diff options
Diffstat (limited to 'lib/rbcodec/codecs/libopus/celt/entenc.c')
-rw-r--r-- | lib/rbcodec/codecs/libopus/celt/entenc.c | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/lib/rbcodec/codecs/libopus/celt/entenc.c b/lib/rbcodec/codecs/libopus/celt/entenc.c new file mode 100644 index 0000000000..0ec6e91fd7 --- /dev/null +++ b/lib/rbcodec/codecs/libopus/celt/entenc.c | |||
@@ -0,0 +1,294 @@ | |||
1 | /* Copyright (c) 2001-2011 Timothy B. Terriberry | ||
2 | Copyright (c) 2008-2009 Xiph.Org Foundation */ | ||
3 | /* | ||
4 | Redistribution and use in source and binary forms, with or without | ||
5 | modification, are permitted provided that the following conditions | ||
6 | are met: | ||
7 | |||
8 | - Redistributions of source code must retain the above copyright | ||
9 | notice, this list of conditions and the following disclaimer. | ||
10 | |||
11 | - Redistributions in binary form must reproduce the above copyright | ||
12 | notice, this list of conditions and the following disclaimer in the | ||
13 | documentation and/or other materials provided with the distribution. | ||
14 | |||
15 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | ||
16 | ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | ||
17 | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | ||
18 | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER | ||
19 | OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, | ||
20 | EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | ||
21 | PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR | ||
22 | PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF | ||
23 | LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING | ||
24 | NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS | ||
25 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | ||
26 | */ | ||
27 | |||
28 | #if defined(HAVE_CONFIG_H) | ||
29 | # include "opus_config.h" | ||
30 | #endif | ||
31 | #include "os_support.h" | ||
32 | #include "arch.h" | ||
33 | #include "entenc.h" | ||
34 | #include "mfrngcod.h" | ||
35 | |||
36 | /*A range encoder. | ||
37 | See entdec.c and the references for implementation details \cite{Mar79,MNW98}. | ||
38 | |||
39 | @INPROCEEDINGS{Mar79, | ||
40 | author="Martin, G.N.N.", | ||
41 | title="Range encoding: an algorithm for removing redundancy from a digitised | ||
42 | message", | ||
43 | booktitle="Video \& Data Recording Conference", | ||
44 | year=1979, | ||
45 | address="Southampton", | ||
46 | month=Jul | ||
47 | } | ||
48 | @ARTICLE{MNW98, | ||
49 | author="Alistair Moffat and Radford Neal and Ian H. Witten", | ||
50 | title="Arithmetic Coding Revisited", | ||
51 | journal="{ACM} Transactions on Information Systems", | ||
52 | year=1998, | ||
53 | volume=16, | ||
54 | number=3, | ||
55 | pages="256--294", | ||
56 | month=Jul, | ||
57 | URL="http://www.stanford.edu/class/ee398/handouts/papers/Moffat98ArithmCoding.pdf" | ||
58 | }*/ | ||
59 | |||
60 | static int ec_write_byte(ec_enc *_this,unsigned _value){ | ||
61 | if(_this->offs+_this->end_offs>=_this->storage)return -1; | ||
62 | _this->buf[_this->offs++]=(unsigned char)_value; | ||
63 | return 0; | ||
64 | } | ||
65 | |||
66 | static int ec_write_byte_at_end(ec_enc *_this,unsigned _value){ | ||
67 | if(_this->offs+_this->end_offs>=_this->storage)return -1; | ||
68 | _this->buf[_this->storage-++(_this->end_offs)]=(unsigned char)_value; | ||
69 | return 0; | ||
70 | } | ||
71 | |||
72 | /*Outputs a symbol, with a carry bit. | ||
73 | If there is a potential to propagate a carry over several symbols, they are | ||
74 | buffered until it can be determined whether or not an actual carry will | ||
75 | occur. | ||
76 | If the counter for the buffered symbols overflows, then the stream becomes | ||
77 | undecodable. | ||
78 | This gives a theoretical limit of a few billion symbols in a single packet on | ||
79 | 32-bit systems. | ||
80 | The alternative is to truncate the range in order to force a carry, but | ||
81 | requires similar carry tracking in the decoder, needlessly slowing it down.*/ | ||
82 | static void ec_enc_carry_out(ec_enc *_this,int _c){ | ||
83 | if(_c!=EC_SYM_MAX){ | ||
84 | /*No further carry propagation possible, flush buffer.*/ | ||
85 | int carry; | ||
86 | carry=_c>>EC_SYM_BITS; | ||
87 | /*Don't output a byte on the first write. | ||
88 | This compare should be taken care of by branch-prediction thereafter.*/ | ||
89 | if(_this->rem>=0)_this->error|=ec_write_byte(_this,_this->rem+carry); | ||
90 | if(_this->ext>0){ | ||
91 | unsigned sym; | ||
92 | sym=(EC_SYM_MAX+carry)&EC_SYM_MAX; | ||
93 | do _this->error|=ec_write_byte(_this,sym); | ||
94 | while(--(_this->ext)>0); | ||
95 | } | ||
96 | _this->rem=_c&EC_SYM_MAX; | ||
97 | } | ||
98 | else _this->ext++; | ||
99 | } | ||
100 | |||
101 | static void ec_enc_normalize(ec_enc *_this){ | ||
102 | /*If the range is too small, output some bits and rescale it.*/ | ||
103 | while(_this->rng<=EC_CODE_BOT){ | ||
104 | ec_enc_carry_out(_this,(int)(_this->val>>EC_CODE_SHIFT)); | ||
105 | /*Move the next-to-high-order symbol into the high-order position.*/ | ||
106 | _this->val=(_this->val<<EC_SYM_BITS)&(EC_CODE_TOP-1); | ||
107 | _this->rng<<=EC_SYM_BITS; | ||
108 | _this->nbits_total+=EC_SYM_BITS; | ||
109 | } | ||
110 | } | ||
111 | |||
112 | void ec_enc_init(ec_enc *_this,unsigned char *_buf,opus_uint32 _size){ | ||
113 | _this->buf=_buf; | ||
114 | _this->end_offs=0; | ||
115 | _this->end_window=0; | ||
116 | _this->nend_bits=0; | ||
117 | /*This is the offset from which ec_tell() will subtract partial bits.*/ | ||
118 | _this->nbits_total=EC_CODE_BITS+1; | ||
119 | _this->offs=0; | ||
120 | _this->rng=EC_CODE_TOP; | ||
121 | _this->rem=-1; | ||
122 | _this->val=0; | ||
123 | _this->ext=0; | ||
124 | _this->storage=_size; | ||
125 | _this->error=0; | ||
126 | } | ||
127 | |||
128 | void ec_encode(ec_enc *_this,unsigned _fl,unsigned _fh,unsigned _ft){ | ||
129 | opus_uint32 r; | ||
130 | r=_this->rng/_ft; | ||
131 | if(_fl>0){ | ||
132 | _this->val+=_this->rng-IMUL32(r,(_ft-_fl)); | ||
133 | _this->rng=IMUL32(r,(_fh-_fl)); | ||
134 | } | ||
135 | else _this->rng-=IMUL32(r,(_ft-_fh)); | ||
136 | ec_enc_normalize(_this); | ||
137 | } | ||
138 | |||
139 | void ec_encode_bin(ec_enc *_this,unsigned _fl,unsigned _fh,unsigned _bits){ | ||
140 | opus_uint32 r; | ||
141 | r=_this->rng>>_bits; | ||
142 | if(_fl>0){ | ||
143 | _this->val+=_this->rng-IMUL32(r,((1U<<_bits)-_fl)); | ||
144 | _this->rng=IMUL32(r,(_fh-_fl)); | ||
145 | } | ||
146 | else _this->rng-=IMUL32(r,((1U<<_bits)-_fh)); | ||
147 | ec_enc_normalize(_this); | ||
148 | } | ||
149 | |||
150 | /*The probability of having a "one" is 1/(1<<_logp).*/ | ||
151 | void ec_enc_bit_logp(ec_enc *_this,int _val,unsigned _logp){ | ||
152 | opus_uint32 r; | ||
153 | opus_uint32 s; | ||
154 | opus_uint32 l; | ||
155 | r=_this->rng; | ||
156 | l=_this->val; | ||
157 | s=r>>_logp; | ||
158 | r-=s; | ||
159 | if(_val)_this->val=l+r; | ||
160 | _this->rng=_val?s:r; | ||
161 | ec_enc_normalize(_this); | ||
162 | } | ||
163 | |||
164 | void ec_enc_icdf(ec_enc *_this,int _s,const unsigned char *_icdf,unsigned _ftb){ | ||
165 | opus_uint32 r; | ||
166 | r=_this->rng>>_ftb; | ||
167 | if(_s>0){ | ||
168 | _this->val+=_this->rng-IMUL32(r,_icdf[_s-1]); | ||
169 | _this->rng=IMUL32(r,_icdf[_s-1]-_icdf[_s]); | ||
170 | } | ||
171 | else _this->rng-=IMUL32(r,_icdf[_s]); | ||
172 | ec_enc_normalize(_this); | ||
173 | } | ||
174 | |||
175 | void ec_enc_uint(ec_enc *_this,opus_uint32 _fl,opus_uint32 _ft){ | ||
176 | unsigned ft; | ||
177 | unsigned fl; | ||
178 | int ftb; | ||
179 | /*In order to optimize EC_ILOG(), it is undefined for the value 0.*/ | ||
180 | celt_assert(_ft>1); | ||
181 | _ft--; | ||
182 | ftb=EC_ILOG(_ft); | ||
183 | if(ftb>EC_UINT_BITS){ | ||
184 | ftb-=EC_UINT_BITS; | ||
185 | ft=(_ft>>ftb)+1; | ||
186 | fl=(unsigned)(_fl>>ftb); | ||
187 | ec_encode(_this,fl,fl+1,ft); | ||
188 | ec_enc_bits(_this,_fl&(((opus_uint32)1<<ftb)-1U),ftb); | ||
189 | } | ||
190 | else ec_encode(_this,_fl,_fl+1,_ft+1); | ||
191 | } | ||
192 | |||
193 | void ec_enc_bits(ec_enc *_this,opus_uint32 _fl,unsigned _bits){ | ||
194 | ec_window window; | ||
195 | int used; | ||
196 | window=_this->end_window; | ||
197 | used=_this->nend_bits; | ||
198 | celt_assert(_bits>0); | ||
199 | if(used+_bits>EC_WINDOW_SIZE){ | ||
200 | do{ | ||
201 | _this->error|=ec_write_byte_at_end(_this,(unsigned)window&EC_SYM_MAX); | ||
202 | window>>=EC_SYM_BITS; | ||
203 | used-=EC_SYM_BITS; | ||
204 | } | ||
205 | while(used>=EC_SYM_BITS); | ||
206 | } | ||
207 | window|=(ec_window)_fl<<used; | ||
208 | used+=_bits; | ||
209 | _this->end_window=window; | ||
210 | _this->nend_bits=used; | ||
211 | _this->nbits_total+=_bits; | ||
212 | } | ||
213 | |||
214 | void ec_enc_patch_initial_bits(ec_enc *_this,unsigned _val,unsigned _nbits){ | ||
215 | int shift; | ||
216 | unsigned mask; | ||
217 | celt_assert(_nbits<=EC_SYM_BITS); | ||
218 | shift=EC_SYM_BITS-_nbits; | ||
219 | mask=((1<<_nbits)-1)<<shift; | ||
220 | if(_this->offs>0){ | ||
221 | /*The first byte has been finalized.*/ | ||
222 | _this->buf[0]=(unsigned char)((_this->buf[0]&~mask)|_val<<shift); | ||
223 | } | ||
224 | else if(_this->rem>=0){ | ||
225 | /*The first byte is still awaiting carry propagation.*/ | ||
226 | _this->rem=(_this->rem&~mask)|_val<<shift; | ||
227 | } | ||
228 | else if(_this->rng<=(EC_CODE_TOP>>_nbits)){ | ||
229 | /*The renormalization loop has never been run.*/ | ||
230 | _this->val=(_this->val&~((opus_uint32)mask<<EC_CODE_SHIFT))| | ||
231 | (opus_uint32)_val<<(EC_CODE_SHIFT+shift); | ||
232 | } | ||
233 | /*The encoder hasn't even encoded _nbits of data yet.*/ | ||
234 | else _this->error=-1; | ||
235 | } | ||
236 | |||
237 | void ec_enc_shrink(ec_enc *_this,opus_uint32 _size){ | ||
238 | celt_assert(_this->offs+_this->end_offs<=_size); | ||
239 | OPUS_MOVE(_this->buf+_size-_this->end_offs, | ||
240 | _this->buf+_this->storage-_this->end_offs,_this->end_offs); | ||
241 | _this->storage=_size; | ||
242 | } | ||
243 | |||
244 | void ec_enc_done(ec_enc *_this){ | ||
245 | ec_window window; | ||
246 | int used; | ||
247 | opus_uint32 msk; | ||
248 | opus_uint32 end; | ||
249 | int l; | ||
250 | /*We output the minimum number of bits that ensures that the symbols encoded | ||
251 | thus far will be decoded correctly regardless of the bits that follow.*/ | ||
252 | l=EC_CODE_BITS-EC_ILOG(_this->rng); | ||
253 | msk=(EC_CODE_TOP-1)>>l; | ||
254 | end=(_this->val+msk)&~msk; | ||
255 | if((end|msk)>=_this->val+_this->rng){ | ||
256 | l++; | ||
257 | msk>>=1; | ||
258 | end=(_this->val+msk)&~msk; | ||
259 | } | ||
260 | while(l>0){ | ||
261 | ec_enc_carry_out(_this,(int)(end>>EC_CODE_SHIFT)); | ||
262 | end=(end<<EC_SYM_BITS)&(EC_CODE_TOP-1); | ||
263 | l-=EC_SYM_BITS; | ||
264 | } | ||
265 | /*If we have a buffered byte flush it into the output buffer.*/ | ||
266 | if(_this->rem>=0||_this->ext>0)ec_enc_carry_out(_this,0); | ||
267 | /*If we have buffered extra bits, flush them as well.*/ | ||
268 | window=_this->end_window; | ||
269 | used=_this->nend_bits; | ||
270 | while(used>=EC_SYM_BITS){ | ||
271 | _this->error|=ec_write_byte_at_end(_this,(unsigned)window&EC_SYM_MAX); | ||
272 | window>>=EC_SYM_BITS; | ||
273 | used-=EC_SYM_BITS; | ||
274 | } | ||
275 | /*Clear any excess space and add any remaining extra bits to the last byte.*/ | ||
276 | if(!_this->error){ | ||
277 | OPUS_CLEAR(_this->buf+_this->offs, | ||
278 | _this->storage-_this->offs-_this->end_offs); | ||
279 | if(used>0){ | ||
280 | /*If there's no range coder data at all, give up.*/ | ||
281 | if(_this->end_offs>=_this->storage)_this->error=-1; | ||
282 | else{ | ||
283 | l=-l; | ||
284 | /*If we've busted, don't add too many extra bits to the last byte; it | ||
285 | would corrupt the range coder data, and that's more important.*/ | ||
286 | if(_this->offs+_this->end_offs>=_this->storage&&l<used){ | ||
287 | window&=(1<<l)-1; | ||
288 | _this->error=-1; | ||
289 | } | ||
290 | _this->buf[_this->storage-_this->end_offs-1]|=(unsigned char)window; | ||
291 | } | ||
292 | } | ||
293 | } | ||
294 | } | ||