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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 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 #ifndef AVCODEC_FFV1_H
24 #define AVCODEC_FFV1_H
25 
26 /**
27  * @file
28  * FF Video Codec 1 (a lossless codec)
29  */
30 
31 #include "libavutil/avassert.h"
32 #include "libavutil/crc.h"
33 #include "libavutil/opt.h"
34 #include "libavutil/imgutils.h"
35 #include "libavutil/pixdesc.h"
36 #include "libavutil/timer.h"
37 #include "avcodec.h"
38 #include "dsputil.h"
39 #include "get_bits.h"
40 #include "internal.h"
41 #include "mathops.h"
42 #include "put_bits.h"
43 #include "rangecoder.h"
44 
45 #ifdef __INTEL_COMPILER
46 #undef av_flatten
47 #define av_flatten
48 #endif
49 
50 #define MAX_PLANES 4
51 #define CONTEXT_SIZE 32
52 
53 #define MAX_QUANT_TABLES 8
54 #define MAX_CONTEXT_INPUTS 5
55 
56 extern const uint8_t ff_log2_run[41];
57 
58 typedef struct VlcState {
59  int16_t drift;
60  uint16_t error_sum;
61  int8_t bias;
63 } VlcState;
64 
65 typedef struct PlaneContext {
72 } PlaneContext;
73 
74 #define MAX_SLICES 256
75 
76 typedef struct FFV1Context {
77  AVClass *class;
82  uint64_t rc_stat[256][2];
83  uint64_t (*rc_stat2[MAX_QUANT_TABLES])[32][2];
84  int version;
86  int width, height;
90  int flags;
95  int ac; ///< 1=range coder <-> 0=golomb rice
96  int ac_byte_count; ///< number of bytes used for AC coding
105  int16_t *sample_buffer;
106 
107  int ec;
110 
113 
116 
118 
125  int slice_x;
126  int slice_y;
127 } FFV1Context;
128 
136 
137 static av_always_inline int fold(int diff, int bits)
138 {
139  if (bits == 8)
140  diff = (int8_t)diff;
141  else {
142  diff += 1 << (bits - 1);
143  diff &= (1 << bits) - 1;
144  diff -= 1 << (bits - 1);
145  }
146 
147  return diff;
148 }
149 
150 static inline int predict(int16_t *src, int16_t *last)
151 {
152  const int LT = last[-1];
153  const int T = last[0];
154  const int L = src[-1];
155 
156  return mid_pred(L, L + T - LT, T);
157 }
158 
159 static inline int get_context(PlaneContext *p, int16_t *src,
160  int16_t *last, int16_t *last2)
161 {
162  const int LT = last[-1];
163  const int T = last[0];
164  const int RT = last[1];
165  const int L = src[-1];
166 
167  if (p->quant_table[3][127]) {
168  const int TT = last2[0];
169  const int LL = src[-2];
170  return p->quant_table[0][(L - LT) & 0xFF] +
171  p->quant_table[1][(LT - T) & 0xFF] +
172  p->quant_table[2][(T - RT) & 0xFF] +
173  p->quant_table[3][(LL - L) & 0xFF] +
174  p->quant_table[4][(TT - T) & 0xFF];
175  } else
176  return p->quant_table[0][(L - LT) & 0xFF] +
177  p->quant_table[1][(LT - T) & 0xFF] +
178  p->quant_table[2][(T - RT) & 0xFF];
179 }
180 
181 static inline void update_vlc_state(VlcState *const state, const int v)
182 {
183  int drift = state->drift;
184  int count = state->count;
185  state->error_sum += FFABS(v);
186  drift += v;
187 
188  if (count == 128) { // FIXME: variable
189  count >>= 1;
190  drift >>= 1;
191  state->error_sum >>= 1;
192  }
193  count++;
194 
195  if (drift <= -count) {
196  if (state->bias > -128)
197  state->bias--;
198 
199  drift += count;
200  if (drift <= -count)
201  drift = -count + 1;
202  } else if (drift > 0) {
203  if (state->bias < 127)
204  state->bias++;
205 
206  drift -= count;
207  if (drift > 0)
208  drift = 0;
209  }
210 
211  state->drift = drift;
212  state->count = count;
213 }
214 
215 #endif /* AVCODEC_FFV1_H */