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godot/drivers/theora/tokenize.c

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GODOT IS OPEN SOURCE
2014-02-10 01:10:30 +00:00
/********************************************************************
* *
* THIS FILE IS PART OF THE OggTheora SOFTWARE CODEC SOURCE CODE. *
* USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
* GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
* IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
* *
* THE Theora SOURCE CODE IS COPYRIGHT (C) 2002-2009 *
* by the Xiph.Org Foundation http://www.xiph.org/ *
* *
********************************************************************
function:
last mod: $Id: tokenize.c 16503 2009-08-22 18:14:02Z giles $
********************************************************************/
#include <stdlib.h>
#include <string.h>
#include "encint.h"
static int oc_make_eob_token(int _run_count){
if(_run_count<4)return OC_DCT_EOB1_TOKEN+_run_count-1;
else{
int cat;
cat=OC_ILOGNZ_32(_run_count)-3;
cat=OC_MINI(cat,3);
return OC_DCT_REPEAT_RUN0_TOKEN+cat;
}
}
static int oc_make_eob_token_full(int _run_count,int *_eb){
if(_run_count<4){
*_eb=0;
return OC_DCT_EOB1_TOKEN+_run_count-1;
}
else{
int cat;
cat=OC_ILOGNZ_32(_run_count)-3;
cat=OC_MINI(cat,3);
*_eb=_run_count-OC_BYTE_TABLE32(4,8,16,0,cat);
return OC_DCT_REPEAT_RUN0_TOKEN+cat;
}
}
/*Returns the number of blocks ended by an EOB token.*/
static int oc_decode_eob_token(int _token,int _eb){
return (0x20820C41U>>_token*5&0x1F)+_eb;
}
/*TODO: This is now only used during DCT tokenization, and never for runs; it
should be simplified.*/
static int oc_make_dct_token_full(int _zzi,int _zzj,int _val,int *_eb){
int neg;
int zero_run;
int token;
int eb;
neg=_val<0;
_val=abs(_val);
zero_run=_zzj-_zzi;
if(zero_run>0){
int adj;
/*Implement a minor restriction on stack 1 so that we know during DC fixups
that extending a dctrun token from stack 1 will never overflow.*/
adj=_zzi!=1;
if(_val<2&&zero_run<17+adj){
if(zero_run<6){
token=OC_DCT_RUN_CAT1A+zero_run-1;
eb=neg;
}
else if(zero_run<10){
token=OC_DCT_RUN_CAT1B;
eb=zero_run-6+(neg<<2);
}
else{
token=OC_DCT_RUN_CAT1C;
eb=zero_run-10+(neg<<3);
}
}
else if(_val<4&&zero_run<3+adj){
if(zero_run<2){
token=OC_DCT_RUN_CAT2A;
eb=_val-2+(neg<<1);
}
else{
token=OC_DCT_RUN_CAT2B;
eb=zero_run-2+(_val-2<<1)+(neg<<2);
}
}
else{
if(zero_run<9)token=OC_DCT_SHORT_ZRL_TOKEN;
else token=OC_DCT_ZRL_TOKEN;
eb=zero_run-1;
}
}
else if(_val<3){
token=OC_ONE_TOKEN+(_val-1<<1)+neg;
eb=0;
}
else if(_val<7){
token=OC_DCT_VAL_CAT2+_val-3;
eb=neg;
}
else if(_val<9){
token=OC_DCT_VAL_CAT3;
eb=_val-7+(neg<<1);
}
else if(_val<13){
token=OC_DCT_VAL_CAT4;
eb=_val-9+(neg<<2);
}
else if(_val<21){
token=OC_DCT_VAL_CAT5;
eb=_val-13+(neg<<3);
}
else if(_val<37){
token=OC_DCT_VAL_CAT6;
eb=_val-21+(neg<<4);
}
else if(_val<69){
token=OC_DCT_VAL_CAT7;
eb=_val-37+(neg<<5);
}
else{
token=OC_DCT_VAL_CAT8;
eb=_val-69+(neg<<9);
}
*_eb=eb;
return token;
}
/*Token logging to allow a few fragments of efficient rollback.
Late SKIP analysis is tied up in the tokenization process, so we need to be
able to undo a fragment's tokens on a whim.*/
static const unsigned char OC_ZZI_HUFF_OFFSET[64]={
0,16,16,16,16,16,32,32,
32,32,32,32,32,32,32,48,
48,48,48,48,48,48,48,48,
48,48,48,48,64,64,64,64,
64,64,64,64,64,64,64,64,
64,64,64,64,64,64,64,64,
64,64,64,64,64,64,64,64
};
static int oc_token_bits(oc_enc_ctx *_enc,int _huffi,int _zzi,int _token){
return _enc->huff_codes[_huffi+OC_ZZI_HUFF_OFFSET[_zzi]][_token].nbits
+OC_DCT_TOKEN_EXTRA_BITS[_token];
}
static void oc_enc_tokenlog_checkpoint(oc_enc_ctx *_enc,
oc_token_checkpoint *_cp,int _pli,int _zzi){
_cp->pli=_pli;
_cp->zzi=_zzi;
_cp->eob_run=_enc->eob_run[_pli][_zzi];
_cp->ndct_tokens=_enc->ndct_tokens[_pli][_zzi];
}
void oc_enc_tokenlog_rollback(oc_enc_ctx *_enc,
const oc_token_checkpoint *_stack,int _n){
int i;
for(i=_n;i-->0;){
int pli;
int zzi;
pli=_stack[i].pli;
zzi=_stack[i].zzi;
_enc->eob_run[pli][zzi]=_stack[i].eob_run;
_enc->ndct_tokens[pli][zzi]=_stack[i].ndct_tokens;
}
}
static void oc_enc_token_log(oc_enc_ctx *_enc,
int _pli,int _zzi,int _token,int _eb){
ptrdiff_t ti;
ti=_enc->ndct_tokens[_pli][_zzi]++;
_enc->dct_tokens[_pli][_zzi][ti]=(unsigned char)_token;
_enc->extra_bits[_pli][_zzi][ti]=(ogg_uint16_t)_eb;
}
static void oc_enc_eob_log(oc_enc_ctx *_enc,
int _pli,int _zzi,int _run_count){
int token;
int eb;
token=oc_make_eob_token_full(_run_count,&eb);
oc_enc_token_log(_enc,_pli,_zzi,token,eb);
}
void oc_enc_tokenize_start(oc_enc_ctx *_enc){
memset(_enc->ndct_tokens,0,sizeof(_enc->ndct_tokens));
memset(_enc->eob_run,0,sizeof(_enc->eob_run));
memset(_enc->dct_token_offs,0,sizeof(_enc->dct_token_offs));
memset(_enc->dc_pred_last,0,sizeof(_enc->dc_pred_last));
}
typedef struct oc_quant_token oc_quant_token;
/*A single node in the Viterbi trellis.
We maintain up to 2 of these per coefficient:
- A token to code if the value is zero (EOB, zero run, or combo token).
- A token to code if the value is not zero (DCT value token).*/
struct oc_quant_token{
unsigned char next;
signed char token;
ogg_int16_t eb;
ogg_uint32_t cost;
int bits;
int qc;
};
/*Tokenizes the AC coefficients, possibly adjusting the quantization, and then
dequantizes and de-zig-zags the result.
The DC coefficient is not preserved; it should be restored by the caller.*/
int oc_enc_tokenize_ac(oc_enc_ctx *_enc,int _pli,ptrdiff_t _fragi,
ogg_int16_t *_qdct,const ogg_uint16_t *_dequant,const ogg_int16_t *_dct,
int _zzi,oc_token_checkpoint **_stack,int _acmin){
oc_token_checkpoint *stack;
ogg_int64_t zflags;
ogg_int64_t nzflags;
ogg_int64_t best_flags;
ogg_uint32_t d2_accum[64];
oc_quant_token tokens[64][2];
ogg_uint16_t *eob_run;
const unsigned char *dct_fzig_zag;
ogg_uint32_t cost;
int bits;
int eob;
int token;
int eb;
int next;
int huffi;
int zzi;
int ti;
int zzj;
int qc;
huffi=_enc->huff_idxs[_enc->state.frame_type][1][_pli+1>>1];
eob_run=_enc->eob_run[_pli];
memset(tokens[0],0,sizeof(tokens[0]));
best_flags=nzflags=0;
zflags=1;
d2_accum[0]=0;
zzj=64;
for(zzi=OC_MINI(_zzi,63);zzi>0;zzi--){
ogg_int32_t lambda;
ogg_uint32_t best_cost;
int best_bits=best_bits;
int best_next=best_next;
int best_token=best_token;
int best_eb=best_eb;
int best_qc=best_qc;
int flush_bits;
ogg_uint32_t d2;
int dq;
int e;
int c;
int s;
int tj;
lambda=_enc->lambda;
qc=_qdct[zzi];
s=-(qc<0);
qc=qc+s^s;
c=_dct[OC_FZIG_ZAG[zzi]];
if(qc<=1){
ogg_uint32_t sum_d2;
int nzeros;
int dc_reserve;
/*The hard case: try a zero run.*/
if(!qc){
/*Skip runs that are already quantized to zeros.
If we considered each zero coefficient in turn, we might
theoretically find a better way to partition long zero runs (e.g.,
a run of > 17 zeros followed by a 1 might be better coded as a short
zero run followed by a combo token, rather than the longer zero
token followed by a 1 value token), but zeros are so common that
this becomes very computationally expensive (quadratic instead of
linear in the number of coefficients), for a marginal gain.*/
while(zzi>1&&!_qdct[zzi-1])zzi--;
/*The distortion of coefficients originally quantized to zero is
treated as zero (since we'll never quantize them to anything else).*/
d2=0;
}
else{
c=c+s^s;
d2=c*(ogg_int32_t)c;
}
eob=eob_run[zzi];
nzeros=zzj-zzi;
zzj&=63;
sum_d2=d2+d2_accum[zzj];
d2_accum[zzi]=sum_d2;
flush_bits=eob>0?oc_token_bits(_enc,huffi,zzi,oc_make_eob_token(eob)):0;
/*We reserve 1 spot for combo run tokens that start in the 1st AC stack
to ensure they can be extended to include the DC coefficient if
necessary; this greatly simplifies stack-rewriting later on.*/
dc_reserve=zzi+62>>6;
best_cost=0xFFFFFFFF;
for(;;){
if(nzflags>>zzj&1){
int cat;
int val;
int val_s;
int zzk;
int tk;
next=tokens[zzj][1].next;
tk=next&1;
zzk=next>>1;
/*Try a pure zero run to this point.*/
cat=nzeros+55>>6;
token=OC_DCT_SHORT_ZRL_TOKEN+cat;
bits=flush_bits+oc_token_bits(_enc,huffi,zzi,token);
d2=sum_d2-d2_accum[zzj];
cost=d2+lambda*bits+tokens[zzj][1].cost;
if(cost<=best_cost){
best_next=(zzj<<1)+1;
best_token=token;
best_eb=nzeros-1;
best_cost=cost;
best_bits=bits+tokens[zzj][1].bits;
best_qc=0;
}
if(nzeros<16+dc_reserve){
val=_qdct[zzj];
val_s=-(val<0);
val=val+val_s^val_s;
if(val<=2){
/*Try a +/- 1 combo token.*/
if(nzeros<6){
token=OC_DCT_RUN_CAT1A+nzeros-1;
eb=-val_s;
}
else{
cat=nzeros+54>>6;
token=OC_DCT_RUN_CAT1B+cat;
eb=(-val_s<<cat+2)+nzeros-6-(cat<<2);
}
e=(_dct[OC_FZIG_ZAG[zzj]]+val_s^val_s)-_dequant[zzj];
d2=e*(ogg_int32_t)e+sum_d2-d2_accum[zzj];
bits=flush_bits+oc_token_bits(_enc,huffi,zzi,token);
cost=d2+lambda*bits+tokens[zzk][tk].cost;
if(cost<=best_cost){
best_next=next;
best_token=token;
best_eb=eb;
best_cost=cost;
best_bits=bits+tokens[zzk][tk].bits;
best_qc=1+val_s^val_s;
}
}
if(nzeros<2+dc_reserve&&2<=val&&val<=4){
/*Try a +/- 2/3 combo token.*/
cat=nzeros>>1;
token=OC_DCT_RUN_CAT2A+cat;
bits=flush_bits+oc_token_bits(_enc,huffi,zzi,token);
val=2+((val+val_s^val_s)>2);
e=(_dct[OC_FZIG_ZAG[zzj]]+val_s^val_s)-_dequant[zzj]*val;
d2=e*(ogg_int32_t)e+sum_d2-d2_accum[zzj];
cost=d2+lambda*bits+tokens[zzk][tk].cost;
if(cost<=best_cost){
best_cost=cost;
best_bits=bits+tokens[zzk][tk].bits;
best_next=next;
best_token=token;
best_eb=(-val_s<<1+cat)+(val-2<<cat)+(nzeros-1>>1);
best_qc=val+val_s^val_s;
}
}
}
/*zzj can't be coded as a zero, so stop trying to extend the run.*/
if(!(zflags>>zzj&1))break;
}
/*We could try to consider _all_ potentially non-zero coefficients, but
if we already found a bunch of them not worth coding, it's fairly
unlikely they would now be worth coding from this position; skipping
them saves a lot of work.*/
zzj=(tokens[zzj][0].next>>1)-(tokens[zzj][0].qc!=0)&63;
if(zzj==0){
/*We made it all the way to the end of the block; try an EOB token.*/
if(eob<4095){
bits=oc_token_bits(_enc,huffi,zzi,oc_make_eob_token(eob+1))
-flush_bits;
}
else bits=oc_token_bits(_enc,huffi,zzi,OC_DCT_EOB1_TOKEN);
cost=sum_d2+bits*lambda;
/*If the best route so far is still a pure zero run to the end of the
block, force coding it as an EOB.
Even if it's not optimal for this block, it has a good chance of
getting combined with an EOB token from subsequent blocks, saving
bits overall.*/
if(cost<=best_cost||best_token<=OC_DCT_ZRL_TOKEN&&zzi+best_eb==63){
best_next=0;
/*This token is just a marker; in reality we may not emit any
tokens, but update eob_run[] instead.*/
best_token=OC_DCT_EOB1_TOKEN;
best_eb=0;
best_cost=cost;
best_bits=bits;
best_qc=0;
}
break;
}
nzeros=zzj-zzi;
}
tokens[zzi][0].next=(unsigned char)best_next;
tokens[zzi][0].token=(signed char)best_token;
tokens[zzi][0].eb=(ogg_int16_t)best_eb;
tokens[zzi][0].cost=best_cost;
tokens[zzi][0].bits=best_bits;
tokens[zzi][0].qc=best_qc;
zflags|=(ogg_int64_t)1<<zzi;
if(qc){
dq=_dequant[zzi];
if(zzi<_acmin)lambda=0;
e=dq-c;
d2=e*(ogg_int32_t)e;
token=OC_ONE_TOKEN-s;
bits=flush_bits+oc_token_bits(_enc,huffi,zzi,token);
zzj=zzi+1&63;
tj=best_flags>>zzj&1;
next=(zzj<<1)+tj;
tokens[zzi][1].next=(unsigned char)next;
tokens[zzi][1].token=(signed char)token;
tokens[zzi][1].eb=0;
tokens[zzi][1].cost=d2+lambda*bits+tokens[zzj][tj].cost;
tokens[zzi][1].bits=bits+tokens[zzj][tj].bits;
tokens[zzi][1].qc=1+s^s;
nzflags|=(ogg_int64_t)1<<zzi;
best_flags|=
(ogg_int64_t)(tokens[zzi][1].cost<tokens[zzi][0].cost)<<zzi;
}
}
else{
eob=eob_run[zzi];
if(zzi<_acmin)lambda=0;
c=c+s^s;
dq=_dequant[zzi];
/*No zero run can extend past this point.*/
d2_accum[zzi]=0;
flush_bits=eob>0?oc_token_bits(_enc,huffi,zzi,oc_make_eob_token(eob)):0;
if(qc<=2){
e=2*dq-c;
d2=e*(ogg_int32_t)e;
best_token=OC_TWO_TOKEN-s;
best_bits=flush_bits+oc_token_bits(_enc,huffi,zzi,best_token);
best_cost=d2+lambda*best_bits;
e-=dq;
d2=e*(ogg_int32_t)e;
token=OC_ONE_TOKEN-s;
bits=flush_bits+oc_token_bits(_enc,huffi,zzi,token);
cost=d2+lambda*bits;
if(cost<=best_cost){
best_token=token;
best_bits=bits;
best_cost=cost;
qc--;
}
best_eb=0;
}
else if(qc<=3){
e=3*dq-c;
d2=e*(ogg_int32_t)e;
best_token=OC_DCT_VAL_CAT2;
best_eb=-s;
best_bits=flush_bits+oc_token_bits(_enc,huffi,zzi,best_token);
best_cost=d2+lambda*best_bits;
e-=dq;
d2=e*(ogg_int32_t)e;
token=OC_TWO_TOKEN-s;
bits=flush_bits+oc_token_bits(_enc,huffi,zzi,token);
cost=d2+lambda*bits;
if(cost<=best_cost){
best_token=token;
best_eb=0;
best_bits=bits;
best_cost=cost;
qc--;
}
}
else if(qc<=6){
e=qc*dq-c;
d2=e*(ogg_int32_t)e;
best_token=OC_DCT_VAL_CAT2+qc-3;
best_eb=-s;
best_bits=flush_bits+oc_token_bits(_enc,huffi,zzi,best_token);
best_cost=d2+lambda*best_bits;
e-=dq;
d2=e*(ogg_int32_t)e;
token=best_token-1;
bits=flush_bits+oc_token_bits(_enc,huffi,zzi,token);
cost=d2+lambda*bits;
if(cost<=best_cost){
best_token=token;
best_bits=bits;
best_cost=cost;
qc--;
}
}
else if(qc<=8){
e=qc*dq-c;
d2=e*(ogg_int32_t)e;
best_token=OC_DCT_VAL_CAT3;
best_eb=(-s<<1)+qc-7;
best_bits=flush_bits+oc_token_bits(_enc,huffi,zzi,best_token);
best_cost=d2+lambda*best_bits;
e=6*dq-c;
d2=e*(ogg_int32_t)e;
token=OC_DCT_VAL_CAT2+3;
bits=flush_bits+oc_token_bits(_enc,huffi,zzi,token);
cost=d2+lambda*bits;
if(cost<=best_cost){
best_token=token;
best_eb=-s;
best_bits=bits;
best_cost=cost;
qc=6;
}
}
else if(qc<=12){
e=qc*dq-c;
d2=e*(ogg_int32_t)e;
best_token=OC_DCT_VAL_CAT4;
best_eb=(-s<<2)+qc-9;
best_bits=flush_bits+oc_token_bits(_enc,huffi,zzi,best_token);
best_cost=d2+lambda*best_bits;
e=8*dq-c;
d2=e*(ogg_int32_t)e;
token=best_token-1;
bits=flush_bits+oc_token_bits(_enc,huffi,zzi,token);
cost=d2+lambda*bits;
if(cost<=best_cost){
best_token=token;
best_eb=(-s<<1)+1;
best_bits=bits;
best_cost=cost;
qc=8;
}
}
else if(qc<=20){
e=qc*dq-c;
d2=e*(ogg_int32_t)e;
best_token=OC_DCT_VAL_CAT5;
best_eb=(-s<<3)+qc-13;
best_bits=flush_bits+oc_token_bits(_enc,huffi,zzi,best_token);
best_cost=d2+lambda*best_bits;
e=12*dq-c;
d2=e*(ogg_int32_t)e;
token=best_token-1;
bits=flush_bits+oc_token_bits(_enc,huffi,zzi,token);
cost=d2+lambda*bits;
if(cost<=best_cost){
best_token=token;
best_eb=(-s<<2)+3;
best_bits=bits;
best_cost=cost;
qc=12;
}
}
else if(qc<=36){
e=qc*dq-c;
d2=e*(ogg_int32_t)e;
best_token=OC_DCT_VAL_CAT6;
best_eb=(-s<<4)+qc-21;
best_bits=flush_bits+oc_token_bits(_enc,huffi,zzi,best_token);
best_cost=d2+lambda*best_bits;
e=20*dq-c;
d2=e*(ogg_int32_t)e;
token=best_token-1;
bits=flush_bits+oc_token_bits(_enc,huffi,zzi,token);
cost=d2+lambda*bits;
if(cost<=best_cost){
best_token=token;
best_eb=(-s<<3)+7;
best_bits=bits;
best_cost=cost;
qc=20;
}
}
else if(qc<=68){
e=qc*dq-c;
d2=e*(ogg_int32_t)e;
best_token=OC_DCT_VAL_CAT7;
best_eb=(-s<<5)+qc-37;
best_bits=flush_bits+oc_token_bits(_enc,huffi,zzi,best_token);
best_cost=d2+lambda*best_bits;
e=36*dq-c;
d2=e*(ogg_int32_t)e;
token=best_token-1;
bits=flush_bits+oc_token_bits(_enc,huffi,zzi,token);
cost=d2+lambda*bits;
if(cost<best_cost){
best_token=token;
best_eb=(-s<<4)+15;
best_bits=bits;
best_cost=cost;
qc=36;
}
}
else{
e=qc*dq-c;
d2=e*(ogg_int32_t)e;
best_token=OC_DCT_VAL_CAT8;
best_eb=(-s<<9)+qc-69;
best_bits=flush_bits+oc_token_bits(_enc,huffi,zzi,best_token);
best_cost=d2+lambda*best_bits;
e=68*dq-c;
d2=e*(ogg_int32_t)e;
token=best_token-1;
bits=flush_bits+oc_token_bits(_enc,huffi,zzi,token);
cost=d2+lambda*bits;
if(cost<best_cost){
best_token=token;
best_eb=(-s<<5)+31;
best_bits=bits;
best_cost=cost;
qc=68;
}
}
zzj=zzi+1&63;
tj=best_flags>>zzj&1;
next=(zzj<<1)+tj;
tokens[zzi][1].next=(unsigned char)next;
tokens[zzi][1].token=(signed char)best_token;
tokens[zzi][1].eb=best_eb;
tokens[zzi][1].cost=best_cost+tokens[zzj][tj].cost;
tokens[zzi][1].bits=best_bits+tokens[zzj][tj].bits;
tokens[zzi][1].qc=qc+s^s;
nzflags|=(ogg_int64_t)1<<zzi;
best_flags|=(ogg_int64_t)1<<zzi;
}
zzj=zzi;
}
/*Emit the tokens from the best path through the trellis.*/
stack=*_stack;
/*We blow away the first entry here so that things vectorize better.
The DC coefficient is not actually stored in the array yet.*/
for(zzi=0;zzi<64;zzi++)_qdct[zzi]=0;
dct_fzig_zag=_enc->state.opt_data.dct_fzig_zag;
zzi=1;
ti=best_flags>>1&1;
bits=tokens[zzi][ti].bits;
do{
oc_enc_tokenlog_checkpoint(_enc,stack++,_pli,zzi);
eob=eob_run[zzi];
if(tokens[zzi][ti].token<OC_NDCT_EOB_TOKEN_MAX){
if(++eob>=4095){
oc_enc_eob_log(_enc,_pli,zzi,eob);
eob=0;
}
eob_run[zzi]=eob;
/*We don't include the actual EOB cost for this block in the return value.
It will be paid for by the fragment that terminates the EOB run.*/
bits-=tokens[zzi][ti].bits;
zzi=_zzi;
break;
}
/*Emit pending EOB run if any.*/
if(eob>0){
oc_enc_eob_log(_enc,_pli,zzi,eob);
eob_run[zzi]=0;
}
oc_enc_token_log(_enc,_pli,zzi,tokens[zzi][ti].token,tokens[zzi][ti].eb);
next=tokens[zzi][ti].next;
qc=tokens[zzi][ti].qc;
zzj=(next>>1)-1&63;
/*TODO: It may be worth saving the dequantized coefficient in the trellis
above; we had to compute it to measure the error anyway.*/
_qdct[dct_fzig_zag[zzj]]=(ogg_int16_t)(qc*(int)_dequant[zzj]);
zzi=next>>1;
ti=next&1;
}
while(zzi);
*_stack=stack;
return bits;
}
void oc_enc_pred_dc_frag_rows(oc_enc_ctx *_enc,
int _pli,int _fragy0,int _frag_yend){
const oc_fragment_plane *fplane;
const oc_fragment *frags;
ogg_int16_t *frag_dc;
ptrdiff_t fragi;
int *pred_last;
int nhfrags;
int fragx;
int fragy;
fplane=_enc->state.fplanes+_pli;
frags=_enc->state.frags;
frag_dc=_enc->frag_dc;
pred_last=_enc->dc_pred_last[_pli];
nhfrags=fplane->nhfrags;
fragi=fplane->froffset+_fragy0*nhfrags;
for(fragy=_fragy0;fragy<_frag_yend;fragy++){
if(fragy==0){
/*For the first row, all of the cases reduce to just using the previous
predictor for the same reference frame.*/
for(fragx=0;fragx<nhfrags;fragx++,fragi++){
if(frags[fragi].coded){
int ref;
ref=OC_FRAME_FOR_MODE(frags[fragi].mb_mode);
frag_dc[fragi]=(ogg_int16_t)(frags[fragi].dc-pred_last[ref]);
pred_last[ref]=frags[fragi].dc;
}
}
}
else{
const oc_fragment *u_frags;
int l_ref;
int ul_ref;
int u_ref;
u_frags=frags-nhfrags;
l_ref=-1;
ul_ref=-1;
u_ref=u_frags[fragi].coded?OC_FRAME_FOR_MODE(u_frags[fragi].mb_mode):-1;
for(fragx=0;fragx<nhfrags;fragx++,fragi++){
int ur_ref;
if(fragx+1>=nhfrags)ur_ref=-1;
else{
ur_ref=u_frags[fragi+1].coded?
OC_FRAME_FOR_MODE(u_frags[fragi+1].mb_mode):-1;
}
if(frags[fragi].coded){
int pred;
int ref;
ref=OC_FRAME_FOR_MODE(frags[fragi].mb_mode);
/*We break out a separate case based on which of our neighbors use
the same reference frames.
This is somewhat faster than trying to make a generic case which
handles all of them, since it reduces lots of poorly predicted
jumps to one switch statement, and also lets a number of the
multiplications be optimized out by strength reduction.*/
switch((l_ref==ref)|(ul_ref==ref)<<1|
(u_ref==ref)<<2|(ur_ref==ref)<<3){
default:pred=pred_last[ref];break;
case 1:
case 3:pred=frags[fragi-1].dc;break;
case 2:pred=u_frags[fragi-1].dc;break;
case 4:
case 6:
case 12:pred=u_frags[fragi].dc;break;
case 5:pred=(frags[fragi-1].dc+u_frags[fragi].dc)/2;break;
case 8:pred=u_frags[fragi+1].dc;break;
case 9:
case 11:
case 13:{
pred=(75*frags[fragi-1].dc+53*u_frags[fragi+1].dc)/128;
}break;
case 10:pred=(u_frags[fragi-1].dc+u_frags[fragi+1].dc)/2;break;
case 14:{
pred=(3*(u_frags[fragi-1].dc+u_frags[fragi+1].dc)
+10*u_frags[fragi].dc)/16;
}break;
case 7:
case 15:{
int p0;
int p1;
int p2;
p0=frags[fragi-1].dc;
p1=u_frags[fragi-1].dc;
p2=u_frags[fragi].dc;
pred=(29*(p0+p2)-26*p1)/32;
if(abs(pred-p2)>128)pred=p2;
else if(abs(pred-p0)>128)pred=p0;
else if(abs(pred-p1)>128)pred=p1;
}break;
}
frag_dc[fragi]=(ogg_int16_t)(frags[fragi].dc-pred);
pred_last[ref]=frags[fragi].dc;
l_ref=ref;
}
else l_ref=-1;
ul_ref=u_ref;
u_ref=ur_ref;
}
}
}
}
void oc_enc_tokenize_dc_frag_list(oc_enc_ctx *_enc,int _pli,
const ptrdiff_t *_coded_fragis,ptrdiff_t _ncoded_fragis,
int _prev_ndct_tokens1,int _prev_eob_run1){
const ogg_int16_t *frag_dc;
ptrdiff_t fragii;
unsigned char *dct_tokens0;
unsigned char *dct_tokens1;
ogg_uint16_t *extra_bits0;
ogg_uint16_t *extra_bits1;
ptrdiff_t ti0;
ptrdiff_t ti1r;
ptrdiff_t ti1w;
int eob_run0;
int eob_run1;
int neobs1;
int token;
int eb;
int token1=token1;
int eb1=eb1;
/*Return immediately if there are no coded fragments; otherwise we'd flush
any trailing EOB run into the AC 1 list and never read it back out.*/
if(_ncoded_fragis<=0)return;
frag_dc=_enc->frag_dc;
dct_tokens0=_enc->dct_tokens[_pli][0];
dct_tokens1=_enc->dct_tokens[_pli][1];
extra_bits0=_enc->extra_bits[_pli][0];
extra_bits1=_enc->extra_bits[_pli][1];
ti0=_enc->ndct_tokens[_pli][0];
ti1w=ti1r=_prev_ndct_tokens1;
eob_run0=_enc->eob_run[_pli][0];
/*Flush any trailing EOB run for the 1st AC coefficient.
This is needed to allow us to track tokens to the end of the list.*/
eob_run1=_enc->eob_run[_pli][1];
if(eob_run1>0)oc_enc_eob_log(_enc,_pli,1,eob_run1);
/*If there was an active EOB run at the start of the 1st AC stack, read it
in and decode it.*/
if(_prev_eob_run1>0){
token1=dct_tokens1[ti1r];
eb1=extra_bits1[ti1r];
ti1r++;
eob_run1=oc_decode_eob_token(token1,eb1);
/*Consume the portion of the run that came before these fragments.*/
neobs1=eob_run1-_prev_eob_run1;
}
else eob_run1=neobs1=0;
for(fragii=0;fragii<_ncoded_fragis;fragii++){
int val;
/*All tokens in the 1st AC coefficient stack are regenerated as the DC
coefficients are produced.
This can be done in-place; stack 1 cannot get larger.*/
if(!neobs1){
/*There's no active EOB run in stack 1; read the next token.*/
token1=dct_tokens1[ti1r];
eb1=extra_bits1[ti1r];
ti1r++;
if(token1<OC_NDCT_EOB_TOKEN_MAX){
neobs1=oc_decode_eob_token(token1,eb1);
/*It's an EOB run; add it to the current (inactive) one.
Because we may have moved entries to stack 0, we may have an
opportunity to merge two EOB runs in stack 1.*/
eob_run1+=neobs1;
}
}
val=frag_dc[_coded_fragis[fragii]];
if(val){
/*There was a non-zero DC value, so there's no alteration to stack 1
for this fragment; just code the stack 0 token.*/
/*Flush any pending EOB run.*/
if(eob_run0>0){
token=oc_make_eob_token_full(eob_run0,&eb);
dct_tokens0[ti0]=(unsigned char)token;
extra_bits0[ti0]=(ogg_uint16_t)eb;
ti0++;
eob_run0=0;
}
token=oc_make_dct_token_full(0,0,val,&eb);
dct_tokens0[ti0]=(unsigned char)token;
extra_bits0[ti0]=(ogg_uint16_t)eb;
ti0++;
}
else{
/*Zero DC value; that means the entry in stack 1 might need to be coded
from stack 0.
This requires a stack 1 fixup.*/
if(neobs1>0){
/*We're in the middle of an active EOB run in stack 1.
Move it to stack 0.*/
if(++eob_run0>=4095){
token=oc_make_eob_token_full(eob_run0,&eb);
dct_tokens0[ti0]=(unsigned char)token;
extra_bits0[ti0]=(ogg_uint16_t)eb;
ti0++;
eob_run0=0;
}
eob_run1--;
}
else{
/*No active EOB run in stack 1, so we can't extend one in stack 0.
Flush it if we've got it.*/
if(eob_run0>0){
token=oc_make_eob_token_full(eob_run0,&eb);
dct_tokens0[ti0]=(unsigned char)token;
extra_bits0[ti0]=(ogg_uint16_t)eb;
ti0++;
eob_run0=0;
}
/*Stack 1 token is one of: a pure zero run token, a single
coefficient token, or a zero run/coefficient combo token.
A zero run token is expanded and moved to token stack 0, and the
stack 1 entry dropped.
A single coefficient value may be transformed into combo token that
is moved to stack 0, or if it cannot be combined, it is left alone
and a single length-1 zero run is emitted in stack 0.
A combo token is extended and moved to stack 0.
During AC coding, we restrict the run lengths on combo tokens for
stack 1 to guarantee we can extend them.*/
switch(token1){
case OC_DCT_SHORT_ZRL_TOKEN:{
if(eb1<7){
dct_tokens0[ti0]=OC_DCT_SHORT_ZRL_TOKEN;
extra_bits0[ti0]=(ogg_uint16_t)(eb1+1);
ti0++;
/*Don't write the AC coefficient back out.*/
continue;
}
/*Fall through.*/
}
case OC_DCT_ZRL_TOKEN:{
dct_tokens0[ti0]=OC_DCT_ZRL_TOKEN;
extra_bits0[ti0]=(ogg_uint16_t)(eb1+1);
ti0++;
/*Don't write the AC coefficient back out.*/
}continue;
case OC_ONE_TOKEN:
case OC_MINUS_ONE_TOKEN:{
dct_tokens0[ti0]=OC_DCT_RUN_CAT1A;
extra_bits0[ti0]=(ogg_uint16_t)(token1-OC_ONE_TOKEN);
ti0++;
/*Don't write the AC coefficient back out.*/
}continue;
case OC_TWO_TOKEN:
case OC_MINUS_TWO_TOKEN:{
dct_tokens0[ti0]=OC_DCT_RUN_CAT2A;
extra_bits0[ti0]=(ogg_uint16_t)(token1-OC_TWO_TOKEN<<1);
ti0++;
/*Don't write the AC coefficient back out.*/
}continue;
case OC_DCT_VAL_CAT2:{
dct_tokens0[ti0]=OC_DCT_RUN_CAT2A;
extra_bits0[ti0]=(ogg_uint16_t)((eb1<<1)+1);
ti0++;
/*Don't write the AC coefficient back out.*/
}continue;
case OC_DCT_RUN_CAT1A:
case OC_DCT_RUN_CAT1A+1:
case OC_DCT_RUN_CAT1A+2:
case OC_DCT_RUN_CAT1A+3:{
dct_tokens0[ti0]=(unsigned char)(token1+1);
extra_bits0[ti0]=(ogg_uint16_t)eb1;
ti0++;
/*Don't write the AC coefficient back out.*/
}continue;
case OC_DCT_RUN_CAT1A+4:{
dct_tokens0[ti0]=OC_DCT_RUN_CAT1B;
extra_bits0[ti0]=(ogg_uint16_t)(eb1<<2);
ti0++;
/*Don't write the AC coefficient back out.*/
}continue;
case OC_DCT_RUN_CAT1B:{
if((eb1&3)<3){
dct_tokens0[ti0]=OC_DCT_RUN_CAT1B;
extra_bits0[ti0]=(ogg_uint16_t)(eb1+1);
ti0++;
/*Don't write the AC coefficient back out.*/
continue;
}
eb1=((eb1&4)<<1)-1;
/*Fall through.*/
}
case OC_DCT_RUN_CAT1C:{
dct_tokens0[ti0]=OC_DCT_RUN_CAT1C;
extra_bits0[ti0]=(ogg_uint16_t)(eb1+1);
ti0++;
/*Don't write the AC coefficient back out.*/
}continue;
case OC_DCT_RUN_CAT2A:{
eb1=(eb1<<1)-1;
/*Fall through.*/
}
case OC_DCT_RUN_CAT2B:{
dct_tokens0[ti0]=OC_DCT_RUN_CAT2B;
extra_bits0[ti0]=(ogg_uint16_t)(eb1+1);
ti0++;
/*Don't write the AC coefficient back out.*/
}continue;
}
/*We can't merge tokens, write a short zero run and keep going.*/
dct_tokens0[ti0]=OC_DCT_SHORT_ZRL_TOKEN;
extra_bits0[ti0]=0;
ti0++;
}
}
if(!neobs1){
/*Flush any (inactive) EOB run.*/
if(eob_run1>0){
token=oc_make_eob_token_full(eob_run1,&eb);
dct_tokens1[ti1w]=(unsigned char)token;
extra_bits1[ti1w]=(ogg_uint16_t)eb;
ti1w++;
eob_run1=0;
}
/*There's no active EOB run, so log the current token.*/
dct_tokens1[ti1w]=(unsigned char)token1;
extra_bits1[ti1w]=(ogg_uint16_t)eb1;
ti1w++;
}
else{
/*Otherwise consume one EOB from the current run.*/
neobs1--;
/*If we have more than 4095 EOBs outstanding in stack1, flush the run.*/
if(eob_run1-neobs1>=4095){
token=oc_make_eob_token_full(4095,&eb);
dct_tokens1[ti1w]=(unsigned char)token;
extra_bits1[ti1w]=(ogg_uint16_t)eb;
ti1w++;
eob_run1-=4095;
}
}
}
/*Save the current state.*/
_enc->ndct_tokens[_pli][0]=ti0;
_enc->ndct_tokens[_pli][1]=ti1w;
_enc->eob_run[_pli][0]=eob_run0;
_enc->eob_run[_pli][1]=eob_run1;
}
/*Final EOB run welding.*/
void oc_enc_tokenize_finish(oc_enc_ctx *_enc){
int pli;
int zzi;
/*Emit final EOB runs.*/
for(pli=0;pli<3;pli++)for(zzi=0;zzi<64;zzi++){
int eob_run;
eob_run=_enc->eob_run[pli][zzi];
if(eob_run>0)oc_enc_eob_log(_enc,pli,zzi,eob_run);
}
/*Merge the final EOB run of one token list with the start of the next, if
possible.*/
for(zzi=0;zzi<64;zzi++)for(pli=0;pli<3;pli++){
int old_tok1;
int old_tok2;
int old_eb1;
int old_eb2;
int new_tok;
int new_eb;
int zzj;
int plj;
ptrdiff_t ti=ti;
int run_count;
/*Make sure this coefficient has tokens at all.*/
if(_enc->ndct_tokens[pli][zzi]<=0)continue;
/*Ensure the first token is an EOB run.*/
old_tok2=_enc->dct_tokens[pli][zzi][0];
if(old_tok2>=OC_NDCT_EOB_TOKEN_MAX)continue;
/*Search for a previous coefficient that has any tokens at all.*/
old_tok1=OC_NDCT_EOB_TOKEN_MAX;
for(zzj=zzi,plj=pli;zzj>=0;zzj--){
while(plj-->0){
ti=_enc->ndct_tokens[plj][zzj]-1;
if(ti>=_enc->dct_token_offs[plj][zzj]){
old_tok1=_enc->dct_tokens[plj][zzj][ti];
break;
}
}
if(plj>=0)break;
plj=3;
}
/*Ensure its last token was an EOB run.*/
if(old_tok1>=OC_NDCT_EOB_TOKEN_MAX)continue;
/*Pull off the associated extra bits, if any, and decode the runs.*/
old_eb1=_enc->extra_bits[plj][zzj][ti];
old_eb2=_enc->extra_bits[pli][zzi][0];
run_count=oc_decode_eob_token(old_tok1,old_eb1)
+oc_decode_eob_token(old_tok2,old_eb2);
/*We can't possibly combine these into one run.
It might be possible to split them more optimally, but we'll just leave
them as-is.*/
if(run_count>=4096)continue;
/*We CAN combine them into one run.*/
new_tok=oc_make_eob_token_full(run_count,&new_eb);
_enc->dct_tokens[plj][zzj][ti]=(unsigned char)new_tok;
_enc->extra_bits[plj][zzj][ti]=(ogg_uint16_t)new_eb;
_enc->dct_token_offs[pli][zzi]++;
}
}