/* there might be a straightforward one-line way to do the below
* that's portable and totally safe against roundoff, but I haven't
* thought of it. Therefore, we opt on the side of caution */
public static long _book_maptype1_quantvals(static_codebook b)
{
long vals;
if (b.entries < 1)
{
return(0);
}
vals = (long)Floor(Pow((float)b.entries, 1f / b.dim));
/* the above *should* be reliable, but we'll not assume that FP is
* ever reliable when bitstream sync is at stake; verify via integer
* means that vals really is the greatest value of dim for which
* vals^b.bim <= b.entries */
/* treat the above as an initial guess */
if (vals < 1)
{
vals = 1;
}
while (true)
{
long acc = 1;
long acc1 = 1;
int i;
for (i = 0; i < b.dim; i++)
{
if (b.entries / vals < acc)
{
break;
}
acc *= vals;
if (long.MaxValue / (vals + 1) < acc1)
{
acc1 = long.MaxValue;
}
else
{
acc1 *= vals + 1;
}
}
if (i >= b.dim && acc <= b.entries && acc1 > b.entries)
{
return(vals);
}
else
{
if (i < b.dim || acc > b.entries)
{
vals--;
}
else
{
vals++;
}
}
}
}
public static void vorbis_staticbook_destroy(static_codebook b)
{
if (b.allocedp != 0)
{
if (b.quantlist != null)
{
b.quantlist = null; //_ogg_free(b.quantlist);
}
if (b.lengthlist != null)
{
b.lengthlist = null; // _ogg_free(b.lengthlist);
}
//memset(b, 0, sizeof(*b));
//_ogg_free(b);
} /* otherwise, it is in static memory */
}
/* unpacks a codebook from the packet buffer into the codebook struct,
* readies the codebook auxiliary structures for decode *************/
public static static_codebook vorbis_staticbook_unpack(oggpack_buffer opb)
{
long i, j;
static_codebook s = new static_codebook(); //_ogg_calloc(1, sizeof(*s));
s.allocedp = 1;
/* make sure alignment is correct */
if (oggpack_read(opb, 24) != 0x564342)
{
goto _eofout;
}
/* first the basic parameters */
s.dim = oggpack_read(opb, 16);
s.entries = oggpack_read(opb, 24);
if (s.entries == -1)
{
goto _eofout;
}
if (ov_ilog((uint)s.dim) + ov_ilog((uint)s.entries) > 24)
{
goto _eofout;
}
/* codeword ordering.... length ordered or unordered? */
switch ((int)oggpack_read(opb, 1))
{
case 0:
{
long unused;
/* allocated but unused entries? */
unused = oggpack_read(opb, 1);
if ((s.entries * (unused != 0 ? 1 : 5) + 7) >> 3 > opb.storage - oggpack_bytes(opb))
{
goto _eofout;
}
/* unordered */
s.lengthlist = new long[s.entries]; //_ogg_malloc(sizeof(*s.lengthlist) * s.entries);
/* allocated but unused entries? */
if (unused != 0)
{
/* yes, unused entries */
for (i = 0; i < s.entries; i++)
{
if (oggpack_read(opb, 1) != 0)
{
long num = oggpack_read(opb, 5);
if (num == -1)
{
goto _eofout;
}
s.lengthlist[i] = num + 1;
}
else
{
s.lengthlist[i] = 0;
}
}
}
else
{
/* all entries used; no tagging */
for (i = 0; i < s.entries; i++)
{
long num = oggpack_read(opb, 5);
if (num == -1)
{
goto _eofout;
}
s.lengthlist[i] = num + 1;
}
}
break;
}
case 1:
/* ordered */
{
long length = oggpack_read(opb, 5) + 1;
if (length == 0)
{
goto _eofout;
}
s.lengthlist = new long[s.entries]; //_ogg_malloc(sizeof(*s.lengthlist) * s.entries);
for (i = 0; i < s.entries;)
{
long num = oggpack_read(opb, ov_ilog((uint)(s.entries - i)));
if (num == -1)
{
goto _eofout;
}
if (length > 32 || num > s.entries - i ||
(num > 0 && (num - 1) >> (int)(length - 1) > 1))
{
goto _errout;
}
if (length > 32)
{
goto _errout;
}
for (j = 0; j < num; j++, i++)
{
s.lengthlist[i] = length;
}
length++;
}
}
break;
default:
/* EOF */
goto _eofout;
}
/* Do we have a mapping to unpack? */
switch ((s.maptype = (int)oggpack_read(opb, 4)))
{
case 0:
/* no mapping */
break;
case 1:
case 2:
/* implicitly populated value mapping */
/* explicitly populated value mapping */
s.q_min = oggpack_read(opb, 32);
s.q_delta = oggpack_read(opb, 32);
s.q_quant = (int)oggpack_read(opb, 4) + 1;
s.q_sequencep = (int)oggpack_read(opb, 1);
if (s.q_sequencep == -1)
{
goto _eofout;
}
{
int quantvals = 0;
switch (s.maptype)
{
case 1:
quantvals = (int)(s.dim == 0 ? 0 : _book_maptype1_quantvals(s));
break;
case 2:
quantvals = (int)(s.entries * s.dim);
break;
}
/* quantized values */
if (((quantvals * s.q_quant + 7) >> 3) > opb.storage - oggpack_bytes(opb))
{
goto _eofout;
}
s.quantlist = new long[quantvals]; //_ogg_malloc(sizeof(*s.quantlist) * quantvals);
for (i = 0; i < quantvals; i++)
{
s.quantlist[i] = oggpack_read(opb, s.q_quant);
}
if (quantvals != 0 && s.quantlist[quantvals - 1] == -1)
{
goto _eofout;
}
}
break;
default:
goto _errout;
}
/* all set */
return(s);
_errout:
_eofout:
vorbis_staticbook_destroy(s);
return(null);
}
