3 * Common code for Vorbis I encoder and decoder
4 * @author Denes Balatoni ( dbalatoni programozo hu )
6 * This file is part of Libav.
8 * Libav is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * Libav is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with Libav; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26 #define ALT_BITSTREAM_READER_LE
33 /* Helper functions */
36 unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n)
38 unsigned int ret = 0, i, j;
42 for (i = 0, j = ret; i < n - 1; i++)
49 // Generate vlc codes from vorbis huffman code lengths
51 // the two bits[p] > 32 checks should be redundant, all calling code should
52 // already ensure that, but since it allows overwriting the stack it seems
53 // reasonable to check redundantly.
54 int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, unsigned num)
56 uint32_t exit_at_level[33] = { 404 };
58 unsigned i, j, p, code;
64 for (p = 0; (bits[p] == 0) && (p < num); ++p)
67 // av_log(vc->avccontext, AV_LOG_INFO, "An empty codebook. Heh?! \n");
74 for (i = 0; i < bits[p]; ++i)
75 exit_at_level[i+1] = 1 << i;
78 av_log(NULL, AV_LOG_INFO, " %u. of %u code len %d code %d - ", p, num, bits[p], codes[p]);
79 init_get_bits(&gb, (uint8_t *)&codes[p], bits[p]);
80 for (i = 0; i < bits[p]; ++i)
81 av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
82 av_log(NULL, AV_LOG_INFO, "\n");
87 for (; p < num; ++p) {
92 // find corresponding exit(node which the tree can grow further from)
93 for (i = bits[p]; i > 0; --i)
96 if (!i) // overspecified tree
98 code = exit_at_level[i];
100 // construct code (append 0s to end) and introduce new exits
101 for (j = i + 1 ;j <= bits[p]; ++j)
102 exit_at_level[j] = code + (1 << (j - 1));
106 av_log(NULL, AV_LOG_INFO, " %d. code len %d code %d - ", p, bits[p], codes[p]);
107 init_get_bits(&gb, (uint8_t *)&codes[p], bits[p]);
108 for (i = 0; i < bits[p]; ++i)
109 av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
110 av_log(NULL, AV_LOG_INFO, "\n");
115 //no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC)
116 for (p = 1; p < 33; p++)
117 if (exit_at_level[p])
123 void ff_vorbis_ready_floor1_list(vorbis_floor1_entry * list, int values)
128 for (i = 2; i < values; i++) {
133 for (j = 2; j < i; j++) {
135 if (tmp < list[i].x) {
136 if (tmp > list[list[i].low].x)
139 if (tmp < list[list[i].high].x)
144 for (i = 0; i < values - 1; i++) {
146 for (j = i + 1; j < values; j++) {
147 if (list[list[i].sort].x > list[list[j].sort].x) {
148 int tmp = list[i].sort;
149 list[i].sort = list[j].sort;
156 static inline void render_line_unrolled(intptr_t x, intptr_t y, int x1,
157 intptr_t sy, int ady, int adx,
168 buf[x++] = ff_vorbis_floor1_inverse_db_table[y];
170 buf[x] = ff_vorbis_floor1_inverse_db_table[y];
175 buf[x] = ff_vorbis_floor1_inverse_db_table[y];
179 static void render_line(int x0, int y0, int x1, int y1, float *buf)
184 int sy = dy < 0 ? -1 : 1;
185 buf[x0] = ff_vorbis_floor1_inverse_db_table[y0];
186 if (ady*2 <= adx) { // optimized common case
187 render_line_unrolled(x0, y0, x1, sy, ady, adx, buf);
193 ady -= FFABS(base) * adx;
201 buf[x] = ff_vorbis_floor1_inverse_db_table[y];
206 void ff_vorbis_floor1_render_list(vorbis_floor1_entry * list, int values,
207 uint16_t *y_list, int *flag,
208 int multiplier, float *out, int samples)
212 ly = y_list[0] * multiplier;
213 for (i = 1; i < values; i++) {
214 int pos = list[i].sort;
216 int x1 = list[pos].x;
217 int y1 = y_list[pos] * multiplier;
219 render_line(lx, ly, FFMIN(x1,samples), y1, out);
227 render_line(lx, ly, samples, ly, out);