libavcodec/zmbvenc.c

   1 /*
   2  * Zip Motion Blocks Video (ZMBV) encoder
   3  * Copyright (c) 2006 Konstantin Shishkov
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; 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
  24  * Zip Motion Blocks Video encoder
  25  */
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29
  30 #include "libavutil/common.h"
  31 #include "libavutil/intreadwrite.h"
  32 #include "avcodec.h"
  33 #include "internal.h"
  34
  35 #include <zlib.h>
  36
  37 #define ZMBV_KEYFRAME 1
  38 #define ZMBV_DELTAPAL 2
  39
  40 #define ZMBV_BLOCK 16
  41
  42 /**
  43  * Encoder context
  44  */
  45 typedef struct ZmbvEncContext {
  46     AVCodecContext *avctx;
  47     AVFrame pic;
  48
  49     int range;
  50     uint8_t *comp_buf, *work_buf;
  51     uint8_t pal[768];
  52     uint32_t pal2[256]; //for quick comparisons
  53     uint8_t *prev;
  54     int pstride;
  55     int comp_size;
  56     int keyint, curfrm;
  57     z_stream zstream;
  58 } ZmbvEncContext;
  59
  60 static int score_tab[256];
  61
  62 /** Block comparing function
  63  * XXX should be optimized and moved to DSPContext
  64  * TODO handle out of edge ME
  65  */
  66 static inline int block_cmp(uint8_t *src, int stride, uint8_t *src2, int stride2,
  67                             int bw, int bh, int *xored)
  68 {
  69     int sum = 0;
  70     int i, j;
  71     uint8_t histogram[256] = {0};
  72
  73     *xored = 0;
  74     for(j = 0; j < bh; j++){
  75         for(i = 0; i < bw; i++){
  76             int t = src[i] ^ src2[i];
  77             histogram[t]++;
  78             *xored |= t;
  79         }
  80         src += stride;
  81         src2 += stride2;
  82     }
  83
  84     for(i = 1; i < 256; i++)
  85         sum += score_tab[histogram[i]];
  86
  87     return sum;
  88 }
  89
  90 /** Motion estimation function
  91  * TODO make better ME decisions
  92  */
  93 static int zmbv_me(ZmbvEncContext *c, uint8_t *src, int sstride, uint8_t *prev,
  94                    int pstride, int x, int y, int *mx, int *my, int *xored)
  95 {
  96     int dx, dy, tx, ty, tv, bv, bw, bh;
  97
  98     *mx = *my = 0;
  99     bw = FFMIN(ZMBV_BLOCK, c->avctx->width - x);
 100     bh = FFMIN(ZMBV_BLOCK, c->avctx->height - y);
 101     bv = block_cmp(src, sstride, prev, pstride, bw, bh, xored);
 102     if(!bv) return 0;
 103     for(ty = FFMAX(y - c->range, 0); ty < FFMIN(y + c->range, c->avctx->height - bh); ty++){
 104         for(tx = FFMAX(x - c->range, 0); tx < FFMIN(x + c->range, c->avctx->width - bw); tx++){
 105             if(tx == x && ty == y) continue; // we already tested this block
 106             dx = tx - x;
 107             dy = ty - y;
 108             tv = block_cmp(src, sstride, prev + dx + dy*pstride, pstride, bw, bh, xored);
 109             if(tv < bv){
 110                  bv = tv;
 111                  *mx = dx;
 112                  *my = dy;
 113                  if(!bv) return 0;
 114              }
 115          }
 116     }
 117     return bv;
 118 }
 119
 120 static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
 121                         const AVFrame *pict, int *got_packet)
 122 {
 123     ZmbvEncContext * const c = avctx->priv_data;
 124     AVFrame * const p = &c->pic;
 125     uint8_t *src, *prev, *buf;
 126     uint32_t *palptr;
 127     int keyframe, chpal;
 128     int fl;
 129     int work_size = 0, pkt_size;
 130     int bw, bh;
 131     int i, j, ret;
 132
 133     keyframe = !c->curfrm;
 134     c->curfrm++;
 135     if(c->curfrm == c->keyint)
 136         c->curfrm = 0;
 137     *p = *pict;
 138     p->pict_type= keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
 139     p->key_frame= keyframe;
 140     chpal = !keyframe && memcmp(p->data[1], c->pal2, 1024);
 141
 142     palptr = (uint32_t*)p->data[1];
 143     src = p->data[0];
 144     prev = c->prev;
 145     if(chpal){
 146         uint8_t tpal[3];
 147         for(i = 0; i < 256; i++){
 148             AV_WB24(tpal, palptr[i]);
 149             c->work_buf[work_size++] = tpal[0] ^ c->pal[i * 3 + 0];
 150             c->work_buf[work_size++] = tpal[1] ^ c->pal[i * 3 + 1];
 151             c->work_buf[work_size++] = tpal[2] ^ c->pal[i * 3 + 2];
 152             c->pal[i * 3 + 0] = tpal[0];
 153             c->pal[i * 3 + 1] = tpal[1];
 154             c->pal[i * 3 + 2] = tpal[2];
 155         }
 156         memcpy(c->pal2, p->data[1], 1024);
 157     }
 158     if(keyframe){
 159         for(i = 0; i < 256; i++){
 160             AV_WB24(c->pal+(i*3), palptr[i]);
 161         }
 162         memcpy(c->work_buf, c->pal, 768);
 163         memcpy(c->pal2, p->data[1], 1024);
 164         work_size = 768;
 165         for(i = 0; i < avctx->height; i++){
 166             memcpy(c->work_buf + work_size, src, avctx->width);
 167             src += p->linesize[0];
 168             work_size += avctx->width;
 169         }
 170     }else{
 171         int x, y, bh2, bw2, xored;
 172         uint8_t *tsrc, *tprev;
 173         uint8_t *mv;
 174         int mx, my;
 175
 176         bw = (avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
 177         bh = (avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
 178         mv = c->work_buf + work_size;
 179         memset(c->work_buf + work_size, 0, (bw * bh * 2 + 3) & ~3);
 180         work_size += (bw * bh * 2 + 3) & ~3;
 181         /* for now just XOR'ing */
 182         for(y = 0; y < avctx->height; y += ZMBV_BLOCK) {
 183             bh2 = FFMIN(avctx->height - y, ZMBV_BLOCK);
 184             for(x = 0; x < avctx->width; x += ZMBV_BLOCK, mv += 2) {
 185                 bw2 = FFMIN(avctx->width - x, ZMBV_BLOCK);
 186
 187                 tsrc = src + x;
 188                 tprev = prev + x;
 189
 190                 zmbv_me(c, tsrc, p->linesize[0], tprev, c->pstride, x, y, &mx, &my, &xored);
 191                 mv[0] = (mx << 1) | !!xored;
 192                 mv[1] = my << 1;
 193                 tprev += mx + my * c->pstride;
 194                 if(xored){
 195                     for(j = 0; j < bh2; j++){
 196                         for(i = 0; i < bw2; i++)
 197                             c->work_buf[work_size++] = tsrc[i] ^ tprev[i];
 198                         tsrc += p->linesize[0];
 199                         tprev += c->pstride;
 200                     }
 201                 }
 202             }
 203             src += p->linesize[0] * ZMBV_BLOCK;
 204             prev += c->pstride * ZMBV_BLOCK;
 205         }
 206     }
 207     /* save the previous frame */
 208     src = p->data[0];
 209     prev = c->prev;
 210     for(i = 0; i < avctx->height; i++){
 211         memcpy(prev, src, avctx->width);
 212         prev += c->pstride;
 213         src += p->linesize[0];
 214     }
 215
 216     if (keyframe)
 217         deflateReset(&c->zstream);
 218
 219     c->zstream.next_in = c->work_buf;
 220     c->zstream.avail_in = work_size;
 221     c->zstream.total_in = 0;
 222
 223     c->zstream.next_out = c->comp_buf;
 224     c->zstream.avail_out = c->comp_size;
 225     c->zstream.total_out = 0;
 226     if(deflate(&c->zstream, Z_SYNC_FLUSH) != Z_OK){
 227         av_log(avctx, AV_LOG_ERROR, "Error compressing data\n");
 228         return -1;
 229     }
 230
 231     pkt_size = c->zstream.total_out + 1 + 6*keyframe;
 232     if ((ret = ff_alloc_packet(pkt, pkt_size)) < 0) {
 233         av_log(avctx, AV_LOG_ERROR, "Error getting packet of size %d.\n", pkt_size);
 234         return ret;
 235     }
 236     buf = pkt->data;
 237
 238     fl = (keyframe ? ZMBV_KEYFRAME : 0) | (chpal ? ZMBV_DELTAPAL : 0);
 239     *buf++ = fl;
 240     if (keyframe) {
 241         *buf++ = 0; // hi ver
 242         *buf++ = 1; // lo ver
 243         *buf++ = 1; // comp
 244         *buf++ = 4; // format - 8bpp
 245         *buf++ = ZMBV_BLOCK; // block width
 246         *buf++ = ZMBV_BLOCK; // block height
 247     }
 248     memcpy(buf, c->comp_buf, c->zstream.total_out);
 249
 250     pkt->flags |= AV_PKT_FLAG_KEY*keyframe;
 251     *got_packet = 1;
 252
 253     return 0;
 254 }
 255
 256
 257 /**
 258  * Init zmbv encoder
 259  */
 260 static av_cold int encode_init(AVCodecContext *avctx)
 261 {
 262     ZmbvEncContext * const c = avctx->priv_data;
 263     int zret; // Zlib return code
 264     int i;
 265     int lvl = 9;
 266
 267     for(i=1; i<256; i++)
 268         score_tab[i]= -i * log(i/(double)(ZMBV_BLOCK*ZMBV_BLOCK)) * (256/M_LN2);
 269
 270     c->avctx = avctx;
 271
 272     c->curfrm = 0;
 273     c->keyint = avctx->keyint_min;
 274     c->range = 8;
 275     if(avctx->me_range > 0)
 276         c->range = FFMIN(avctx->me_range, 127);
 277
 278     if(avctx->compression_level >= 0)
 279         lvl = avctx->compression_level;
 280     if(lvl < 0 || lvl > 9){
 281         av_log(avctx, AV_LOG_ERROR, "Compression level should be 0-9, not %i\n", lvl);
 282         return AVERROR(EINVAL);
 283     }
 284
 285     // Needed if zlib unused or init aborted before deflateInit
 286     memset(&c->zstream, 0, sizeof(z_stream));
 287     c->comp_size = avctx->width * avctx->height + 1024 +
 288         ((avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * ((avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * 2 + 4;
 289     if ((c->work_buf = av_malloc(c->comp_size)) == NULL) {
 290         av_log(avctx, AV_LOG_ERROR, "Can't allocate work buffer.\n");
 291         return AVERROR(ENOMEM);
 292     }
 293     /* Conservative upper bound taken from zlib v1.2.1 source via lcl.c */
 294     c->comp_size = c->comp_size + ((c->comp_size + 7) >> 3) +
 295                            ((c->comp_size + 63) >> 6) + 11;
 296
 297     /* Allocate compression buffer */
 298     if ((c->comp_buf = av_malloc(c->comp_size)) == NULL) {
 299         av_log(avctx, AV_LOG_ERROR, "Can't allocate compression buffer.\n");
 300         return AVERROR(ENOMEM);
 301     }
 302     c->pstride = FFALIGN(avctx->width, 16);
 303     if ((c->prev = av_malloc(c->pstride * avctx->height)) == NULL) {
 304         av_log(avctx, AV_LOG_ERROR, "Can't allocate picture.\n");
 305         return AVERROR(ENOMEM);
 306     }
 307
 308     c->zstream.zalloc = Z_NULL;
 309     c->zstream.zfree = Z_NULL;
 310     c->zstream.opaque = Z_NULL;
 311     zret = deflateInit(&c->zstream, lvl);
 312     if (zret != Z_OK) {
 313         av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
 314         return -1;
 315     }
 316
 317     avctx->coded_frame = &c->pic;
 318
 319     return 0;
 320 }
 321
 322
 323
 324 /**
 325  * Uninit zmbv encoder
 326  */
 327 static av_cold int encode_end(AVCodecContext *avctx)
 328 {
 329     ZmbvEncContext * const c = avctx->priv_data;
 330
 331     av_freep(&c->comp_buf);
 332     av_freep(&c->work_buf);
 333
 334     deflateEnd(&c->zstream);
 335     av_freep(&c->prev);
 336
 337     return 0;
 338 }
 339
 340 AVCodec ff_zmbv_encoder = {
 341     .name           = "zmbv",
 342     .type           = AVMEDIA_TYPE_VIDEO,
 343     .id             = AV_CODEC_ID_ZMBV,
 344     .priv_data_size = sizeof(ZmbvEncContext),
 345     .init           = encode_init,
 346     .encode2        = encode_frame,
 347     .close          = encode_end,
 348     .pix_fmts       = (const enum AVPixelFormat[]){ AV_PIX_FMT_PAL8, AV_PIX_FMT_NONE },
 349     .long_name      = NULL_IF_CONFIG_SMALL("Zip Motion Blocks Video"),
 350 };