2 * This file is part of Libav.
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5 * modify it under the terms of the GNU Lesser General Public
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11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public
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16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 * Common code for Vorbis I encoder and decoder
22 * @author Denes Balatoni ( dbalatoni programozo hu )
25 #include "libavutil/common.h"
31 /* Helper functions */
34 unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n)
36 unsigned int ret = 0, i, j;
40 for (i = 0, j = ret; i < n - 1; i++)
47 // Generate vlc codes from vorbis huffman code lengths
49 // the two bits[p] > 32 checks should be redundant, all calling code should
50 // already ensure that, but since it allows overwriting the stack it seems
51 // reasonable to check redundantly.
52 int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, unsigned num)
54 uint32_t exit_at_level[33] = { 404 };
55 unsigned i, j, p, code;
57 for (p = 0; (bits[p] == 0) && (p < num); ++p)
65 for (i = 0; i < bits[p]; ++i)
66 exit_at_level[i+1] = 1 << i;
70 for (; p < num; ++p) {
75 // find corresponding exit(node which the tree can grow further from)
76 for (i = bits[p]; i > 0; --i)
79 if (!i) // overspecified tree
81 code = exit_at_level[i];
83 // construct code (append 0s to end) and introduce new exits
84 for (j = i + 1 ;j <= bits[p]; ++j)
85 exit_at_level[j] = code + (1 << (j - 1));
89 //no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC)
90 for (p = 1; p < 33; p++)
97 int ff_vorbis_ready_floor1_list(AVCodecContext *avctx,
98 vorbis_floor1_entry *list, int values)
103 for (i = 2; i < values; i++) {
108 for (j = 2; j < i; j++) {
110 if (tmp < list[i].x) {
111 if (tmp > list[list[i].low].x)
114 if (tmp < list[list[i].high].x)
119 for (i = 0; i < values - 1; i++) {
121 for (j = i + 1; j < values; j++) {
122 if (list[i].x == list[j].x) {
123 av_log(avctx, AV_LOG_ERROR,
124 "Duplicate value found in floor 1 X coordinates\n");
125 return AVERROR_INVALIDDATA;
127 if (list[list[i].sort].x > list[list[j].sort].x) {
128 int tmp = list[i].sort;
129 list[i].sort = list[j].sort;
137 static inline void render_line_unrolled(intptr_t x, int y, int x1,
138 intptr_t sy, int ady, int adx,
149 buf[x++] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
151 buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
156 buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
160 static void render_line(int x0, int y0, int x1, int y1, float *buf)
165 int sy = dy < 0 ? -1 : 1;
166 buf[x0] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y0)];
167 if (ady*2 <= adx) { // optimized common case
168 render_line_unrolled(x0, y0, x1, sy, ady, adx, buf);
174 ady -= FFABS(base) * adx;
182 buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
187 void ff_vorbis_floor1_render_list(vorbis_floor1_entry * list, int values,
188 uint16_t *y_list, int *flag,
189 int multiplier, float *out, int samples)
193 ly = y_list[0] * multiplier;
194 for (i = 1; i < values; i++) {
195 int pos = list[i].sort;
197 int x1 = list[pos].x;
198 int y1 = y_list[pos] * multiplier;
200 render_line(lx, ly, FFMIN(x1,samples), y1, out);
208 render_line(lx, ly, samples, ly, out);