekentry); } end_ebml_master_crc32(pb, &dyn_cp, mkv, metaseek); if (seekhead->reserved_size > 0) { uint64_t remaining = seekhead->filepos + seekhead->reserved_size - avio_tell(pb); put_ebml_void(pb, remaining); avio_seek(pb, currentpos, SEEK_SET); currentpos = seekhead->filepos; } fail: av_freep(&mkv->main_seekhead->entries); av_freep(&mkv->main_seekhead); return currentpos; }