FFmpeg
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 #include "libavutil/common.h"
30 
31 #include "avcodec.h"
32 #include "vorbis.h"
33 
34 
35 /* Helper functions */
36 
37 // x^(1/n)
38 unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n)
39 {
40  unsigned int ret = 0, i, j;
41 
42  do {
43  ++ret;
44  for (i = 0, j = ret; i < n - 1; i++)
45  j *= ret;
46  } while (j <= x);
47 
48  return ret - 1;
49 }
50 
51 // Generate vlc codes from vorbis huffman code lengths
52 
53 // the two bits[p] > 32 checks should be redundant, all calling code should
54 // already ensure that, but since it allows overwriting the stack it seems
55 // reasonable to check redundantly.
56 int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, unsigned num)
57 {
58  uint32_t exit_at_level[33] = { 404 };
59  unsigned i, j, p, code;
60 
61  for (p = 0; (p < num) && (bits[p] == 0); ++p)
62  ;
63  if (p == num)
64  return 0;
65 
66  codes[p] = 0;
67  if (bits[p] > 32)
68  return AVERROR_INVALIDDATA;
69  for (i = 0; i < bits[p]; ++i)
70  exit_at_level[i+1] = 1u << i;
71 
72  ++p;
73 
74  for (i = p; (i < num) && (bits[i] == 0); ++i)
75  ;
76  if (i == num)
77  return 0;
78 
79  for (; p < num; ++p) {
80  if (bits[p] > 32)
81  return AVERROR_INVALIDDATA;
82  if (bits[p] == 0)
83  continue;
84  // find corresponding exit(node which the tree can grow further from)
85  for (i = bits[p]; i > 0; --i)
86  if (exit_at_level[i])
87  break;
88  if (!i) // overspecified tree
89  return AVERROR_INVALIDDATA;
90  code = exit_at_level[i];
91  exit_at_level[i] = 0;
92  // construct code (append 0s to end) and introduce new exits
93  for (j = i + 1 ;j <= bits[p]; ++j)
94  exit_at_level[j] = code + (1u << (j - 1));
95  codes[p] = code;
96  }
97 
98  //no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC)
99  for (p = 1; p < 33; p++)
100  if (exit_at_level[p])
101  return AVERROR_INVALIDDATA;
102 
103  return 0;
104 }
105 
108 {
109  int i;
110  list[0].sort = 0;
111  list[1].sort = 1;
112  for (i = 2; i < values; i++) {
113  int j;
114  list[i].low = 0;
115  list[i].high = 1;
116  list[i].sort = i;
117  for (j = 2; j < i; j++) {
118  int tmp = list[j].x;
119  if (tmp < list[i].x) {
120  if (tmp > list[list[i].low].x)
121  list[i].low = j;
122  } else {
123  if (tmp < list[list[i].high].x)
124  list[i].high = j;
125  }
126  }
127  }
128  for (i = 0; i < values - 1; i++) {
129  int j;
130  for (j = i + 1; j < values; j++) {
131  if (list[i].x == list[j].x) {
132  av_log(avctx, AV_LOG_ERROR,
133  "Duplicate value found in floor 1 X coordinates\n");
134  return AVERROR_INVALIDDATA;
135  }
136  if (list[list[i].sort].x > list[list[j].sort].x) {
137  int tmp = list[i].sort;
138  list[i].sort = list[j].sort;
139  list[j].sort = tmp;
140  }
141  }
142  }
143  return 0;
144 }
145 
146 static inline void render_line_unrolled(intptr_t x, int y, int x1,
147  intptr_t sy, int ady, int adx,
148  float *buf)
149 {
150  int err = -adx;
151  x -= x1 - 1;
152  buf += x1 - 1;
153  while (++x < 0) {
154  err += ady;
155  if (err >= 0) {
156  err += ady - adx;
157  y += sy;
158  buf[x++] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
159  }
160  buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
161  }
162  if (x <= 0) {
163  if (err + ady >= 0)
164  y += sy;
165  buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
166  }
167 }
168 
169 static void render_line(int x0, int y0, int x1, int y1, float *buf)
170 {
171  int dy = y1 - y0;
172  int adx = x1 - x0;
173  int ady = FFABS(dy);
174  int sy = dy < 0 ? -1 : 1;
175  buf[x0] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y0)];
176  if (ady*2 <= adx) { // optimized common case
177  render_line_unrolled(x0, y0, x1, sy, ady, adx, buf);
178  } else {
179  int base = dy / adx;
180  int x = x0;
181  int y = y0;
182  int err = -adx;
183  ady -= FFABS(base) * adx;
184  while (++x < x1) {
185  y += base;
186  err += ady;
187  if (err >= 0) {
188  err -= adx;
189  y += sy;
190  }
191  buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
192  }
193  }
194 }
195 
197  uint16_t *y_list, int *flag,
198  int multiplier, float *out, int samples)
199 {
200  int lx, ly, i;
201  lx = 0;
202  ly = y_list[0] * multiplier;
203  for (i = 1; i < values; i++) {
204  int pos = list[i].sort;
205  if (flag[pos]) {
206  int x1 = list[pos].x;
207  int y1 = y_list[pos] * multiplier;
208  if (lx < samples)
209  render_line(lx, ly, FFMIN(x1,samples), y1, out);
210  lx = x1;
211  ly = y1;
212  }
213  if (lx >= samples)
214  break;
215  }
216  if (lx < samples)
217  render_line(lx, ly, samples, ly, out);
218 }
#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:38
const float ff_vorbis_floor1_inverse_db_table[256]
Definition: vorbis_data.c:2123
uint16_t sort
Definition: vorbis.h:34
uint8_t base
Definition: vp3data.h:202
uint8_t
static void render_line(int x0, int y0, int x1, int y1, float *buf)
Definition: vorbis.c:169
#define u(width, name, range_min, range_max)
Definition: cbs_h2645.c:252
#define av_log(a,...)
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
uint16_t x
Definition: vorbis.h:33
uint8_t bits
Definition: vp3data.h:202
#define FFMIN(a, b)
Definition: common.h:96
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return values
int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, unsigned num)
Definition: vorbis.c:56
#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:760
Libavcodec external API header.
main external API structure.
Definition: avcodec.h:1568
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining list
uint16_t low
Definition: vorbis.h:35
void * buf
Definition: avisynth_c.h:766
uint16_t high
Definition: vorbis.h:36
and forward the test the status of outputs and forward it to the corresponding return FFERROR_NOT_READY If the filters stores internally one or a few frame for some it can consider them to be part of the FIFO and delay acknowledging a status change accordingly Example code
common internal and external API header
#define flag(name)
Definition: cbs_av1.c:553
static void render_line_unrolled(intptr_t x, int y, int x1, intptr_t sy, int ady, int adx, float *buf)
Definition: vorbis.c:146
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:196
FILE * out
Definition: movenc.c:54
Filter the word “frame” indicates either a video frame or a group of audio samples
Definition: vorbis.h:32
int ff_vorbis_ready_floor1_list(AVCodecContext *avctx, vorbis_floor1_entry *list, int values)
Definition: vorbis.c:106
static uint8_t tmp[11]
Definition: aes_ctr.c:26