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Diffstat (limited to 'ffmpeg/libavcodec/vorbis.c')
| -rw-r--r-- | ffmpeg/libavcodec/vorbis.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/ffmpeg/libavcodec/vorbis.c b/ffmpeg/libavcodec/vorbis.c new file mode 100644 index 0000000..6eb765d --- /dev/null +++ b/ffmpeg/libavcodec/vorbis.c @@ -0,0 +1,236 @@ +/** + * @file + * 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 + */ + +/** + * @file + * Common code for Vorbis I encoder and decoder + * @author Denes Balatoni ( dbalatoni programozo hu ) + */ + +#define BITSTREAM_READER_LE +#include "avcodec.h" +#include "get_bits.h" + +#include "vorbis.h" + + +/* Helper functions */ + +// x^(1/n) +unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int 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 + +// the two bits[p] > 32 checks should be redundant, all calling code should +// already ensure that, but since it allows overwriting the stack it seems +// reasonable to check redundantly. +int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, unsigned num) +{ + uint32_t exit_at_level[33] = { 404 }; + + unsigned i, j, p, code; + +#ifdef DEBUG + GetBitContext gb; +#endif + + for (p = 0; (bits[p] == 0) && (p < num); ++p) + ; + if (p == num) + return 0; + + codes[p] = 0; + if (bits[p] > 32) + return 1; + for (i = 0; i < bits[p]; ++i) + exit_at_level[i+1] = 1 << i; + +#ifdef DEBUG + av_log(NULL, AV_LOG_INFO, " %u. of %u code len %d code %d - ", p, num, bits[p], codes[p]); + init_get_bits(&gb, (uint8_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] > 32) + return 1; + 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) // overspecified tree + return 1; + 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 DEBUG + av_log(NULL, AV_LOG_INFO, " %d. code len %d code %d - ", p, bits[p], codes[p]); + init_get_bits(&gb, (uint8_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; +} + +int ff_vorbis_ready_floor1_list(AVCodecContext *avctx, + vorbis_floor1_entry *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[i].x == list[j].x) { + av_log(avctx, AV_LOG_ERROR, + "Duplicate value found in floor 1 X coordinates\n"); + return AVERROR_INVALIDDATA; + } + 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; + } + } + } + return 0; +} + +static inline void render_line_unrolled(intptr_t x, int y, int x1, + intptr_t sy, int ady, int adx, + float *buf) +{ + int err = -adx; + x -= x1 - 1; + buf += x1 - 1; + while (++x < 0) { + err += ady; + if (err >= 0) { + err += ady - adx; + y += sy; + buf[x++] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)]; + } + buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)]; + } + if (x <= 0) { + if (err + ady >= 0) + y += sy; + buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)]; + } +} + +static void render_line(int x0, int y0, int x1, int y1, float *buf) +{ + int dy = y1 - y0; + int adx = x1 - x0; + int ady = FFABS(dy); + int sy = dy < 0 ? -1 : 1; + buf[x0] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y0)]; + if (ady*2 <= adx) { // optimized common case + render_line_unrolled(x0, y0, x1, sy, ady, adx, buf); + } else { + int base = dy / adx; + int x = x0; + int y = y0; + int err = -adx; + ady -= FFABS(base) * adx; + while (++x < x1) { + y += base; + err += ady; + if (err >= 0) { + err -= adx; + y += sy; + } + buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)]; + } + } +} + +void ff_vorbis_floor1_render_list(vorbis_floor1_entry * list, int values, + uint16_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); +} |