ffmpeg/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
  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
  48     int range;
  49     uint8_t *comp_buf, *work_buf;
  50     uint8_t pal[768];
  51     uint32_t pal2[256]; //for quick comparisons
  52     uint8_t *prev;
  53     int pstride;
  54     int comp_size;
  55     int keyint, curfrm;
  56     z_stream zstream;
  57 } ZmbvEncContext;
  58
  59 static int score_tab[256];
  60
  61 /** Block comparing function
  62  * XXX should be optimized and moved to DSPContext
  63  * TODO handle out of edge ME
  64  */
  65 static inline int block_cmp(uint8_t *src, int stride, uint8_t *src2, int stride2,
  66                             int bw, int bh, int *xored)
  67 {
  68     int sum = 0;
  69     int i, j;
  70     uint8_t histogram[256] = {0};
  71
  72     *xored = 0;
  73     for(j = 0; j < bh; j++){
  74         for(i = 0; i < bw; i++){
  75             int t = src[i] ^ src2[i];
  76             histogram[t]++;
  77             *xored |= t;
  78         }
  79         src += stride;
  80         src2 += stride2;
  81     }
  82
  83     for(i = 1; i < 256; i++)
  84         sum += score_tab[histogram[i]];
  85
  86     return sum;
  87 }
  88
  89 /** Motion estimation function
  90  * TODO make better ME decisions
  91  */
  92 static int zmbv_me(ZmbvEncContext *c, uint8_t *src, int sstride, uint8_t *prev,
  93                    int pstride, int x, int y, int *mx, int *my, int *xored)
  94 {
  95     int dx, dy, tx, ty, tv, bv, bw, bh;
  96
  97     *mx = *my = 0;
  98     bw = FFMIN(ZMBV_BLOCK, c->avctx->width - x);
  99     bh = FFMIN(ZMBV_BLOCK, c->avctx->height - y);
 100     bv = block_cmp(src, sstride, prev, pstride, bw, bh, xored);
 101     if(!bv) return 0;
 102     for(ty = FFMAX(y - c->range, 0); ty < FFMIN(y + c->range, c->avctx->height - bh); ty++){
 103         for(tx = FFMAX(x - c->range, 0); tx < FFMIN(x + c->range, c->avctx->width - bw); tx++){
 104             if(tx == x && ty == y) continue; // we already tested this block
 105             dx = tx - x;
 106             dy = ty - y;
 107             tv = block_cmp(src, sstride, prev + dx + dy*pstride, pstride, bw, bh, xored);
 108             if(tv < bv){
 109                  bv = tv;
 110                  *mx = dx;
 111                  *my = dy;
 112                  if(!bv) return 0;
 113              }
 114          }
 115     }
 116     return bv;
 117 }
 118
 119 static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
 120                         const AVFrame *pict, int *got_packet)
 121 {
 122     ZmbvEncContext * const c = avctx->priv_data;
 123     const AVFrame * const p = pict;
 124     uint8_t *src, *prev, *buf;
 125     uint32_t *palptr;
 126     int keyframe, chpal;
 127     int fl;
 128     int work_size = 0, pkt_size;
 129     int bw, bh;
 130     int i, j, ret;
 131
 132     keyframe = !c->curfrm;
 133     c->curfrm++;
 134     if(c->curfrm == c->keyint)
 135         c->curfrm = 0;
 136     avctx->coded_frame->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
 137     avctx->coded_frame->key_frame = keyframe;
 138     chpal = !keyframe && memcmp(p->data[1], c->pal2, 1024);
 139
 140     palptr = (uint32_t*)p->data[1];
 141     src = p->data[0];
 142     prev = c->prev;
 143     if(chpal){
 144         uint8_t tpal[3];
 145         for(i = 0; i < 256; i++){
 146             AV_WB24(tpal, palptr[i]);
 147             c->work_buf[work_size++] = tpal[0] ^ c->pal[i * 3 + 0];
 148             c->work_buf[work_size++] = tpal[1] ^ c->pal[i * 3 + 1];
 149             c->work_buf[work_size++] = tpal[2] ^ c->pal[i * 3 + 2];
 150             c->pal[i * 3 + 0] = tpal[0];
 151             c->pal[i * 3 + 1] = tpal[1];
 152             c->pal[i * 3 + 2] = tpal[2];
 153         }
 154         memcpy(c->pal2, p->data[1], 1024);
 155     }
 156     if(keyframe){
 157         for(i = 0; i < 256; i++){
 158             AV_WB24(c->pal+(i*3), palptr[i]);
 159         }
 160         memcpy(c->work_buf, c->pal, 768);
 161         memcpy(c->pal2, p->data[1], 1024);
 162         work_size = 768;
 163         for(i = 0; i < avctx->height; i++){
 164             memcpy(c->work_buf + work_size, src, avctx->width);
 165             src += p->linesize[0];
 166             work_size += avctx->width;
 167         }
 168     }else{
 169         int x, y, bh2, bw2, xored;
 170         uint8_t *tsrc, *tprev;
 171         uint8_t *mv;
 172         int mx, my;
 173
 174         bw = (avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
 175         bh = (avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
 176         mv = c->work_buf + work_size;
 177         memset(c->work_buf + work_size, 0, (bw * bh * 2 + 3) & ~3);
 178         work_size += (bw * bh * 2 + 3) & ~3;
 179         /* for now just XOR'ing */
 180         for(y = 0; y < avctx->height; y += ZMBV_BLOCK) {
 181             bh2 = FFMIN(avctx->height - y, ZMBV_BLOCK);
 182             for(x = 0; x < avctx->width; x += ZMBV_BLOCK, mv += 2) {
 183                 bw2 = FFMIN(avctx->width - x, ZMBV_BLOCK);
 184
 185                 tsrc = src + x;
 186                 tprev = prev + x;
 187
 188                 zmbv_me(c, tsrc, p->linesize[0], tprev, c->pstride, x, y, &mx, &my, &xored);
 189                 mv[0] = (mx << 1) | !!xored;
 190                 mv[1] = my << 1;
 191                 tprev += mx + my * c->pstride;
 192                 if(xored){
 193                     for(j = 0; j < bh2; j++){
 194                         for(i = 0; i < bw2; i++)
 195                             c->work_buf[work_size++] = tsrc[i] ^ tprev[i];
 196                         tsrc += p->linesize[0];
 197                         tprev += c->pstride;
 198                     }
 199                 }
 200             }
 201             src += p->linesize[0] * ZMBV_BLOCK;
 202             prev += c->pstride * ZMBV_BLOCK;
 203         }
 204     }
 205     /* save the previous frame */
 206     src = p->data[0];
 207     prev = c->prev;
 208     for(i = 0; i < avctx->height; i++){
 209         memcpy(prev, src, avctx->width);
 210         prev += c->pstride;
 211         src += p->linesize[0];
 212     }
 213
 214     if (keyframe)
 215         deflateReset(&c->zstream);
 216
 217     c->zstream.next_in = c->work_buf;
 218     c->zstream.avail_in = work_size;
 219     c->zstream.total_in = 0;
 220
 221     c->zstream.next_out = c->comp_buf;
 222     c->zstream.avail_out = c->comp_size;
 223     c->zstream.total_out = 0;
 224     if(deflate(&c->zstream, Z_SYNC_FLUSH) != Z_OK){
 225         av_log(avctx, AV_LOG_ERROR, "Error compressing data\n");
 226         return -1;
 227     }
 228
 229     pkt_size = c->zstream.total_out + 1 + 6*keyframe;
 230     if ((ret = ff_alloc_packet2(avctx, pkt, pkt_size)) < 0)
 231         return ret;
 232     buf = pkt->data;
 233
 234     fl = (keyframe ? ZMBV_KEYFRAME : 0) | (chpal ? ZMBV_DELTAPAL : 0);
 235     *buf++ = fl;
 236     if (keyframe) {
 237         *buf++ = 0; // hi ver
 238         *buf++ = 1; // lo ver
 239         *buf++ = 1; // comp
 240         *buf++ = 4; // format - 8bpp
 241         *buf++ = ZMBV_BLOCK; // block width
 242         *buf++ = ZMBV_BLOCK; // block height
 243     }
 244     memcpy(buf, c->comp_buf, c->zstream.total_out);
 245
 246     pkt->flags |= AV_PKT_FLAG_KEY*keyframe;
 247     *got_packet = 1;
 248
 249     return 0;
 250 }
 251
 252 static av_cold int encode_end(AVCodecContext *avctx)
 253 {
 254     ZmbvEncContext * const c = avctx->priv_data;
 255
 256     av_freep(&c->comp_buf);
 257     av_freep(&c->work_buf);
 258
 259     deflateEnd(&c->zstream);
 260     av_freep(&c->prev);
 261
 262     av_frame_free(&avctx->coded_frame);
 263
 264     return 0;
 265 }
 266
 267 /**
 268  * Init zmbv encoder
 269  */
 270 static av_cold int encode_init(AVCodecContext *avctx)
 271 {
 272     ZmbvEncContext * const c = avctx->priv_data;
 273     int zret; // Zlib return code
 274     int i;
 275     int lvl = 9;
 276
 277     for(i=1; i<256; i++)
 278         score_tab[i]= -i * log(i/(double)(ZMBV_BLOCK*ZMBV_BLOCK)) * (256/M_LN2);
 279
 280     c->avctx = avctx;
 281
 282     c->curfrm = 0;
 283     c->keyint = avctx->keyint_min;
 284     c->range = 8;
 285     if(avctx->me_range > 0)
 286         c->range = FFMIN(avctx->me_range, 127);
 287
 288     if(avctx->compression_level >= 0)
 289         lvl = avctx->compression_level;
 290     if(lvl < 0 || lvl > 9){
 291         av_log(avctx, AV_LOG_ERROR, "Compression level should be 0-9, not %i\n", lvl);
 292         return AVERROR(EINVAL);
 293     }
 294
 295     // Needed if zlib unused or init aborted before deflateInit
 296     memset(&c->zstream, 0, sizeof(z_stream));
 297     c->comp_size = avctx->width * avctx->height + 1024 +
 298         ((avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * ((avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * 2 + 4;
 299     if (!(c->work_buf = av_malloc(c->comp_size))) {
 300         av_log(avctx, AV_LOG_ERROR, "Can't allocate work buffer.\n");
 301         return AVERROR(ENOMEM);
 302     }
 303     /* Conservative upper bound taken from zlib v1.2.1 source via lcl.c */
 304     c->comp_size = c->comp_size + ((c->comp_size + 7) >> 3) +
 305                            ((c->comp_size + 63) >> 6) + 11;
 306
 307     /* Allocate compression buffer */
 308     if (!(c->comp_buf = av_malloc(c->comp_size))) {
 309         av_log(avctx, AV_LOG_ERROR, "Can't allocate compression buffer.\n");
 310         return AVERROR(ENOMEM);
 311     }
 312     c->pstride = FFALIGN(avctx->width, 16);
 313     if (!(c->prev = av_malloc(c->pstride * avctx->height))) {
 314         av_log(avctx, AV_LOG_ERROR, "Can't allocate picture.\n");
 315         return AVERROR(ENOMEM);
 316     }
 317
 318     c->zstream.zalloc = Z_NULL;
 319     c->zstream.zfree = Z_NULL;
 320     c->zstream.opaque = Z_NULL;
 321     zret = deflateInit(&c->zstream, lvl);
 322     if (zret != Z_OK) {
 323         av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
 324         return -1;
 325     }
 326
 327     avctx->coded_frame = av_frame_alloc();
 328     if (!avctx->coded_frame) {
 329         encode_end(avctx);
 330         return AVERROR(ENOMEM);
 331     }
 332
 333     return 0;
 334 }
 335
 336 AVCodec ff_zmbv_encoder = {
 337     .name           = "zmbv",
 338     .long_name      = NULL_IF_CONFIG_SMALL("Zip Motion Blocks Video"),
 339     .type           = AVMEDIA_TYPE_VIDEO,
 340     .id             = AV_CODEC_ID_ZMBV,
 341     .priv_data_size = sizeof(ZmbvEncContext),
 342     .init           = encode_init,
 343     .encode2        = encode_frame,
 344     .close          = encode_end,
 345     .pix_fmts       = (const enum AVPixelFormat[]){ AV_PIX_FMT_PAL8, AV_PIX_FMT_NONE },
 346 };