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/intreadwrite.h"
31#include "avcodec.h"
32
33#include <zlib.h>
34
35#define ZMBV_KEYFRAME 1
36#define ZMBV_DELTAPAL 2
37
38#define ZMBV_BLOCK 16
39
40/**
41 * Encoder context
42 */
43typedef struct ZmbvEncContext {
44    AVCodecContext *avctx;
45    AVFrame pic;
46
47    int range;
48    uint8_t *comp_buf, *work_buf;
49    uint8_t pal[768];
50    uint32_t pal2[256]; //for quick comparisons
51    uint8_t *prev;
52    int pstride;
53    int comp_size;
54    int keyint, curfrm;
55    z_stream zstream;
56} ZmbvEncContext;
57
58static 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 */
64static 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 */
91static 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
118static int encode_frame(AVCodecContext *avctx, uint8_t *buf, int buf_size, void *data)
119{
120    ZmbvEncContext * const c = avctx->priv_data;
121    AVFrame *pict = data;
122    AVFrame * const p = &c->pic;
123    uint8_t *src, *prev;
124    uint32_t *palptr;
125    int len = 0;
126    int keyframe, chpal;
127    int fl;
128    int work_size = 0;
129    int bw, bh;
130    int i, j;
131
132    keyframe = !c->curfrm;
133    c->curfrm++;
134    if(c->curfrm == c->keyint)
135        c->curfrm = 0;
136    *p = *pict;
137    p->pict_type= keyframe ? FF_I_TYPE : FF_P_TYPE;
138    p->key_frame= keyframe;
139    chpal = !keyframe && memcmp(p->data[1], c->pal2, 1024);
140
141    fl = (keyframe ? ZMBV_KEYFRAME : 0) | (chpal ? ZMBV_DELTAPAL : 0);
142    *buf++ = fl; len++;
143    if(keyframe){
144        deflateReset(&c->zstream);
145        *buf++ = 0; len++; // hi ver
146        *buf++ = 1; len++; // lo ver
147        *buf++ = 1; len++; // comp
148        *buf++ = 4; len++; // format - 8bpp
149        *buf++ = ZMBV_BLOCK; len++; // block width
150        *buf++ = ZMBV_BLOCK; len++; // block height
151    }
152    palptr = (uint32_t*)p->data[1];
153    src = p->data[0];
154    prev = c->prev;
155    if(chpal){
156        uint8_t tpal[3];
157        for(i = 0; i < 256; i++){
158            AV_WB24(tpal, palptr[i]);
159            c->work_buf[work_size++] = tpal[0] ^ c->pal[i * 3 + 0];
160            c->work_buf[work_size++] = tpal[1] ^ c->pal[i * 3 + 1];
161            c->work_buf[work_size++] = tpal[2] ^ c->pal[i * 3 + 2];
162            c->pal[i * 3 + 0] = tpal[0];
163            c->pal[i * 3 + 1] = tpal[1];
164            c->pal[i * 3 + 2] = tpal[2];
165        }
166        memcpy(c->pal2, p->data[1], 1024);
167    }
168    if(keyframe){
169        for(i = 0; i < 256; i++){
170            AV_WB24(c->pal+(i*3), palptr[i]);
171        }
172        memcpy(c->work_buf, c->pal, 768);
173        memcpy(c->pal2, p->data[1], 1024);
174        work_size = 768;
175        for(i = 0; i < avctx->height; i++){
176            memcpy(c->work_buf + work_size, src, avctx->width);
177            src += p->linesize[0];
178            work_size += avctx->width;
179        }
180    }else{
181        int x, y, bh2, bw2, xored;
182        uint8_t *tsrc, *tprev;
183        uint8_t *mv;
184        int mx, my, bv;
185
186        bw = (avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
187        bh = (avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
188        mv = c->work_buf + work_size;
189        memset(c->work_buf + work_size, 0, (bw * bh * 2 + 3) & ~3);
190        work_size += (bw * bh * 2 + 3) & ~3;
191        /* for now just XOR'ing */
192        for(y = 0; y < avctx->height; y += ZMBV_BLOCK) {
193            bh2 = FFMIN(avctx->height - y, ZMBV_BLOCK);
194            for(x = 0; x < avctx->width; x += ZMBV_BLOCK, mv += 2) {
195                bw2 = FFMIN(avctx->width - x, ZMBV_BLOCK);
196
197                tsrc = src + x;
198                tprev = prev + x;
199
200                bv = zmbv_me(c, tsrc, p->linesize[0], tprev, c->pstride, x, y, &mx, &my, &xored);
201                mv[0] = (mx << 1) | !!xored;
202                mv[1] = my << 1;
203                tprev += mx + my * c->pstride;
204                if(xored){
205                    for(j = 0; j < bh2; j++){
206                        for(i = 0; i < bw2; i++)
207                            c->work_buf[work_size++] = tsrc[i] ^ tprev[i];
208                        tsrc += p->linesize[0];
209                        tprev += c->pstride;
210                    }
211                }
212            }
213            src += p->linesize[0] * ZMBV_BLOCK;
214            prev += c->pstride * ZMBV_BLOCK;
215        }
216    }
217    /* save the previous frame */
218    src = p->data[0];
219    prev = c->prev;
220    for(i = 0; i < avctx->height; i++){
221        memcpy(prev, src, avctx->width);
222        prev += c->pstride;
223        src += p->linesize[0];
224    }
225
226    c->zstream.next_in = c->work_buf;
227    c->zstream.avail_in = work_size;
228    c->zstream.total_in = 0;
229
230    c->zstream.next_out = c->comp_buf;
231    c->zstream.avail_out = c->comp_size;
232    c->zstream.total_out = 0;
233    if(deflate(&c->zstream, Z_SYNC_FLUSH) != Z_OK){
234        av_log(avctx, AV_LOG_ERROR, "Error compressing data\n");
235        return -1;
236    }
237
238    memcpy(buf, c->comp_buf, c->zstream.total_out);
239    return len + c->zstream.total_out;
240}
241
242
243/**
244 * Init zmbv encoder
245 */
246static av_cold int encode_init(AVCodecContext *avctx)
247{
248    ZmbvEncContext * const c = avctx->priv_data;
249    int zret; // Zlib return code
250    int i;
251    int lvl = 9;
252
253    for(i=1; i<256; i++)
254        score_tab[i]= -i * log(i/(double)(ZMBV_BLOCK*ZMBV_BLOCK)) * (256/M_LN2);
255
256    c->avctx = avctx;
257
258    c->curfrm = 0;
259    c->keyint = avctx->keyint_min;
260    c->range = 8;
261    if(avctx->me_range > 0)
262        c->range = FFMIN(avctx->me_range, 127);
263
264    if(avctx->compression_level >= 0)
265        lvl = avctx->compression_level;
266    if(lvl < 0 || lvl > 9){
267        av_log(avctx, AV_LOG_ERROR, "Compression level should be 0-9, not %i\n", lvl);
268        return -1;
269    }
270
271    // Needed if zlib unused or init aborted before deflateInit
272    memset(&(c->zstream), 0, sizeof(z_stream));
273    c->comp_size = avctx->width * avctx->height + 1024 +
274        ((avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * ((avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * 2 + 4;
275    if ((c->work_buf = av_malloc(c->comp_size)) == NULL) {
276        av_log(avctx, AV_LOG_ERROR, "Can't allocate work buffer.\n");
277        return -1;
278    }
279    /* Conservative upper bound taken from zlib v1.2.1 source via lcl.c */
280    c->comp_size = c->comp_size + ((c->comp_size + 7) >> 3) +
281                           ((c->comp_size + 63) >> 6) + 11;
282
283    /* Allocate compression buffer */
284    if ((c->comp_buf = av_malloc(c->comp_size)) == NULL) {
285        av_log(avctx, AV_LOG_ERROR, "Can't allocate compression buffer.\n");
286        return -1;
287    }
288    c->pstride = FFALIGN(avctx->width, 16);
289    if ((c->prev = av_malloc(c->pstride * avctx->height)) == NULL) {
290        av_log(avctx, AV_LOG_ERROR, "Can't allocate picture.\n");
291        return -1;
292    }
293
294    c->zstream.zalloc = Z_NULL;
295    c->zstream.zfree = Z_NULL;
296    c->zstream.opaque = Z_NULL;
297    zret = deflateInit(&(c->zstream), lvl);
298    if (zret != Z_OK) {
299        av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
300        return -1;
301    }
302
303    avctx->coded_frame = (AVFrame*)&c->pic;
304
305    return 0;
306}
307
308
309
310/**
311 * Uninit zmbv encoder
312 */
313static av_cold int encode_end(AVCodecContext *avctx)
314{
315    ZmbvEncContext * const c = avctx->priv_data;
316
317    av_freep(&c->comp_buf);
318    av_freep(&c->work_buf);
319
320    deflateEnd(&(c->zstream));
321    av_freep(&c->prev);
322
323    return 0;
324}
325
326AVCodec zmbv_encoder = {
327    "zmbv",
328    AVMEDIA_TYPE_VIDEO,
329    CODEC_ID_ZMBV,
330    sizeof(ZmbvEncContext),
331    encode_init,
332    encode_frame,
333    encode_end,
334    .pix_fmts = (const enum PixelFormat[]){PIX_FMT_PAL8, PIX_FMT_NONE},
335    .long_name = NULL_IF_CONFIG_SMALL("Zip Motion Blocks Video"),
336};
337