libavcodec/ffv1.h

   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;
  52     uint8_t count;
  53 } VlcState;
  54
  55 typedef struct PlaneContext {
  56     int16_t quant_table[MAX_CONTEXT_INPUTS][256];
  57     int quant_table_index;
  58     int context_count;
  59     uint8_t (*state)[CONTEXT_SIZE];
  60     VlcState *vlc_state;
  61     uint8_t interlace_bit_state[2];
  62 } PlaneContext;
  63
  64 #define MAX_SLICES 256
  65
  66 typedef struct FFV1Context {
  67     AVClass *class;
  68     AVCodecContext *avctx;
  69     RangeCoder c;
  70     GetBitContext gb;
  71     PutBitContext pb;
  72     uint64_t rc_stat[256][2];
  73     uint64_t (*rc_stat2[MAX_QUANT_TABLES])[32][2];
  74     int version;
  75     int minor_version;
  76     int width, height;
  77     int chroma_planes;
  78     int chroma_h_shift, chroma_v_shift;
  79     int transparency;
  80     int flags;
  81     int picture_number;
  82     AVFrame picture, last_picture;
  83     int plane_count;
  84     int ac;     // 1 = range coder <-> 0 = golomb rice
  85     int ac_byte_count;      // number of bytes used for AC coding
  86     PlaneContext plane[MAX_PLANES];
  87     int16_t quant_table[MAX_CONTEXT_INPUTS][256];
  88     int16_t quant_tables[MAX_QUANT_TABLES][MAX_CONTEXT_INPUTS][256];
  89     int context_count[MAX_QUANT_TABLES];
  90     uint8_t state_transition[256];
  91     uint8_t (*initial_states[MAX_QUANT_TABLES])[32];
  92     int run_index;
  93     int colorspace;
  94     int16_t *sample_buffer;
  95
  96     int ec;
  97     int slice_damaged;
  98     int key_frame_ok;
  99
 100     int bits_per_raw_sample;
 101     int packed_at_lsb;
 102
 103     int gob_count;
 104     int quant_table_count;
 105
 106     DSPContext dsp;
 107
 108     struct FFV1Context *slice_context[MAX_SLICES];
 109     int slice_count;
 110     int num_v_slices;
 111     int num_h_slices;
 112     int slice_width;
 113     int slice_height;
 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
 196 int ffv1_common_init(AVCodecContext *avctx);
 197 int ffv1_init_slice_state(FFV1Context *f, FFV1Context *fs);
 198 int ffv1_init_slice_contexts(FFV1Context *f);
 199 int ffv1_allocate_initial_states(FFV1Context *f);
 200 void ffv1_clear_slice_state(FFV1Context *f, FFV1Context *fs);
 201 int ffv1_close(AVCodecContext *avctx);
 202
 203 #endif /* AVCODEC_FFV1_H */