diff options
Diffstat (limited to 'lib/rbcodec/codecs/libwavpack/words.c')
-rw-r--r-- | lib/rbcodec/codecs/libwavpack/words.c | 786 |
1 files changed, 786 insertions, 0 deletions
diff --git a/lib/rbcodec/codecs/libwavpack/words.c b/lib/rbcodec/codecs/libwavpack/words.c new file mode 100644 index 0000000000..3d9e753e4b --- /dev/null +++ b/lib/rbcodec/codecs/libwavpack/words.c | |||
@@ -0,0 +1,786 @@ | |||
1 | //////////////////////////////////////////////////////////////////////////// | ||
2 | // **** WAVPACK **** // | ||
3 | // Hybrid Lossless Wavefile Compressor // | ||
4 | // Copyright (c) 1998 - 2004 Conifer Software. // | ||
5 | // All Rights Reserved. // | ||
6 | //////////////////////////////////////////////////////////////////////////// | ||
7 | |||
8 | // words.c | ||
9 | |||
10 | // This module provides entropy word encoding and decoding functions using | ||
11 | // a variation on the Rice method. This was introduced in version 3.93 | ||
12 | // because it allows splitting the data into a "lossy" stream and a | ||
13 | // "correction" stream in a very efficient manner and is therefore ideal | ||
14 | // for the "hybrid" mode. For 4.0, the efficiency of this method was | ||
15 | // significantly improved by moving away from the normal Rice restriction of | ||
16 | // using powers of two for the modulus divisions and now the method can be | ||
17 | // used for both hybrid and pure lossless encoding. | ||
18 | |||
19 | // Samples are divided by median probabilities at 5/7 (71.43%), 10/49 (20.41%), | ||
20 | // and 20/343 (5.83%). Each zone has 3.5 times fewer samples than the | ||
21 | // previous. Using standard Rice coding on this data would result in 1.4 | ||
22 | // bits per sample average (not counting sign bit). However, there is a | ||
23 | // very simple encoding that is over 99% efficient with this data and | ||
24 | // results in about 1.22 bits per sample. | ||
25 | |||
26 | #include "wavpack.h" | ||
27 | |||
28 | #include <string.h> | ||
29 | |||
30 | //////////////////////////////// local macros ///////////////////////////////// | ||
31 | |||
32 | #define LIMIT_ONES 16 // maximum consecutive 1s sent for "div" data | ||
33 | |||
34 | // these control the time constant "slow_level" which is used for hybrid mode | ||
35 | // that controls bitrate as a function of residual level (HYBRID_BITRATE). | ||
36 | #define SLS 8 | ||
37 | #define SLO ((1 << (SLS - 1))) | ||
38 | |||
39 | // these control the time constant of the 3 median level breakpoints | ||
40 | #define DIV0 128 // 5/7 of samples | ||
41 | #define DIV1 64 // 10/49 of samples | ||
42 | #define DIV2 32 // 20/343 of samples | ||
43 | |||
44 | // this macro retrieves the specified median breakpoint (without frac; min = 1) | ||
45 | #define GET_MED(med) (((c->median [med]) >> 4) + 1) | ||
46 | |||
47 | // These macros update the specified median breakpoints. Note that the median | ||
48 | // is incremented when the sample is higher than the median, else decremented. | ||
49 | // They are designed so that the median will never drop below 1 and the value | ||
50 | // is essentially stationary if there are 2 increments for every 5 decrements. | ||
51 | |||
52 | #define INC_MED0() (c->median [0] += ((c->median [0] + DIV0) / DIV0) * 5) | ||
53 | #define DEC_MED0() (c->median [0] -= ((c->median [0] + (DIV0-2)) / DIV0) * 2) | ||
54 | #define INC_MED1() (c->median [1] += ((c->median [1] + DIV1) / DIV1) * 5) | ||
55 | #define DEC_MED1() (c->median [1] -= ((c->median [1] + (DIV1-2)) / DIV1) * 2) | ||
56 | #define INC_MED2() (c->median [2] += ((c->median [2] + DIV2) / DIV2) * 5) | ||
57 | #define DEC_MED2() (c->median [2] -= ((c->median [2] + (DIV2-2)) / DIV2) * 2) | ||
58 | |||
59 | #define count_bits(av) ( \ | ||
60 | (av) < (1 << 8) ? nbits_table [av] : \ | ||
61 | ( \ | ||
62 | (av) < (1L << 16) ? nbits_table [(av) >> 8] + 8 : \ | ||
63 | ((av) < (1L << 24) ? nbits_table [(av) >> 16] + 16 : nbits_table [(av) >> 24] + 24) \ | ||
64 | ) \ | ||
65 | ) | ||
66 | |||
67 | ///////////////////////////// local table storage //////////////////////////// | ||
68 | |||
69 | static const char nbits_table [] ICONST_ATTR = { | ||
70 | 0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, // 0 - 15 | ||
71 | 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, // 16 - 31 | ||
72 | 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, // 32 - 47 | ||
73 | 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, // 48 - 63 | ||
74 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, // 64 - 79 | ||
75 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, // 80 - 95 | ||
76 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, // 96 - 111 | ||
77 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, // 112 - 127 | ||
78 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, // 128 - 143 | ||
79 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, // 144 - 159 | ||
80 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, // 160 - 175 | ||
81 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, // 176 - 191 | ||
82 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, // 192 - 207 | ||
83 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, // 208 - 223 | ||
84 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, // 224 - 239 | ||
85 | 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8 // 240 - 255 | ||
86 | }; | ||
87 | |||
88 | static const uchar log2_table [] = { | ||
89 | 0x00, 0x01, 0x03, 0x04, 0x06, 0x07, 0x09, 0x0a, 0x0b, 0x0d, 0x0e, 0x10, 0x11, 0x12, 0x14, 0x15, | ||
90 | 0x16, 0x18, 0x19, 0x1a, 0x1c, 0x1d, 0x1e, 0x20, 0x21, 0x22, 0x24, 0x25, 0x26, 0x28, 0x29, 0x2a, | ||
91 | 0x2c, 0x2d, 0x2e, 0x2f, 0x31, 0x32, 0x33, 0x34, 0x36, 0x37, 0x38, 0x39, 0x3b, 0x3c, 0x3d, 0x3e, | ||
92 | 0x3f, 0x41, 0x42, 0x43, 0x44, 0x45, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4d, 0x4e, 0x4f, 0x50, 0x51, | ||
93 | 0x52, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5c, 0x5d, 0x5e, 0x5f, 0x60, 0x61, 0x62, 0x63, | ||
94 | 0x64, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x74, 0x75, | ||
95 | 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, | ||
96 | 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, | ||
97 | 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, | ||
98 | 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, 0xb0, 0xb1, 0xb2, 0xb2, | ||
99 | 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0, 0xc0, | ||
100 | 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcb, 0xcc, 0xcd, 0xce, | ||
101 | 0xcf, 0xd0, 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd8, 0xd9, 0xda, 0xdb, | ||
102 | 0xdc, 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe4, 0xe5, 0xe6, 0xe7, 0xe7, | ||
103 | 0xe8, 0xe9, 0xea, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xee, 0xef, 0xf0, 0xf1, 0xf1, 0xf2, 0xf3, 0xf4, | ||
104 | 0xf4, 0xf5, 0xf6, 0xf7, 0xf7, 0xf8, 0xf9, 0xf9, 0xfa, 0xfb, 0xfc, 0xfc, 0xfd, 0xfe, 0xff, 0xff | ||
105 | }; | ||
106 | |||
107 | static const uchar exp2_table [] ICONST_ATTR = { | ||
108 | 0x00, 0x01, 0x01, 0x02, 0x03, 0x03, 0x04, 0x05, 0x06, 0x06, 0x07, 0x08, 0x08, 0x09, 0x0a, 0x0b, | ||
109 | 0x0b, 0x0c, 0x0d, 0x0e, 0x0e, 0x0f, 0x10, 0x10, 0x11, 0x12, 0x13, 0x13, 0x14, 0x15, 0x16, 0x16, | ||
110 | 0x17, 0x18, 0x19, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1d, 0x1e, 0x1f, 0x20, 0x20, 0x21, 0x22, 0x23, | ||
111 | 0x24, 0x24, 0x25, 0x26, 0x27, 0x28, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, | ||
112 | 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3a, 0x3b, 0x3c, 0x3d, | ||
113 | 0x3e, 0x3f, 0x40, 0x41, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x48, 0x49, 0x4a, 0x4b, | ||
114 | 0x4c, 0x4d, 0x4e, 0x4f, 0x50, 0x51, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, | ||
115 | 0x5b, 0x5c, 0x5d, 0x5e, 0x5e, 0x5f, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, | ||
116 | 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, | ||
117 | 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x87, 0x88, 0x89, 0x8a, | ||
118 | 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0x90, 0x91, 0x92, 0x93, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, | ||
119 | 0x9c, 0x9d, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, | ||
120 | 0xaf, 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0, | ||
121 | 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc8, 0xc9, 0xca, 0xcb, 0xcd, 0xce, 0xcf, 0xd0, 0xd2, 0xd3, 0xd4, | ||
122 | 0xd6, 0xd7, 0xd8, 0xd9, 0xdb, 0xdc, 0xdd, 0xde, 0xe0, 0xe1, 0xe2, 0xe4, 0xe5, 0xe6, 0xe8, 0xe9, | ||
123 | 0xea, 0xec, 0xed, 0xee, 0xf0, 0xf1, 0xf2, 0xf4, 0xf5, 0xf6, 0xf8, 0xf9, 0xfa, 0xfc, 0xfd, 0xff | ||
124 | }; | ||
125 | |||
126 | static const char ones_count_table [] ICONST_ATTR = { | ||
127 | 0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,5, | ||
128 | 0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,6, | ||
129 | 0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,5, | ||
130 | 0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,7, | ||
131 | 0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,5, | ||
132 | 0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,6, | ||
133 | 0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,5, | ||
134 | 0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,8 | ||
135 | }; | ||
136 | |||
137 | ///////////////////////////// executable code //////////////////////////////// | ||
138 | |||
139 | void init_words (WavpackStream *wps) | ||
140 | { | ||
141 | CLEAR (wps->w); | ||
142 | } | ||
143 | |||
144 | static int mylog2 (uint32_t avalue); | ||
145 | |||
146 | // Read the median log2 values from the specifed metadata structure, convert | ||
147 | // them back to 32-bit unsigned values and store them. If length is not | ||
148 | // exactly correct then we flag and return an error. | ||
149 | |||
150 | int read_entropy_vars (WavpackStream *wps, WavpackMetadata *wpmd) | ||
151 | { | ||
152 | uchar *byteptr = wpmd->data; | ||
153 | |||
154 | if (wpmd->byte_length != ((wps->wphdr.flags & MONO_DATA) ? 6 : 12)) | ||
155 | return FALSE; | ||
156 | |||
157 | wps->w.c [0].median [0] = exp2s (byteptr [0] + (byteptr [1] << 8)); | ||
158 | wps->w.c [0].median [1] = exp2s (byteptr [2] + (byteptr [3] << 8)); | ||
159 | wps->w.c [0].median [2] = exp2s (byteptr [4] + (byteptr [5] << 8)); | ||
160 | |||
161 | if (!(wps->wphdr.flags & MONO_DATA)) { | ||
162 | wps->w.c [1].median [0] = exp2s (byteptr [6] + (byteptr [7] << 8)); | ||
163 | wps->w.c [1].median [1] = exp2s (byteptr [8] + (byteptr [9] << 8)); | ||
164 | wps->w.c [1].median [2] = exp2s (byteptr [10] + (byteptr [11] << 8)); | ||
165 | } | ||
166 | |||
167 | return TRUE; | ||
168 | } | ||
169 | |||
170 | // Allocates the correct space in the metadata structure and writes the | ||
171 | // current median values to it. Values are converted from 32-bit unsigned | ||
172 | // to our internal 16-bit mylog2 values, and read_entropy_vars () is called | ||
173 | // to read the values back because we must compensate for the loss through | ||
174 | // the log function. | ||
175 | |||
176 | void write_entropy_vars (WavpackStream *wps, WavpackMetadata *wpmd) | ||
177 | { | ||
178 | uchar *byteptr; | ||
179 | int temp; | ||
180 | |||
181 | byteptr = wpmd->data = wpmd->temp_data; | ||
182 | wpmd->id = ID_ENTROPY_VARS; | ||
183 | |||
184 | *byteptr++ = temp = mylog2 (wps->w.c [0].median [0]); | ||
185 | *byteptr++ = temp >> 8; | ||
186 | *byteptr++ = temp = mylog2 (wps->w.c [0].median [1]); | ||
187 | *byteptr++ = temp >> 8; | ||
188 | *byteptr++ = temp = mylog2 (wps->w.c [0].median [2]); | ||
189 | *byteptr++ = temp >> 8; | ||
190 | |||
191 | if (!(wps->wphdr.flags & MONO_FLAG)) { | ||
192 | *byteptr++ = temp = mylog2 (wps->w.c [1].median [0]); | ||
193 | *byteptr++ = temp >> 8; | ||
194 | *byteptr++ = temp = mylog2 (wps->w.c [1].median [1]); | ||
195 | *byteptr++ = temp >> 8; | ||
196 | *byteptr++ = temp = mylog2 (wps->w.c [1].median [2]); | ||
197 | *byteptr++ = temp >> 8; | ||
198 | } | ||
199 | |||
200 | wpmd->byte_length = byteptr - (uchar *) wpmd->data; | ||
201 | read_entropy_vars (wps, wpmd); | ||
202 | } | ||
203 | |||
204 | // Read the hybrid related values from the specifed metadata structure, convert | ||
205 | // them back to their internal formats and store them. The extended profile | ||
206 | // stuff is not implemented yet, so return an error if we get more data than | ||
207 | // we know what to do with. | ||
208 | |||
209 | int read_hybrid_profile (WavpackStream *wps, WavpackMetadata *wpmd) | ||
210 | { | ||
211 | uchar *byteptr = wpmd->data; | ||
212 | uchar *endptr = byteptr + wpmd->byte_length; | ||
213 | |||
214 | if (wps->wphdr.flags & HYBRID_BITRATE) { | ||
215 | wps->w.c [0].slow_level = exp2s (byteptr [0] + (byteptr [1] << 8)); | ||
216 | byteptr += 2; | ||
217 | |||
218 | if (!(wps->wphdr.flags & MONO_DATA)) { | ||
219 | wps->w.c [1].slow_level = exp2s (byteptr [0] + (byteptr [1] << 8)); | ||
220 | byteptr += 2; | ||
221 | } | ||
222 | } | ||
223 | |||
224 | wps->w.bitrate_acc [0] = (int32_t)(byteptr [0] + (byteptr [1] << 8)) << 16; | ||
225 | byteptr += 2; | ||
226 | |||
227 | if (!(wps->wphdr.flags & MONO_DATA)) { | ||
228 | wps->w.bitrate_acc [1] = (int32_t)(byteptr [0] + (byteptr [1] << 8)) << 16; | ||
229 | byteptr += 2; | ||
230 | } | ||
231 | |||
232 | if (byteptr < endptr) { | ||
233 | wps->w.bitrate_delta [0] = exp2s ((short)(byteptr [0] + (byteptr [1] << 8))); | ||
234 | byteptr += 2; | ||
235 | |||
236 | if (!(wps->wphdr.flags & MONO_DATA)) { | ||
237 | wps->w.bitrate_delta [1] = exp2s ((short)(byteptr [0] + (byteptr [1] << 8))); | ||
238 | byteptr += 2; | ||
239 | } | ||
240 | |||
241 | if (byteptr < endptr) | ||
242 | return FALSE; | ||
243 | } | ||
244 | else | ||
245 | wps->w.bitrate_delta [0] = wps->w.bitrate_delta [1] = 0; | ||
246 | |||
247 | return TRUE; | ||
248 | } | ||
249 | |||
250 | // This function is called during both encoding and decoding of hybrid data to | ||
251 | // update the "error_limit" variable which determines the maximum sample error | ||
252 | // allowed in the main bitstream. In the HYBRID_BITRATE mode (which is the only | ||
253 | // currently implemented) this is calculated from the slow_level values and the | ||
254 | // bitrate accumulators. Note that the bitrate accumulators can be changing. | ||
255 | |||
256 | static void update_error_limit (struct words_data *w, uint32_t flags) | ||
257 | { | ||
258 | int bitrate_0 = (w->bitrate_acc [0] += w->bitrate_delta [0]) >> 16; | ||
259 | |||
260 | if (flags & MONO_DATA) { | ||
261 | if (flags & HYBRID_BITRATE) { | ||
262 | int slow_log_0 = (w->c [0].slow_level + SLO) >> SLS; | ||
263 | |||
264 | if (slow_log_0 - bitrate_0 > -0x100) | ||
265 | w->c [0].error_limit = exp2s (slow_log_0 - bitrate_0 + 0x100); | ||
266 | else | ||
267 | w->c [0].error_limit = 0; | ||
268 | } | ||
269 | else | ||
270 | w->c [0].error_limit = exp2s (bitrate_0); | ||
271 | } | ||
272 | else { | ||
273 | int bitrate_1 = (w->bitrate_acc [1] += w->bitrate_delta [1]) >> 16; | ||
274 | |||
275 | if (flags & HYBRID_BITRATE) { | ||
276 | int slow_log_0 = (w->c [0].slow_level + SLO) >> SLS; | ||
277 | int slow_log_1 = (w->c [1].slow_level + SLO) >> SLS; | ||
278 | |||
279 | if (flags & HYBRID_BALANCE) { | ||
280 | int balance = (slow_log_1 - slow_log_0 + bitrate_1 + 1) >> 1; | ||
281 | |||
282 | if (balance > bitrate_0) { | ||
283 | bitrate_1 = bitrate_0 * 2; | ||
284 | bitrate_0 = 0; | ||
285 | } | ||
286 | else if (-balance > bitrate_0) { | ||
287 | bitrate_0 = bitrate_0 * 2; | ||
288 | bitrate_1 = 0; | ||
289 | } | ||
290 | else { | ||
291 | bitrate_1 = bitrate_0 + balance; | ||
292 | bitrate_0 = bitrate_0 - balance; | ||
293 | } | ||
294 | } | ||
295 | |||
296 | if (slow_log_0 - bitrate_0 > -0x100) | ||
297 | w->c [0].error_limit = exp2s (slow_log_0 - bitrate_0 + 0x100); | ||
298 | else | ||
299 | w->c [0].error_limit = 0; | ||
300 | |||
301 | if (slow_log_1 - bitrate_1 > -0x100) | ||
302 | w->c [1].error_limit = exp2s (slow_log_1 - bitrate_1 + 0x100); | ||
303 | else | ||
304 | w->c [1].error_limit = 0; | ||
305 | } | ||
306 | else { | ||
307 | w->c [0].error_limit = exp2s (bitrate_0); | ||
308 | w->c [1].error_limit = exp2s (bitrate_1); | ||
309 | } | ||
310 | } | ||
311 | } | ||
312 | |||
313 | static uint32_t read_code (Bitstream *bs, uint32_t maxcode); | ||
314 | |||
315 | // Read the next word from the bitstream "wvbits" and return the value. This | ||
316 | // function can be used for hybrid or lossless streams, but since an | ||
317 | // optimized version is available for lossless this function would normally | ||
318 | // be used for hybrid only. If a hybrid lossless stream is being read then | ||
319 | // the "correction" offset is written at the specified pointer. A return value | ||
320 | // of WORD_EOF indicates that the end of the bitstream was reached (all 1s) or | ||
321 | // some other error occurred. | ||
322 | |||
323 | int32_t get_words (int32_t *buffer, int nsamples, uint32_t flags, | ||
324 | struct words_data *w, Bitstream *bs) | ||
325 | { | ||
326 | register struct entropy_data *c = w->c; | ||
327 | int csamples; | ||
328 | |||
329 | if (!(flags & MONO_DATA)) | ||
330 | nsamples *= 2; | ||
331 | |||
332 | for (csamples = 0; csamples < nsamples; ++csamples) { | ||
333 | uint32_t ones_count, low, mid, high; | ||
334 | |||
335 | if (!(flags & MONO_DATA)) | ||
336 | c = w->c + (csamples & 1); | ||
337 | |||
338 | if (!(w->c [0].median [0] & ~1) && !w->holding_zero && !w->holding_one && !(w->c [1].median [0] & ~1)) { | ||
339 | uint32_t mask; | ||
340 | int cbits; | ||
341 | |||
342 | if (w->zeros_acc) { | ||
343 | if (--w->zeros_acc) { | ||
344 | c->slow_level -= (c->slow_level + SLO) >> SLS; | ||
345 | *buffer++ = 0; | ||
346 | continue; | ||
347 | } | ||
348 | } | ||
349 | else { | ||
350 | for (cbits = 0; cbits < 33 && getbit (bs); ++cbits); | ||
351 | |||
352 | if (cbits == 33) | ||
353 | break; | ||
354 | |||
355 | if (cbits < 2) | ||
356 | w->zeros_acc = cbits; | ||
357 | else { | ||
358 | for (mask = 1, w->zeros_acc = 0; --cbits; mask <<= 1) | ||
359 | if (getbit (bs)) | ||
360 | w->zeros_acc |= mask; | ||
361 | |||
362 | w->zeros_acc |= mask; | ||
363 | } | ||
364 | |||
365 | if (w->zeros_acc) { | ||
366 | c->slow_level -= (c->slow_level + SLO) >> SLS; | ||
367 | CLEAR (w->c [0].median); | ||
368 | CLEAR (w->c [1].median); | ||
369 | *buffer++ = 0; | ||
370 | continue; | ||
371 | } | ||
372 | } | ||
373 | } | ||
374 | |||
375 | if (w->holding_zero) | ||
376 | ones_count = w->holding_zero = 0; | ||
377 | else { | ||
378 | int next8; | ||
379 | |||
380 | if (bs->bc < 8) { | ||
381 | if (++(bs->ptr) == bs->end) | ||
382 | bs->wrap (bs); | ||
383 | |||
384 | next8 = (bs->sr |= *(bs->ptr) << bs->bc) & 0xff; | ||
385 | bs->bc += 8; | ||
386 | } | ||
387 | else | ||
388 | next8 = bs->sr & 0xff; | ||
389 | |||
390 | if (next8 == 0xff) { | ||
391 | bs->bc -= 8; | ||
392 | bs->sr >>= 8; | ||
393 | |||
394 | for (ones_count = 8; ones_count < (LIMIT_ONES + 1) && getbit (bs); ++ones_count); | ||
395 | |||
396 | if (ones_count == (LIMIT_ONES + 1)) | ||
397 | break; | ||
398 | |||
399 | if (ones_count == LIMIT_ONES) { | ||
400 | uint32_t mask; | ||
401 | int cbits; | ||
402 | |||
403 | for (cbits = 0; cbits < 33 && getbit (bs); ++cbits); | ||
404 | |||
405 | if (cbits == 33) | ||
406 | break; | ||
407 | |||
408 | if (cbits < 2) | ||
409 | ones_count = cbits; | ||
410 | else { | ||
411 | for (mask = 1, ones_count = 0; --cbits; mask <<= 1) | ||
412 | if (getbit (bs)) | ||
413 | ones_count |= mask; | ||
414 | |||
415 | ones_count |= mask; | ||
416 | } | ||
417 | |||
418 | ones_count += LIMIT_ONES; | ||
419 | } | ||
420 | } | ||
421 | else { | ||
422 | bs->bc -= (ones_count = ones_count_table [next8]) + 1; | ||
423 | bs->sr >>= ones_count + 1; | ||
424 | } | ||
425 | |||
426 | if (w->holding_one) { | ||
427 | w->holding_one = ones_count & 1; | ||
428 | ones_count = (ones_count >> 1) + 1; | ||
429 | } | ||
430 | else { | ||
431 | w->holding_one = ones_count & 1; | ||
432 | ones_count >>= 1; | ||
433 | } | ||
434 | |||
435 | w->holding_zero = ~w->holding_one & 1; | ||
436 | } | ||
437 | |||
438 | if ((flags & HYBRID_FLAG) && ((flags & MONO_DATA) || !(csamples & 1))) | ||
439 | update_error_limit (w, flags); | ||
440 | |||
441 | if (ones_count == 0) { | ||
442 | low = 0; | ||
443 | high = GET_MED (0) - 1; | ||
444 | DEC_MED0 (); | ||
445 | } | ||
446 | else { | ||
447 | low = GET_MED (0); | ||
448 | INC_MED0 (); | ||
449 | |||
450 | if (ones_count == 1) { | ||
451 | high = low + GET_MED (1) - 1; | ||
452 | DEC_MED1 (); | ||
453 | } | ||
454 | else { | ||
455 | low += GET_MED (1); | ||
456 | INC_MED1 (); | ||
457 | |||
458 | if (ones_count == 2) { | ||
459 | high = low + GET_MED (2) - 1; | ||
460 | DEC_MED2 (); | ||
461 | } | ||
462 | else { | ||
463 | low += (ones_count - 2) * GET_MED (2); | ||
464 | high = low + GET_MED (2) - 1; | ||
465 | INC_MED2 (); | ||
466 | } | ||
467 | } | ||
468 | } | ||
469 | |||
470 | mid = (high + low + 1) >> 1; | ||
471 | |||
472 | if (!c->error_limit) | ||
473 | mid = read_code (bs, high - low) + low; | ||
474 | else while (high - low > c->error_limit) { | ||
475 | if (getbit (bs)) | ||
476 | mid = (high + (low = mid) + 1) >> 1; | ||
477 | else | ||
478 | mid = ((high = mid - 1) + low + 1) >> 1; | ||
479 | } | ||
480 | |||
481 | *buffer++ = getbit (bs) ? ~mid : mid; | ||
482 | |||
483 | if (flags & HYBRID_BITRATE) | ||
484 | c->slow_level = c->slow_level - ((c->slow_level + SLO) >> SLS) + mylog2 (mid); | ||
485 | } | ||
486 | |||
487 | return (flags & MONO_DATA) ? csamples : (csamples / 2); | ||
488 | } | ||
489 | |||
490 | // Read a single unsigned value from the specified bitstream with a value | ||
491 | // from 0 to maxcode. If there are exactly a power of two number of possible | ||
492 | // codes then this will read a fixed number of bits; otherwise it reads the | ||
493 | // minimum number of bits and then determines whether another bit is needed | ||
494 | // to define the code. | ||
495 | |||
496 | static uint32_t read_code (Bitstream *bs, uint32_t maxcode) | ||
497 | { | ||
498 | int bitcount = count_bits (maxcode); | ||
499 | uint32_t extras = (1L << bitcount) - maxcode - 1, code; | ||
500 | |||
501 | if (!bitcount) | ||
502 | return 0; | ||
503 | |||
504 | getbits (&code, bitcount - 1, bs); | ||
505 | code &= (1L << (bitcount - 1)) - 1; | ||
506 | |||
507 | if (code >= extras) { | ||
508 | code = (code << 1) - extras; | ||
509 | |||
510 | if (getbit (bs)) | ||
511 | ++code; | ||
512 | } | ||
513 | |||
514 | return code; | ||
515 | } | ||
516 | |||
517 | void send_words (int32_t *buffer, int nsamples, uint32_t flags, | ||
518 | struct words_data *w, Bitstream *bs) | ||
519 | { | ||
520 | register struct entropy_data *c = w->c; | ||
521 | |||
522 | if (!(flags & MONO_FLAG)) | ||
523 | nsamples *= 2; | ||
524 | |||
525 | while (nsamples--) { | ||
526 | int32_t value = *buffer++; | ||
527 | int sign = (value < 0) ? 1 : 0; | ||
528 | uint32_t ones_count, low, high; | ||
529 | |||
530 | if (!(flags & MONO_FLAG)) | ||
531 | c = w->c + (~nsamples & 1); | ||
532 | |||
533 | if (!(w->c [0].median [0] & ~1) && !w->holding_zero && !(w->c [1].median [0] & ~1)) { | ||
534 | if (w->zeros_acc) { | ||
535 | if (value) | ||
536 | flush_word (w, bs); | ||
537 | else { | ||
538 | w->zeros_acc++; | ||
539 | continue; | ||
540 | } | ||
541 | } | ||
542 | else if (value) { | ||
543 | putbit_0 (bs); | ||
544 | } | ||
545 | else { | ||
546 | CLEAR (w->c [0].median); | ||
547 | CLEAR (w->c [1].median); | ||
548 | w->zeros_acc = 1; | ||
549 | continue; | ||
550 | } | ||
551 | } | ||
552 | |||
553 | if (sign) | ||
554 | value = ~value; | ||
555 | |||
556 | if ((uint32_t) value < GET_MED (0)) { | ||
557 | ones_count = low = 0; | ||
558 | high = GET_MED (0) - 1; | ||
559 | DEC_MED0 (); | ||
560 | } | ||
561 | else { | ||
562 | low = GET_MED (0); | ||
563 | INC_MED0 (); | ||
564 | |||
565 | if (value - low < GET_MED (1)) { | ||
566 | ones_count = 1; | ||
567 | high = low + GET_MED (1) - 1; | ||
568 | DEC_MED1 (); | ||
569 | } | ||
570 | else { | ||
571 | low += GET_MED (1); | ||
572 | INC_MED1 (); | ||
573 | |||
574 | if (value - low < GET_MED (2)) { | ||
575 | ones_count = 2; | ||
576 | high = low + GET_MED (2) - 1; | ||
577 | DEC_MED2 (); | ||
578 | } | ||
579 | else { | ||
580 | ones_count = 2 + (value - low) / GET_MED (2); | ||
581 | low += (ones_count - 2) * GET_MED (2); | ||
582 | high = low + GET_MED (2) - 1; | ||
583 | INC_MED2 (); | ||
584 | } | ||
585 | } | ||
586 | } | ||
587 | |||
588 | if (w->holding_zero) { | ||
589 | if (ones_count) | ||
590 | w->holding_one++; | ||
591 | |||
592 | flush_word (w, bs); | ||
593 | |||
594 | if (ones_count) { | ||
595 | w->holding_zero = 1; | ||
596 | ones_count--; | ||
597 | } | ||
598 | else | ||
599 | w->holding_zero = 0; | ||
600 | } | ||
601 | else | ||
602 | w->holding_zero = 1; | ||
603 | |||
604 | w->holding_one = ones_count * 2; | ||
605 | |||
606 | if (high != low) { | ||
607 | uint32_t maxcode = high - low, code = value - low; | ||
608 | int bitcount = count_bits (maxcode); | ||
609 | uint32_t extras = (1L << bitcount) - maxcode - 1; | ||
610 | |||
611 | if (code < extras) { | ||
612 | w->pend_data |= code << w->pend_count; | ||
613 | w->pend_count += bitcount - 1; | ||
614 | } | ||
615 | else { | ||
616 | w->pend_data |= ((code + extras) >> 1) << w->pend_count; | ||
617 | w->pend_count += bitcount - 1; | ||
618 | w->pend_data |= ((code + extras) & 1) << w->pend_count++; | ||
619 | } | ||
620 | } | ||
621 | |||
622 | w->pend_data |= ((int32_t) sign << w->pend_count++); | ||
623 | |||
624 | if (!w->holding_zero) | ||
625 | flush_word (w, bs); | ||
626 | } | ||
627 | } | ||
628 | |||
629 | // Used by send_word() and send_word_lossless() to actually send most the | ||
630 | // accumulated data onto the bitstream. This is also called directly from | ||
631 | // clients when all words have been sent. | ||
632 | |||
633 | void flush_word (struct words_data *w, Bitstream *bs) | ||
634 | { | ||
635 | int cbits; | ||
636 | |||
637 | if (w->zeros_acc) { | ||
638 | cbits = count_bits (w->zeros_acc); | ||
639 | |||
640 | while (cbits--) { | ||
641 | putbit_1 (bs); | ||
642 | } | ||
643 | |||
644 | putbit_0 (bs); | ||
645 | |||
646 | while (w->zeros_acc > 1) { | ||
647 | putbit (w->zeros_acc & 1, bs); | ||
648 | w->zeros_acc >>= 1; | ||
649 | } | ||
650 | |||
651 | w->zeros_acc = 0; | ||
652 | } | ||
653 | |||
654 | if (w->holding_one) { | ||
655 | if (w->holding_one >= LIMIT_ONES) { | ||
656 | putbits ((1L << LIMIT_ONES) - 1, LIMIT_ONES + 1, bs); | ||
657 | w->holding_one -= LIMIT_ONES; | ||
658 | cbits = count_bits (w->holding_one); | ||
659 | |||
660 | while (cbits--) { | ||
661 | putbit_1 (bs); | ||
662 | } | ||
663 | |||
664 | putbit_0 (bs); | ||
665 | |||
666 | while (w->holding_one > 1) { | ||
667 | putbit (w->holding_one & 1, bs); | ||
668 | w->holding_one >>= 1; | ||
669 | } | ||
670 | |||
671 | w->holding_zero = 0; | ||
672 | } | ||
673 | else | ||
674 | putbits ((1L << w->holding_one) - 1, w->holding_one, bs); | ||
675 | |||
676 | w->holding_one = 0; | ||
677 | } | ||
678 | |||
679 | if (w->holding_zero) { | ||
680 | putbit_0 (bs); | ||
681 | w->holding_zero = 0; | ||
682 | } | ||
683 | |||
684 | if (w->pend_count) { | ||
685 | |||
686 | while (w->pend_count > 24) { | ||
687 | putbit (w->pend_data & 1, bs); | ||
688 | w->pend_data >>= 1; | ||
689 | w->pend_count--; | ||
690 | } | ||
691 | |||
692 | putbits (w->pend_data, w->pend_count, bs); | ||
693 | w->pend_data = w->pend_count = 0; | ||
694 | } | ||
695 | } | ||
696 | |||
697 | // The concept of a base 2 logarithm is used in many parts of WavPack. It is | ||
698 | // a way of sufficiently accurately representing 32-bit signed and unsigned | ||
699 | // values storing only 16 bits (actually fewer). It is also used in the hybrid | ||
700 | // mode for quickly comparing the relative magnitude of large values (i.e. | ||
701 | // division) and providing smooth exponentials using only addition. | ||
702 | |||
703 | // These are not strict logarithms in that they become linear around zero and | ||
704 | // can therefore represent both zero and negative values. They have 8 bits | ||
705 | // of precision and in "roundtrip" conversions the total error never exceeds 1 | ||
706 | // part in 225 except for the cases of +/-115 and +/-195 (which error by 1). | ||
707 | |||
708 | |||
709 | // This function returns the log2 for the specified 32-bit unsigned value. | ||
710 | // The maximum value allowed is about 0xff800000 and returns 8447. | ||
711 | |||
712 | static int mylog2 (uint32_t avalue) | ||
713 | { | ||
714 | int dbits; | ||
715 | |||
716 | if ((avalue += avalue >> 9) < (1 << 8)) { | ||
717 | dbits = nbits_table [avalue]; | ||
718 | return (dbits << 8) + log2_table [(avalue << (9 - dbits)) & 0xff]; | ||
719 | } | ||
720 | else { | ||
721 | if (avalue < (1L << 16)) | ||
722 | dbits = nbits_table [avalue >> 8] + 8; | ||
723 | else if (avalue < (1L << 24)) | ||
724 | dbits = nbits_table [avalue >> 16] + 16; | ||
725 | else | ||
726 | dbits = nbits_table [avalue >> 24] + 24; | ||
727 | |||
728 | return (dbits << 8) + log2_table [(avalue >> (dbits - 9)) & 0xff]; | ||
729 | } | ||
730 | } | ||
731 | |||
732 | // This function returns the log2 for the specified 32-bit signed value. | ||
733 | // All input values are valid and the return values are in the range of | ||
734 | // +/- 8192. | ||
735 | |||
736 | int log2s (int32_t value) | ||
737 | { | ||
738 | return (value < 0) ? -mylog2 (-value) : mylog2 (value); | ||
739 | } | ||
740 | |||
741 | // This function returns the original integer represented by the supplied | ||
742 | // logarithm (at least within the provided accuracy). The log is signed, | ||
743 | // but since a full 32-bit value is returned this can be used for unsigned | ||
744 | // conversions as well (i.e. the input range is -8192 to +8447). | ||
745 | |||
746 | int32_t exp2s (int log) | ||
747 | { | ||
748 | uint32_t value; | ||
749 | |||
750 | if (log < 0) | ||
751 | return -exp2s (-log); | ||
752 | |||
753 | value = exp2_table [log & 0xff] | 0x100; | ||
754 | |||
755 | if ((log >>= 8) <= 9) | ||
756 | return value >> (9 - log); | ||
757 | else | ||
758 | return value << (log - 9); | ||
759 | } | ||
760 | |||
761 | // These two functions convert internal weights (which are normally +/-1024) | ||
762 | // to and from an 8-bit signed character version for storage in metadata. The | ||
763 | // weights are clipped here in the case that they are outside that range. | ||
764 | |||
765 | signed char store_weight (int weight) | ||
766 | { | ||
767 | if (weight > 1024) | ||
768 | weight = 1024; | ||
769 | else if (weight < -1024) | ||
770 | weight = -1024; | ||
771 | |||
772 | if (weight > 0) | ||
773 | weight -= (weight + 64) >> 7; | ||
774 | |||
775 | return (weight + 4) >> 3; | ||
776 | } | ||
777 | |||
778 | int restore_weight (signed char weight) | ||
779 | { | ||
780 | int result; | ||
781 | |||
782 | if ((result = (int) weight << 3) > 0) | ||
783 | result += (result + 64) >> 7; | ||
784 | |||
785 | return result; | ||
786 | } | ||