// sync the stream and get a page. Keep trying until we find a page.
// Supress 'sync errors' after reporting the first.
//
// return values:
// -1) recapture (hole in data)
// 0) need more data
// 1) page returned
//
// Returns pointers into buffered data; invalidated by next call to
// _stream, _clear, _init, or _buffer
public int pageout(Page og)
{
// all we need to do is verify a page at the head of the stream
// buffer. If it doesn't verify, we look for the next potential
// frame
while(true) {
int ret=pageseek(og);
if(ret>0) {
// have a page
return(1);
}
if(ret==0) {
// need more data
return(0);
}
// head did not start a synced page... skipped some bytes
if(unsynced==0) {
unsynced=1;
return(-1);
}
// loop. keep looking
}
}
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);
}
// headerbytes=0;
// bodybytes=0;
// next=0;
// for(int ii=0; ii<bytes-1; ii++){
// if(data[page+1+ii]=='O'){next=page+1+ii;}
// }
// //next=memchr(page+1,'O',bytes-1);
// if(next==0) next=fill;
// returned=next;
// return(-(next-page));
}
private int get_next_page(Page page, long boundary)
{
if(boundary>0) { boundary+=offset; }
while(true) {
int more;
if(boundary>0 && offset>=boundary) { return OV_FALSE; }
more=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();
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)
{
long begin=offset; //!!!
int ret;
int offst=-1;
while(offst==-1) {
begin-=CHUNKSIZE;
if(begin<0) {
begin=0;
}
seek_helper(begin);
while(offset<begin+CHUNKSIZE) {
ret=get_next_page(page, begin+CHUNKSIZE-offset);
if(ret==OV_EREAD) { return OV_EREAD; }
if(ret<0) { break; }
else { offst=ret; }
}
}
seek_helper(offst); //!!!
ret=get_next_page(page, CHUNKSIZE);
if(ret<0) {
//System.err.println("Missed page fencepost at end of logical bitstream Exiting");
//System.exit(1);
return OV_EFAULT;
}
return offst;
}
int bisect_forward_serialno(long begin, long searched, long end, int currentno, int m)
{
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);
ret=get_next_page(page, -1);
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);
ret=get_next_page(page, -1);
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);
if(ret==OV_EREAD) { return OV_EREAD; }
}
offsets[m]=begin;
return 0;
}
// uses the local ogg_stream storage in vf; this is important for
// non-streaming input sources
int fetch_headers(Info vi, Comment vc, int[] serialno, Page og_ptr)
{
//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);
if(ret==OV_EREAD) { return OV_EREAD; }
if(ret<0) { return OV_ENOTVORBIS; }
og_ptr=og;
}
if(serialno!=null) { serialno[0]=og_ptr.serialno(); }
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) {
os.pagein(og_ptr);
while(i<3) {
int result=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();
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();
os.clear();
return -1;
}
i++;
}
if(i<3)
if(get_next_page(og_ptr, 1)<0) {
Console.Error.WriteLine("Missing header in logical bitstream.");
//goto bail_header;
vi.clear();
vc.clear();
os.clear();
return -1;
}
}
return 0;
}
// fetch and process a packet. Handles the case where we're at a
// bitstream boundary and dumps the decoding machine. If the decoding
// machine is unloaded, it loads it. It also keeps pcm_offset up to
// date (seek and read both use this. seek uses a special hack with
// readp).
//
// return: -1) hole in the data (lost packet)
// 0) need more date (only if readp==0)/eof
// 1) got a packet
int process_packet(int readp)
{
Page og=new Page();
// handle one packet. Try to fetch it from current stream state
// extract packets from page
while(true) {
// process a packet if we can. If the machine isn't loaded,
// neither is a page
if(decode_ready) {
Packet op=new Packet();
int result=os.packetout(op);
long granulepos;
// if(result==-1)return(-1); // hole in the data. For now, swallow
// and go. We'll need to add a real
// error code in a bit.
if(result>0) {
// got a packet. process it
granulepos=op.granulepos;
if(vb.synthesis(op)==0) {
// lazy check for lazy
// header handling. The
// header packets aren't
// audio, so if/when we
// submit them,
// vorbis_synthesis will
// reject them
// suck in the synthesis data and track bitrate
{
int oldsamples=vd.synthesis_pcmout(null, null);
vd.synthesis_blockin(vb);
samptrack+=vd.synthesis_pcmout(null, null)-oldsamples;
bittrack+=op.bytes*8;
}
// update the pcm offset.
if(granulepos!=-1 && op.e_o_s==0) {
int link=(skable?current_link:0);
int samples;
// this packet has a pcm_offset on it (the last packet
// completed on a page carries the offset) After processing
// (above), we know the pcm position of the *last* sample
// ready to be returned. Find the offset of the *first*
//
// As an aside, this trick is inaccurate if we begin
// reading anew right at the last page; the end-of-stream
// granulepos declares the last frame in the stream, and the
// last packet of the last page may be a partial frame.
// So, we need a previous granulepos from an in-sequence page
// to have a reference point. Thus the !op.e_o_s clause above
samples=vd.synthesis_pcmout(null, null);
granulepos-=samples;
for(int i=0; i<link; i++) {
granulepos+=pcmlengths[i];
}
pcm_offset=granulepos;
}
return(1);
}
}
}
if(readp==0) { return(0); }
if(get_next_page(og,-1)<0) { return(0); } // eof. leave unitialized
// bitrate tracking; add the header's bytes here, the body bytes
// are done by packet above
bittrack+=og.header_len*8;
// has our decoding just traversed a bitstream boundary?
if(decode_ready) {
if(current_serialno!=og.serialno()) {
decode_clear();
}
}
// Do we need to load a new machine before submitting the page?
// This is different in the seekable and non-seekable cases.
//
// In the seekable case, we already have all the header
// information loaded and cached; we just initialize the machine
// with it and continue on our merry way.
//
// In the non-seekable (streaming) case, we'll only be at a
// boundary if we just left the previous logical bitstream and
// we're now nominally at the header of the next bitstream
if(!decode_ready) {
int i;
if(skable) {
current_serialno=og.serialno();
// match the serialno to bitstream section. We use this rather than
// offset positions to avoid problems near logical bitstream
// boundaries
for(i=0; i<links; i++) {
if(serialnos[i]==current_serialno) { break; }
}
if(i==links) { return(-1); } // sign of a bogus stream. error out,
// leave machine uninitialized
current_link=i;
os.init(current_serialno);
os.reset();
}
else {
// we're streaming
// fetch the three header packets, build the info struct
int[] foo = new int[1];
int ret=fetch_headers(vi[0], vc[0], foo, og);
current_serialno=foo[0];
if(ret!=0) { return ret; }
current_link++;
i=0;
}
make_decode_ready();
}
os.pagein(og);
}
}
// seek to a sample offset relative to the decompressed pcm stream
// returns zero on success, nonzero on failure
public int pcm_seek(long pos)
{
int link=-1;
long total=pcm_total(-1);
if(!skable) { return(-1); } // don't dump machine if we can't seek
if(pos<0 || pos>total) {
//goto seek_error;
pcm_offset=-1;
decode_clear();
return -1;
}
// which bitstream section does this pcm offset occur in?
for(link=links-1; link>=0; link--) {
total-=pcmlengths[link];
if(pos>=total) { break; }
}
// search within the logical bitstream for the page with the highest
// pcm_pos preceeding (or equal to) pos. There is a danger here;
// missing pages or incorrect frame number information in the
// bitstream could make our task impossible. Account for that (it
// would be an error condition)
{
long target=pos-total;
long end=offsets[link+1];
long begin=offsets[link];
int best=(int)begin;
Page og=new Page();
while(begin<end) {
long bisect;
int ret;
if(end-begin<CHUNKSIZE) {
bisect=begin;
}
else {
bisect=(end+begin)/2;
}
seek_helper(bisect);
ret=get_next_page(og,end-bisect);
if(ret==-1) {
end=bisect;
}
else {
long granulepos=og.granulepos();
if(granulepos<target) {
best=ret; // raw offset of packet with granulepos
begin=offset; // raw offset of next packet
}
else {
end=bisect;
}
}
}
// found our page. seek to it (call raw_seek).
if(raw_seek(best)!=0) {
//goto seek_error;
pcm_offset=-1;
decode_clear();
return -1;
}
}
// verify result
if(pcm_offset>=pos) {
//goto seek_error;
pcm_offset=-1;
decode_clear();
return -1;
}
if(pos>pcm_total(-1)) {
//goto seek_error;
pcm_offset=-1;
decode_clear();
return -1;
}
// discard samples until we reach the desired position. Crossing a
// logical bitstream boundary with abandon is OK.
while(pcm_offset<pos) {
float[][] pcm;
int target=(int)(pos-pcm_offset);
float[][][] _pcm=new float[1][][];
int[] _index=new int[getInfo(-1).channels];
int samples=vd.synthesis_pcmout(_pcm, _index);
pcm=_pcm[0];
if(samples>target) { samples=target; }
vd.synthesis_read(samples);
pcm_offset+=samples;
if(samples<target)
if(process_packet(1)==0) {
pcm_offset=pcm_total(-1); // eof
}
}
return 0;
// seek_error:
// dump machine so we're in a known state
//pcm_offset=-1;
//decode_clear();
//return -1;
}
// 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)
void prefetch_all_headers(Info first_i,Comment first_c, int dataoffset)
{
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]); //!!!
if(fetch_headers(vi[i], vc[i], null, null)==-1) {
Console.Error.WriteLine("Error opening logical bitstream #"+(i+1)+"\n");
dataoffsets[i]=-1;
}
else {
dataoffsets[i]=offset;
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);
while(true) {
ret=get_prev_page(og);
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;
}
}
}
}
int open_seekable()
{
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);
serialno=foo[0];
dataoffset=(int)offset; //!!
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);
// 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)<0) {
clear();
return OV_EREAD;
}
}
else {
// Only one logical bitstream
if(bisect_forward_serialno(0,end,end+1,serialno,0)<0) {
clear();
return OV_EREAD;
}
}
prefetch_all_headers(initial_i, initial_c, dataoffset);
return(raw_seek(0));
}
/* This constructs pages from buffered packet segments. The pointers
returned are to static buffers; do not free. The returned buffers are
good only until the next call (using the same ogg_stream_state) */
public int pageout(Page og)
{
if((e_o_s!=0&&lacing_fill!=0) || /* 'were done, now flush' case */
body_fill-body_returned> 4096 || /* 'page nominal size' case */
lacing_fill>=255 || /* 'segment table full' case */
(lacing_fill!=0&&b_o_s==0))
{ /* 'initial header page' case */
return flush(og);
}
return 0;
}
/* 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);
}
// add the incoming page to the stream state; we decompose the page
// into packet segments here as well.
public int pagein(Page og)
{
byte[] header_base=og.header_base;
int header=og.header;
byte[] body_base=og.body_base;
int body=og.body;
int bodysize=og.body_len;
int segptr=0;
int version=og.version();
int continued=og.continued();
int bos=og.bos();
int eos=og.eos();
long granulepos=og.granulepos();
int _serialno=og.serialno();
int _pageno=og.pageno();
int segments=header_base[header+26]&0xff;
// clean up 'returned data'
{
int lr=lacing_returned;
int br=body_returned;
// body data
//System.out.println("br="+br+", body_fill="+body_fill);
if(br!=0)
{
body_fill-=br;
if(body_fill!=0)
{
Array.Copy(body_data, br, body_data, 0, body_fill);
}
body_returned=0;
}
//System.out.println("?? br="+br+", body_fill="+body_fill+" body_returned="+body_returned);
if(lr!=0)
{
// segment table
if((lacing_fill-lr)!=0)
{
Array.Copy(lacing_vals, lr, lacing_vals, 0, lacing_fill-lr);
Array.Copy(granule_vals, lr, granule_vals, 0, lacing_fill-lr);
}
lacing_fill-=lr;
lacing_packet-=lr;
lacing_returned=0;
}
}
// check the serial number
if(_serialno!=serialno)return(-1);
if(version>0)return(-1);
lacing_expand(segments+1);
// are we in sequence?
if(_pageno!=pageno)
{
int i;
// unroll previous partial packet (if any)
for(i=lacing_packet;i<lacing_fill;i++)
{
body_fill-=lacing_vals[i]&0xff;
//System.out.println("??");
}
lacing_fill=lacing_packet;
// make a note of dropped data in segment table
if(pageno!=-1)
{
lacing_vals[lacing_fill++]=0x400;
lacing_packet++;
}
// are we a 'continued packet' page? If so, we'll need to skip
// some segments
if(continued!=0)
{
bos=0;
for(;segptr<segments;segptr++)
{
int val=(header_base[header+27+segptr]&0xff);
body+=val;
bodysize-=val;
if(val<255)
{
segptr++;
break;
}
}
}
}
//System.out.println("bodysize="+bodysize);
if(bodysize!=0)
{
body_expand(bodysize);
Array.Copy(body_base, body, body_data, body_fill, bodysize);
body_fill+=bodysize;
}
//System.out.println("bodyfill="+body_fill);
{
int saved=-1;
while(segptr<segments)
{
int val=(header_base[header+27+segptr]&0xff);
lacing_vals[lacing_fill]=val;
granule_vals[lacing_fill]=-1;
if(bos!=0)
{
lacing_vals[lacing_fill]|=0x100;
bos=0;
}
if(val<255)saved=lacing_fill;
lacing_fill++;
segptr++;
if(val<255)lacing_packet=lacing_fill;
}
/* set the granulepos on the last pcmval of the last full packet */
if(saved!=-1)
{
granule_vals[saved]=granulepos;
}
}
if(eos!=0)
{
e_o_s=1;
if(lacing_fill>0)
lacing_vals[lacing_fill-1]|=0x200;
}
pageno=_pageno+1;
return(0);
}
