public int pageseek(Page og)
{
int page = returned;
int next;
int bytes = fill - returned;
if (headerbytes == 0)
{
int _headerbytes, i;
if (bytes < 27)
{
return(0); // not enough for a header
}
/* verify capture pattern */
//!!!!!!!!!!!
if (data[page] != 'O' || data[page + 1] != 'g' || data[page + 2] != 'g' || data[page + 3] != 'S')
{
headerbytes = 0;
bodybytes = 0;
// search for possible capture
next = 0;
for (int ii = 0; ii < bytes - 1; ii++)
{
if (data[page + 1 + ii] == 'O')
{
next = page + 1 + ii; break;
}
}
//next=memchr(page+1,'O',bytes-1);
if (next == 0)
{
next = fill;
}
returned = next;
return(-(next - page));
}
_headerbytes = (data[page + 26] & 0xff) + 27;
if (bytes < _headerbytes)
{
return(0); // not enough for header + seg table
}
// count up body length in the segment table
for (i = 0; i < (data[page + 26] & 0xff); i++)
{
bodybytes += (data[page + 27 + i] & 0xff);
}
headerbytes = _headerbytes;
}
if (bodybytes + headerbytes > bytes)
{
return(0);
}
// The whole test page is buffered. Verify the checksum
lock (chksum)
{
// Grab the checksum bytes, set the header field to zero
Array.Copy(data, page + 22, chksum, 0, 4);
data[page + 22] = 0;
data[page + 23] = 0;
data[page + 24] = 0;
data[page + 25] = 0;
// set up a temp page struct and recompute the checksum
Page log = pageseek_p;
log.header_base = data;
log.header = page;
log.header_len = headerbytes;
log.body_base = data;
log.body = page + headerbytes;
log.body_len = bodybytes;
log.checksum();
// Compare
if (chksum[0] != data[page + 22] ||
chksum[1] != data[page + 23] ||
chksum[2] != data[page + 24] ||
chksum[3] != data[page + 25])
{
// D'oh. Mismatch! Corrupt page (or miscapture and not a page at all)
// replace the computed checksum with the one actually read in
Array.Copy(chksum, 0, data, page + 22, 4);
// Bad checksum. Lose sync */
headerbytes = 0;
bodybytes = 0;
// search for possible capture
next = 0;
for (int ii = 0; ii < bytes - 1; ii++)
{
if (data[page + 1 + ii] == 'O')
{
next = page + 1 + ii; break;
}
}
//next=memchr(page+1,'O',bytes-1);
if (next == 0)
{
next = fill;
}
returned = next;
return(-(next - page));
}
}
// yes, have a whole page all ready to go
{
page = returned;
if (og != null)
{
og.header_base = data;
og.header = page;
og.header_len = headerbytes;
og.body_base = data;
og.body = page + headerbytes;
og.body_len = bodybytes;
}
unsynced = 0;
returned += (bytes = headerbytes + bodybytes);
headerbytes = 0;
bodybytes = 0;
return(bytes);
}
}
/* This will flush remaining packets into a page (returning nonzero),
even if there is not enough data to trigger a flush normally
(undersized page). If there are no packets or partial packets to
flush, ogg_stream_flush returns 0. Note that ogg_stream_flush will
try to flush a normal sized page like ogg_stream_pageout; a call to
ogg_stream_flush does not gurantee that all packets have flushed.
Only a return value of 0 from ogg_stream_flush indicates all packet
data is flushed into pages.
ogg_stream_page will flush the last page in a stream even if it's
undersized; you almost certainly want to use ogg_stream_pageout
(and *not* ogg_stream_flush) unless you need to flush an undersized
page in the middle of a stream for some reason. */
public int flush(Page og)
{
//System.out.println(this+" ---body_returned: "+body_returned);
int i;
int vals=0;
int maxvals=(lacing_fill>255?255:lacing_fill);
int bytes=0;
int acc=0;
long granule_pos=granule_vals[0];
if(maxvals==0)return(0);
/* construct a page */
/* decide how many segments to include */
/* If this is the initial header case, the first page must only include
the initial header packet */
if(b_o_s==0)
{ /* 'initial header page' case */
granule_pos=0;
for(vals=0;vals<maxvals;vals++)
{
if((lacing_vals[vals]&0x0ff)<255)
{
vals++;
break;
}
}
}
else
{
for(vals=0;vals<maxvals;vals++)
{
if(acc>4096)break;
acc+=(lacing_vals[vals]&0x0ff);
granule_pos=granule_vals[vals];
}
}
/* construct the header in temp storage */
String oggs_str = "OggS";
Encoding AE = Encoding.UTF8;
byte[] oggs_byt = AE.GetBytes(oggs_str);
Array.Copy(oggs_byt, 0, header, 0, oggs_byt.Length);
/* stream structure version */
header[4]=0x00;
/* continued packet flag? */
header[5]=0x00;
if((lacing_vals[0]&0x100)==0)header[5]|=0x01;
/* first page flag? */
if(b_o_s==0) header[5]|=0x02;
/* last page flag? */
if(e_o_s!=0 && lacing_fill==vals) header[5]|=0x04;
b_o_s=1;
/* 64 bits of PCM position */
for(i=6;i<14;i++)
{
header[i]=(byte)granule_pos;
granule_pos>>=8;
}
/* 32 bits of stream serial number */
{
int _serialno=serialno;
for(i=14;i<18;i++)
{
header[i]=(byte)_serialno;
_serialno>>=8;
}
}
/* 32 bits of page counter (we have both counter and page header
because this val can roll over) */
if(pageno==-1)pageno=0; /* because someone called
stream_reset; this would be a
strange thing to do in an
encode stream, but it has
plausible uses */
{
int _pageno=pageno++;
for(i=18;i<22;i++)
{
header[i]=(byte)_pageno;
_pageno>>=8;
}
}
/* zero for computation; filled in later */
header[22]=0;
header[23]=0;
header[24]=0;
header[25]=0;
/* segment table */
header[26]=(byte)vals;
for(i=0;i<vals;i++)
{
header[i+27]=(byte)lacing_vals[i];
bytes+=(header[i+27]&0xff);
}
/* set pointers in the ogg_page struct */
og.header_base=header;
og.header=0;
og.header_len=header_fill=vals+27;
og.body_base=body_data;
og.body=body_returned;
og.body_len=bytes;
/* advance the lacing data and set the body_returned pointer */
lacing_fill-=vals;
Array.Copy(lacing_vals, vals, lacing_vals, 0, lacing_fill*4);
Array.Copy(granule_vals, vals, granule_vals, 0, lacing_fill*8);
body_returned+=bytes;
/* calculate the checksum */
og.checksum();
/* done */
return(1);
}
/* This will flush remaining packets into a page (returning nonzero),
* even if there is not enough data to trigger a flush normally
* (undersized page). If there are no packets or partial packets to
* flush, ogg_stream_flush returns 0. Note that ogg_stream_flush will
* try to flush a normal sized page like ogg_stream_pageout; a call to
* ogg_stream_flush does not gurantee that all packets have flushed.
* Only a return value of 0 from ogg_stream_flush indicates all packet
* data is flushed into pages.
*
* ogg_stream_page will flush the last page in a stream even if it's
* undersized; you almost certainly want to use ogg_stream_pageout
* (and *not* ogg_stream_flush) unless you need to flush an undersized
* page in the middle of a stream for some reason. */
public int flush(Page og)
{
//System.out.println(this+" ---body_returned: "+body_returned);
int i;
int vals = 0;
int maxvals = (lacing_fill > 255?255:lacing_fill);
int bytes = 0;
int acc = 0;
long granule_pos = granule_vals[0];
if (maxvals == 0)
{
return(0);
}
/* construct a page */
/* decide how many segments to include */
/* If this is the initial header case, the first page must only include
* the initial header packet */
if (b_o_s == 0)
{ /* 'initial header page' case */
granule_pos = 0;
for (vals = 0; vals < maxvals; vals++)
{
if ((lacing_vals[vals] & 0x0ff) < 255)
{
vals++;
break;
}
}
}
else
{
for (vals = 0; vals < maxvals; vals++)
{
if (acc > 4096)
{
break;
}
acc += (lacing_vals[vals] & 0x0ff);
granule_pos = granule_vals[vals];
}
}
/* construct the header in temp storage */
String oggs_str = "OggS";
Encoding AE = Encoding.UTF8;
byte[] oggs_byt = AE.GetBytes(oggs_str);
Array.Copy(oggs_byt, 0, header, 0, oggs_byt.Length);
/* stream structure version */
header[4] = 0x00;
/* continued packet flag? */
header[5] = 0x00;
if ((lacing_vals[0] & 0x100) == 0)
{
header[5] |= 0x01;
}
/* first page flag? */
if (b_o_s == 0)
{
header[5] |= 0x02;
}
/* last page flag? */
if (e_o_s != 0 && lacing_fill == vals)
{
header[5] |= 0x04;
}
b_o_s = 1;
/* 64 bits of PCM position */
for (i = 6; i < 14; i++)
{
header[i] = (byte)granule_pos;
granule_pos >>= 8;
}
/* 32 bits of stream serial number */
{
int _serialno = serialno;
for (i = 14; i < 18; i++)
{
header[i] = (byte)_serialno;
_serialno >>= 8;
}
}
/* 32 bits of page counter (we have both counter and page header
* because this val can roll over) */
if (pageno == -1)
{
pageno = 0; /* because someone called
* stream_reset; this would be a
* strange thing to do in an
* encode stream, but it has
* plausible uses */
}
{
int _pageno = pageno++;
for (i = 18; i < 22; i++)
{
header[i] = (byte)_pageno;
_pageno >>= 8;
}
}
/* zero for computation; filled in later */
header[22] = 0;
header[23] = 0;
header[24] = 0;
header[25] = 0;
/* segment table */
header[26] = (byte)vals;
for (i = 0; i < vals; i++)
{
header[i + 27] = (byte)lacing_vals[i];
bytes += (header[i + 27] & 0xff);
}
/* set pointers in the ogg_page struct */
og.header_base = header;
og.header = 0;
og.header_len = header_fill = vals + 27;
og.body_base = body_data;
og.body = body_returned;
og.body_len = bytes;
/* advance the lacing data and set the body_returned pointer */
lacing_fill -= vals;
Array.Copy(lacing_vals, vals, lacing_vals, 0, lacing_fill * 4);
Array.Copy(granule_vals, vals, granule_vals, 0, lacing_fill * 8);
body_returned += bytes;
/* calculate the checksum */
og.checksum();
/* done */
return(1);
}
