FFmpeg: libavcodec/vorbis.c Source File

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 #include "libavutil/error.h"
31 #include "libavutil/log.h"
32 #include "libavutil/macros.h"
33 
34 #include "vorbis.h"
35 #include "vorbis_data.h"
36 
37 
38 /* Helper functions */
39 
40 // x^(1/n)
41  unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n)
42 {
43  unsigned int ret = 0, i, j;
44 
45  do {
46  ++ret;
47  for (i = 0, j = ret; i < n - 1; i++)
48  j *= ret;
49  } while (j <= x);
50 
51  return ret - 1;
52 }
53 
54 // Generate vlc codes from vorbis huffman code lengths
55 
56 // the two bits[p] > 32 checks should be redundant, all calling code should
57 // already ensure that, but since it allows overwriting the stack it seems
58 // reasonable to check redundantly.
59  int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, unsigned num)
60 {
61  uint32_t exit_at_level[33] = { 404 };
62  unsigned i, j, p, code;
63 
64  for (p = 0; (p < num) && (bits[p] == 0); ++p)
65  ;
66  if (p == num)
67  return 0;
68 
69  codes[p] = 0;
70  if (bits[p] > 32)
71  return AVERROR_INVALIDDATA;
72  for (i = 0; i < bits[p]; ++i)
73  exit_at_level[i+1] = 1u << i;
74 
75  ++p;
76 
77  for (i = p; (i < num) && (bits[i] == 0); ++i)
78  ;
79  if (i == num)
80  return 0;
81 
82  for (; p < num; ++p) {
83  if (bits[p] > 32)
84  return AVERROR_INVALIDDATA;
85  if (bits[p] == 0)
86  continue;
87  // find corresponding exit(node which the tree can grow further from)
88  for (i = bits[p]; i > 0; --i)
89  if (exit_at_level[i])
90  break;
91  if (!i) // overspecified tree
92  return AVERROR_INVALIDDATA;
93  code = exit_at_level[i];
94  exit_at_level[i] = 0;
95  // construct code (append 0s to end) and introduce new exits
96  for (j = i + 1 ;j <= bits[p]; ++j)
97  exit_at_level[j] = code + (1u << (j - 1));
98  codes[p] = code;
99  }
100 
101  //no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC)
102  for (p = 1; p < 33; p++)
103  if (exit_at_level[p])
104  return AVERROR_INVALIDDATA;
105 
106  return 0;
107 }
108 
109  int ff_vorbis_ready_floor1_list(void *logctx,
110  vorbis_floor1_entry *list, int values)
111 {
112  int i;
113  list[0].sort = 0;
114  list[1].sort = 1;
115  for (i = 2; i < values; i++) {
116  int j;
117  list[i].low = 0;
118  list[i].high = 1;
119  list[i].sort = i;
120  for (j = 2; j < i; j++) {
121  int tmp = list[j].x;
122  if (tmp < list[i].x) {
123  if (tmp > list[list[i].low].x)
124  list[i].low = j;
125  } else {
126  if (tmp < list[list[i].high].x)
127  list[i].high = j;
128  }
129  }
130  }
131  for (i = 0; i < values - 1; i++) {
132  int j;
133  for (j = i + 1; j < values; j++) {
134  if (list[i].x == list[j].x) {
135  av_log(logctx, AV_LOG_ERROR,
136  "Duplicate value found in floor 1 X coordinates\n");
137  return AVERROR_INVALIDDATA;
138  }
139  if (list[list[i].sort].x > list[list[j].sort].x) {
140  int tmp = list[i].sort;
141  list[i].sort = list[j].sort;
142  list[j].sort = tmp;
143  }
144  }
145  }
146  return 0;
147 }
148 
149  static inline void render_line_unrolled(intptr_t x, int y, int x1,
150  intptr_t sy, int ady, int adx,
151  float *buf)
152 {
153  int err = -adx;
154  x -= x1 - 1;
155  buf += x1 - 1;
156  while (++x < 0) {
157  err += ady;
158  if (err >= 0) {
159  err += ady - adx;
160  y += sy;
161  buf[x++] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
162  }
163  buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
164  }
165  if (x <= 0) {
166  if (err + ady >= 0)
167  y += sy;
168  buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
169  }
170 }
171 
172  static void render_line(int x0, int y0, int x1, int y1, float *buf)
173 {
174  int dy = y1 - y0;
175  int adx = x1 - x0;
176  int ady = FFABS(dy);
177  int sy = dy < 0 ? -1 : 1;
178  buf[x0] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y0)];
179  if (ady*2 <= adx) { // optimized common case
180  render_line_unrolled(x0, y0, x1, sy, ady, adx, buf);
181  } else {
182  int base = dy / adx;
183  int x = x0;
184  int y = y0;
185  int err = -adx;
186  ady -= FFABS(base) * adx;
187  while (++x < x1) {
188  y += base;
189  err += ady;
190  if (err >= 0) {
191  err -= adx;
192  y += sy;
193  }
194  buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
195  }
196  }
197 }
198 
199  void ff_vorbis_floor1_render_list(vorbis_floor1_entry * list, int values,
200  uint16_t *y_list, int *flag,
201  int multiplier, float *out, int samples)
202 {
203  int lx, ly, i;
204  lx = 0;
205  ly = y_list[0] * multiplier;
206  for (i = 1; i < values; i++) {
207  int pos = list[i].sort;
208  if (flag[pos]) {
209  int x1 = list[pos].x;
210  int y1 = y_list[pos] * multiplier;
211  if (lx < samples)
212  render_line(lx, ly, FFMIN(x1,samples), y1, out);
213  lx = x1;
214  ly = y1;
215  }
216  if (lx >= samples)
217  break;
218  }
219  if (lx < samples)
220  render_line(lx, ly, samples, ly, out);
221 }
render_line_unrolled
static void render_line_unrolled(intptr_t x, int y, int x1, intptr_t sy, int ady, int adx, float *buf)
Definition: vorbis.c:149
out
FILE * out
Definition: movenc.c:55
u
#define u(width, name, range_min, range_max)
Definition: cbs_h2645.c:251
ff_vorbis_ready_floor1_list
int ff_vorbis_ready_floor1_list(void *logctx, vorbis_floor1_entry *list, int values)
Definition: vorbis.c:109
tmp
static uint8_t tmp[11]
Definition: aes_ctr.c:28
high
int high
Definition: dovi_rpuenc.c:38
base
uint8_t base
Definition: vp3data.h:128
vorbis_data.h
ff_vorbis_nth_root
unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n)
Definition: vorbis.c:41
macros.h
ff_vorbis_floor1_render_list
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:199
ff_vorbis_floor1_inverse_db_table
const float ff_vorbis_floor1_inverse_db_table[256]
Definition: vorbis_data.c:2117
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
vorbis_floor1_entry
Definition: vorbis.h:26
bits
uint8_t bits
Definition: vp3data.h:128
ff_vorbis_len2vlc
int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, unsigned num)
Definition: vorbis.c:59
FFABS
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:74
list
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
Definition: filter_design.txt:25
error.h
flag
#define flag(name)
Definition: cbs_av1.c:474
log.h
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
code
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
Definition: filter_design.txt:178
vorbis.h
render_line
static void render_line(int x0, int y0, int x1, int y1, float *buf)
Definition: vorbis.c:172
common.h
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
ret
ret
Definition: filter_design.txt:187
pos
unsigned int pos
Definition: spdifenc.c:414
values
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
Definition: filter_design.txt:263
samples
Filter the word "frame" indicates either a video frame or a group of audio samples
Definition: filter_design.txt:8
av_clip_uint8
#define av_clip_uint8
Definition: common.h:106
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
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