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