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vorbis.c
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1 /**
2  * @file
3  * Common code for Vorbis I encoder and decoder
4  * @author Denes Balatoni ( dbalatoni programozo hu )
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /**
24  * @file
25  * Common code for Vorbis I encoder and decoder
26  * @author Denes Balatoni ( dbalatoni programozo hu )
27  */
28 
29 #define BITSTREAM_READER_LE
30 #include "avcodec.h"
31 #include "get_bits.h"
32 
33 #include "vorbis.h"
34 
35 
36 /* Helper functions */
37 
38 // x^(1/n)
39 unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n)
40 {
41  unsigned int ret = 0, i, j;
42 
43  do {
44  ++ret;
45  for (i = 0, j = ret; i < n - 1; i++)
46  j *= ret;
47  } while (j <= x);
48 
49  return ret - 1;
50 }
51 
52 // Generate vlc codes from vorbis huffman code lengths
53 
54 // the two bits[p] > 32 checks should be redundant, all calling code should
55 // already ensure that, but since it allows overwriting the stack it seems
56 // reasonable to check redundantly.
57 int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, unsigned num)
58 {
59  uint32_t exit_at_level[33] = { 404 };
60 
61  unsigned i, j, p, code;
62 
63 #ifdef DEBUG
64  GetBitContext gb;
65 #endif
66 
67  for (p = 0; (bits[p] == 0) && (p < num); ++p)
68  ;
69  if (p == num)
70  return 0;
71 
72  codes[p] = 0;
73  if (bits[p] > 32)
74  return AVERROR_INVALIDDATA;
75  for (i = 0; i < bits[p]; ++i)
76  exit_at_level[i+1] = 1 << i;
77 
78 #ifdef DEBUG
79  av_log(NULL, AV_LOG_INFO, " %u. of %u code len %d code %d - ", p, num, bits[p], codes[p]);
80  init_get_bits(&gb, (uint8_t *)&codes[p], bits[p]);
81  for (i = 0; i < bits[p]; ++i)
82  av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
83  av_log(NULL, AV_LOG_INFO, "\n");
84 #endif
85 
86  ++p;
87 
88  for (i = p; (bits[i] == 0) && (i < num); ++i)
89  ;
90  if (i == num)
91  return 0;
92 
93  for (; p < num; ++p) {
94  if (bits[p] > 32)
95  return AVERROR_INVALIDDATA;
96  if (bits[p] == 0)
97  continue;
98  // find corresponding exit(node which the tree can grow further from)
99  for (i = bits[p]; i > 0; --i)
100  if (exit_at_level[i])
101  break;
102  if (!i) // overspecified tree
103  return AVERROR_INVALIDDATA;
104  code = exit_at_level[i];
105  exit_at_level[i] = 0;
106  // construct code (append 0s to end) and introduce new exits
107  for (j = i + 1 ;j <= bits[p]; ++j)
108  exit_at_level[j] = code + (1 << (j - 1));
109  codes[p] = code;
110 
111 #ifdef DEBUG
112  av_log(NULL, AV_LOG_INFO, " %d. code len %d code %d - ", p, bits[p], codes[p]);
113  init_get_bits(&gb, (uint8_t *)&codes[p], bits[p]);
114  for (i = 0; i < bits[p]; ++i)
115  av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
116  av_log(NULL, AV_LOG_INFO, "\n");
117 #endif
118 
119  }
120 
121  //no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC)
122  for (p = 1; p < 33; p++)
123  if (exit_at_level[p])
124  return AVERROR_INVALIDDATA;
125 
126  return 0;
127 }
128 
130  vorbis_floor1_entry *list, int values)
131 {
132  int i;
133  list[0].sort = 0;
134  list[1].sort = 1;
135  for (i = 2; i < values; i++) {
136  int j;
137  list[i].low = 0;
138  list[i].high = 1;
139  list[i].sort = i;
140  for (j = 2; j < i; j++) {
141  int tmp = list[j].x;
142  if (tmp < list[i].x) {
143  if (tmp > list[list[i].low].x)
144  list[i].low = j;
145  } else {
146  if (tmp < list[list[i].high].x)
147  list[i].high = j;
148  }
149  }
150  }
151  for (i = 0; i < values - 1; i++) {
152  int j;
153  for (j = i + 1; j < values; j++) {
154  if (list[i].x == list[j].x) {
155  av_log(avctx, AV_LOG_ERROR,
156  "Duplicate value found in floor 1 X coordinates\n");
157  return AVERROR_INVALIDDATA;
158  }
159  if (list[list[i].sort].x > list[list[j].sort].x) {
160  int tmp = list[i].sort;
161  list[i].sort = list[j].sort;
162  list[j].sort = tmp;
163  }
164  }
165  }
166  return 0;
167 }
168 
169 static inline void render_line_unrolled(intptr_t x, int y, int x1,
170  intptr_t sy, int ady, int adx,
171  float *buf)
172 {
173  int err = -adx;
174  x -= x1 - 1;
175  buf += x1 - 1;
176  while (++x < 0) {
177  err += ady;
178  if (err >= 0) {
179  err += ady - adx;
180  y += sy;
181  buf[x++] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
182  }
183  buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
184  }
185  if (x <= 0) {
186  if (err + ady >= 0)
187  y += sy;
188  buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
189  }
190 }
191 
192 static void render_line(int x0, int y0, int x1, int y1, float *buf)
193 {
194  int dy = y1 - y0;
195  int adx = x1 - x0;
196  int ady = FFABS(dy);
197  int sy = dy < 0 ? -1 : 1;
198  buf[x0] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y0)];
199  if (ady*2 <= adx) { // optimized common case
200  render_line_unrolled(x0, y0, x1, sy, ady, adx, buf);
201  } else {
202  int base = dy / adx;
203  int x = x0;
204  int y = y0;
205  int err = -adx;
206  ady -= FFABS(base) * adx;
207  while (++x < x1) {
208  y += base;
209  err += ady;
210  if (err >= 0) {
211  err -= adx;
212  y += sy;
213  }
214  buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
215  }
216  }
217 }
218 
220  uint16_t *y_list, int *flag,
221  int multiplier, float *out, int samples)
222 {
223  int lx, ly, i;
224  lx = 0;
225  ly = y_list[0] * multiplier;
226  for (i = 1; i < values; i++) {
227  int pos = list[i].sort;
228  if (flag[pos]) {
229  int x1 = list[pos].x;
230  int y1 = y_list[pos] * multiplier;
231  if (lx < samples)
232  render_line(lx, ly, FFMIN(x1,samples), y1, out);
233  lx = x1;
234  ly = y1;
235  }
236  if (lx >= samples)
237  break;
238  }
239  if (lx < samples)
240  render_line(lx, ly, samples, ly, out);
241 }
#define NULL
Definition: coverity.c:32
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n)
Definition: vorbis.c:39
const float ff_vorbis_floor1_inverse_db_table[256]
Definition: vorbis_data.c:2123
uint16_t sort
Definition: vorbis.h:34
uint8_t bits
Definition: crc.c:296
uint8_t
static void render_line(int x0, int y0, int x1, int y1, float *buf)
Definition: vorbis.c:192
bitstream reader API header.
#define av_log(a,...)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
uint16_t x
Definition: vorbis.h:33
int flag
Definition: cpu-test.c:33
#define FFMIN(a, b)
Definition: common.h:96
static uint8_t tmp[8]
Definition: des-test.c:38
int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, unsigned num)
Definition: vorbis.c:57
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:72
int n
Definition: avisynth_c.h:547
FILE * out
Definition: movenc-test.c:54
#define AV_LOG_INFO
Standard information.
Definition: log.h:187
Libavcodec external API header.
main external API structure.
Definition: avcodec.h:1642
uint16_t low
Definition: vorbis.h:35
void * buf
Definition: avisynth_c.h:553
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:312
uint16_t high
Definition: vorbis.h:36
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:418
static void render_line_unrolled(intptr_t x, int y, int x1, intptr_t sy, int ady, int adx, float *buf)
Definition: vorbis.c:169
void ff_vorbis_floor1_render_list(vorbis_floor1_entry *list, int values, uint16_t *y_list, int *flag, int multiplier, float *out, int samples)
Definition: vorbis.c:219
Definition: vorbis.h:32
int ff_vorbis_ready_floor1_list(AVCodecContext *avctx, vorbis_floor1_entry *list, int values)
Definition: vorbis.c:129