2 * Zip Motion Blocks Video (ZMBV) encoder
3 * Copyright (c) 2006 Konstantin Shishkov
5 * This file is part of FFmpeg.
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.
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.
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
24 * Zip Motion Blocks Video encoder
30 #include "libavutil/common.h"
31 #include "libavutil/intreadwrite.h"
37 #define ZMBV_KEYFRAME 1
38 #define ZMBV_DELTAPAL 2
45 typedef struct ZmbvEncContext {
46 AVCodecContext *avctx;
49 uint8_t *comp_buf, *work_buf;
51 uint32_t pal2[256]; //for quick comparisons
52 uint8_t *prev, *prev_buf;
58 int score_tab[ZMBV_BLOCK * ZMBV_BLOCK + 1];
62 /** Block comparing function
63 * XXX should be optimized and moved to DSPContext
65 static inline int block_cmp(ZmbvEncContext *c, uint8_t *src, int stride,
66 uint8_t *src2, int stride2, int bw, int bh,
71 uint16_t histogram[256] = {0};
73 /* Build frequency histogram of byte values for src[] ^ src2[] */
74 for(j = 0; j < bh; j++){
75 for(i = 0; i < bw; i++){
76 int t = src[i] ^ src2[i];
83 /* If not all the xored values were 0, then the blocks are different */
84 *xored = (histogram[0] < bw * bh);
86 /* Exit early if blocks are equal */
87 if (!*xored) return 0;
89 /* Sum the entropy of all values */
90 for(i = 0; i < 256; i++)
91 sum += c->score_tab[histogram[i]];
96 /** Motion estimation function
97 * TODO make better ME decisions
99 static int zmbv_me(ZmbvEncContext *c, uint8_t *src, int sstride, uint8_t *prev,
100 int pstride, int x, int y, int *mx, int *my, int *xored)
102 int dx, dy, txored, tv, bv, bw, bh;
107 bw = FFMIN(ZMBV_BLOCK, c->avctx->width - x);
108 bh = FFMIN(ZMBV_BLOCK, c->avctx->height - y);
111 bv = block_cmp(c, src, sstride, prev, pstride, bw, bh, xored);
115 /* Try previous block's MV (if not 0,0) */
117 tv = block_cmp(c, src, sstride, prev + mx0 + my0 * pstride, pstride, bw, bh, &txored);
127 /* Try other MVs from top-to-bottom, left-to-right */
128 for(dy = -c->lrange; dy <= c->urange; dy++){
129 for(dx = -c->lrange; dx <= c->urange; dx++){
130 if(!dx && !dy) continue; // we already tested this block
131 if(dx == mx0 && dy == my0) continue; // this one too
132 tv = block_cmp(c, src, sstride, prev + dx + dy * pstride, pstride, bw, bh, &txored);
145 static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
146 const AVFrame *pict, int *got_packet)
148 ZmbvEncContext * const c = avctx->priv_data;
149 const AVFrame * const p = pict;
150 uint8_t *src, *prev, *buf;
154 int work_size = 0, pkt_size;
158 keyframe = !c->curfrm;
160 if(c->curfrm == c->keyint)
162 #if FF_API_CODED_FRAME
163 FF_DISABLE_DEPRECATION_WARNINGS
164 avctx->coded_frame->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
165 avctx->coded_frame->key_frame = keyframe;
166 FF_ENABLE_DEPRECATION_WARNINGS
168 chpal = !keyframe && memcmp(p->data[1], c->pal2, 1024);
170 palptr = (uint32_t*)p->data[1];
175 for(i = 0; i < 256; i++){
176 AV_WB24(tpal, palptr[i]);
177 c->work_buf[work_size++] = tpal[0] ^ c->pal[i * 3 + 0];
178 c->work_buf[work_size++] = tpal[1] ^ c->pal[i * 3 + 1];
179 c->work_buf[work_size++] = tpal[2] ^ c->pal[i * 3 + 2];
180 c->pal[i * 3 + 0] = tpal[0];
181 c->pal[i * 3 + 1] = tpal[1];
182 c->pal[i * 3 + 2] = tpal[2];
184 memcpy(c->pal2, p->data[1], 1024);
187 for(i = 0; i < 256; i++){
188 AV_WB24(c->pal+(i*3), palptr[i]);
190 memcpy(c->work_buf, c->pal, 768);
191 memcpy(c->pal2, p->data[1], 1024);
193 for(i = 0; i < avctx->height; i++){
194 memcpy(c->work_buf + work_size, src, avctx->width);
195 src += p->linesize[0];
196 work_size += avctx->width;
199 int x, y, bh2, bw2, xored;
200 uint8_t *tsrc, *tprev;
204 bw = (avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
205 bh = (avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
206 mv = c->work_buf + work_size;
207 memset(c->work_buf + work_size, 0, (bw * bh * 2 + 3) & ~3);
208 work_size += (bw * bh * 2 + 3) & ~3;
209 /* for now just XOR'ing */
210 for(y = 0; y < avctx->height; y += ZMBV_BLOCK) {
211 bh2 = FFMIN(avctx->height - y, ZMBV_BLOCK);
212 for(x = 0; x < avctx->width; x += ZMBV_BLOCK, mv += 2) {
213 bw2 = FFMIN(avctx->width - x, ZMBV_BLOCK);
218 zmbv_me(c, tsrc, p->linesize[0], tprev, c->pstride, x, y, &mx, &my, &xored);
219 mv[0] = (mx << 1) | !!xored;
221 tprev += mx + my * c->pstride;
223 for(j = 0; j < bh2; j++){
224 for(i = 0; i < bw2; i++)
225 c->work_buf[work_size++] = tsrc[i] ^ tprev[i];
226 tsrc += p->linesize[0];
231 src += p->linesize[0] * ZMBV_BLOCK;
232 prev += c->pstride * ZMBV_BLOCK;
235 /* save the previous frame */
238 for(i = 0; i < avctx->height; i++){
239 memcpy(prev, src, avctx->width);
241 src += p->linesize[0];
245 deflateReset(&c->zstream);
247 c->zstream.next_in = c->work_buf;
248 c->zstream.avail_in = work_size;
249 c->zstream.total_in = 0;
251 c->zstream.next_out = c->comp_buf;
252 c->zstream.avail_out = c->comp_size;
253 c->zstream.total_out = 0;
254 if(deflate(&c->zstream, Z_SYNC_FLUSH) != Z_OK){
255 av_log(avctx, AV_LOG_ERROR, "Error compressing data\n");
259 pkt_size = c->zstream.total_out + 1 + 6*keyframe;
260 if ((ret = ff_alloc_packet2(avctx, pkt, pkt_size, 0)) < 0)
264 fl = (keyframe ? ZMBV_KEYFRAME : 0) | (chpal ? ZMBV_DELTAPAL : 0);
267 *buf++ = 0; // hi ver
268 *buf++ = 1; // lo ver
270 *buf++ = 4; // format - 8bpp
271 *buf++ = ZMBV_BLOCK; // block width
272 *buf++ = ZMBV_BLOCK; // block height
274 memcpy(buf, c->comp_buf, c->zstream.total_out);
276 pkt->flags |= AV_PKT_FLAG_KEY*keyframe;
282 static av_cold int encode_end(AVCodecContext *avctx)
284 ZmbvEncContext * const c = avctx->priv_data;
286 av_freep(&c->comp_buf);
287 av_freep(&c->work_buf);
289 deflateEnd(&c->zstream);
290 av_freep(&c->prev_buf);
298 static av_cold int encode_init(AVCodecContext *avctx)
300 ZmbvEncContext * const c = avctx->priv_data;
301 int zret; // Zlib return code
304 int prev_size, prev_offset;
306 /* Entropy-based score tables for comparing blocks.
307 * Suitable for blocks up to (ZMBV_BLOCK * ZMBV_BLOCK) bytes.
308 * Scores are nonnegative, lower is better.
310 for(i = 1; i <= ZMBV_BLOCK * ZMBV_BLOCK; i++)
311 c->score_tab[i] = -i * log2(i / (double)(ZMBV_BLOCK * ZMBV_BLOCK)) * 256;
316 c->keyint = avctx->keyint_min;
318 /* Motion estimation range: maximum distance is -64..63 */
319 c->lrange = c->urange = 8;
320 if(avctx->me_range > 0){
321 c->lrange = FFMIN(avctx->me_range, 64);
322 c->urange = FFMIN(avctx->me_range, 63);
325 if(avctx->compression_level >= 0)
326 lvl = avctx->compression_level;
327 if(lvl < 0 || lvl > 9){
328 av_log(avctx, AV_LOG_ERROR, "Compression level should be 0-9, not %i\n", lvl);
329 return AVERROR(EINVAL);
332 // Needed if zlib unused or init aborted before deflateInit
333 memset(&c->zstream, 0, sizeof(z_stream));
334 c->comp_size = avctx->width * avctx->height + 1024 +
335 ((avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * ((avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * 2 + 4;
336 if (!(c->work_buf = av_malloc(c->comp_size))) {
337 av_log(avctx, AV_LOG_ERROR, "Can't allocate work buffer.\n");
338 return AVERROR(ENOMEM);
340 /* Conservative upper bound taken from zlib v1.2.1 source via lcl.c */
341 c->comp_size = c->comp_size + ((c->comp_size + 7) >> 3) +
342 ((c->comp_size + 63) >> 6) + 11;
344 /* Allocate compression buffer */
345 if (!(c->comp_buf = av_malloc(c->comp_size))) {
346 av_log(avctx, AV_LOG_ERROR, "Can't allocate compression buffer.\n");
347 return AVERROR(ENOMEM);
350 /* Allocate prev buffer - pad around the image to allow out-of-edge ME:
351 * - The image should be padded with `lrange` rows before and `urange` rows
353 * - The stride should be padded with `lrange` pixels, then rounded up to a
354 * multiple of 16 bytes.
355 * - The first row should also be padded with `lrange` pixels before, then
356 * aligned up to a multiple of 16 bytes.
358 c->pstride = FFALIGN(avctx->width + c->lrange, 16);
359 prev_size = FFALIGN(c->lrange, 16) + c->pstride * (c->lrange + avctx->height + c->urange);
360 prev_offset = FFALIGN(c->lrange, 16) + c->pstride * c->lrange;
361 if (!(c->prev_buf = av_mallocz(prev_size))) {
362 av_log(avctx, AV_LOG_ERROR, "Can't allocate picture.\n");
363 return AVERROR(ENOMEM);
365 c->prev = c->prev_buf + prev_offset;
367 c->zstream.zalloc = Z_NULL;
368 c->zstream.zfree = Z_NULL;
369 c->zstream.opaque = Z_NULL;
370 zret = deflateInit(&c->zstream, lvl);
372 av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
379 AVCodec ff_zmbv_encoder = {
381 .long_name = NULL_IF_CONFIG_SMALL("Zip Motion Blocks Video"),
382 .type = AVMEDIA_TYPE_VIDEO,
383 .id = AV_CODEC_ID_ZMBV,
384 .priv_data_size = sizeof(ZmbvEncContext),
386 .encode2 = encode_frame,
388 .pix_fmts = (const enum AVPixelFormat[]){ AV_PIX_FMT_PAL8, AV_PIX_FMT_NONE },