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 libavcodec/loco.c
  24  * LOCO codec.
  25  */
  26
  27 #include "avcodec.h"
  28 #include "bitstream.h"
  29 #include "golomb.h"
  30 #include "mathops.h"
  31
  32 enum LOCO_MODE {LOCO_UNKN=0, LOCO_CYUY2=-1, LOCO_CRGB=-2, LOCO_CRGBA=-3, LOCO_CYV12=-4,
  33  LOCO_YUY2=1, LOCO_UYVY=2, LOCO_RGB=3, LOCO_RGBA=4, LOCO_YV12=5};
  34
  35 typedef struct LOCOContext{
  36     AVCodecContext *avctx;
  37     AVFrame pic;
  38     int lossy;
  39     int mode;
  40 } LOCOContext;
  41
  42 typedef struct RICEContext{
  43     GetBitContext gb;
  44     int save, run, run2; /* internal rice decoder state */
  45     int sum, count; /* sum and count for getting rice parameter */
  46     int lossy;
  47 }RICEContext;
  48
  49 static int loco_get_rice_param(RICEContext *r)
  50 {
  51     int cnt = 0;
  52     int val = r->count;
  53
  54     while(r->sum > val && cnt < 9) {
  55         val <<= 1;
  56         cnt++;
  57     }
  58
  59     return cnt;
  60 }
  61
  62 static inline void loco_update_rice_param(RICEContext *r, int val)
  63 {
  64     r->sum += val;
  65     r->count++;
  66
  67     if(r->count == 16) {
  68         r->sum >>= 1;
  69         r->count >>= 1;
  70     }
  71 }
  72
  73 static inline int loco_get_rice(RICEContext *r)
  74 {
  75     int v;
  76     if (r->run > 0) { /* we have zero run */
  77         r->run--;
  78         loco_update_rice_param(r, 0);
  79         return 0;
  80     }
  81     v = get_ur_golomb_jpegls(&r->gb, loco_get_rice_param(r), INT_MAX, 0);
  82     loco_update_rice_param(r, (v+1)>>1);
  83     if (!v) {
  84         if (r->save >= 0) {
  85             r->run = get_ur_golomb_jpegls(&r->gb, 2, INT_MAX, 0);
  86             if(r->run > 1)
  87                 r->save += r->run + 1;
  88             else
  89                 r->save -= 3;
  90         }
  91         else
  92             r->run2++;
  93     } else {
  94         v = ((v>>1) + r->lossy) ^ -(v&1);
  95         if (r->run2 > 0) {
  96             if (r->run2 > 2)
  97                 r->save += r->run2;
  98             else
  99                 r->save -= 3;
 100             r->run2 = 0;
 101         }
 102     }
 103
 104     return v;
 105 }
 106
 107 /* LOCO main predictor - LOCO-I/JPEG-LS predictor */
 108 static inline int loco_predict(uint8_t* data, int stride, int step)
 109 {
 110     int a, b, c;
 111
 112     a = data[-stride];
 113     b = data[-step];
 114     c = data[-stride - step];
 115
 116     return mid_pred(a, a + b - c, b);
 117 }
 118
 119 static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int height,
 120                              int stride, const uint8_t *buf, int buf_size, int step)
 121 {
 122     RICEContext rc;
 123     int val;
 124     int i, j;
 125
 126     init_get_bits(&rc.gb, buf, buf_size*8);
 127     rc.save = 0;
 128     rc.run = 0;
 129     rc.run2 = 0;
 130     rc.lossy = l->lossy;
 131
 132     rc.sum = 8;
 133     rc.count = 1;
 134
 135     /* restore top left pixel */
 136     val = loco_get_rice(&rc);
 137     data[0] = 128 + val;
 138     /* restore top line */
 139     for (i = 1; i < width; i++) {
 140         val = loco_get_rice(&rc);
 141         data[i * step] = data[i * step - step] + val;
 142     }
 143     data += stride;
 144     for (j = 1; j < height; j++) {
 145         /* restore left column */
 146         val = loco_get_rice(&rc);
 147         data[0] = data[-stride] + val;
 148         /* restore all other pixels */
 149         for (i = 1; i < width; i++) {
 150             val = loco_get_rice(&rc);
 151             data[i * step] = loco_predict(&data[i * step], stride, step) + val;
 152         }
 153         data += stride;
 154     }
 155
 156     return (get_bits_count(&rc.gb) + 7) >> 3;
 157 }
 158
 159 static int decode_frame(AVCodecContext *avctx,
 160                         void *data, int *data_size,
 161                         const uint8_t *buf, int buf_size)
 162 {
 163     LOCOContext * const l = avctx->priv_data;
 164     AVFrame * const p= (AVFrame*)&l->pic;
 165     int decoded;
 166
 167     if(p->data[0])
 168         avctx->release_buffer(avctx, p);
 169
 170     p->reference = 0;
 171     if(avctx->get_buffer(avctx, p) < 0){
 172         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 173         return -1;
 174     }
 175     p->key_frame = 1;
 176
 177     switch(l->mode) {
 178     case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
 179         decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
 180                                     p->linesize[0], buf, buf_size, 1);
 181         buf += decoded; buf_size -= decoded;
 182         decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
 183                                     p->linesize[1], buf, buf_size, 1);
 184         buf += decoded; buf_size -= decoded;
 185         decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height,
 186                                     p->linesize[2], buf, buf_size, 1);
 187         break;
 188     case LOCO_CYV12: case LOCO_YV12:
 189         decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
 190                                     p->linesize[0], buf, buf_size, 1);
 191         buf += decoded; buf_size -= decoded;
 192         decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
 193                                     p->linesize[2], buf, buf_size, 1);
 194         buf += decoded; buf_size -= decoded;
 195         decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height / 2,
 196                                     p->linesize[1], buf, buf_size, 1);
 197         break;
 198     case LOCO_CRGB: case LOCO_RGB:
 199         decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
 200                                     -p->linesize[0], buf, buf_size, 3);
 201         buf += decoded; buf_size -= decoded;
 202         decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 1, avctx->width, avctx->height,
 203                                     -p->linesize[0], buf, buf_size, 3);
 204         buf += decoded; buf_size -= decoded;
 205         decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1) + 2, avctx->width, avctx->height,
 206                                     -p->linesize[0], buf, buf_size, 3);
 207         break;
 208     case LOCO_RGBA:
 209         decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
 210                                     p->linesize[0], buf, buf_size, 4);
 211         buf += decoded; buf_size -= decoded;
 212         decoded = loco_decode_plane(l, p->data[0] + 1, avctx->width, avctx->height,
 213                                     p->linesize[0], buf, buf_size, 4);
 214         buf += decoded; buf_size -= decoded;
 215         decoded = loco_decode_plane(l, p->data[0] + 2, avctx->width, avctx->height,
 216                                     p->linesize[0], buf, buf_size, 4);
 217         buf += decoded; buf_size -= decoded;
 218         decoded = loco_decode_plane(l, p->data[0] + 3, avctx->width, avctx->height,
 219                                     p->linesize[0], buf, buf_size, 4);
 220         break;
 221     }
 222
 223     *data_size = sizeof(AVFrame);
 224     *(AVFrame*)data = l->pic;
 225
 226     return buf_size;
 227 }
 228
 229 static av_cold int decode_init(AVCodecContext *avctx){
 230     LOCOContext * const l = avctx->priv_data;
 231     int version;
 232
 233     l->avctx = avctx;
 234     if (avctx->extradata_size < 12) {
 235         av_log(avctx, AV_LOG_ERROR, "Extradata size must be >= 12 instead of %i\n",
 236                avctx->extradata_size);
 237         return -1;
 238     }
 239     version = AV_RL32(avctx->extradata);
 240     switch(version) {
 241     case 1:
 242         l->lossy = 0;
 243         break;
 244     case 2:
 245         l->lossy = AV_RL32(avctx->extradata + 8);
 246         break;
 247     default:
 248         l->lossy = AV_RL32(avctx->extradata + 8);
 249         av_log(avctx, AV_LOG_INFO, "This is LOCO codec version %i, please upload file for study\n", version);
 250     }
 251
 252     l->mode = AV_RL32(avctx->extradata + 4);
 253     switch(l->mode) {
 254     case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
 255         avctx->pix_fmt = PIX_FMT_YUV422P;
 256         break;
 257     case LOCO_CRGB: case LOCO_RGB:
 258         avctx->pix_fmt = PIX_FMT_BGR24;
 259         break;
 260     case LOCO_CYV12: case LOCO_YV12:
 261         avctx->pix_fmt = PIX_FMT_YUV420P;
 262         break;
 263     case LOCO_CRGBA: case LOCO_RGBA:
 264         avctx->pix_fmt = PIX_FMT_RGB32;
 265         break;
 266     default:
 267         av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);
 268         return -1;
 269     }
 270     if(avctx->debug & FF_DEBUG_PICT_INFO)
 271         av_log(avctx, AV_LOG_INFO, "lossy:%i, version:%i, mode: %i\n", l->lossy, version, l->mode);
 272
 273     return 0;
 274 }
 275
 276 AVCodec loco_decoder = {
 277     "loco",
 278     CODEC_TYPE_VIDEO,
 279     CODEC_ID_LOCO,
 280     sizeof(LOCOContext),
 281     decode_init,
 282     NULL,
 283     NULL,
 284     decode_frame,
 285     CODEC_CAP_DR1,
 286     .long_name = NULL_IF_CONFIG_SMALL("LOCO"),
 287 };