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
26 #define ALT_BITSTREAM_READER_LE
28 #include "bitstream.h"
33 /* Helper functions */
35 unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n) { // x^(1/n)
36 unsigned int ret=0, i, j;
40 for(i=0,j=ret;i<n-1;i++) j*=ret;
46 // Generate vlc codes from vorbis huffman code lengths
48 int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, uint_fast32_t num) {
49 uint_fast32_t exit_at_level[33]={404,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
50 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
59 for(p=0;(bits[p]==0) && (p<num);++p);
61 // av_log(vc->avccontext, AV_LOG_INFO, "An empty codebook. Heh?! \n");
66 for(i=0;i<bits[p];++i) {
67 exit_at_level[i+1]=1<<i;
71 av_log(NULL, AV_LOG_INFO, " %d. of %d code len %d code %d - ", p, num, bits[p], codes[p]);
72 init_get_bits(&gb, (uint_fast8_t *)&codes[p], bits[p]);
73 for(i=0;i<bits[p];++i) {
74 av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
76 av_log(NULL, AV_LOG_INFO, "\n");
82 if (bits[p]==0) continue;
83 // find corresponding exit(node which the tree can grow further from)
84 for(i=bits[p];i>0;--i) {
85 if (exit_at_level[i]) break;
87 if (!i) return 1; // overspecified tree
88 code=exit_at_level[i];
90 // construct code (append 0s to end) and introduce new exits
91 for(j=i+1;j<=bits[p];++j) {
92 exit_at_level[j]=code+(1<<(j-1));
97 av_log(NULL, AV_LOG_INFO, " %d. code len %d code %d - ", p, bits[p], codes[p]);
98 init_get_bits(&gb, (uint_fast8_t *)&codes[p], bits[p]);
99 for(i=0;i<bits[p];++i) {
100 av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
102 av_log(NULL, AV_LOG_INFO, "\n");
107 //no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC)
109 if (exit_at_level[p]) return 1;
114 void ff_vorbis_ready_floor1_list(floor1_entry_t * list, int values) {
118 for (i = 2; i < values; i++) {
123 for (j = 2; j < i; j++) {
125 if (tmp < list[i].x) {
126 if (tmp > list[list[i].low].x) list[i].low = j;
128 if (tmp < list[list[i].high].x) list[i].high = j;
132 for (i = 0; i < values - 1; i++) {
134 for (j = i + 1; j < values; j++) {
135 if (list[list[i].sort].x > list[list[j].sort].x) {
136 int tmp = list[i].sort;
137 list[i].sort = list[j].sort;
144 static void render_line(int x0, int y0, int x1, int y1, float * buf) {
148 int ady = FFABS(dy) - FFABS(base) * adx;
152 int sy = dy<0 ? -1 : 1;
153 buf[x] = ff_vorbis_floor1_inverse_db_table[y];
161 buf[x] = ff_vorbis_floor1_inverse_db_table[y];
165 void ff_vorbis_floor1_render_list(floor1_entry_t * list, int values, uint_fast16_t * y_list, int * flag, int multiplier, float * out, int samples) {
168 ly = y_list[0] * multiplier;
169 for (i = 1; i < values; i++) {
170 int pos = list[i].sort;
172 int x1 = list[pos].x;
173 int y1 = y_list[pos] * multiplier;
175 render_line(lx, ly, FFMIN(x1,samples), y1, out);
179 if (lx >= samples) break;
181 if (lx < samples) render_line(lx, ly, samples, ly, out);