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/avassert.h"

32 #include "libavutil/common.h"

33 #include "libavutil/intreadwrite.h"

35 #define DITHERSTEPS 8

36 #define CHARSET_CHARS 256

37 #define INTERLACED 1

38 #define CROP_SCREENS 1

40 #define C64XRES 320

41 #define C64YRES 200

43 typedef struct A64Context {

44 /* variables for multicolor modes */

45 AVLFG randctx;

46 int mc_lifetime;

47 int mc_use_5col;

48 unsigned mc_frame_counter;

49 int *mc_meta_charset;

50 int *mc_charmap;

51 int *mc_best_cb;

52 int mc_luma_vals[5];

53 uint8_t *mc_charset;

54 uint8_t *mc_colram;

55 uint8_t *mc_palette;

56 int mc_pal_size;

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

59 int64_t next_pts;

60 } A64Context;

62 /* gray gradient */

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

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

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

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

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

70 {

71 int blockx, blocky, x, y;

72 int luma = 0;

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

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

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

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

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

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

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

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

82 if (x + 1 < width) {

83 /* build average over 2 pixels */

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

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

86 } else {

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

88 }

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

90 dest[0] = luma;

91 }

92 dest++;

93 }

94 }

95 }

96 }

97 }

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

100 uint8_t *colrammap)

101 {

102 A64Context *c = avctx->priv_data;

103 uint8_t row1, row2;

104 int charpos, x, y;

105 int a, b;

106 uint8_t pix;

107 int lowdiff, highdiff;

108 int *best_cb = c->mc_best_cb;

109 static uint8_t index1[256];

110 static uint8_t index2[256];

111 static uint8_t dither[256];

112 int i;

113 int distance;

114

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

116 i = 0;

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

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

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

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

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

122 }

123 i++;

124 }

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

126 index1[a] = i;

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

128 }

129

130 /* and render charset */

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

132 lowdiff = 0;

133 highdiff = 0;

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

135 row1 = 0; row2 = 0;

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

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

138

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

140 if (index1[pix] >= 3)

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

142 if (index1[pix] < 1)

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

144

145 row1 <<= 2;

146

147 if (INTERLACED) {

148 row2 <<= 2;

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

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

151 else

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

153

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

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

156 else

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

158 }

159 else {

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

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

162 else

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

164 }

165 }

166 charset[y+0x000] = row1;

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

168 }

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

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

171 if (lowdiff > highdiff) {

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

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

174 } else {

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

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

177 }

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

179 /* no adjustment needed, all fine */

180 } else {

181 /* advance pointers */

182 best_cb += 32;

183 charset += 8;

184

185 /* remember colorram value */

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

187 }

188 }

189 }

190

191 static av_cold int a64multi_close_encoder(AVCodecContext *avctx)

192 {

193 A64Context *c = avctx->priv_data;

194 av_freep(&c->mc_meta_charset);

195 av_freep(&c->mc_best_cb);

196 av_freep(&c->mc_charset);

197 av_freep(&c->mc_charmap);

198 av_freep(&c->mc_colram);

199 return 0;

200 }

201

202 static av_cold int a64multi_encode_init(AVCodecContext *avctx)

203 {

204 A64Context *c = avctx->priv_data;

205 int a;

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

207

208 if (avctx->global_quality < 1) {

209 c->mc_lifetime = 4;

210 } else {

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

212 }

213

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

215

216 c->mc_frame_counter = 0;

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

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

219

220 /* precalc luma values for later use */

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

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

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

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

225 }

226

227 if (!(c->mc_meta_charset = av_mallocz_array(c->mc_lifetime, 32000 * sizeof(int))) ||

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

229 !(c->mc_charmap = av_mallocz_array(c->mc_lifetime, 1000 * sizeof(int))) ||

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

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

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

233 return AVERROR(ENOMEM);

234 }

235

236 /* set up extradata */

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

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

239 return AVERROR(ENOMEM);

240 }

241 avctx->extradata_size = 8 * 4;

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

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

244

245 if (!avctx->codec_tag)

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

247

248 c->next_pts = AV_NOPTS_VALUE;

249

250 return 0;

251 }

252

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

254 {

255 int a;

256 uint8_t temp;

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

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

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

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

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

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

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

264 buf[a] = temp << 2;

265 }

266 }

267

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

269 const AVFrame *p, int *got_packet)

270 {

271 A64Context *c = avctx->priv_data;

272

273 int frame;

274 int x, y;

275 int b_height;

276 int b_width;

277

278 int req_size, ret;

279 uint8_t *buf = NULL;

280

281 int *charmap = c->mc_charmap;

282 uint8_t *colram = c->mc_colram;

283 uint8_t *charset = c->mc_charset;

284 int *meta = c->mc_meta_charset;

285 int *best_cb = c->mc_best_cb;

286

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

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

289 int screen_size;

290

291 if(CROP_SCREENS) {

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

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

294 screen_size = b_width * b_height;

295 } else {

296 b_height = C64YRES >> 3;

297 b_width = C64XRES >> 3;

298 screen_size = 0x400;

299 }

300

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

302 if (!p) {

303 /* all done, end encoding */

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

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

306 if (!c->mc_frame_counter) {

307 c->mc_lifetime = 0;

308 }

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

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

311 /* still new data available */

312 } else {

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

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

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

316 c->mc_frame_counter++;

317 if (c->next_pts == AV_NOPTS_VALUE)

318 c->next_pts = p->pts;

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

320 return 0;

321 }

322 }

323

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

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

326 req_size = 0;

327 /* any frames to encode? */

328 if (c->mc_lifetime) {

329 int alloc_size = charset_size + c->mc_lifetime*(screen_size + colram_size);

330 if ((ret = ff_alloc_packet2(avctx, pkt, alloc_size)) < 0)

331 return ret;

332 buf = pkt->data;

333

334 /* calc optimal new charset + charmaps */

335 ret = avpriv_init_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb,

336 CHARSET_CHARS, 50, charmap, &c->randctx);

337 if (ret < 0)

338 return ret;

339 ret = avpriv_do_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb,

340 CHARSET_CHARS, 50, charmap, &c->randctx);

341 if (ret < 0)

342 return ret;

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 req_size += 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 av_assert0(pkt->size >= req_size);

390 pkt->size = req_size;

391 pkt->flags |= AV_PKT_FLAG_KEY;

392 *got_packet = !!req_size;

393 }

394 return 0;

395 }

396

397 #if CONFIG_A64MULTI_ENCODER

398 AVCodec ff_a64multi_encoder = {

399 .name = "a64multi",

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

401 .type = AVMEDIA_TYPE_VIDEO,

402 .id = AV_CODEC_ID_A64_MULTI,

403 .priv_data_size = sizeof(A64Context),

404 .init = a64multi_encode_init,

405 .encode2 = a64multi_encode_frame,

406 .close = a64multi_close_encoder,

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

408 .capabilities = CODEC_CAP_DELAY,

409 };

410 #endif

411 #if CONFIG_A64MULTI5_ENCODER

412 AVCodec ff_a64multi5_encoder = {

413 .name = "a64multi5",

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

415 .type = AVMEDIA_TYPE_VIDEO,

416 .id = AV_CODEC_ID_A64_MULTI5,

417 .priv_data_size = sizeof(A64Context),

418 .init = a64multi_encode_init,

419 .encode2 = a64multi_encode_frame,

420 .close = a64multi_close_encoder,

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

422 .capabilities = CODEC_CAP_DELAY,

423 };

424 #endif

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