FFmpeg: libavcodec/zmbvenc.c Source File

00001 /*
00002  * Zip Motion Blocks Video (ZMBV) encoder
00003  * Copyright (c) 2006 Konstantin Shishkov
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00027 #include <stdio.h>
00028 #include <stdlib.h>
00029 
00030 #include "libavutil/intreadwrite.h"
00031 #include "avcodec.h"
00032 
00033 #include <zlib.h>
00034 
00035 #define ZMBV_KEYFRAME 1
00036 #define ZMBV_DELTAPAL 2
00037 
00038 #define ZMBV_BLOCK 16
00039 
00043 typedef struct ZmbvEncContext {
00044     AVCodecContext *avctx;
00045     AVFrame pic;
00046 
00047     int range;
00048     uint8_t *comp_buf, *work_buf;
00049     uint8_t pal[768];
00050     uint32_t pal2[256]; //for quick comparisons
00051     uint8_t *prev;
00052     int pstride;
00053     int comp_size;
00054     int keyint, curfrm;
00055     z_stream zstream;
00056 } ZmbvEncContext;
00057 
00058 static int score_tab[256];
00059 
00064 static inline int block_cmp(uint8_t *src, int stride, uint8_t *src2, int stride2,
00065                             int bw, int bh, int *xored)
00066 {
00067     int sum = 0;
00068     int i, j;
00069     uint8_t histogram[256] = {0};
00070 
00071     *xored = 0;
00072     for(j = 0; j < bh; j++){
00073         for(i = 0; i < bw; i++){
00074             int t = src[i] ^ src2[i];
00075             histogram[t]++;
00076             *xored |= t;
00077         }
00078         src += stride;
00079         src2 += stride2;
00080     }
00081 
00082     for(i = 1; i < 256; i++)
00083         sum += score_tab[histogram[i]];
00084 
00085     return sum;
00086 }
00087 
00091 static int zmbv_me(ZmbvEncContext *c, uint8_t *src, int sstride, uint8_t *prev,
00092                    int pstride, int x, int y, int *mx, int *my, int *xored)
00093 {
00094     int dx, dy, tx, ty, tv, bv, bw, bh;
00095 
00096     *mx = *my = 0;
00097     bw = FFMIN(ZMBV_BLOCK, c->avctx->width - x);
00098     bh = FFMIN(ZMBV_BLOCK, c->avctx->height - y);
00099     bv = block_cmp(src, sstride, prev, pstride, bw, bh, xored);
00100     if(!bv) return 0;
00101     for(ty = FFMAX(y - c->range, 0); ty < FFMIN(y + c->range, c->avctx->height - bh); ty++){
00102         for(tx = FFMAX(x - c->range, 0); tx < FFMIN(x + c->range, c->avctx->width - bw); tx++){
00103             if(tx == x && ty == y) continue; // we already tested this block
00104             dx = tx - x;
00105             dy = ty - y;
00106             tv = block_cmp(src, sstride, prev + dx + dy*pstride, pstride, bw, bh, xored);
00107             if(tv < bv){
00108                  bv = tv;
00109                  *mx = dx;
00110                  *my = dy;
00111                  if(!bv) return 0;
00112              }
00113          }
00114     }
00115     return bv;
00116 }
00117 
00118 static int encode_frame(AVCodecContext *avctx, uint8_t *buf, int buf_size, void *data)
00119 {
00120     ZmbvEncContext * const c = avctx->priv_data;
00121     AVFrame *pict = data;
00122     AVFrame * const p = &c->pic;
00123     uint8_t *src, *prev;
00124     uint32_t *palptr;
00125     int len = 0;
00126     int keyframe, chpal;
00127     int fl;
00128     int work_size = 0;
00129     int bw, bh;
00130     int i, j;
00131 
00132     keyframe = !c->curfrm;
00133     c->curfrm++;
00134     if(c->curfrm == c->keyint)
00135         c->curfrm = 0;
00136     *p = *pict;
00137     p->pict_type= keyframe ? FF_I_TYPE : FF_P_TYPE;
00138     p->key_frame= keyframe;
00139     chpal = !keyframe && memcmp(p->data[1], c->pal2, 1024);
00140 
00141     fl = (keyframe ? ZMBV_KEYFRAME : 0) | (chpal ? ZMBV_DELTAPAL : 0);
00142     *buf++ = fl; len++;
00143     if(keyframe){
00144         deflateReset(&c->zstream);
00145         *buf++ = 0; len++; // hi ver
00146         *buf++ = 1; len++; // lo ver
00147         *buf++ = 1; len++; // comp
00148         *buf++ = 4; len++; // format - 8bpp
00149         *buf++ = ZMBV_BLOCK; len++; // block width
00150         *buf++ = ZMBV_BLOCK; len++; // block height
00151     }
00152     palptr = (uint32_t*)p->data[1];
00153     src = p->data[0];
00154     prev = c->prev;
00155     if(chpal){
00156         uint8_t tpal[3];
00157         for(i = 0; i < 256; i++){
00158             AV_WB24(tpal, palptr[i]);
00159             c->work_buf[work_size++] = tpal[0] ^ c->pal[i * 3 + 0];
00160             c->work_buf[work_size++] = tpal[1] ^ c->pal[i * 3 + 1];
00161             c->work_buf[work_size++] = tpal[2] ^ c->pal[i * 3 + 2];
00162             c->pal[i * 3 + 0] = tpal[0];
00163             c->pal[i * 3 + 1] = tpal[1];
00164             c->pal[i * 3 + 2] = tpal[2];
00165         }
00166         memcpy(c->pal2, p->data[1], 1024);
00167     }
00168     if(keyframe){
00169         for(i = 0; i < 256; i++){
00170             AV_WB24(c->pal+(i*3), palptr[i]);
00171         }
00172         memcpy(c->work_buf, c->pal, 768);
00173         memcpy(c->pal2, p->data[1], 1024);
00174         work_size = 768;
00175         for(i = 0; i < avctx->height; i++){
00176             memcpy(c->work_buf + work_size, src, avctx->width);
00177             src += p->linesize[0];
00178             work_size += avctx->width;
00179         }
00180     }else{
00181         int x, y, bh2, bw2, xored;
00182         uint8_t *tsrc, *tprev;
00183         uint8_t *mv;
00184         int mx, my, bv;
00185 
00186         bw = (avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
00187         bh = (avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
00188         mv = c->work_buf + work_size;
00189         memset(c->work_buf + work_size, 0, (bw * bh * 2 + 3) & ~3);
00190         work_size += (bw * bh * 2 + 3) & ~3;
00191         /* for now just XOR'ing */
00192         for(y = 0; y < avctx->height; y += ZMBV_BLOCK) {
00193             bh2 = FFMIN(avctx->height - y, ZMBV_BLOCK);
00194             for(x = 0; x < avctx->width; x += ZMBV_BLOCK, mv += 2) {
00195                 bw2 = FFMIN(avctx->width - x, ZMBV_BLOCK);
00196 
00197                 tsrc = src + x;
00198                 tprev = prev + x;
00199 
00200                 bv = zmbv_me(c, tsrc, p->linesize[0], tprev, c->pstride, x, y, &mx, &my, &xored);
00201                 mv[0] = (mx << 1) | !!xored;
00202                 mv[1] = my << 1;
00203                 tprev += mx + my * c->pstride;
00204                 if(xored){
00205                     for(j = 0; j < bh2; j++){
00206                         for(i = 0; i < bw2; i++)
00207                             c->work_buf[work_size++] = tsrc[i] ^ tprev[i];
00208                         tsrc += p->linesize[0];
00209                         tprev += c->pstride;
00210                     }
00211                 }
00212             }
00213             src += p->linesize[0] * ZMBV_BLOCK;
00214             prev += c->pstride * ZMBV_BLOCK;
00215         }
00216     }
00217     /* save the previous frame */
00218     src = p->data[0];
00219     prev = c->prev;
00220     for(i = 0; i < avctx->height; i++){
00221         memcpy(prev, src, avctx->width);
00222         prev += c->pstride;
00223         src += p->linesize[0];
00224     }
00225 
00226     c->zstream.next_in = c->work_buf;
00227     c->zstream.avail_in = work_size;
00228     c->zstream.total_in = 0;
00229 
00230     c->zstream.next_out = c->comp_buf;
00231     c->zstream.avail_out = c->comp_size;
00232     c->zstream.total_out = 0;
00233     if(deflate(&c->zstream, Z_SYNC_FLUSH) != Z_OK){
00234         av_log(avctx, AV_LOG_ERROR, "Error compressing data\n");
00235         return -1;
00236     }
00237 
00238     memcpy(buf, c->comp_buf, c->zstream.total_out);
00239     return len + c->zstream.total_out;
00240 }
00241 
00242 
00246 static av_cold int encode_init(AVCodecContext *avctx)
00247 {
00248     ZmbvEncContext * const c = avctx->priv_data;
00249     int zret; // Zlib return code
00250     int i;
00251     int lvl = 9;
00252 
00253     for(i=1; i<256; i++)
00254         score_tab[i]= -i * log(i/(double)(ZMBV_BLOCK*ZMBV_BLOCK)) * (256/M_LN2);
00255 
00256     c->avctx = avctx;
00257 
00258     c->curfrm = 0;
00259     c->keyint = avctx->keyint_min;
00260     c->range = 8;
00261     if(avctx->me_range > 0)
00262         c->range = FFMIN(avctx->me_range, 127);
00263 
00264     if(avctx->compression_level >= 0)
00265         lvl = avctx->compression_level;
00266     if(lvl < 0 || lvl > 9){
00267         av_log(avctx, AV_LOG_ERROR, "Compression level should be 0-9, not %i\n", lvl);
00268         return -1;
00269     }
00270 
00271     // Needed if zlib unused or init aborted before deflateInit
00272     memset(&(c->zstream), 0, sizeof(z_stream));
00273     c->comp_size = avctx->width * avctx->height + 1024 +
00274         ((avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * ((avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * 2 + 4;
00275     if ((c->work_buf = av_malloc(c->comp_size)) == NULL) {
00276         av_log(avctx, AV_LOG_ERROR, "Can't allocate work buffer.\n");
00277         return -1;
00278     }
00279     /* Conservative upper bound taken from zlib v1.2.1 source via lcl.c */
00280     c->comp_size = c->comp_size + ((c->comp_size + 7) >> 3) +
00281                            ((c->comp_size + 63) >> 6) + 11;
00282 
00283     /* Allocate compression buffer */
00284     if ((c->comp_buf = av_malloc(c->comp_size)) == NULL) {
00285         av_log(avctx, AV_LOG_ERROR, "Can't allocate compression buffer.\n");
00286         return -1;
00287     }
00288     c->pstride = FFALIGN(avctx->width, 16);
00289     if ((c->prev = av_malloc(c->pstride * avctx->height)) == NULL) {
00290         av_log(avctx, AV_LOG_ERROR, "Can't allocate picture.\n");
00291         return -1;
00292     }
00293 
00294     c->zstream.zalloc = Z_NULL;
00295     c->zstream.zfree = Z_NULL;
00296     c->zstream.opaque = Z_NULL;
00297     zret = deflateInit(&(c->zstream), lvl);
00298     if (zret != Z_OK) {
00299         av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
00300         return -1;
00301     }
00302 
00303     avctx->coded_frame = (AVFrame*)&c->pic;
00304 
00305     return 0;
00306 }
00307 
00308 
00309 
00313 static av_cold int encode_end(AVCodecContext *avctx)
00314 {
00315     ZmbvEncContext * const c = avctx->priv_data;
00316 
00317     av_freep(&c->comp_buf);
00318     av_freep(&c->work_buf);
00319 
00320     deflateEnd(&(c->zstream));
00321     av_freep(&c->prev);
00322 
00323     return 0;
00324 }
00325 
00326 AVCodec zmbv_encoder = {
00327     "zmbv",
00328     AVMEDIA_TYPE_VIDEO,
00329     CODEC_ID_ZMBV,
00330     sizeof(ZmbvEncContext),
00331     encode_init,
00332     encode_frame,
00333     encode_end,
00334     .pix_fmts = (const enum PixelFormat[]){PIX_FMT_PAL8, PIX_FMT_NONE},
00335     .long_name = NULL_IF_CONFIG_SMALL("Zip Motion Blocks Video"),
00336 };