diff options
Diffstat (limited to 'contrib/ffmpeg/libavcodec/vorbis.c')
| -rw-r--r-- | contrib/ffmpeg/libavcodec/vorbis.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/contrib/ffmpeg/libavcodec/vorbis.c b/contrib/ffmpeg/libavcodec/vorbis.c new file mode 100644 index 000000000..76d6308b5 --- /dev/null +++ b/contrib/ffmpeg/libavcodec/vorbis.c @@ -0,0 +1,182 @@ +/** + * @file vorbis.c + * Common code for Vorbis I encoder and decoder + * @author Denes Balatoni ( dbalatoni programozo hu ) + + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#undef V_DEBUG +//#define V_DEBUG + +#define ALT_BITSTREAM_READER_LE +#include "avcodec.h" +#include "bitstream.h" + +#include "vorbis.h" + + +/* Helper functions */ + +unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n) { // x^(1/n) + unsigned int ret=0, i, j; + + do { + ++ret; + for(i=0,j=ret;i<n-1;i++) j*=ret; + } while (j<=x); + + return (ret-1); +} + +// Generate vlc codes from vorbis huffman code lengths + +int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, uint_fast32_t num) { + uint_fast32_t exit_at_level[33]={404,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; + + uint_fast8_t i,j; + uint_fast32_t code,p; + +#ifdef V_DEBUG + GetBitContext gb; +#endif + + for(p=0;(bits[p]==0) && (p<num);++p); + if (p==num) { +// av_log(vc->avccontext, AV_LOG_INFO, "An empty codebook. Heh?! \n"); + return 0; + } + + codes[p]=0; + for(i=0;i<bits[p];++i) { + exit_at_level[i+1]=1<<i; + } + +#ifdef V_DEBUG + av_log(NULL, AV_LOG_INFO, " %d. of %d code len %d code %d - ", p, num, bits[p], codes[p]); + init_get_bits(&gb, (uint_fast8_t *)&codes[p], bits[p]); + for(i=0;i<bits[p];++i) { + av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0"); + } + av_log(NULL, AV_LOG_INFO, "\n"); +#endif + + ++p; + + for(;p<num;++p) { + if (bits[p]==0) continue; + // find corresponding exit(node which the tree can grow further from) + for(i=bits[p];i>0;--i) { + if (exit_at_level[i]) break; + } + if (!i) return 1; // overspecified tree + code=exit_at_level[i]; + exit_at_level[i]=0; + // construct code (append 0s to end) and introduce new exits + for(j=i+1;j<=bits[p];++j) { + exit_at_level[j]=code+(1<<(j-1)); + } + codes[p]=code; + +#ifdef V_DEBUG + av_log(NULL, AV_LOG_INFO, " %d. code len %d code %d - ", p, bits[p], codes[p]); + init_get_bits(&gb, (uint_fast8_t *)&codes[p], bits[p]); + for(i=0;i<bits[p];++i) { + av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0"); + } + av_log(NULL, AV_LOG_INFO, "\n"); +#endif + + } + + //no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC) + for (p=1; p<33; p++) + if (exit_at_level[p]) return 1; + + return 0; +} + +void ff_vorbis_ready_floor1_list(floor1_entry_t * list, int values) { + int i; + list[0].sort = 0; + list[1].sort = 1; + for (i = 2; i < values; i++) { + int j; + list[i].low = 0; + list[i].high = 1; + list[i].sort = i; + for (j = 2; j < i; j++) { + int tmp = list[j].x; + if (tmp < list[i].x) { + if (tmp > list[list[i].low].x) list[i].low = j; + } else { + if (tmp < list[list[i].high].x) list[i].high = j; + } + } + } + for (i = 0; i < values - 1; i++) { + int j; + for (j = i + 1; j < values; j++) { + if (list[list[i].sort].x > list[list[j].sort].x) { + int tmp = list[i].sort; + list[i].sort = list[j].sort; + list[j].sort = tmp; + } + } + } +} + +static void render_line(int x0, int y0, int x1, int y1, float * buf) { + int dy = y1 - y0; + int adx = x1 - x0; + int base = dy / adx; + int ady = FFABS(dy) - FFABS(base) * adx; + int x = x0; + int y = y0; + int err = 0; + int sy = dy<0 ? -1 : 1; + buf[x] = ff_vorbis_floor1_inverse_db_table[y]; + while (++x < x1) { + err += ady; + if (err >= adx) { + err -= adx; + y += sy; + } + y += base; + buf[x] = ff_vorbis_floor1_inverse_db_table[y]; + } +} + +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) { + int lx, ly, i; + lx = 0; + ly = y_list[0] * multiplier; + for (i = 1; i < values; i++) { + int pos = list[i].sort; + if (flag[pos]) { + int x1 = list[pos].x; + int y1 = y_list[pos] * multiplier; + if (lx < samples) + render_line(lx, ly, FFMIN(x1,samples), y1, out); + lx = x1; + ly = y1; + } + if (lx >= samples) break; + } + if (lx < samples) render_line(lx, ly, samples, ly, out); +} |