ffv1.h
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1 /*
2  * FFV1 codec for libavcodec
3  *
4  * Copyright (c) 2003-2012 Michael Niedermayer <michaelni@gmx.at>
5  *
6  * This file is part of Libav.
7  *
8  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #ifndef AVCODEC_FFV1_H
24 #define AVCODEC_FFV1_H
25 
26 #include <stdint.h>
27 
28 #include "avcodec.h"
29 #include "dsputil.h"
30 #include "get_bits.h"
31 #include "put_bits.h"
32 #include "rangecoder.h"
33 
34 #define MAX_PLANES 4
35 #define CONTEXT_SIZE 32
36 
37 #define MAX_QUANT_TABLES 8
38 #define MAX_CONTEXT_INPUTS 5
39 
40 extern const uint8_t ff_log2_run[41];
41 
42 extern const int8_t ffv1_quant5_10bit[256];
43 extern const int8_t ffv1_quant5[256];
44 extern const int8_t ffv1_quant9_10bit[256];
45 extern const int8_t ffv1_quant11[256];
46 extern const uint8_t ffv1_ver2_state[256];
47 
48 typedef struct VlcState {
49  int16_t drift;
50  uint16_t error_sum;
51  int8_t bias;
53 } VlcState;
54 
55 typedef struct PlaneContext {
62 } PlaneContext;
63 
64 #define MAX_SLICES 256
65 
66 typedef struct FFV1Context {
67  AVClass *class;
72  uint64_t rc_stat[256][2];
73  uint64_t (*rc_stat2[MAX_QUANT_TABLES])[32][2];
74  int version;
76  int width, height;
80  int flags;
84  int ac; // 1 = range coder <-> 0 = golomb rice
85  int ac_byte_count; // number of bytes used for AC coding
92  int run_index;
94  int16_t *sample_buffer;
95 
96  int ec;
99 
102 
105 
107 
114  int slice_x;
115  int slice_y;
116 } FFV1Context;
117 
118 static av_always_inline int fold(int diff, int bits)
119 {
120  if (bits == 8)
121  diff = (int8_t)diff;
122  else {
123  diff += 1 << (bits - 1);
124  diff &= (1 << bits) - 1;
125  diff -= 1 << (bits - 1);
126  }
127 
128  return diff;
129 }
130 
131 static inline int predict(int16_t *src, int16_t *last)
132 {
133  const int LT = last[-1];
134  const int T = last[0];
135  const int L = src[-1];
136 
137  return mid_pred(L, L + T - LT, T);
138 }
139 
140 static inline int get_context(PlaneContext *p, int16_t *src,
141  int16_t *last, int16_t *last2)
142 {
143  const int LT = last[-1];
144  const int T = last[0];
145  const int RT = last[1];
146  const int L = src[-1];
147 
148  if (p->quant_table[3][127]) {
149  const int TT = last2[0];
150  const int LL = src[-2];
151  return p->quant_table[0][(L - LT) & 0xFF] +
152  p->quant_table[1][(LT - T) & 0xFF] +
153  p->quant_table[2][(T - RT) & 0xFF] +
154  p->quant_table[3][(LL - L) & 0xFF] +
155  p->quant_table[4][(TT - T) & 0xFF];
156  } else
157  return p->quant_table[0][(L - LT) & 0xFF] +
158  p->quant_table[1][(LT - T) & 0xFF] +
159  p->quant_table[2][(T - RT) & 0xFF];
160 }
161 
162 static inline void update_vlc_state(VlcState *const state, const int v)
163 {
164  int drift = state->drift;
165  int count = state->count;
166  state->error_sum += FFABS(v);
167  drift += v;
168 
169  if (count == 128) { // FIXME: variable
170  count >>= 1;
171  drift >>= 1;
172  state->error_sum >>= 1;
173  }
174  count++;
175 
176  if (drift <= -count) {
177  if (state->bias > -128)
178  state->bias--;
179 
180  drift += count;
181  if (drift <= -count)
182  drift = -count + 1;
183  } else if (drift > 0) {
184  if (state->bias < 127)
185  state->bias++;
186 
187  drift -= count;
188  if (drift > 0)
189  drift = 0;
190  }
191 
192  state->drift = drift;
193  state->count = count;
194 }
195 
202 
203 #endif /* AVCODEC_FFV1_H */