return (av_log2(id+1)-1)/7+1;
}
+/**
+ * Write an EBML size meaning "unknown size"
+ *
+ * @param bytes The number of bytes the size should occupy. Maximum of 8.
+ */
+static void put_ebml_size_unknown(ByteIOContext *pb, int bytes)
+{
+ uint64_t value = 0;
+ int i;
+
+ bytes = FFMIN(bytes, 8);
+ for (i = 0; i < bytes*7 + 1; i++)
+ value |= 1ULL << i;
+ for (i = bytes-1; i >= 0; i--)
+ put_byte(pb, value >> i*8);
+}
+
// XXX: test this thoroughly and get rid of minbytes hack (currently needed to
// use up all of the space reserved in start_ebml_master)
static void put_ebml_size(ByteIOContext *pb, uint64_t size, int minbytes)
// sizes larger than this are currently undefined in EBML
// so write "unknown" size
- size = FFMIN(size, (1ULL<<56)-1);
+ if (size >= (1ULL<<56)-1) {
+ put_ebml_size_unknown(pb, 1);
+ return;
+ }
- while (size >> (bytes*7 + 7)) bytes++;
+ while ((size+1) >> (bytes*7 + 7)) bytes++;
put_byte(pb, (0x80 >> bytes) | (size >> bytes*8));
for (bytes -= 1; bytes >= 0; bytes--)
put_ebml_id(pb, elementid);
// XXX: this always reserves the maximum needed space to store any size value
// we should be smarter (additional parameter for expected size?)
- put_ebml_size(pb, (1ULL<<56)-1, 0); // largest unknown size
+ put_ebml_size_unknown(pb, 8);
return url_ftell(pb);
}