| /** |
| * @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 AVERROR_INVALIDDATA; |
| 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 (i = p; (bits[i] == 0) && (i < num); ++i) |
| ; |
| if (i == num) |
| return 0; |
| |
| for (; p < num; ++p) { |
| if (bits[p] > 32) |
| return AVERROR_INVALIDDATA; |
| 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 AVERROR_INVALIDDATA; |
| 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 AVERROR_INVALIDDATA; |
| |
| 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); |
| } |
