FFmpeg: libavcodec/a64multienc.c Source File

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libavcodec

a64multienc.c

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1 /*

2 * a64 video encoder - multicolor modes

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 * a64 video encoder - multicolor modes

25 */

27 #include "a64colors.h"

28 #include "a64tables.h"

29 #include "elbg.h"

30 #include "internal.h"

31 #include "libavutil/common.h"

32 #include "libavutil/intreadwrite.h"

34 #define DITHERSTEPS 8

35 #define CHARSET_CHARS 256

36 #define INTERLACED 1

37 #define CROP_SCREENS 1

39 #define C64XRES 320

40 #define C64YRES 200

42 typedef struct A64Context {

43 /* general variables */

44 AVFrame picture;

46 /* variables for multicolor modes */

47 AVLFG randctx;

48 int mc_lifetime;

49 int mc_use_5col;

50 unsigned mc_frame_counter;

51 int *mc_meta_charset;

52 int *mc_charmap;

53 int *mc_best_cb;

54 int mc_luma_vals[5];

55 uint8_t *mc_charset;

56 uint8_t *mc_colram;

57 uint8_t *mc_palette;

58 int mc_pal_size;

60 /* pts of the next packet that will be output */

61 int64_t next_pts;

62 } A64Context;

64 /* gray gradient */

65 static const int mc_colors[5]={0x0,0xb,0xc,0xf,0x1};

67 /* other possible gradients - to be tested */

68 //static const int mc_colors[5]={0x0,0x8,0xa,0xf,0x7};

69 //static const int mc_colors[5]={0x0,0x9,0x8,0xa,0x3};

71 static void to_meta_with_crop(AVCodecContext *avctx, AVFrame *p, int *dest)

72 {

73 int blockx, blocky, x, y;

74 int luma = 0;

75 int height = FFMIN(avctx->height, C64YRES);

76 int width = FFMIN(avctx->width , C64XRES);

77 uint8_t *src = p->data[0];

79 for (blocky = 0; blocky < C64YRES; blocky += 8) {

80 for (blockx = 0; blockx < C64XRES; blockx += 8) {

81 for (y = blocky; y < blocky + 8 && y < C64YRES; y++) {

82 for (x = blockx; x < blockx + 8 && x < C64XRES; x += 2) {

83 if(x < width && y < height) {

84 /* build average over 2 pixels */

85 luma = (src[(x + 0 + y * p->linesize[0])] +

86 src[(x + 1 + y * p->linesize[0])]) / 2;

87 /* write blocks as linear data now so they are suitable for elbg */

88 dest[0] = luma;

89 }

90 dest++;

91 }

92 }

93 }

94 }

95 }

97 static void render_charset(AVCodecContext *avctx, uint8_t *charset,

98 uint8_t *colrammap)

99 {

100 A64Context *c = avctx->priv_data;

101 uint8_t row1, row2;

102 int charpos, x, y;

103 int a, b;

104 uint8_t pix;

105 int lowdiff, highdiff;

106 int *best_cb = c->mc_best_cb;

107 static uint8_t index1[256];

108 static uint8_t index2[256];

109 static uint8_t dither[256];

110 int i;

111 int distance;

112

113 /* generate lookup-tables for dither and index before looping */

114 i = 0;

115 for (a=0; a < 256; a++) {

116 if(i < c->mc_pal_size -1 && a == c->mc_luma_vals[i + 1]) {

117 distance = c->mc_luma_vals[i + 1] - c->mc_luma_vals[i];

118 for(b = 0; b <= distance; b++) {

119 dither[c->mc_luma_vals[i] + b] = b * (DITHERSTEPS - 1) / distance;

120 }

121 i++;

122 }

123 if(i >= c->mc_pal_size - 1) dither[a] = 0;

124 index1[a] = i;

125 index2[a] = FFMIN(i + 1, c->mc_pal_size - 1);

126 }

127

128 /* and render charset */

129 for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {

130 lowdiff = 0;

131 highdiff = 0;

132 for (y = 0; y < 8; y++) {

133 row1 = 0; row2 = 0;

134 for (x = 0; x < 4; x++) {

135 pix = best_cb[y * 4 + x];

136

137 /* accumulate error for brightest/darkest color */

138 if (index1[pix] >= 3)

139 highdiff += pix - c->mc_luma_vals[3];

140 if (index1[pix] < 1)

141 lowdiff += c->mc_luma_vals[1] - pix;

142

143 row1 <<= 2;

144

145 if (INTERLACED) {

146 row2 <<= 2;

147 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])

148 row1 |= 3-(index2[pix] & 3);

149 else

150 row1 |= 3-(index1[pix] & 3);

151

152 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])

153 row2 |= 3-(index2[pix] & 3);

154 else

155 row2 |= 3-(index1[pix] & 3);

156 }

157 else {

158 if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])

159 row1 |= 3-(index2[pix] & 3);

160 else

161 row1 |= 3-(index1[pix] & 3);

162 }

163 }

164 charset[y+0x000] = row1;

165 if (INTERLACED) charset[y+0x800] = row2;

166 }

167 /* do we need to adjust pixels? */

168 if (highdiff > 0 && lowdiff > 0 && c->mc_use_5col) {

169 if (lowdiff > highdiff) {

170 for (x = 0; x < 32; x++)

171 best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);

172 } else {

173 for (x = 0; x < 32; x++)

174 best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);

175 }

176 charpos--; /* redo now adjusted char */

177 /* no adjustment needed, all fine */

178 } else {

179 /* advance pointers */

180 best_cb += 32;

181 charset += 8;

182

183 /* remember colorram value */

184 colrammap[charpos] = (highdiff > 0);

185 }

186 }

187 }

188

189 static av_cold int a64multi_close_encoder(AVCodecContext *avctx)

190 {

191 A64Context *c = avctx->priv_data;

192 av_free(c->mc_meta_charset);

193 av_free(c->mc_best_cb);

194 av_free(c->mc_charset);

195 av_free(c->mc_charmap);

196 av_free(c->mc_colram);

197 return 0;

198 }

199

200 static av_cold int a64multi_init_encoder(AVCodecContext *avctx)

201 {

202 A64Context *c = avctx->priv_data;

203 int a;

204 av_lfg_init(&c->randctx, 1);

205

206 if (avctx->global_quality < 1) {

207 c->mc_lifetime = 4;

208 } else {

209 c->mc_lifetime = avctx->global_quality /= FF_QP2LAMBDA;

210 }

211

212 av_log(avctx, AV_LOG_INFO, "charset lifetime set to %d frame(s)\n", c->mc_lifetime);

213

214 c->mc_frame_counter = 0;

215 c->mc_use_5col = avctx->codec->id == AV_CODEC_ID_A64_MULTI5;

216 c->mc_pal_size = 4 + c->mc_use_5col;

217

218 /* precalc luma values for later use */

219 for (a = 0; a < c->mc_pal_size; a++) {

220 c->mc_luma_vals[a]=a64_palette[mc_colors[a]][0] * 0.30 +

221 a64_palette[mc_colors[a]][1] * 0.59 +

222 a64_palette[mc_colors[a]][2] * 0.11;

223 }

224

225 if (!(c->mc_meta_charset = av_malloc(32000 * c->mc_lifetime * sizeof(int))) ||

226 !(c->mc_best_cb = av_malloc(CHARSET_CHARS * 32 * sizeof(int))) ||

227 !(c->mc_charmap = av_mallocz(1000 * c->mc_lifetime * sizeof(int))) ||

228 !(c->mc_colram = av_mallocz(CHARSET_CHARS * sizeof(uint8_t))) ||

229 !(c->mc_charset = av_malloc(0x800 * (INTERLACED+1) * sizeof(uint8_t)))) {

230 av_log(avctx, AV_LOG_ERROR, "Failed to allocate buffer memory.\n");

231 return AVERROR(ENOMEM);

232 }

233

234 /* set up extradata */

235 if (!(avctx->extradata = av_mallocz(8 * 4 + FF_INPUT_BUFFER_PADDING_SIZE))) {

236 av_log(avctx, AV_LOG_ERROR, "Failed to allocate memory for extradata.\n");

237 return AVERROR(ENOMEM);

238 }

239 avctx->extradata_size = 8 * 4;

240 AV_WB32(avctx->extradata, c->mc_lifetime);

241 AV_WB32(avctx->extradata + 16, INTERLACED);

242

243 avcodec_get_frame_defaults(&c->picture);

244 avctx->coded_frame = &c->picture;

245 avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;

246 avctx->coded_frame->key_frame = 1;

247 if (!avctx->codec_tag)

248 avctx->codec_tag = AV_RL32("a64m");

249

250 c->next_pts = AV_NOPTS_VALUE;

251

252 return 0;

253 }

254

255 static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)

256 {

257 int a;

258 uint8_t temp;

259 /* only needs to be done in 5col mode */

260 /* XXX could be squeezed to 0x80 bytes */

261 for (a = 0; a < 256; a++) {

262 temp = colram[charmap[a + 0x000]] << 0;

263 temp |= colram[charmap[a + 0x100]] << 1;

264 temp |= colram[charmap[a + 0x200]] << 2;

265 if (a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;

266 buf[a] = temp << 2;

267 }

268 }

269

270 static int a64multi_encode_frame(AVCodecContext *avctx, AVPacket *pkt,

271 const AVFrame *pict, int *got_packet)

272 {

273 A64Context *c = avctx->priv_data;

274 AVFrame *const p = &c->picture;

275

276 int frame;

277 int x, y;

278 int b_height;

279 int b_width;

280

281 int req_size, ret;

282 uint8_t *buf = NULL;

283

284 int *charmap = c->mc_charmap;

285 uint8_t *colram = c->mc_colram;

286 uint8_t *charset = c->mc_charset;

287 int *meta = c->mc_meta_charset;

288 int *best_cb = c->mc_best_cb;

289

290 int charset_size = 0x800 * (INTERLACED + 1);

291 int colram_size = 0x100 * c->mc_use_5col;

292 int screen_size;

293

294 if(CROP_SCREENS) {

295 b_height = FFMIN(avctx->height,C64YRES) >> 3;

296 b_width = FFMIN(avctx->width ,C64XRES) >> 3;

297 screen_size = b_width * b_height;

298 } else {

299 b_height = C64YRES >> 3;

300 b_width = C64XRES >> 3;

301 screen_size = 0x400;

302 }

303

304 /* no data, means end encoding asap */

305 if (!pict) {

306 /* all done, end encoding */

307 if (!c->mc_lifetime) return 0;

308 /* no more frames in queue, prepare to flush remaining frames */

309 if (!c->mc_frame_counter) {

310 c->mc_lifetime = 0;

311 }

312 /* still frames in queue so limit lifetime to remaining frames */

313 else c->mc_lifetime = c->mc_frame_counter;

314 /* still new data available */

315 } else {

316 /* fill up mc_meta_charset with data until lifetime exceeds */

317 if (c->mc_frame_counter < c->mc_lifetime) {

318 *p = *pict;

319 p->pict_type = AV_PICTURE_TYPE_I;

320 p->key_frame = 1;

321 to_meta_with_crop(avctx, p, meta + 32000 * c->mc_frame_counter);

322 c->mc_frame_counter++;

323 if (c->next_pts == AV_NOPTS_VALUE)

324 c->next_pts = pict->pts;

325 /* lifetime is not reached so wait for next frame first */

326 return 0;

327 }

328 }

329

330 /* lifetime reached so now convert X frames at once */

331 if (c->mc_frame_counter == c->mc_lifetime) {

332 req_size = 0;

333 /* any frames to encode? */

334 if (c->mc_lifetime) {

335 req_size = charset_size + c->mc_lifetime*(screen_size + colram_size);

336 if ((ret = ff_alloc_packet2(avctx, pkt, req_size)) < 0)

337 return ret;

338 buf = pkt->data;

339

340 /* calc optimal new charset + charmaps */

341 ff_init_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb, CHARSET_CHARS, 50, charmap, &c->randctx);

342 ff_do_elbg (meta, 32, 1000 * c->mc_lifetime, best_cb, CHARSET_CHARS, 50, charmap, &c->randctx);

343

344 /* create colorram map and a c64 readable charset */

345 render_charset(avctx, charset, colram);

346

347 /* copy charset to buf */

348 memcpy(buf, charset, charset_size);

349

350 /* advance pointers */

351 buf += charset_size;

352 charset += charset_size;

353 }

354

355 /* write x frames to buf */

356 for (frame = 0; frame < c->mc_lifetime; frame++) {

357 /* copy charmap to buf. buf is uchar*, charmap is int*, so no memcpy here, sorry */

358 for (y = 0; y < b_height; y++) {

359 for (x = 0; x < b_width; x++) {

360 buf[y * b_width + x] = charmap[y * b_width + x];

361 }

362 }

363 /* advance pointers */

364 buf += screen_size;

365 req_size += screen_size;

366

367 /* compress and copy colram to buf */

368 if (c->mc_use_5col) {

369 a64_compress_colram(buf, charmap, colram);

370 /* advance pointers */

371 buf += colram_size;

372 req_size += colram_size;

373 }

374

375 /* advance to next charmap */

376 charmap += 1000;

377 }

378

379 AV_WB32(avctx->extradata + 4, c->mc_frame_counter);

380 AV_WB32(avctx->extradata + 8, charset_size);

381 AV_WB32(avctx->extradata + 12, screen_size + colram_size);

382

383 /* reset counter */

384 c->mc_frame_counter = 0;

385

386 pkt->pts = pkt->dts = c->next_pts;

387 c->next_pts = AV_NOPTS_VALUE;

388

389 pkt->size = req_size;

390 pkt->flags |= AV_PKT_FLAG_KEY;

391 *got_packet = !!req_size;

392 }

393 return 0;

394 }

395

396 #if CONFIG_A64MULTI_ENCODER

397 AVCodec ff_a64multi_encoder = {

398 .name = "a64multi",

399 .type = AVMEDIA_TYPE_VIDEO,

400 .id = AV_CODEC_ID_A64_MULTI,

401 .priv_data_size = sizeof(A64Context),

402 .init = a64multi_init_encoder,

403 .encode2 = a64multi_encode_frame,

404 .close = a64multi_close_encoder,

405 .pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},

406 .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),

407 .capabilities = CODEC_CAP_DELAY,

408 };

409 #endif

410 #if CONFIG_A64MULTI5_ENCODER

411 AVCodec ff_a64multi5_encoder = {

412 .name = "a64multi5",

413 .type = AVMEDIA_TYPE_VIDEO,

414 .id = AV_CODEC_ID_A64_MULTI5,

415 .priv_data_size = sizeof(A64Context),

416 .init = a64multi_init_encoder,

417 .encode2 = a64multi_encode_frame,

418 .close = a64multi_close_encoder,

419 .pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},

420 .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),

421 .capabilities = CODEC_CAP_DELAY,

422 };

423 #endif

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