static int mxf_read_local_tags(MXFContext *mxf, KLVPacket *klv, MXFMetadataReadFunc *read_child, int ctx_size, enum MXFMetadataSetType type) { AVIOContext *pb = mxf->fc->pb; MXFMetadataSet *ctx = ctx_size ? av_mallocz(ctx_size) : mxf; uint64_t klv_end = avio_tell(pb) + klv->length; if (!ctx) return AVERROR(ENOMEM); mxf_metadataset_init(ctx, type); while (avio_tell(pb) + 4 < klv_end && !avio_feof(pb)) { int ret; int tag = avio_rb16(pb); int size = avio_rb16(pb); /* KLV specified by 0x53 */ uint64_t next = avio_tell(pb) + size; UID uid = {0}; av_dlog(mxf->fc, "local tag %#04x size %d\n", tag, size); if (!size) { /* ignore empty tag, needed for some files with empty UMID tag */ av_log(mxf->fc, AV_LOG_ERROR, "local tag %#04x with 0 size\n", tag); continue; } if (tag > 0x7FFF) { /* dynamic tag */ int i; for (i = 0; i < mxf->local_tags_count; i++) { int local_tag = AV_RB16(mxf->local_tags+i*18); if (local_tag == tag) { memcpy(uid, mxf->local_tags+i*18+2, 16); av_dlog(mxf->fc, "local tag %#04x\n", local_tag); PRINT_KEY(mxf->fc, "uid", uid); } } } if (ctx_size && tag == 0x3C0A) avio_read(pb, ctx->uid, 16); else if ((ret = read_child(ctx, pb, tag, size, uid, -1)) < 0) return ret; /* Accept the 64k local set limit being exceeded (Avid). Don't accept * it extending past the end of the KLV though (zzuf5.mxf). */ if (avio_tell(pb) > klv_end) { if (ctx_size) av_free(ctx); av_log(mxf->fc, AV_LOG_ERROR, "local tag %#04x extends past end of local set @ %#"PRIx64"\n", tag, klv->offset); return AVERROR_INVALIDDATA; } else if (avio_tell(pb) <= next) /* only seek forward, else this can loop for a long time */ avio_seek(pb, next, SEEK_SET); } if (ctx_size) ctx->type = type; return ctx_size ? mxf_add_metadata_set(mxf, ctx) : 0; }