libavcodec/loco.c

   1 /*
   2  * LOCO codec
   3  * Copyright (c) 2005 Konstantin Shishkov
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file loco.c
  24  * LOCO codec.
  25  */
  26
  27 #include "avcodec.h"
  28 #include "bitstream.h"
  29 #include "golomb.h"
  30
  31 enum LOCO_MODE {LOCO_UNKN=0, LOCO_CYUY2=-1, LOCO_CRGB=-2, LOCO_CRGBA=-3, LOCO_CYV12=-4,
  32  LOCO_YUY2=1, LOCO_UYVY=2, LOCO_RGB=3, LOCO_RGBA=4, LOCO_YV12=5};
  33
  34 typedef struct LOCOContext{
  35     AVCodecContext *avctx;
  36     AVFrame pic;
  37     int lossy;
  38     int mode;
  39 } LOCOContext;
  40
  41 typedef struct RICEContext{
  42     GetBitContext gb;
  43     int save, run, run2; /* internal rice decoder state */
  44     int sum, count; /* sum and count for getting rice parameter */
  45     int lossy;
  46 }RICEContext;
  47
  48 static int loco_get_rice_param(RICEContext *r)
  49 {
  50     int cnt = 0;
  51     int val = r->count;
  52
  53     while(r->sum > val && cnt < 9) {
  54         val <<= 1;
  55         cnt++;
  56     }
  57
  58     return cnt;
  59 }
  60
  61 static inline void loco_update_rice_param(RICEContext *r, int val)
  62 {
  63     r->sum += val;
  64     r->count++;
  65
  66     if(r->count == 16) {
  67         r->sum >>= 1;
  68         r->count >>= 1;
  69     }
  70 }
  71
  72 static inline int loco_get_rice(RICEContext *r)
  73 {
  74     int v;
  75     if (r->run > 0) { /* we have zero run */
  76         r->run--;
  77         loco_update_rice_param(r, 0);
  78         return 0;
  79     }
  80     v = get_ur_golomb_jpegls(&r->gb, loco_get_rice_param(r), INT_MAX, 0);
  81     loco_update_rice_param(r, (v+1)>>1);
  82     if (!v) {
  83         if (r->save >= 0) {
  84             r->run = get_ur_golomb_jpegls(&r->gb, 2, INT_MAX, 0);
  85             if(r->run > 1)
  86                 r->save += r->run + 1;
  87             else
  88                 r->save -= 3;
  89         }
  90         else
  91             r->run2++;
  92     } else {
  93         v = ((v>>1) + r->lossy) ^ -(v&1);
  94         if (r->run2 > 0) {
  95             if (r->run2 > 2)
  96                 r->save += r->run2;
  97             else
  98                 r->save -= 3;
  99             r->run2 = 0;
 100         }
 101     }
 102
 103     return v;
 104 }
 105
 106 /* LOCO main predictor - LOCO-I/JPEG-LS predictor */
 107 static inline int loco_predict(uint8_t* data, int stride, int step)
 108 {
 109     int a, b, c;
 110
 111     a = data[-stride];
 112     b = data[-step];
 113     c = data[-stride - step];
 114
 115     return mid_pred(a, a + b - c, b);
 116 }
 117
 118 static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int height,
 119                              int stride, const uint8_t *buf, int buf_size, int step)
 120 {
 121     RICEContext rc;
 122     int val;
 123     int i, j;
 124
 125     init_get_bits(&rc.gb, buf, buf_size*8);
 126     rc.save = 0;
 127     rc.run = 0;
 128     rc.run2 = 0;
 129     rc.lossy = l->lossy;
 130
 131     rc.sum = 8;
 132     rc.count = 1;
 133
 134     /* restore top left pixel */
 135     val = loco_get_rice(&rc);
 136     data[0] = 128 + val;
 137     /* restore top line */
 138     for (i = 1; i < width; i++) {
 139         val = loco_get_rice(&rc);
 140         data[i * step] = data[i * step - step] + val;
 141     }
 142     data += stride;
 143     for (j = 1; j < height; j++) {
 144         /* restore left column */
 145         val = loco_get_rice(&rc);
 146         data[0] = data[-stride] + val;
 147         /* restore all other pixels */
 148         for (i = 1; i < width; i++) {
 149             val = loco_get_rice(&rc);
 150             data[i * step] = loco_predict(&data[i * step], stride, step) + val;
 151         }
 152         data += stride;
 153     }
 154
 155     return ((get_bits_count(&rc.gb) + 7) >> 3);
 156 }
 157
 158 static int decode_frame(AVCodecContext *avctx,
 159                         void *data, int *data_size,
 160                         const uint8_t *buf, int buf_size)
 161 {
 162     LOCOContext * const l = avctx->priv_data;
 163     AVFrame * const p= (AVFrame*)&l->pic;
 164     int decoded;
 165
 166     if(p->data[0])
 167         avctx->release_buffer(avctx, p);
 168
 169     p->reference = 0;
 170     if(avctx->get_buffer(avctx, p) < 0){
 171         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 172         return -1;
 173     }
 174     p->key_frame = 1;
 175
 176     switch(l->mode) {
 177     case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
 178         decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
 179                                     p->linesize[0], buf, buf_size, 1);
 180         buf += decoded; buf_size -= decoded;
 181         decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
 182                                     p->linesize[1], buf, buf_size, 1);
 183         buf += decoded; buf_size -= decoded;
 184         decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height,
 185                                     p->linesize[2], buf, buf_size, 1);
 186         break;
 187     case LOCO_CYV12: case LOCO_YV12:
 188         decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
 189                                     p->linesize[0], buf, buf_size, 1);
 190         buf += decoded; buf_size -= decoded;
 191         decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
 192                                     p->linesize[2], buf, buf_size, 1);
 193         buf += decoded; buf_size -= decoded;
 194         decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height / 2,
 195                                     p->linesize[1], buf, buf_size, 1);
 196         break;
 197     case LOCO_CRGB: case LOCO_RGB:
 198         decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
 199                                     -p->linesize[0], buf, buf_size, 3);
 200         buf += decoded; buf_size -= decoded;
 201         decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 1, avctx->width, avctx->height,
 202                                     -p->linesize[0], buf, buf_size, 3);
 203         buf += decoded; buf_size -= decoded;
 204         decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 2, avctx->width, avctx->height,
 205                                     -p->linesize[0], buf, buf_size, 3);
 206         break;
 207     case LOCO_RGBA:
 208         decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
 209                                     p->linesize[0], buf, buf_size, 4);
 210         buf += decoded; buf_size -= decoded;
 211         decoded = loco_decode_plane(l, p->data[0] + 1, avctx->width, avctx->height,
 212                                     p->linesize[0], buf, buf_size, 4);
 213         buf += decoded; buf_size -= decoded;
 214         decoded = loco_decode_plane(l, p->data[0] + 2, avctx->width, avctx->height,
 215                                     p->linesize[0], buf, buf_size, 4);
 216         buf += decoded; buf_size -= decoded;
 217         decoded = loco_decode_plane(l, p->data[0] + 3, avctx->width, avctx->height,
 218                                     p->linesize[0], buf, buf_size, 4);
 219         break;
 220     }
 221
 222     *data_size = sizeof(AVFrame);
 223     *(AVFrame*)data = l->pic;
 224
 225     return buf_size;
 226 }
 227
 228 static av_cold int decode_init(AVCodecContext *avctx){
 229     LOCOContext * const l = avctx->priv_data;
 230     int version;
 231
 232     l->avctx = avctx;
 233     if (avctx->extradata_size < 12) {
 234         av_log(avctx, AV_LOG_ERROR, "Extradata size must be >= 12 instead of %i\n",
 235                avctx->extradata_size);
 236         return -1;
 237     }
 238     version = AV_RL32(avctx->extradata);
 239     switch(version) {
 240     case 1:
 241         l->lossy = 0;
 242         break;
 243     case 2:
 244         l->lossy = AV_RL32(avctx->extradata + 8);
 245         break;
 246     default:
 247         l->lossy = AV_RL32(avctx->extradata + 8);
 248         av_log(avctx, AV_LOG_INFO, "This is LOCO codec version %i, please upload file for study\n", version);
 249     }
 250
 251     l->mode = AV_RL32(avctx->extradata + 4);
 252     switch(l->mode) {
 253     case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
 254         avctx->pix_fmt = PIX_FMT_YUV422P;
 255         break;
 256     case LOCO_CRGB: case LOCO_RGB:
 257         avctx->pix_fmt = PIX_FMT_BGR24;
 258         break;
 259     case LOCO_CYV12: case LOCO_YV12:
 260         avctx->pix_fmt = PIX_FMT_YUV420P;
 261         break;
 262     case LOCO_CRGBA: case LOCO_RGBA:
 263         avctx->pix_fmt = PIX_FMT_RGB32;
 264         break;
 265     default:
 266         av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);
 267         return -1;
 268     }
 269     if(avctx->debug & FF_DEBUG_PICT_INFO)
 270         av_log(avctx, AV_LOG_INFO, "lossy:%i, version:%i, mode: %i\n", l->lossy, version, l->mode);
 271
 272     return 0;
 273 }
 274
 275 AVCodec loco_decoder = {
 276     "loco",
 277     CODEC_TYPE_VIDEO,
 278     CODEC_ID_LOCO,
 279     sizeof(LOCOContext),
 280     decode_init,
 281     NULL,
 282     NULL,
 283     decode_frame,
 284     CODEC_CAP_DR1,
 285 };