public void seek_helper(long offst, VorbisFileInstance instance)
{
//callbacks.seek_func(datasource, offst, SEEK_SET);
fseek(datasource, offst, SEEK_SET);
this.offset = offst;
instance.oy.reset();
}
int open_seekable()
{
VorbisFileInstance instance = makeInstance();
Info initial_i = new Info();
Comment initial_c = new Comment();
int serialno;
long end;
int ret;
int dataoffset;
Page og = new Page();
// is this even vorbis...?
int[] foo = new int[1];
ret = fetch_headers(initial_i, initial_c, foo, null, instance);
serialno = foo[0];
dataoffset = (int)offset; //!!
instance.os.clear();
if (ret == -1)
{
return(-1);
}
// we can seek, so set out learning all about this file
skable = true;
//(callbacks.seek_func)(datasource, 0, SEEK_END);
fseek(datasource, 0, SEEK_END);
//offset=end=(callbacks.tell_func)(datasource);
offset = ftell(datasource);
end = offset;
// We get the offset for the last page of the physical bitstream.
// Most OggVorbis files will contain a single logical bitstream
end = get_prev_page(og, instance);
// moer than one logical bitstream?
if (og.serialno() != serialno)
{
// Chained bitstream. Bisect-search each logical bitstream
// section. Do so based on serial number only
if (bisect_forward_serialno(0, 0, end + 1, serialno, 0, instance) < 0)
{
clear();
return(OV_EREAD);
}
}
else
{
// Only one logical bitstream
if (bisect_forward_serialno(0, end, end + 1, serialno, 0, instance) < 0)
{
clear();
return(OV_EREAD);
}
}
prefetch_all_headers(initial_i, initial_c, dataoffset, instance);
//return(raw_seek(0));
return(0);
}
public int get_next_page(Page page, long boundary, VorbisFileInstance instance)
{
if (boundary > 0)
{
boundary += offset;
}
while (true)
{
int more;
if (boundary > 0 && offset >= boundary)
{
return(OV_FALSE);
}
more = instance.oy.pageseek(page);
if (more < 0)
{
offset -= more;
}
else
{
if (more == 0)
{
if (boundary == 0)
{
return(OV_FALSE);
}
// if(get_data()<=0)return -1;
int ret = get_data(instance);
if (ret == 0)
{
return(OV_EOF);
}
if (ret < 0)
{
return(OV_EREAD);
}
}
else
{
int ret = (int)offset; //!!!
offset += more;
return(ret);
}
}
}
}
private int get_prev_page(Page page, VorbisFileInstance instance)
{
long begin = offset; //!!!
int ret;
int offst = -1;
while (offst == -1)
{
begin -= CHUNKSIZE;
if (begin < 0)
{
begin = 0;
}
seek_helper(begin, instance);
while (offset < begin + CHUNKSIZE)
{
ret = get_next_page(page, begin + CHUNKSIZE - offset, instance);
if (ret == OV_EREAD)
{
return(OV_EREAD);
}
if (ret < 0)
{
break;
}
else
{
offst = ret;
}
}
}
seek_helper(offst, instance); //!!!
ret = get_next_page(page, CHUNKSIZE, instance);
if (ret < 0)
{
//System.err.println("Missed page fencepost at end of logical bitstream Exiting");
//System.exit(1);
return(OV_EFAULT);
}
return(offst);
}
public int get_data(VorbisFileInstance instance)
{
int index = instance.oy.buffer(CHUNKSIZE);
byte[] buffer = instance.oy.data;
// int bytes=callbacks.read_func(buffer, index, 1, CHUNKSIZE, datasource);
int bytes = 0;
try
{
bytes = datasource.Read(buffer, index, CHUNKSIZE);
}
catch (Exception e)
{
Console.Error.WriteLine(e.Message);
return(OV_EREAD);
}
instance.oy.wrote(bytes);
if (bytes == -1)
{
bytes = 0;
}
return(bytes);
}
public VorbisFileInstance makeInstance()
{
VorbisFileInstance instance = new VorbisFileInstance(this);
return(instance);
}
// last step of the OggVorbis_File initialization; get all the
// vorbis_info structs and PCM positions. Only called by the seekable
// initialization (local stream storage is hacked slightly; pay
// attention to how that's done)
public void prefetch_all_headers(Info first_i, Comment first_c, int dataoffset,
VorbisFileInstance instance)
{
Page og = new Page();
int ret;
vi = new Info[links];
vc = new Comment[links];
dataoffsets = new long[links];
pcmlengths = new long[links];
serialnos = new int[links];
for (int i = 0; i < links; i++)
{
if (first_i != null && first_c != null && i == 0)
{
// we already grabbed the initial header earlier. This just
// saves the waste of grabbing it again
// !!!!!!!!!!!!!
vi[i] = first_i;
//memcpy(vf->vi+i,first_i,sizeof(vorbis_info));
vc[i] = first_c;
//memcpy(vf->vc+i,first_c,sizeof(vorbis_comment));
dataoffsets[i] = dataoffset;
}
else
{
// seek to the location of the initial header
seek_helper(offsets[i], instance); //!!!
if (fetch_headers(vi[i], vc[i], null, null, instance) == -1)
{
Console.Error.WriteLine("Error opening logical bitstream #" + (i + 1) + "\n");
dataoffsets[i] = -1;
}
else
{
dataoffsets[i] = offset;
instance.os.clear();
}
}
// get the serial number and PCM length of this link. To do this,
// get the last page of the stream
long end = offsets[i + 1]; //!!!
seek_helper(end, instance);
while (true)
{
ret = get_prev_page(og, instance);
if (ret == -1)
{
// this should not be possible
Console.Error.WriteLine("Could not find last page of logical " +
"bitstream #" + (i) + "\n");
vi[i].clear();
vc[i].clear();
break;
}
if (og.granulepos() != -1)
{
serialnos[i] = og.serialno();
pcmlengths[i] = og.granulepos();
break;
}
}
}
}
// uses the local ogg_stream storage in vf; this is important for
// non-streaming input sources
public int fetch_headers(Info vi, Comment vc, int[] serialno, Page og_ptr, VorbisFileInstance instance)
{
//System.err.println("fetch_headers");
Page og = new Page();
Packet op = new Packet();
int ret;
if (og_ptr == null)
{
ret = get_next_page(og, CHUNKSIZE, instance);
if (ret == OV_EREAD)
{
return(OV_EREAD);
}
if (ret < 0)
{
return(OV_ENOTVORBIS);
}
og_ptr = og;
}
if (serialno != null)
{
serialno[0] = og_ptr.serialno();
}
instance.os.init(og_ptr.serialno());
// extract the initial header from the first page and verify that the
// Ogg bitstream is in fact Vorbis data
vi.init();
vc.init();
int i = 0;
while (i < 3)
{
instance.os.pagein(og_ptr);
while (i < 3)
{
int result = instance.os.packetout(op);
if (result == 0)
{
break;
}
if (result == -1)
{
Console.Error.WriteLine("Corrupt header in logical bitstream.");
//goto bail_header;
vi.clear();
vc.clear();
instance.os.clear();
return(-1);
}
if (vi.synthesis_headerin(vc, op) != 0)
{
Console.Error.WriteLine("Illegal header in logical bitstream.");
//goto bail_header;
vi.clear();
vc.clear();
instance.os.clear();
return(-1);
}
i++;
}
if (i < 3)
{
if (get_next_page(og_ptr, 1, instance) < 0)
{
Console.Error.WriteLine("Missing header in logical bitstream.");
//goto bail_header;
vi.clear();
vc.clear();
instance.os.clear();
return(-1);
}
}
}
return(0);
}
public int bisect_forward_serialno(long begin, long searched, long end, int currentno, int m, VorbisFileInstance instance)
{
long endsearched = end;
long next = end;
Page page = new Page();
int ret;
while (searched < endsearched)
{
long bisect;
if (endsearched - searched < CHUNKSIZE)
{
bisect = searched;
}
else
{
bisect = (searched + endsearched) / 2;
}
seek_helper(bisect, instance);
ret = get_next_page(page, -1, instance);
if (ret == OV_EREAD)
{
return(OV_EREAD);
}
if (ret < 0 || page.serialno() != currentno)
{
endsearched = bisect;
if (ret >= 0)
{
next = ret;
}
}
else
{
searched = ret + page.header_len + page.body_len;
}
}
seek_helper(next, instance);
ret = get_next_page(page, -1, instance);
if (ret == OV_EREAD)
{
return(OV_EREAD);
}
if (searched >= end || ret == -1)
{
links = m + 1;
offsets = new long[m + 2];
offsets[m + 1] = searched;
}
else
{
ret = bisect_forward_serialno(next, offset, end, page.serialno(), m + 1, instance);
if (ret == OV_EREAD)
{
return(OV_EREAD);
}
}
offsets[m] = begin;
return(0);
}
