FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
ffv1.h
Go to the documentation of this file.
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 #include "thread.h"
45 
46 #ifdef __INTEL_COMPILER
47 #undef av_flatten
48 #define av_flatten
49 #endif
50 
51 #define MAX_PLANES 4
52 #define CONTEXT_SIZE 32
53 
54 #define MAX_QUANT_TABLES 8
55 #define MAX_CONTEXT_INPUTS 5
56 
57 extern const uint8_t ff_log2_run[41];
58 
59 typedef struct VlcState {
60  int16_t drift;
61  uint16_t error_sum;
62  int8_t bias;
64 } VlcState;
65 
66 typedef struct PlaneContext {
73 } PlaneContext;
74 
75 #define MAX_SLICES 256
76 
77 typedef struct FFV1Context {
78  AVClass *class;
83  uint64_t rc_stat[256][2];
84  uint64_t (*rc_stat2[MAX_QUANT_TABLES])[32][2];
85  int version;
87  int width, height;
91  int flags;
94  struct FFV1Context *fsrc;
95 
98  int ac; ///< 1=range coder <-> 0=golomb rice
99  int ac_byte_count; ///< number of bytes used for AC coding
108  int16_t *sample_buffer;
109 
110  int ec;
111  int intra;
114 
117 
120 
122 
129  int slice_x;
130  int slice_y;
135 } FFV1Context;
136 
144 
145 static av_always_inline int fold(int diff, int bits)
146 {
147  if (bits == 8)
148  diff = (int8_t)diff;
149  else {
150  diff += 1 << (bits - 1);
151  diff &= (1 << bits) - 1;
152  diff -= 1 << (bits - 1);
153  }
154 
155  return diff;
156 }
157 
158 static inline int predict(int16_t *src, int16_t *last)
159 {
160  const int LT = last[-1];
161  const int T = last[0];
162  const int L = src[-1];
163 
164  return mid_pred(L, L + T - LT, T);
165 }
166 
167 static inline int get_context(PlaneContext *p, int16_t *src,
168  int16_t *last, int16_t *last2)
169 {
170  const int LT = last[-1];
171  const int T = last[0];
172  const int RT = last[1];
173  const int L = src[-1];
174 
175  if (p->quant_table[3][127]) {
176  const int TT = last2[0];
177  const int LL = src[-2];
178  return p->quant_table[0][(L - LT) & 0xFF] +
179  p->quant_table[1][(LT - T) & 0xFF] +
180  p->quant_table[2][(T - RT) & 0xFF] +
181  p->quant_table[3][(LL - L) & 0xFF] +
182  p->quant_table[4][(TT - T) & 0xFF];
183  } else
184  return p->quant_table[0][(L - LT) & 0xFF] +
185  p->quant_table[1][(LT - T) & 0xFF] +
186  p->quant_table[2][(T - RT) & 0xFF];
187 }
188 
189 static inline void update_vlc_state(VlcState *const state, const int v)
190 {
191  int drift = state->drift;
192  int count = state->count;
193  state->error_sum += FFABS(v);
194  drift += v;
195 
196  if (count == 128) { // FIXME: variable
197  count >>= 1;
198  drift >>= 1;
199  state->error_sum >>= 1;
200  }
201  count++;
202 
203  if (drift <= -count) {
204  if (state->bias > -128)
205  state->bias--;
206 
207  drift += count;
208  if (drift <= -count)
209  drift = -count + 1;
210  } else if (drift > 0) {
211  if (state->bias < 127)
212  state->bias++;
213 
214  drift -= count;
215  if (drift > 0)
216  drift = 0;
217  }
218 
219  state->drift = drift;
220  state->count = count;
221 }
222 
223 #endif /* AVCODEC_FFV1_H */