FFmpeg: libavcodec/zmbvenc.c Source File

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libavcodec

zmbvenc.c

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1 /*

2 * Zip Motion Blocks Video (ZMBV) encoder

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 */

22 /**

23 * @file

24 * Zip Motion Blocks Video encoder

25 */

27 #include <stdio.h>

28 #include <stdlib.h>

30 #include "libavutil/common.h"

31 #include "libavutil/intreadwrite.h"

32 #include "avcodec.h"

33 #include "internal.h"

35 #include <zlib.h>

37 #define ZMBV_KEYFRAME 1

38 #define ZMBV_DELTAPAL 2

40 #define ZMBV_BLOCK 16

42 /**

43 * Encoder context

44 */

45 typedef struct ZmbvEncContext {

46 AVCodecContext *avctx;

47 AVFrame pic;

49 int range;

50 uint8_t *comp_buf, *work_buf;

51 uint8_t pal[768];

52 uint32_t pal2[256]; //for quick comparisons

53 uint8_t *prev;

54 int pstride;

55 int comp_size;

56 int keyint, curfrm;

57 z_stream zstream;

58 } ZmbvEncContext;

60 static int score_tab[256];

62 /** Block comparing function

63 * XXX should be optimized and moved to DSPContext

64 * TODO handle out of edge ME

65 */

66 static inline int block_cmp(uint8_t *src, int stride, uint8_t *src2, int stride2,

67 int bw, int bh, int *xored)

68 {

69 int sum = 0;

70 int i, j;

71 uint8_t histogram[256] = {0};

73 *xored = 0;

74 for(j = 0; j < bh; j++){

75 for(i = 0; i < bw; i++){

76 int t = src[i] ^ src2[i];

77 histogram[t]++;

78 *xored |= t;

79 }

80 src += stride;

81 src2 += stride2;

82 }

84 for(i = 1; i < 256; i++)

85 sum += score_tab[histogram[i]];

87 return sum;

88 }

90 /** Motion estimation function

91 * TODO make better ME decisions

92 */

93 static int zmbv_me(ZmbvEncContext *c, uint8_t *src, int sstride, uint8_t *prev,

94 int pstride, int x, int y, int *mx, int *my, int *xored)

95 {

96 int dx, dy, tx, ty, tv, bv, bw, bh;

98 *mx = *my = 0;

99 bw = FFMIN(ZMBV_BLOCK, c->avctx->width - x);

100 bh = FFMIN(ZMBV_BLOCK, c->avctx->height - y);

101 bv = block_cmp(src, sstride, prev, pstride, bw, bh, xored);

102 if(!bv) return 0;

103 for(ty = FFMAX(y - c->range, 0); ty < FFMIN(y + c->range, c->avctx->height - bh); ty++){

104 for(tx = FFMAX(x - c->range, 0); tx < FFMIN(x + c->range, c->avctx->width - bw); tx++){

105 if(tx == x && ty == y) continue; // we already tested this block

106 dx = tx - x;

107 dy = ty - y;

108 tv = block_cmp(src, sstride, prev + dx + dy*pstride, pstride, bw, bh, xored);

109 if(tv < bv){

110 bv = tv;

111 *mx = dx;

112 *my = dy;

113 if(!bv) return 0;

114 }

115 }

116 }

117 return bv;

118 }

119

120 static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,

121 const AVFrame *pict, int *got_packet)

122 {

123 ZmbvEncContext * const c = avctx->priv_data;

124 AVFrame * const p = &c->pic;

125 uint8_t *src, *prev, *buf;

126 uint32_t *palptr;

127 int keyframe, chpal;

128 int fl;

129 int work_size = 0, pkt_size;

130 int bw, bh;

131 int i, j, ret;

132

133 keyframe = !c->curfrm;

134 c->curfrm++;

135 if(c->curfrm == c->keyint)

136 c->curfrm = 0;

137 *p = *pict;

138 p->pict_type= keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;

139 p->key_frame= keyframe;

140 chpal = !keyframe && memcmp(p->data[1], c->pal2, 1024);

141

142 palptr = (uint32_t*)p->data[1];

143 src = p->data[0];

144 prev = c->prev;

145 if(chpal){

146 uint8_t tpal[3];

147 for(i = 0; i < 256; i++){

148 AV_WB24(tpal, palptr[i]);

149 c->work_buf[work_size++] = tpal[0] ^ c->pal[i * 3 + 0];

150 c->work_buf[work_size++] = tpal[1] ^ c->pal[i * 3 + 1];

151 c->work_buf[work_size++] = tpal[2] ^ c->pal[i * 3 + 2];

152 c->pal[i * 3 + 0] = tpal[0];

153 c->pal[i * 3 + 1] = tpal[1];

154 c->pal[i * 3 + 2] = tpal[2];

155 }

156 memcpy(c->pal2, p->data[1], 1024);

157 }

158 if(keyframe){

159 for(i = 0; i < 256; i++){

160 AV_WB24(c->pal+(i*3), palptr[i]);

161 }

162 memcpy(c->work_buf, c->pal, 768);

163 memcpy(c->pal2, p->data[1], 1024);

164 work_size = 768;

165 for(i = 0; i < avctx->height; i++){

166 memcpy(c->work_buf + work_size, src, avctx->width);

167 src += p->linesize[0];

168 work_size += avctx->width;

169 }

170 }else{

171 int x, y, bh2, bw2, xored;

172 uint8_t *tsrc, *tprev;

173 uint8_t *mv;

174 int mx, my;

175

176 bw = (avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK;

177 bh = (avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK;

178 mv = c->work_buf + work_size;

179 memset(c->work_buf + work_size, 0, (bw * bh * 2 + 3) & ~3);

180 work_size += (bw * bh * 2 + 3) & ~3;

181 /* for now just XOR'ing */

182 for(y = 0; y < avctx->height; y += ZMBV_BLOCK) {

183 bh2 = FFMIN(avctx->height - y, ZMBV_BLOCK);

184 for(x = 0; x < avctx->width; x += ZMBV_BLOCK, mv += 2) {

185 bw2 = FFMIN(avctx->width - x, ZMBV_BLOCK);

186

187 tsrc = src + x;

188 tprev = prev + x;

189

190 zmbv_me(c, tsrc, p->linesize[0], tprev, c->pstride, x, y, &mx, &my, &xored);

191 mv[0] = (mx << 1) | !!xored;

192 mv[1] = my << 1;

193 tprev += mx + my * c->pstride;

194 if(xored){

195 for(j = 0; j < bh2; j++){

196 for(i = 0; i < bw2; i++)

197 c->work_buf[work_size++] = tsrc[i] ^ tprev[i];

198 tsrc += p->linesize[0];

199 tprev += c->pstride;

200 }

201 }

202 }

203 src += p->linesize[0] * ZMBV_BLOCK;

204 prev += c->pstride * ZMBV_BLOCK;

205 }

206 }

207 /* save the previous frame */

208 src = p->data[0];

209 prev = c->prev;

210 for(i = 0; i < avctx->height; i++){

211 memcpy(prev, src, avctx->width);

212 prev += c->pstride;

213 src += p->linesize[0];

214 }

215

216 if (keyframe)

217 deflateReset(&c->zstream);

218

219 c->zstream.next_in = c->work_buf;

220 c->zstream.avail_in = work_size;

221 c->zstream.total_in = 0;

222

223 c->zstream.next_out = c->comp_buf;

224 c->zstream.avail_out = c->comp_size;

225 c->zstream.total_out = 0;

226 if(deflate(&c->zstream, Z_SYNC_FLUSH) != Z_OK){

227 av_log(avctx, AV_LOG_ERROR, "Error compressing data\n");

228 return -1;

229 }

230

231 pkt_size = c->zstream.total_out + 1 + 6*keyframe;

232 if ((ret = ff_alloc_packet2(avctx, pkt, pkt_size)) < 0)

233 return ret;

234 buf = pkt->data;

235

236 fl = (keyframe ? ZMBV_KEYFRAME : 0) | (chpal ? ZMBV_DELTAPAL : 0);

237 *buf++ = fl;

238 if (keyframe) {

239 *buf++ = 0; // hi ver

240 *buf++ = 1; // lo ver

241 *buf++ = 1; // comp

242 *buf++ = 4; // format - 8bpp

243 *buf++ = ZMBV_BLOCK; // block width

244 *buf++ = ZMBV_BLOCK; // block height

245 }

246 memcpy(buf, c->comp_buf, c->zstream.total_out);

247

248 pkt->flags |= AV_PKT_FLAG_KEY*keyframe;

249 *got_packet = 1;

250

251 return 0;

252 }

253

254

255 /**

256 * Init zmbv encoder

257 */

258 static av_cold int encode_init(AVCodecContext *avctx)

259 {

260 ZmbvEncContext * const c = avctx->priv_data;

261 int zret; // Zlib return code

262 int i;

263 int lvl = 9;

264

265 for(i=1; i<256; i++)

266 score_tab[i]= -i * log(i/(double)(ZMBV_BLOCK*ZMBV_BLOCK)) * (256/M_LN2);

267

268 c->avctx = avctx;

269

270 c->curfrm = 0;

271 c->keyint = avctx->keyint_min;

272 c->range = 8;

273 if(avctx->me_range > 0)

274 c->range = FFMIN(avctx->me_range, 127);

275

276 if(avctx->compression_level >= 0)

277 lvl = avctx->compression_level;

278 if(lvl < 0 || lvl > 9){

279 av_log(avctx, AV_LOG_ERROR, "Compression level should be 0-9, not %i\n", lvl);

280 return AVERROR(EINVAL);

281 }

282

283 // Needed if zlib unused or init aborted before deflateInit

284 memset(&c->zstream, 0, sizeof(z_stream));

285 c->comp_size = avctx->width * avctx->height + 1024 +

286 ((avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * ((avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * 2 + 4;

287 if ((c->work_buf = av_malloc(c->comp_size)) == NULL) {

288 av_log(avctx, AV_LOG_ERROR, "Can't allocate work buffer.\n");

289 return AVERROR(ENOMEM);

290 }

291 /* Conservative upper bound taken from zlib v1.2.1 source via lcl.c */

292 c->comp_size = c->comp_size + ((c->comp_size + 7) >> 3) +

293 ((c->comp_size + 63) >> 6) + 11;

294

295 /* Allocate compression buffer */

296 if ((c->comp_buf = av_malloc(c->comp_size)) == NULL) {

297 av_log(avctx, AV_LOG_ERROR, "Can't allocate compression buffer.\n");

298 return AVERROR(ENOMEM);

299 }

300 c->pstride = FFALIGN(avctx->width, 16);

301 if ((c->prev = av_malloc(c->pstride * avctx->height)) == NULL) {

302 av_log(avctx, AV_LOG_ERROR, "Can't allocate picture.\n");

303 return AVERROR(ENOMEM);

304 }

305

306 c->zstream.zalloc = Z_NULL;

307 c->zstream.zfree = Z_NULL;

308 c->zstream.opaque = Z_NULL;

309 zret = deflateInit(&c->zstream, lvl);

310 if (zret != Z_OK) {

311 av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);

312 return -1;

313 }

314

315 avctx->coded_frame = &c->pic;

316

317 return 0;

318 }

319

320

321

322 /**

323 * Uninit zmbv encoder

324 */

325 static av_cold int encode_end(AVCodecContext *avctx)

326 {

327 ZmbvEncContext * const c = avctx->priv_data;

328

329 av_freep(&c->comp_buf);

330 av_freep(&c->work_buf);

331

332 deflateEnd(&c->zstream);

333 av_freep(&c->prev);

334

335 return 0;

336 }

337

338 AVCodec ff_zmbv_encoder = {

339 .name = "zmbv",

340 .type = AVMEDIA_TYPE_VIDEO,

341 .id = AV_CODEC_ID_ZMBV,

342 .priv_data_size = sizeof(ZmbvEncContext),

343 .init = encode_init,

344 .encode2 = encode_frame,

345 .close = encode_end,

346 .pix_fmts = (const enum AVPixelFormat[]){ AV_PIX_FMT_PAL8, AV_PIX_FMT_NONE },

347 .long_name = NULL_IF_CONFIG_SMALL("Zip Motion Blocks Video"),

348 };

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