mirror of https://github.com/FFmpeg/FFmpeg.git
Originally committed as revision 8980 to svn://svn.ffmpeg.org/ffmpeg/trunkpull/126/head
Aurelien Jacobs
18 years ago
parent
dccabd4c68
commit
f6bd6eeffd
3 changed files with 188 additions and 154 deletions
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/**
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* @file vorbis_common.c |
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* Common code for Vorbis I encoder and decoder |
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* @author Denes Balatoni ( dbalatoni programozo hu ) |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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* |
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*/ |
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#undef V_DEBUG |
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//#define V_DEBUG
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#define ALT_BITSTREAM_READER_LE |
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#include "avcodec.h" |
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#include "bitstream.h" |
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#include "vorbis.h" |
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/* Helper functions */ |
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unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n) { // x^(1/n)
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unsigned int ret=0, i, j; |
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do { |
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++ret; |
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for(i=0,j=ret;i<n-1;i++) j*=ret; |
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} while (j<=x); |
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return (ret-1); |
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} |
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// Generate vlc codes from vorbis huffman code lengths
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int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, uint_fast32_t num) { |
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uint_fast32_t exit_at_level[33]={404,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; |
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uint_fast8_t i,j; |
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uint_fast32_t code,p; |
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#ifdef V_DEBUG |
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GetBitContext gb; |
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#endif |
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for(p=0;(bits[p]==0) && (p<num);++p); |
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if (p==num) { |
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// av_log(vc->avccontext, AV_LOG_INFO, "An empty codebook. Heh?! \n");
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return 0; |
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} |
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codes[p]=0; |
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for(i=0;i<bits[p];++i) { |
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exit_at_level[i+1]=1<<i; |
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} |
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#ifdef V_DEBUG |
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av_log(NULL, AV_LOG_INFO, " %d. of %d code len %d code %d - ", p, num, bits[p], codes[p]); |
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init_get_bits(&gb, (uint_fast8_t *)&codes[p], bits[p]); |
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for(i=0;i<bits[p];++i) { |
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av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0"); |
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} |
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av_log(NULL, AV_LOG_INFO, "\n"); |
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#endif |
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++p; |
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for(;p<num;++p) { |
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if (bits[p]==0) continue; |
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// find corresponding exit(node which the tree can grow further from)
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for(i=bits[p];i>0;--i) { |
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if (exit_at_level[i]) break; |
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} |
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if (!i) return 1; // overspecified tree
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code=exit_at_level[i]; |
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exit_at_level[i]=0; |
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// construct code (append 0s to end) and introduce new exits
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for(j=i+1;j<=bits[p];++j) { |
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exit_at_level[j]=code+(1<<(j-1)); |
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} |
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codes[p]=code; |
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#ifdef V_DEBUG |
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av_log(NULL, AV_LOG_INFO, " %d. code len %d code %d - ", p, bits[p], codes[p]); |
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init_get_bits(&gb, (uint_fast8_t *)&codes[p], bits[p]); |
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for(i=0;i<bits[p];++i) { |
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av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0"); |
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} |
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av_log(NULL, AV_LOG_INFO, "\n"); |
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#endif |
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} |
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//no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC)
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for (p=1; p<33; p++) |
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if (exit_at_level[p]) return 1; |
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return 0; |
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} |
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void ff_vorbis_ready_floor1_list(floor1_entry_t * list, int values) { |
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int i; |
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list[0].sort = 0; |
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list[1].sort = 1; |
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for (i = 2; i < values; i++) { |
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int j; |
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list[i].low = 0; |
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list[i].high = 1; |
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list[i].sort = i; |
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for (j = 2; j < i; j++) { |
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int tmp = list[j].x; |
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if (tmp < list[i].x) { |
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if (tmp > list[list[i].low].x) list[i].low = j; |
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} else { |
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if (tmp < list[list[i].high].x) list[i].high = j; |
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} |
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} |
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} |
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for (i = 0; i < values - 1; i++) { |
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int j; |
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for (j = i + 1; j < values; j++) { |
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if (list[list[i].sort].x > list[list[j].sort].x) { |
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int tmp = list[i].sort; |
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list[i].sort = list[j].sort; |
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list[j].sort = tmp; |
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} |
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} |
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} |
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} |
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static void render_line(int x0, int y0, int x1, int y1, float * buf, int n) { |
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int dy = y1 - y0; |
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int adx = x1 - x0; |
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int ady = FFABS(dy); |
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int base = dy / adx; |
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int x = x0; |
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int y = y0; |
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int err = 0; |
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int sy; |
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if (dy < 0) sy = base - 1; |
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else sy = base + 1; |
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ady = ady - FFABS(base) * adx; |
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if (x >= n) return; |
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buf[x] = ff_vorbis_floor1_inverse_db_table[y]; |
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for (x = x0 + 1; x < x1; x++) { |
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if (x >= n) return; |
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err += ady; |
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if (err >= adx) { |
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err -= adx; |
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y += sy; |
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} else { |
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y += base; |
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} |
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buf[x] = ff_vorbis_floor1_inverse_db_table[y]; |
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} |
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} |
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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) { |
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int lx, ly, i; |
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lx = 0; |
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ly = y_list[0] * multiplier; |
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for (i = 1; i < values; i++) { |
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int pos = list[i].sort; |
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if (flag[pos]) { |
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render_line(lx, ly, list[pos].x, y_list[pos] * multiplier, out, samples); |
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lx = list[pos].x; |
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ly = y_list[pos] * multiplier; |
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} |
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if (lx >= samples) break; |
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} |
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if (lx < samples) render_line(lx, ly, samples, ly, out, samples); |
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} |
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