libavcodec/a64multienc.c

   1 /*
   2  * a64 video encoder - multicolor modes
   3  * Copyright (c) 2009 Tobias Bindhammer
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; 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  * a64 video encoder - multicolor modes
  25  */
  26
  27 #include "a64enc.h"
  28 #include "a64colors.h"
  29 #include "a64tables.h"
  30 #include "elbg.h"
  31 #include "internal.h"
  32 #include "libavutil/common.h"
  33 #include "libavutil/intreadwrite.h"
  34
  35 #define DITHERSTEPS   8
  36 #define CHARSET_CHARS 256
  37 #define INTERLACED    1
  38 #define CROP_SCREENS  1
  39
  40 /* gray gradient */
  41 static const int mc_colors[5]={0x0,0xb,0xc,0xf,0x1};
  42
  43 /* other possible gradients - to be tested */
  44 //static const int mc_colors[5]={0x0,0x8,0xa,0xf,0x7};
  45 //static const int mc_colors[5]={0x0,0x9,0x8,0xa,0x3};
  46
  47 static void to_meta_with_crop(AVCodecContext *avctx, AVFrame *p, int *dest)
  48 {
  49     int blockx, blocky, x, y;
  50     int luma = 0;
  51     int height = FFMIN(avctx->height, C64YRES);
  52     int width  = FFMIN(avctx->width , C64XRES);
  53     uint8_t *src = p->data[0];
  54
  55     for (blocky = 0; blocky < C64YRES; blocky += 8) {
  56         for (blockx = 0; blockx < C64XRES; blockx += 8) {
  57             for (y = blocky; y < blocky + 8 && y < C64YRES; y++) {
  58                 for (x = blockx; x < blockx + 8 && x < C64XRES; x += 2) {
  59                     if(x < width && y < height) {
  60                         /* build average over 2 pixels */
  61                         luma = (src[(x + 0 + y * p->linesize[0])] +
  62                                 src[(x + 1 + y * p->linesize[0])]) / 2;
  63                         /* write blocks as linear data now so they are suitable for elbg */
  64                         dest[0] = luma;
  65                     }
  66                     dest++;
  67                 }
  68             }
  69         }
  70     }
  71 }
  72
  73 static void render_charset(AVCodecContext *avctx, uint8_t *charset,
  74                            uint8_t *colrammap)
  75 {
  76     A64Context *c = avctx->priv_data;
  77     uint8_t row1, row2;
  78     int charpos, x, y;
  79     int a, b;
  80     uint8_t pix;
  81     int lowdiff, highdiff;
  82     int *best_cb = c->mc_best_cb;
  83     static uint8_t index1[256];
  84     static uint8_t index2[256];
  85     static uint8_t dither[256];
  86     int i;
  87     int distance;
  88
  89     /* generate lookup-tables for dither and index before looping */
  90     i = 0;
  91     for (a=0; a < 256; a++) {
  92         if(i < c->mc_pal_size -1 && a == c->mc_luma_vals[i + 1]) {
  93             distance = c->mc_luma_vals[i + 1] - c->mc_luma_vals[i];
  94             for(b = 0; b <= distance; b++) {
  95                   dither[c->mc_luma_vals[i] + b] = b * (DITHERSTEPS - 1) / distance;
  96             }
  97             i++;
  98         }
  99         if(i >= c->mc_pal_size - 1) dither[a] = 0;
 100         index1[a] = i;
 101         index2[a] = FFMIN(i + 1, c->mc_pal_size - 1);
 102     }
 103
 104     /* and render charset */
 105     for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {
 106         lowdiff  = 0;
 107         highdiff = 0;
 108         for (y = 0; y < 8; y++) {
 109             row1 = 0; row2 = 0;
 110             for (x = 0; x < 4; x++) {
 111                 pix = best_cb[y * 4 + x];
 112
 113                 /* accumulate error for brightest/darkest color */
 114                 if (index1[pix] >= 3)
 115                     highdiff += pix - c->mc_luma_vals[3];
 116                 if (index1[pix] < 1)
 117                     lowdiff += c->mc_luma_vals[1] - pix;
 118
 119                 row1 <<= 2;
 120
 121                 if (INTERLACED) {
 122                     row2 <<= 2;
 123                     if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])
 124                         row1 |= 3-(index2[pix] & 3);
 125                     else
 126                         row1 |= 3-(index1[pix] & 3);
 127
 128                     if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])
 129                         row2 |= 3-(index2[pix] & 3);
 130                     else
 131                         row2 |= 3-(index1[pix] & 3);
 132                 }
 133                 else {
 134                     if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])
 135                         row1 |= 3-(index2[pix] & 3);
 136                     else
 137                         row1 |= 3-(index1[pix] & 3);
 138                 }
 139             }
 140             charset[y+0x000] = row1;
 141             if (INTERLACED) charset[y+0x800] = row2;
 142         }
 143         /* do we need to adjust pixels? */
 144         if (highdiff > 0 && lowdiff > 0 && c->mc_use_5col) {
 145             if (lowdiff > highdiff) {
 146                 for (x = 0; x < 32; x++)
 147                     best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);
 148             } else {
 149                 for (x = 0; x < 32; x++)
 150                     best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);
 151             }
 152             charpos--;          /* redo now adjusted char */
 153         /* no adjustment needed, all fine */
 154         } else {
 155             /* advance pointers */
 156             best_cb += 32;
 157             charset += 8;
 158
 159             /* remember colorram value */
 160             colrammap[charpos] = (highdiff > 0);
 161         }
 162     }
 163 }
 164
 165 static av_cold int a64multi_close_encoder(AVCodecContext *avctx)
 166 {
 167     A64Context *c = avctx->priv_data;
 168     av_free(c->mc_meta_charset);
 169     av_free(c->mc_best_cb);
 170     av_free(c->mc_charset);
 171     av_free(c->mc_charmap);
 172     av_free(c->mc_colram);
 173     return 0;
 174 }
 175
 176 static av_cold int a64multi_init_encoder(AVCodecContext *avctx)
 177 {
 178     A64Context *c = avctx->priv_data;
 179     int a;
 180     av_lfg_init(&c->randctx, 1);
 181
 182     if (avctx->global_quality < 1) {
 183         c->mc_lifetime = 4;
 184     } else {
 185         c->mc_lifetime = avctx->global_quality /= FF_QP2LAMBDA;
 186     }
 187
 188     av_log(avctx, AV_LOG_INFO, "charset lifetime set to %d frame(s)\n", c->mc_lifetime);
 189
 190     c->mc_frame_counter = 0;
 191     c->mc_use_5col      = avctx->codec->id == AV_CODEC_ID_A64_MULTI5;
 192     c->mc_pal_size      = 4 + c->mc_use_5col;
 193
 194     /* precalc luma values for later use */
 195     for (a = 0; a < c->mc_pal_size; a++) {
 196         c->mc_luma_vals[a]=a64_palette[mc_colors[a]][0] * 0.30 +
 197                            a64_palette[mc_colors[a]][1] * 0.59 +
 198                            a64_palette[mc_colors[a]][2] * 0.11;
 199     }
 200
 201     if (!(c->mc_meta_charset = av_malloc(32000 * c->mc_lifetime * sizeof(int))) ||
 202        !(c->mc_best_cb       = av_malloc(CHARSET_CHARS * 32 * sizeof(int)))     ||
 203        !(c->mc_charmap       = av_mallocz(1000 * c->mc_lifetime * sizeof(int))) ||
 204        !(c->mc_colram        = av_mallocz(CHARSET_CHARS * sizeof(uint8_t)))     ||
 205        !(c->mc_charset       = av_malloc(0x800 * (INTERLACED+1) * sizeof(uint8_t)))) {
 206         av_log(avctx, AV_LOG_ERROR, "Failed to allocate buffer memory.\n");
 207         return AVERROR(ENOMEM);
 208     }
 209
 210     /* set up extradata */
 211     if (!(avctx->extradata = av_mallocz(8 * 4 + FF_INPUT_BUFFER_PADDING_SIZE))) {
 212         av_log(avctx, AV_LOG_ERROR, "Failed to allocate memory for extradata.\n");
 213         return AVERROR(ENOMEM);
 214     }
 215     avctx->extradata_size = 8 * 4;
 216     AV_WB32(avctx->extradata, c->mc_lifetime);
 217     AV_WB32(avctx->extradata + 16, INTERLACED);
 218
 219     avcodec_get_frame_defaults(&c->picture);
 220     avctx->coded_frame            = &c->picture;
 221     avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
 222     avctx->coded_frame->key_frame = 1;
 223     if (!avctx->codec_tag)
 224          avctx->codec_tag = AV_RL32("a64m");
 225
 226     c->next_pts = AV_NOPTS_VALUE;
 227
 228     return 0;
 229 }
 230
 231 static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
 232 {
 233     int a;
 234     uint8_t temp;
 235     /* only needs to be done in 5col mode */
 236     /* XXX could be squeezed to 0x80 bytes */
 237     for (a = 0; a < 256; a++) {
 238         temp  = colram[charmap[a + 0x000]] << 0;
 239         temp |= colram[charmap[a + 0x100]] << 1;
 240         temp |= colram[charmap[a + 0x200]] << 2;
 241         if (a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;
 242         buf[a] = temp << 2;
 243     }
 244 }
 245
 246 static int a64multi_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
 247                                  const AVFrame *pict, int *got_packet)
 248 {
 249     A64Context *c = avctx->priv_data;
 250     AVFrame *const p = &c->picture;
 251
 252     int frame;
 253     int x, y;
 254     int b_height;
 255     int b_width;
 256
 257     int req_size, ret;
 258     uint8_t *buf;
 259
 260     int *charmap     = c->mc_charmap;
 261     uint8_t *colram  = c->mc_colram;
 262     uint8_t *charset = c->mc_charset;
 263     int *meta        = c->mc_meta_charset;
 264     int *best_cb     = c->mc_best_cb;
 265
 266     int charset_size = 0x800 * (INTERLACED + 1);
 267     int colram_size  = 0x100 * c->mc_use_5col;
 268     int screen_size;
 269
 270     if(CROP_SCREENS) {
 271         b_height = FFMIN(avctx->height,C64YRES) >> 3;
 272         b_width  = FFMIN(avctx->width ,C64XRES) >> 3;
 273         screen_size = b_width * b_height;
 274     } else {
 275         b_height = C64YRES >> 3;
 276         b_width  = C64XRES >> 3;
 277         screen_size = 0x400;
 278     }
 279
 280     /* no data, means end encoding asap */
 281     if (!pict) {
 282         /* all done, end encoding */
 283         if (!c->mc_lifetime) return 0;
 284         /* no more frames in queue, prepare to flush remaining frames */
 285         if (!c->mc_frame_counter) {
 286             c->mc_lifetime = 0;
 287         }
 288         /* still frames in queue so limit lifetime to remaining frames */
 289         else c->mc_lifetime = c->mc_frame_counter;
 290     /* still new data available */
 291     } else {
 292         /* fill up mc_meta_charset with data until lifetime exceeds */
 293         if (c->mc_frame_counter < c->mc_lifetime) {
 294             *p = *pict;
 295             p->pict_type = AV_PICTURE_TYPE_I;
 296             p->key_frame = 1;
 297             to_meta_with_crop(avctx, p, meta + 32000 * c->mc_frame_counter);
 298             c->mc_frame_counter++;
 299             if (c->next_pts == AV_NOPTS_VALUE)
 300                 c->next_pts = pict->pts;
 301             /* lifetime is not reached so wait for next frame first */
 302             return 0;
 303         }
 304     }
 305
 306     /* lifetime reached so now convert X frames at once */
 307     if (c->mc_frame_counter == c->mc_lifetime) {
 308         req_size = 0;
 309         /* any frames to encode? */
 310         if (c->mc_lifetime) {
 311             req_size = charset_size + c->mc_lifetime*(screen_size + colram_size);
 312             if ((ret = ff_alloc_packet(pkt, req_size)) < 0) {
 313                 av_log(avctx, AV_LOG_ERROR, "Error getting output packet of size %d.\n", req_size);
 314                 return ret;
 315             }
 316             buf = pkt->data;
 317
 318             /* calc optimal new charset + charmaps */
 319             ff_init_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb, CHARSET_CHARS, 50, charmap, &c->randctx);
 320             ff_do_elbg  (meta, 32, 1000 * c->mc_lifetime, best_cb, CHARSET_CHARS, 50, charmap, &c->randctx);
 321
 322             /* create colorram map and a c64 readable charset */
 323             render_charset(avctx, charset, colram);
 324
 325             /* copy charset to buf */
 326             memcpy(buf, charset, charset_size);
 327
 328             /* advance pointers */
 329             buf      += charset_size;
 330             charset  += charset_size;
 331         }
 332
 333         /* write x frames to buf */
 334         for (frame = 0; frame < c->mc_lifetime; frame++) {
 335             /* copy charmap to buf. buf is uchar*, charmap is int*, so no memcpy here, sorry */
 336             for (y = 0; y < b_height; y++) {
 337                 for (x = 0; x < b_width; x++) {
 338                     buf[y * b_width + x] = charmap[y * b_width + x];
 339                 }
 340             }
 341             /* advance pointers */
 342             buf += screen_size;
 343             req_size += screen_size;
 344
 345             /* compress and copy colram to buf */
 346             if (c->mc_use_5col) {
 347                 a64_compress_colram(buf, charmap, colram);
 348                 /* advance pointers */
 349                 buf += colram_size;
 350                 req_size += colram_size;
 351             }
 352
 353             /* advance to next charmap */
 354             charmap += 1000;
 355         }
 356
 357         AV_WB32(avctx->extradata + 4,  c->mc_frame_counter);
 358         AV_WB32(avctx->extradata + 8,  charset_size);
 359         AV_WB32(avctx->extradata + 12, screen_size + colram_size);
 360
 361         /* reset counter */
 362         c->mc_frame_counter = 0;
 363
 364         pkt->pts = pkt->dts = c->next_pts;
 365         c->next_pts         = AV_NOPTS_VALUE;
 366
 367         pkt->size   = req_size;
 368         pkt->flags |= AV_PKT_FLAG_KEY;
 369         *got_packet = !!req_size;
 370     }
 371     return 0;
 372 }
 373
 374 AVCodec ff_a64multi_encoder = {
 375     .name           = "a64multi",
 376     .type           = AVMEDIA_TYPE_VIDEO,
 377     .id             = AV_CODEC_ID_A64_MULTI,
 378     .priv_data_size = sizeof(A64Context),
 379     .init           = a64multi_init_encoder,
 380     .encode2        = a64multi_encode_frame,
 381     .close          = a64multi_close_encoder,
 382     .pix_fmts       = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
 383     .long_name      = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),
 384     .capabilities   = CODEC_CAP_DELAY,
 385 };
 386
 387 AVCodec ff_a64multi5_encoder = {
 388     .name           = "a64multi5",
 389     .type           = AVMEDIA_TYPE_VIDEO,
 390     .id             = AV_CODEC_ID_A64_MULTI5,
 391     .priv_data_size = sizeof(A64Context),
 392     .init           = a64multi_init_encoder,
 393     .encode2        = a64multi_encode_frame,
 394     .close          = a64multi_close_encoder,
 395     .pix_fmts       = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
 396     .long_name      = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),
 397     .capabilities   = CODEC_CAP_DELAY,
 398 };