3 * Common code for Vorbis I encoder and decoder
4 * @author Denes Balatoni ( dbalatoni programozo hu )
6 * This file is part of FFmpeg.
8 * FFmpeg 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 * FFmpeg 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 FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 * Common code for Vorbis I encoder and decoder
26 * @author Denes Balatoni ( dbalatoni programozo hu )
29 #define BITSTREAM_READER_LE
36 /* Helper functions */
39 unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n)
41 unsigned int ret = 0, i, j;
45 for (i = 0, j = ret; i < n - 1; i++)
52 // Generate vlc codes from vorbis huffman code lengths
54 // the two bits[p] > 32 checks should be redundant, all calling code should
55 // already ensure that, but since it allows overwriting the stack it seems
56 // reasonable to check redundantly.
57 int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, unsigned num)
59 uint32_t exit_at_level[33] = { 404 };
61 unsigned i, j, p, code;
67 for (p = 0; (bits[p] == 0) && (p < num); ++p)
70 // av_log(vc->avccontext, AV_LOG_INFO, "An empty codebook. Heh?! \n");
77 for (i = 0; i < bits[p]; ++i)
78 exit_at_level[i+1] = 1 << i;
81 av_log(NULL, AV_LOG_INFO, " %u. of %u code len %d code %d - ", p, num, bits[p], codes[p]);
82 init_get_bits(&gb, (uint8_t *)&codes[p], bits[p]);
83 for (i = 0; i < bits[p]; ++i)
84 av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
85 av_log(NULL, AV_LOG_INFO, "\n");
90 for (; p < num; ++p) {
95 // find corresponding exit(node which the tree can grow further from)
96 for (i = bits[p]; i > 0; --i)
99 if (!i) // overspecified tree
101 code = exit_at_level[i];
102 exit_at_level[i] = 0;
103 // construct code (append 0s to end) and introduce new exits
104 for (j = i + 1 ;j <= bits[p]; ++j)
105 exit_at_level[j] = code + (1 << (j - 1));
109 av_log(NULL, AV_LOG_INFO, " %d. code len %d code %d - ", p, bits[p], codes[p]);
110 init_get_bits(&gb, (uint8_t *)&codes[p], bits[p]);
111 for (i = 0; i < bits[p]; ++i)
112 av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
113 av_log(NULL, AV_LOG_INFO, "\n");
118 //no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC)
119 for (p = 1; p < 33; p++)
120 if (exit_at_level[p])
126 void ff_vorbis_ready_floor1_list(vorbis_floor1_entry * list, int values)
131 for (i = 2; i < values; i++) {
136 for (j = 2; j < i; j++) {
138 if (tmp < list[i].x) {
139 if (tmp > list[list[i].low].x)
142 if (tmp < list[list[i].high].x)
147 for (i = 0; i < values - 1; i++) {
149 for (j = i + 1; j < values; j++) {
150 if (list[list[i].sort].x > list[list[j].sort].x) {
151 int tmp = list[i].sort;
152 list[i].sort = list[j].sort;
159 static inline void render_line_unrolled(intptr_t x, uint8_t y, int x1,
160 intptr_t sy, int ady, int adx,
171 buf[x++] = ff_vorbis_floor1_inverse_db_table[y];
173 buf[x] = ff_vorbis_floor1_inverse_db_table[y];
178 buf[x] = ff_vorbis_floor1_inverse_db_table[y];
182 static void render_line(int x0, uint8_t y0, int x1, int y1, float *buf)
187 int sy = dy < 0 ? -1 : 1;
188 buf[x0] = ff_vorbis_floor1_inverse_db_table[y0];
189 if (ady*2 <= adx) { // optimized common case
190 render_line_unrolled(x0, y0, x1, sy, ady, adx, buf);
196 ady -= FFABS(base) * adx;
204 buf[x] = ff_vorbis_floor1_inverse_db_table[y];
209 void ff_vorbis_floor1_render_list(vorbis_floor1_entry * list, int values,
210 uint16_t *y_list, int *flag,
211 int multiplier, float *out, int samples)
216 ly = y_list[0] * multiplier;
217 for (i = 1; i < values; i++) {
218 int pos = list[i].sort;
220 int x1 = list[pos].x;
221 int y1 = y_list[pos] * multiplier;
223 render_line(lx, ly, FFMIN(x1,samples), y1, out);
231 render_line(lx, ly, samples, ly, out);