FFmpeg
ffv1dec_template.c
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1 /*
2  * FFV1 decoder template
3  *
4  * Copyright (c) 2003-2016 Michael Niedermayer <michaelni@gmx.at>
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 static av_always_inline int RENAME(decode_line)(FFV1Context *s, int w,
24  TYPE *sample[2],
25  int plane_index, int bits)
26 {
27  PlaneContext *const p = &s->plane[plane_index];
28  RangeCoder *const c = &s->c;
29  int x;
30  int run_count = 0;
31  int run_mode = 0;
32  int run_index = s->run_index;
33 
34  if (is_input_end(s))
35  return AVERROR_INVALIDDATA;
36 
37  if (s->slice_coding_mode == 1) {
38  int i;
39  for (x = 0; x < w; x++) {
40  int v = 0;
41  for (i=0; i<bits; i++) {
42  uint8_t state = 128;
43  v += v + get_rac(c, &state);
44  }
45  sample[1][x] = v;
46  }
47  return 0;
48  }
49 
50  for (x = 0; x < w; x++) {
51  int diff, context, sign;
52 
53  if (!(x & 1023)) {
54  if (is_input_end(s))
55  return AVERROR_INVALIDDATA;
56  }
57 
58  context = RENAME(get_context)(p, sample[1] + x, sample[0] + x, sample[1] + x);
59  if (context < 0) {
60  context = -context;
61  sign = 1;
62  } else
63  sign = 0;
64 
65  av_assert2(context < p->context_count);
66 
67  if (s->ac != AC_GOLOMB_RICE) {
68  diff = get_symbol_inline(c, p->state[context], 1);
69  } else {
70  if (context == 0 && run_mode == 0)
71  run_mode = 1;
72 
73  if (run_mode) {
74  if (run_count == 0 && run_mode == 1) {
75  if (get_bits1(&s->gb)) {
76  run_count = 1 << ff_log2_run[run_index];
77  if (x + run_count <= w)
78  run_index++;
79  } else {
80  if (ff_log2_run[run_index])
81  run_count = get_bits(&s->gb, ff_log2_run[run_index]);
82  else
83  run_count = 0;
84  if (run_index)
85  run_index--;
86  run_mode = 2;
87  }
88  }
89  if (sample[1][x - 1] == sample[0][x - 1]) {
90  while (run_count > 1 && w-x > 1) {
91  sample[1][x] = sample[0][x];
92  x++;
93  run_count--;
94  }
95  } else {
96  while (run_count > 1 && w-x > 1) {
97  sample[1][x] = RENAME(predict)(sample[1] + x, sample[0] + x);
98  x++;
99  run_count--;
100  }
101  }
102  run_count--;
103  if (run_count < 0) {
104  run_mode = 0;
105  run_count = 0;
106  diff = get_vlc_symbol(&s->gb, &p->vlc_state[context],
107  bits);
108  if (diff >= 0)
109  diff++;
110  } else
111  diff = 0;
112  } else
113  diff = get_vlc_symbol(&s->gb, &p->vlc_state[context], bits);
114 
115  ff_dlog(s->avctx, "count:%d index:%d, mode:%d, x:%d pos:%d\n",
116  run_count, run_index, run_mode, x, get_bits_count(&s->gb));
117  }
118 
119  if (sign)
120  diff = -(unsigned)diff;
121 
122  sample[1][x] = av_mod_uintp2(RENAME(predict)(sample[1] + x, sample[0] + x) + (SUINT)diff, bits);
123  }
124  s->run_index = run_index;
125  return 0;
126 }
127 
128 static int RENAME(decode_rgb_frame)(FFV1Context *s, uint8_t *src[4], int w, int h, int stride[4])
129 {
130  int x, y, p;
131  TYPE *sample[4][2];
132  int lbd = s->avctx->bits_per_raw_sample <= 8;
133  int bits = s->avctx->bits_per_raw_sample > 0 ? s->avctx->bits_per_raw_sample : 8;
134  int offset = 1 << bits;
135  int transparency = s->transparency;
136 
137  for (x = 0; x < 4; x++) {
138  sample[x][0] = RENAME(s->sample_buffer) + x * 2 * (w + 6) + 3;
139  sample[x][1] = RENAME(s->sample_buffer) + (x * 2 + 1) * (w + 6) + 3;
140  }
141 
142  s->run_index = 0;
143 
144  memset(RENAME(s->sample_buffer), 0, 8 * (w + 6) * sizeof(*RENAME(s->sample_buffer)));
145 
146  for (y = 0; y < h; y++) {
147  for (p = 0; p < 3 + transparency; p++) {
148  int ret;
149  TYPE *temp = sample[p][0]; // FIXME: try a normal buffer
150 
151  sample[p][0] = sample[p][1];
152  sample[p][1] = temp;
153 
154  sample[p][1][-1]= sample[p][0][0 ];
155  sample[p][0][ w]= sample[p][0][w-1];
156  if (lbd && s->slice_coding_mode == 0)
157  ret = RENAME(decode_line)(s, w, sample[p], (p + 1)/2, 9);
158  else
159  ret = RENAME(decode_line)(s, w, sample[p], (p + 1)/2, bits + (s->slice_coding_mode != 1));
160  if (ret < 0)
161  return ret;
162  }
163  for (x = 0; x < w; x++) {
164  int g = sample[0][1][x];
165  int b = sample[1][1][x];
166  int r = sample[2][1][x];
167  int a = sample[3][1][x];
168 
169  if (s->slice_coding_mode != 1) {
170  b -= offset;
171  r -= offset;
172  g -= (b * s->slice_rct_by_coef + r * s->slice_rct_ry_coef) >> 2;
173  b += g;
174  r += g;
175  }
176 
177  if (lbd)
178  *((uint32_t*)(src[0] + x*4 + stride[0]*y)) = b + ((unsigned)g<<8) + ((unsigned)r<<16) + ((unsigned)a<<24);
179  else if (sizeof(TYPE) == 4 || transparency) {
180  *((uint16_t*)(src[0] + x*2 + stride[0]*y)) = g;
181  *((uint16_t*)(src[1] + x*2 + stride[1]*y)) = b;
182  *((uint16_t*)(src[2] + x*2 + stride[2]*y)) = r;
183  if (transparency)
184  *((uint16_t*)(src[3] + x*2 + stride[3]*y)) = a;
185  } else {
186  *((uint16_t*)(src[0] + x*2 + stride[0]*y)) = b;
187  *((uint16_t*)(src[1] + x*2 + stride[1]*y)) = g;
188  *((uint16_t*)(src[2] + x*2 + stride[2]*y)) = r;
189  }
190  }
191  }
192  return 0;
193 }
const uint8_t ff_log2_run[41]
Definition: bitstream.c:39
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
else temp
Definition: vf_mcdeint.c:256
const char * g
Definition: vf_curves.c:115
#define RENAME(name)
Definition: ffv1.h:197
static av_flatten int get_symbol_inline(RangeCoder *c, uint8_t *state, int is_signed)
Definition: ffv1dec.c:42
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:36
#define SUINT
static av_always_inline void predict(PredictorState *ps, float *coef, int output_enable)
Definition: aacdec.c:174
#define src
Definition: vp8dsp.c:254
#define sample
static int is_input_end(FFV1Context *s)
Definition: ffv1dec.c:96
uint8_t
static int get_rac(RangeCoder *c, uint8_t *const state)
Definition: rangecoder.h:136
#define av_assert2(cond)
assert() equivalent, that does lie in speed critical code.
Definition: avassert.h:64
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
static int get_bits_count(const GetBitContext *s)
Definition: get_bits.h:219
#define ff_dlog(a,...)
VlcState * vlc_state
Definition: ffv1.h:73
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
const char * r
Definition: vf_curves.c:114
uint8_t bits
Definition: vp3data.h:202
static int get_vlc_symbol(GetBitContext *gb, VlcState *const state, int bits)
Definition: ffv1dec.c:71
int run_index
Definition: ffv1.h:109
#define b
Definition: input.c:41
uint8_t w
Definition: llviddspenc.c:38
#define s(width, name)
Definition: cbs_vp9.c:257
int context_count[MAX_QUANT_TABLES]
Definition: ffv1.h:106
static struct @320 state
#define TYPE
Definition: ffv1.h:196
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:498
#define AC_GOLOMB_RICE
Definition: ffv1.h:56
GLint GLenum GLboolean GLsizei stride
Definition: opengl_enc.c:104
uint8_t(* state)[CONTEXT_SIZE]
Definition: ffv1.h:72
int transparency
Definition: ffv1.h:92
static av_always_inline int diff(const uint32_t a, const uint32_t b)
#define av_always_inline
Definition: attributes.h:39
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default minimum maximum flags name is the option keep it simple and lowercase description are in without and describe what they for example set the foo of the bar offset is the offset of the field in your local context