libavcodec/zmbvenc.c

   1 /*
   2  * Zip Motion Blocks Video (ZMBV) encoder
   3  * Copyright (c) 2006 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/zmbvenc.c
  24  * Zip Motion Blocks Video encoder
  25  */
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29
  30 #include "libavutil/intreadwrite.h"
  31 #include "avcodec.h"
  32
  33 #include <zlib.h>
  34
  35 #define ZMBV_KEYFRAME 1
  36 #define ZMBV_DELTAPAL 2
  37
  38 #define ZMBV_BLOCK 16
  39
  40 /**
  41  * Encoder context
  42  */
  43 typedef struct ZmbvEncContext {
  44     AVCodecContext *avctx;
  45     AVFrame pic;
  46
  47     int range;
  48     uint8_t *comp_buf, *work_buf;
  49     uint8_t pal[768];
  50     uint32_t pal2[256]; //for quick comparisons
  51     uint8_t *prev;
  52     int pstride;
  53     int comp_size;
  54     int keyint, curfrm;
  55     z_stream zstream;
  56 } ZmbvEncContext;
  57
  58 static int score_tab[256];
  59
  60 /** Block comparing function
  61  * XXX should be optimized and moved to DSPContext
  62  * TODO handle out of edge ME
  63  */
  64 static inline int block_cmp(uint8_t *src, int stride, uint8_t *src2, int stride2, int bw, int bh)
  65 {
  66     int sum = 0;
  67     int i, j;
  68     uint8_t histogram[256]={0};
  69
  70     for(j = 0; j < bh; j++){
  71         for(i = 0; i < bw; i++)
  72             histogram[src[i] ^ src2[i]]++;
  73         src += stride;
  74         src2 += stride2;
  75     }
  76
  77     for(i=1; i<256; i++)
  78         sum+= score_tab[histogram[i]];
  79
  80     return sum;
  81 }
  82
  83 /** Motion estimation function
  84  * TODO make better ME decisions
  85  */
  86 static int zmbv_me(ZmbvEncContext *c, uint8_t *src, int sstride, uint8_t *prev, int pstride,
  87                     int x, int y, int *mx, int *my)
  88 {
  89     int dx, dy, tx, ty, tv, bv, bw, bh;
  90
  91     *mx = *my = 0;
  92     bw = FFMIN(ZMBV_BLOCK, c->avctx->width - x);
  93     bh = FFMIN(ZMBV_BLOCK, c->avctx->height - y);
  94     bv = block_cmp(src, sstride, prev, pstride, bw, bh);
  95     if(!bv) return 0;
  96     for(ty = FFMAX(y - c->range, 0); ty < FFMIN(y + c->range, c->avctx->height - bh); ty++){
  97         for(tx = FFMAX(x - c->range, 0); tx < FFMIN(x + c->range, c->avctx->width - bw); tx++){
  98             if(tx == x && ty == y) continue; // we already tested this block
  99             dx = tx - x;
 100             dy = ty - y;
 101             tv = block_cmp(src, sstride, prev + dx + dy*pstride, pstride, bw, bh);
 102             if(tv < bv){
 103                  bv = tv;
 104                  *mx = dx;
 105                  *my = dy;
 106                  if(!bv) return 0;
 107              }
 108          }
 109     }
 110     return bv;
 111 }
 112
 113 static int encode_frame(AVCodecContext *avctx, uint8_t *buf, int buf_size, void *data)
 114 {
 115     ZmbvEncContext * const c = avctx->priv_data;
 116     AVFrame *pict = data;
 117     AVFrame * const p = &c->pic;
 118     uint8_t *src, *prev;
 119     uint32_t *palptr;
 120     int len = 0;
 121     int keyframe, chpal;
 122     int fl;
 123     int work_size = 0;
 124     int bw, bh;
 125     int i, j;
 126
 127     keyframe = !c->curfrm;
 128     c->curfrm++;
 129     if(c->curfrm == c->keyint)
 130         c->curfrm = 0;
 131     *p = *pict;
 132     p->pict_type= keyframe ? FF_I_TYPE : FF_P_TYPE;
 133     p->key_frame= keyframe;
 134     chpal = !keyframe && memcmp(p->data[1], c->pal2, 1024);
 135
 136     fl = (keyframe ? ZMBV_KEYFRAME : 0) | (chpal ? ZMBV_DELTAPAL : 0);
 137     *buf++ = fl; len++;
 138     if(keyframe){
 139         deflateReset(&c->zstream);
 140         *buf++ = 0; len++; // hi ver
 141         *buf++ = 1; len++; // lo ver
 142         *buf++ = 1; len++; // comp
 143         *buf++ = 4; len++; // format - 8bpp
 144         *buf++ = ZMBV_BLOCK; len++; // block width
 145         *buf++ = ZMBV_BLOCK; len++; // block height
 146     }
 147     palptr = (uint32_t*)p->data[1];
 148     src = p->data[0];
 149     prev = c->prev;
 150     if(chpal){
 151         uint8_t tpal[3];
 152         for(i = 0; i < 256; i++){
 153             AV_WB24(tpal, palptr[i]);
 154             c->work_buf[work_size++] = tpal[0] ^ c->pal[i * 3 + 0];
 155             c->work_buf[work_size++] = tpal[1] ^ c->pal[i * 3 + 1];
 156             c->work_buf[work_size++] = tpal[2] ^ c->pal[i * 3 + 2];
 157             c->pal[i * 3 + 0] = tpal[0];
 158             c->pal[i * 3 + 1] = tpal[1];
 159             c->pal[i * 3 + 2] = tpal[2];
 160         }
 161         memcpy(c->pal2, p->data[1], 1024);
 162     }
 163     if(keyframe){
 164         for(i = 0; i < 256; i++){
 165             AV_WB24(c->pal+(i*3), palptr[i]);
 166         }
 167         memcpy(c->work_buf, c->pal, 768);
 168         memcpy(c->pal2, p->data[1], 1024);
 169         work_size = 768;
 170         for(i = 0; i < avctx->height; i++){
 171             memcpy(c->work_buf + work_size, src, avctx->width);
 172             src += p->linesize[0];
 173             work_size += avctx->width;
 174         }
 175     }else{
 176         int x, y, bh2, bw2;
 177         uint8_t *tsrc, *tprev;
 178         uint8_t *mv;
 179         int mx, my, bv;
 180
 181         bw = (avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
 182         bh = (avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
 183         mv = c->work_buf + work_size;
 184         memset(c->work_buf + work_size, 0, (bw * bh * 2 + 3) & ~3);
 185         work_size += (bw * bh * 2 + 3) & ~3;
 186         /* for now just XOR'ing */
 187         for(y = 0; y < avctx->height; y += ZMBV_BLOCK) {
 188             bh2 = FFMIN(avctx->height - y, ZMBV_BLOCK);
 189             for(x = 0; x < avctx->width; x += ZMBV_BLOCK, mv += 2) {
 190                 bw2 = FFMIN(avctx->width - x, ZMBV_BLOCK);
 191
 192                 tsrc = src + x;
 193                 tprev = prev + x;
 194
 195                 bv = zmbv_me(c, tsrc, p->linesize[0], tprev, c->pstride, x, y, &mx, &my);
 196                 mv[0] = (mx << 1) | !!bv;
 197                 mv[1] = my << 1;
 198                 tprev += mx + my * c->pstride;
 199                 if(bv){
 200                     for(j = 0; j < bh2; j++){
 201                         for(i = 0; i < bw2; i++)
 202                             c->work_buf[work_size++] = tsrc[i] ^ tprev[i];
 203                         tsrc += p->linesize[0];
 204                         tprev += c->pstride;
 205                     }
 206                 }
 207             }
 208             src += p->linesize[0] * ZMBV_BLOCK;
 209             prev += c->pstride * ZMBV_BLOCK;
 210         }
 211     }
 212     /* save the previous frame */
 213     src = p->data[0];
 214     prev = c->prev;
 215     for(i = 0; i < avctx->height; i++){
 216         memcpy(prev, src, avctx->width);
 217         prev += c->pstride;
 218         src += p->linesize[0];
 219     }
 220
 221     c->zstream.next_in = c->work_buf;
 222     c->zstream.avail_in = work_size;
 223     c->zstream.total_in = 0;
 224
 225     c->zstream.next_out = c->comp_buf;
 226     c->zstream.avail_out = c->comp_size;
 227     c->zstream.total_out = 0;
 228     if(deflate(&c->zstream, Z_SYNC_FLUSH) != Z_OK){
 229         av_log(avctx, AV_LOG_ERROR, "Error compressing data\n");
 230         return -1;
 231     }
 232
 233     memcpy(buf, c->comp_buf, c->zstream.total_out);
 234     return len + c->zstream.total_out;
 235 }
 236
 237
 238 /**
 239  * Init zmbv encoder
 240  */
 241 static av_cold int encode_init(AVCodecContext *avctx)
 242 {
 243     ZmbvEncContext * const c = avctx->priv_data;
 244     int zret; // Zlib return code
 245     int i;
 246     int lvl = 9;
 247
 248     for(i=1; i<256; i++)
 249         score_tab[i]= -i * log(i/(double)(ZMBV_BLOCK*ZMBV_BLOCK)) * (256/M_LN2);
 250
 251     c->avctx = avctx;
 252
 253     c->curfrm = 0;
 254     c->keyint = avctx->keyint_min;
 255     c->range = 8;
 256     if(avctx->me_range > 0)
 257         c->range = FFMIN(avctx->me_range, 127);
 258
 259     if(avctx->compression_level >= 0)
 260         lvl = avctx->compression_level;
 261     if(lvl < 0 || lvl > 9){
 262         av_log(avctx, AV_LOG_ERROR, "Compression level should be 0-9, not %i\n", lvl);
 263         return -1;
 264     }
 265
 266     // Needed if zlib unused or init aborted before deflateInit
 267     memset(&(c->zstream), 0, sizeof(z_stream));
 268     c->comp_size = avctx->width * avctx->height + 1024 +
 269         ((avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * ((avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * 2 + 4;
 270     if ((c->work_buf = av_malloc(c->comp_size)) == NULL) {
 271         av_log(avctx, AV_LOG_ERROR, "Can't allocate work buffer.\n");
 272         return -1;
 273     }
 274     /* Conservative upper bound taken from zlib v1.2.1 source via lcl.c */
 275     c->comp_size = c->comp_size + ((c->comp_size + 7) >> 3) +
 276                            ((c->comp_size + 63) >> 6) + 11;
 277
 278     /* Allocate compression buffer */
 279     if ((c->comp_buf = av_malloc(c->comp_size)) == NULL) {
 280         av_log(avctx, AV_LOG_ERROR, "Can't allocate compression buffer.\n");
 281         return -1;
 282     }
 283     c->pstride = FFALIGN(avctx->width, 16);
 284     if ((c->prev = av_malloc(c->pstride * avctx->height)) == NULL) {
 285         av_log(avctx, AV_LOG_ERROR, "Can't allocate picture.\n");
 286         return -1;
 287     }
 288
 289     c->zstream.zalloc = Z_NULL;
 290     c->zstream.zfree = Z_NULL;
 291     c->zstream.opaque = Z_NULL;
 292     zret = deflateInit(&(c->zstream), lvl);
 293     if (zret != Z_OK) {
 294         av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
 295         return -1;
 296     }
 297
 298     avctx->coded_frame = (AVFrame*)&c->pic;
 299
 300     return 0;
 301 }
 302
 303
 304
 305 /**
 306  * Uninit zmbv encoder
 307  */
 308 static av_cold int encode_end(AVCodecContext *avctx)
 309 {
 310     ZmbvEncContext * const c = avctx->priv_data;
 311
 312     av_freep(&c->comp_buf);
 313     av_freep(&c->work_buf);
 314
 315     deflateEnd(&(c->zstream));
 316     av_freep(&c->prev);
 317
 318     return 0;
 319 }
 320
 321 AVCodec zmbv_encoder = {
 322     "zmbv",
 323     CODEC_TYPE_VIDEO,
 324     CODEC_ID_ZMBV,
 325     sizeof(ZmbvEncContext),
 326     encode_init,
 327     encode_frame,
 328     encode_end,
 329     .pix_fmts = (const enum PixelFormat[]){PIX_FMT_PAL8, PIX_FMT_NONE},
 330     .long_name = NULL_IF_CONFIG_SMALL("Zip Motion Blocks Video"),
 331 };