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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 "get_bits.h"
39 #include "internal.h"
40 #include "mathops.h"
41 #include "put_bits.h"
42 #include "rangecoder.h"
43 #include "thread.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 typedef struct VlcState {
57  int16_t drift;
58  uint16_t error_sum;
59  int8_t bias;
61 } VlcState;
62 
63 typedef struct PlaneContext {
70 } PlaneContext;
71 
72 #define MAX_SLICES 256
73 
74 typedef struct FFV1Context {
75  AVClass *class;
80  uint64_t rc_stat[256][2];
81  uint64_t (*rc_stat2[MAX_QUANT_TABLES])[32][2];
82  int version;
84  int width, height;
88  int flags;
91  struct FFV1Context *fsrc;
92 
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;
108  int intra;
111 
114 
117 
124  int slice_x;
125  int slice_y;
130 } FFV1Context;
131 
139 
140 static av_always_inline int fold(int diff, int bits)
141 {
142  if (bits == 8)
143  diff = (int8_t)diff;
144  else {
145  diff += 1 << (bits - 1);
146  diff = av_mod_uintp2(diff, bits);
147  diff -= 1 << (bits - 1);
148  }
149 
150  return diff;
151 }
152 
153 static inline int predict(int16_t *src, int16_t *last)
154 {
155  const int LT = last[-1];
156  const int T = last[0];
157  const int L = src[-1];
158 
159  return mid_pred(L, L + T - LT, T);
160 }
161 
162 static inline int get_context(PlaneContext *p, int16_t *src,
163  int16_t *last, int16_t *last2)
164 {
165  const int LT = last[-1];
166  const int T = last[0];
167  const int RT = last[1];
168  const int L = src[-1];
169 
170  if (p->quant_table[3][127]) {
171  const int TT = last2[0];
172  const int LL = src[-2];
173  return p->quant_table[0][(L - LT) & 0xFF] +
174  p->quant_table[1][(LT - T) & 0xFF] +
175  p->quant_table[2][(T - RT) & 0xFF] +
176  p->quant_table[3][(LL - L) & 0xFF] +
177  p->quant_table[4][(TT - T) & 0xFF];
178  } else
179  return p->quant_table[0][(L - LT) & 0xFF] +
180  p->quant_table[1][(LT - T) & 0xFF] +
181  p->quant_table[2][(T - RT) & 0xFF];
182 }
183 
184 static inline void update_vlc_state(VlcState *const state, const int v)
185 {
186  int drift = state->drift;
187  int count = state->count;
188  state->error_sum += FFABS(v);
189  drift += v;
190 
191  if (count == 128) { // FIXME: variable
192  count >>= 1;
193  drift >>= 1;
194  state->error_sum >>= 1;
195  }
196  count++;
197 
198  if (drift <= -count) {
199  if (state->bias > -128)
200  state->bias--;
201 
202  drift += count;
203  if (drift <= -count)
204  drift = -count + 1;
205  } else if (drift > 0) {
206  if (state->bias < 127)
207  state->bias++;
208 
209  drift -= count;
210  if (drift > 0)
211  drift = 0;
212  }
213 
214  state->drift = drift;
215  state->count = count;
216 }
217 
218 #endif /* AVCODEC_FFV1_H */