public int header_out(Packet op)
{
csBuffer opb=new csBuffer();
opb.writeinit();
if(pack(opb)!=0) { return OV_EIMPL; }
op.packet_base = new byte[opb.bytes()];
op.packet=0;
op.bytes=opb.bytes();
Array.Copy(opb.buf(), 0, op.packet_base, 0, op.bytes);
op.b_o_s=0;
op.e_o_s=0;
op.granulepos=0;
return 0;
}
// The Vorbis header is in three packets; the initial small packet in
// the first page that identifies basic parameters, a second packet
// with bitstream comments and a third packet that holds the
// codebook.
public int synthesis_headerin(Comment vc, Packet op)
{
csBuffer opb=new csBuffer();
if(op!=null) {
opb.readinit(op.packet_base, op.packet, op.bytes);
// Which of the three types of header is this?
// Also verify header-ness, vorbis
{
byte[] buffer=new byte[6];
int packtype=opb.read(8);
//memset(buffer,0,6);
opb.read(buffer,6);
if(buffer[0]!='v' || buffer[1]!='o' || buffer[2]!='r' ||
buffer[3]!='b' || buffer[4]!='i' || buffer[5]!='s') {
// not a vorbis header
return(-1);
}
switch(packtype) {
case 0x01: // least significant *bit* is read first
if(op.b_o_s==0) {
// Not the initial packet
return(-1);
}
if(rate!=0) {
// previously initialized info header
return(-1);
}
return(unpack_info(opb));
case 0x03: // least significant *bit* is read first
if(rate==0) {
// um... we didn't get the initial header
return(-1);
}
return(vc.unpack(opb));
case 0x05: // least significant *bit* is read first
if(rate==0 || vc.vendor==null) {
// um... we didn;t get the initial header or comments yet
return(-1);
}
return(unpack_books(opb));
default:
// Not a valid vorbis header type
//return(-1);
break;
}
}
}
return(-1);
}
// static void v_writestring(csBuffer o, byte[] s){
// int i=0;
// while(s[i]!=0){
// o.write(s[i++],8);
// }
// }
// static void v_readstring(csBuffer o, byte[] buf, int bytes){
// int i=0
// while(bytes--!=0){
// buf[i++]=o.read(8);
// }
// }
// private csBuffer opb_blocksize=new csBuffer();
public int blocksize(Packet op)
{
//codec_setup_info *ci=vi->codec_setup;
csBuffer opb=new csBuffer();
// synchronized(opb_blocksize){
int mode;
opb.readinit(op.packet_base, op.packet, op.bytes);
/* Check the packet type */
if(opb.read(1)!=0) {
/* Oops. This is not an audio data packet */
return(OV_ENOTAUDIO);
}
{
int modebits=0;
int v=modes;
while(v>1) {
modebits++;
v = (int)((uint)v >> 1);
}
/* read our mode and pre/post windowsize */
mode=opb.read(modebits);
}
if(mode==-1) { return(OV_EBADPACKET); }
return(blocksizes[mode_param[mode].blockflag]);
// }
}
public int synthesis(Packet op)
{
Info vi=vd.vi;
// first things first. Make sure decode is ready
// ripcord();
opb.readinit(op.packet_base, op.packet, op.bytes);
// Check the packet type
if(opb.read(1)!=0)
{
// Oops. This is not an audio data packet
return(-1);
}
// read our mode and pre/post windowsize
int _mode=opb.read(vd.modebits);
if(_mode==-1)return(-1);
mode=_mode;
W=vi.mode_param[mode].blockflag;
if(W!=0)
{
lW=opb.read(1);
nW=opb.read(1);
if(nW==-1) return(-1);
}
else
{
lW=0;
nW=0;
}
// more setup
granulepos=op.granulepos;
sequence=op.packetno-3; // first block is third packet
eofflag=op.e_o_s;
// alloc pcm passback storage
pcmend=vi.blocksizes[W];
//pcm=alloc(vi.channels);
if(pcm.Length<vi.channels)
{
pcm=new float[vi.channels][];
}
for(int i=0;i<vi.channels;i++)
{
if(pcm[i]==null || pcm[i].Length<pcmend)
{
pcm[i]=new float[pcmend];
//pcm[i]=alloc(pcmend);
}
else
{
for(int j=0;j<pcmend;j++){ pcm[i][j]=0; }
}
}
// unpack_header enforces range checking
int type=vi.map_type[vi.mode_param[mode].mapping];
return(FuncMapping.mapping_P[type].inverse(this, vd.mode[mode]));
}
// 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);
}
}
public int packetout(Packet op)
{
/* The last part of decode. We have the stream broken into packet
segments. Now we need to group them into packets (or return the
out of sync markers) */
int ptr=lacing_returned;
if(lacing_packet<=ptr)
{
return(0);
}
if((lacing_vals[ptr]&0x400)!=0)
{
/* We lost sync here; let the app know */
lacing_returned++;
/* we need to tell the codec there's a gap; it might need to
handle previous packet dependencies. */
packetno++;
return(-1);
}
/* Gather the whole packet. We'll have no holes or a partial packet */
{
int size=lacing_vals[ptr]&0xff;
int bytes=0;
op.packet_base=body_data;
op.packet=body_returned;
op.e_o_s=lacing_vals[ptr]&0x200; /* last packet of the stream? */
op.b_o_s=lacing_vals[ptr]&0x100; /* first packet of the stream? */
bytes+=size;
while(size==255)
{
int val=lacing_vals[++ptr];
size=val&0xff;
if((val&0x200)!=0)op.e_o_s=0x200;
bytes+=size;
}
op.packetno=packetno;
op.granulepos=granule_vals[ptr];
op.bytes=bytes;
//System.out.println(this+" # body_returned="+body_returned);
body_returned+=bytes;
//System.out.println(this+"## body_returned="+body_returned);
lacing_returned=ptr+1;
}
packetno++;
return(1);
}
/* submit data to the internal buffer of the framing engine */
public int packetin(Packet op)
{
int lacing_val=op.bytes/255+1;
if(body_returned!=0)
{
/* advance packet data according to the body_returned pointer. We
had to keep it around to return a pointer into the buffer last
call */
body_fill-=body_returned;
if(body_fill!=0)
{
Array.Copy(body_data, body_returned, body_data, 0, body_fill);
}
body_returned=0;
}
/* make sure we have the buffer storage */
body_expand(op.bytes);
lacing_expand(lacing_val);
/* Copy in the submitted packet. Yes, the copy is a waste; this is
the liability of overly clean abstraction for the time being. It
will actually be fairly easy to eliminate the extra copy in the
future */
Array.Copy(op.packet_base, op.packet, body_data, body_fill, op.bytes);
body_fill+=op.bytes;
//System.out.println("add: "+body_fill);
/* Store lacing vals for this packet */
int j;
for(j=0;j<lacing_val-1;j++)
{
lacing_vals[lacing_fill+j]=255;
granule_vals[lacing_fill+j]=granulepos;
}
lacing_vals[lacing_fill+j]=(op.bytes)%255;
granulepos=granule_vals[lacing_fill+j]=op.granulepos;
/* flag the first segment as the beginning of the packet */
lacing_vals[lacing_fill]|= 0x100;
lacing_fill+=lacing_val;
/* for the sake of completeness */
packetno++;
if(op.e_o_s!=0)e_o_s=1;
return(0);
}