libavcodec/kmvc.c

   1 /*
   2  * KMVC decoder
   3  * Copyright (c) 2006 Konstantin Shishkov
   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  * Karl Morton's Video Codec decoder
  25  */
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29
  30 #include "avcodec.h"
  31 #include "bytestream.h"
  32
  33 #define KMVC_KEYFRAME 0x80
  34 #define KMVC_PALETTE  0x40
  35 #define KMVC_METHOD   0x0F
  36
  37 /*
  38  * Decoder context
  39  */
  40 typedef struct KmvcContext {
  41     AVCodecContext *avctx;
  42     AVFrame pic;
  43
  44     int setpal;
  45     int palsize;
  46     uint32_t pal[256];
  47     uint8_t *cur, *prev;
  48     uint8_t *frm0, *frm1;
  49 } KmvcContext;
  50
  51 typedef struct BitBuf {
  52     int bits;
  53     int bitbuf;
  54 } BitBuf;
  55
  56 #define BLK(data, x, y)  data[(x) + (y) * 320]
  57
  58 #define kmvc_init_getbits(bb, src)  bb.bits = 7; bb.bitbuf = *src++;
  59
  60 #define kmvc_getbit(bb, src, src_end, res) {\
  61     res = 0; \
  62     if (bb.bitbuf & (1 << bb.bits)) res = 1; \
  63     bb.bits--; \
  64     if(bb.bits == -1) { \
  65         if (src >= src_end) { \
  66             av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n"); \
  67             return AVERROR_INVALIDDATA; \
  68         } \
  69         bb.bitbuf = *src++; \
  70         bb.bits = 7; \
  71     } \
  72 }
  73
  74 static int kmvc_decode_intra_8x8(KmvcContext * ctx, const uint8_t * src, int src_size, int w, int h)
  75 {
  76     BitBuf bb;
  77     int res, val;
  78     int i, j;
  79     int bx, by;
  80     int l0x, l1x, l0y, l1y;
  81     int mx, my;
  82     const uint8_t *src_end = src + src_size;
  83
  84     kmvc_init_getbits(bb, src);
  85
  86     for (by = 0; by < h; by += 8)
  87         for (bx = 0; bx < w; bx += 8) {
  88             kmvc_getbit(bb, src, src_end, res);
  89             if (!res) {         // fill whole 8x8 block
  90                 if (src >= src_end) {
  91                     av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
  92                     return AVERROR_INVALIDDATA;
  93                 }
  94                 val = *src++;
  95                 for (i = 0; i < 64; i++)
  96                     BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
  97             } else {            // handle four 4x4 subblocks
  98                 for (i = 0; i < 4; i++) {
  99                     l0x = bx + (i & 1) * 4;
 100                     l0y = by + (i & 2) * 2;
 101                     kmvc_getbit(bb, src, src_end, res);
 102                     if (!res) {
 103                         kmvc_getbit(bb, src, src_end, res);
 104                         if (!res) {     // fill whole 4x4 block
 105                             if (src >= src_end) {
 106                                 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
 107                                 return AVERROR_INVALIDDATA;
 108                             }
 109                             val = *src++;
 110                             for (j = 0; j < 16; j++)
 111                                 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
 112                         } else {        // copy block from already decoded place
 113                             if (src >= src_end) {
 114                                 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
 115                                 return AVERROR_INVALIDDATA;
 116                             }
 117                             val = *src++;
 118                             mx = val & 0xF;
 119                             my = val >> 4;
 120                             for (j = 0; j < 16; j++)
 121                                 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
 122                                     BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my);
 123                         }
 124                     } else {    // descend to 2x2 sub-sub-blocks
 125                         for (j = 0; j < 4; j++) {
 126                             l1x = l0x + (j & 1) * 2;
 127                             l1y = l0y + (j & 2);
 128                             kmvc_getbit(bb, src, src_end, res);
 129                             if (!res) {
 130                                 kmvc_getbit(bb, src, src_end, res);
 131                                 if (!res) {     // fill whole 2x2 block
 132                                     if (src >= src_end) {
 133                                         av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
 134                                         return AVERROR_INVALIDDATA;
 135                                     }
 136                                     val = *src++;
 137                                     BLK(ctx->cur, l1x, l1y) = val;
 138                                     BLK(ctx->cur, l1x + 1, l1y) = val;
 139                                     BLK(ctx->cur, l1x, l1y + 1) = val;
 140                                     BLK(ctx->cur, l1x + 1, l1y + 1) = val;
 141                                 } else {        // copy block from already decoded place
 142                                     if (src >= src_end) {
 143                                         av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
 144                                         return AVERROR_INVALIDDATA;
 145                                     }
 146                                     val = *src++;
 147                                     mx = val & 0xF;
 148                                     my = val >> 4;
 149                                     BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my);
 150                                     BLK(ctx->cur, l1x + 1, l1y) =
 151                                         BLK(ctx->cur, l1x + 1 - mx, l1y - my);
 152                                     BLK(ctx->cur, l1x, l1y + 1) =
 153                                         BLK(ctx->cur, l1x - mx, l1y + 1 - my);
 154                                     BLK(ctx->cur, l1x + 1, l1y + 1) =
 155                                         BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my);
 156                                 }
 157                             } else {    // read values for block
 158                                 BLK(ctx->cur, l1x, l1y) = *src++;
 159                                 BLK(ctx->cur, l1x + 1, l1y) = *src++;
 160                                 BLK(ctx->cur, l1x, l1y + 1) = *src++;
 161                                 BLK(ctx->cur, l1x + 1, l1y + 1) = *src++;
 162                             }
 163                         }
 164                     }
 165                 }
 166             }
 167         }
 168
 169     return 0;
 170 }
 171
 172 static int kmvc_decode_inter_8x8(KmvcContext * ctx, const uint8_t * src, int src_size, int w, int h)
 173 {
 174     BitBuf bb;
 175     int res, val;
 176     int i, j;
 177     int bx, by;
 178     int l0x, l1x, l0y, l1y;
 179     int mx, my;
 180     const uint8_t *src_end = src + src_size;
 181
 182     kmvc_init_getbits(bb, src);
 183
 184     for (by = 0; by < h; by += 8)
 185         for (bx = 0; bx < w; bx += 8) {
 186             kmvc_getbit(bb, src, src_end, res);
 187             if (!res) {
 188                 kmvc_getbit(bb, src, src_end, res);
 189                 if (!res) {     // fill whole 8x8 block
 190                     if (src >= src_end) {
 191                         av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
 192                         return AVERROR_INVALIDDATA;
 193                     }
 194                     val = *src++;
 195                     for (i = 0; i < 64; i++)
 196                         BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
 197                 } else {        // copy block from previous frame
 198                     for (i = 0; i < 64; i++)
 199                         BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) =
 200                             BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3));
 201                 }
 202             } else {            // handle four 4x4 subblocks
 203                 for (i = 0; i < 4; i++) {
 204                     l0x = bx + (i & 1) * 4;
 205                     l0y = by + (i & 2) * 2;
 206                     kmvc_getbit(bb, src, src_end, res);
 207                     if (!res) {
 208                         kmvc_getbit(bb, src, src_end, res);
 209                         if (!res) {     // fill whole 4x4 block
 210                             if (src >= src_end) {
 211                                 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
 212                                 return AVERROR_INVALIDDATA;
 213                             }
 214                             val = *src++;
 215                             for (j = 0; j < 16; j++)
 216                                 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
 217                         } else {        // copy block
 218                             if (src >= src_end) {
 219                                 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
 220                                 return AVERROR_INVALIDDATA;
 221                             }
 222                             val = *src++;
 223                             mx = (val & 0xF) - 8;
 224                             my = (val >> 4) - 8;
 225                             for (j = 0; j < 16; j++)
 226                                 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
 227                                     BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my);
 228                         }
 229                     } else {    // descend to 2x2 sub-sub-blocks
 230                         for (j = 0; j < 4; j++) {
 231                             l1x = l0x + (j & 1) * 2;
 232                             l1y = l0y + (j & 2);
 233                             kmvc_getbit(bb, src, src_end, res);
 234                             if (!res) {
 235                                 kmvc_getbit(bb, src, src_end, res);
 236                                 if (!res) {     // fill whole 2x2 block
 237                                     if (src >= src_end) {
 238                                         av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
 239                                         return AVERROR_INVALIDDATA;
 240                                     }
 241                                     val = *src++;
 242                                     BLK(ctx->cur, l1x, l1y) = val;
 243                                     BLK(ctx->cur, l1x + 1, l1y) = val;
 244                                     BLK(ctx->cur, l1x, l1y + 1) = val;
 245                                     BLK(ctx->cur, l1x + 1, l1y + 1) = val;
 246                                 } else {        // copy block
 247                                     if (src >= src_end) {
 248                                         av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
 249                                         return AVERROR_INVALIDDATA;
 250                                     }
 251                                     val = *src++;
 252                                     mx = (val & 0xF) - 8;
 253                                     my = (val >> 4) - 8;
 254                                     BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my);
 255                                     BLK(ctx->cur, l1x + 1, l1y) =
 256                                         BLK(ctx->prev, l1x + 1 + mx, l1y + my);
 257                                     BLK(ctx->cur, l1x, l1y + 1) =
 258                                         BLK(ctx->prev, l1x + mx, l1y + 1 + my);
 259                                     BLK(ctx->cur, l1x + 1, l1y + 1) =
 260                                         BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my);
 261                                 }
 262                             } else {    // read values for block
 263                                 BLK(ctx->cur, l1x, l1y) = *src++;
 264                                 BLK(ctx->cur, l1x + 1, l1y) = *src++;
 265                                 BLK(ctx->cur, l1x, l1y + 1) = *src++;
 266                                 BLK(ctx->cur, l1x + 1, l1y + 1) = *src++;
 267                             }
 268                         }
 269                     }
 270                 }
 271             }
 272         }
 273
 274     return 0;
 275 }
 276
 277 static int decode_frame(AVCodecContext * avctx, void *data, int *data_size, AVPacket *avpkt)
 278 {
 279     const uint8_t *buf = avpkt->data;
 280     int buf_size = avpkt->size;
 281     KmvcContext *const ctx = avctx->priv_data;
 282     uint8_t *out, *src;
 283     int i;
 284     int header;
 285     int blocksize;
 286     const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
 287
 288     if (ctx->pic.data[0])
 289         avctx->release_buffer(avctx, &ctx->pic);
 290
 291     ctx->pic.reference = 1;
 292     ctx->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
 293     if (avctx->get_buffer(avctx, &ctx->pic) < 0) {
 294         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 295         return -1;
 296     }
 297
 298     header = *buf++;
 299
 300     /* blocksize 127 is really palette change event */
 301     if (buf[0] == 127) {
 302         buf += 3;
 303         for (i = 0; i < 127; i++) {
 304             ctx->pal[i + (header & 0x81)] = AV_RB24(buf);
 305             buf += 4;
 306         }
 307         buf -= 127 * 4 + 3;
 308     }
 309
 310     if (header & KMVC_KEYFRAME) {
 311         ctx->pic.key_frame = 1;
 312         ctx->pic.pict_type = AV_PICTURE_TYPE_I;
 313     } else {
 314         ctx->pic.key_frame = 0;
 315         ctx->pic.pict_type = AV_PICTURE_TYPE_P;
 316     }
 317
 318     if (header & KMVC_PALETTE) {
 319         ctx->pic.palette_has_changed = 1;
 320         // palette starts from index 1 and has 127 entries
 321         for (i = 1; i <= ctx->palsize; i++) {
 322             ctx->pal[i] = bytestream_get_be24(&buf);
 323         }
 324     }
 325
 326     if (pal) {
 327         ctx->pic.palette_has_changed = 1;
 328         memcpy(ctx->pal, pal, AVPALETTE_SIZE);
 329     }
 330
 331     if (ctx->setpal) {
 332         ctx->setpal = 0;
 333         ctx->pic.palette_has_changed = 1;
 334     }
 335
 336     /* make the palette available on the way out */
 337     memcpy(ctx->pic.data[1], ctx->pal, 1024);
 338
 339     blocksize = *buf++;
 340
 341     if (blocksize != 8 && blocksize != 127) {
 342         av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize);
 343         return -1;
 344     }
 345     memset(ctx->cur, 0, 320 * 200);
 346     switch (header & KMVC_METHOD) {
 347     case 0:
 348     case 1: // used in palette changed event
 349         memcpy(ctx->cur, ctx->prev, 320 * 200);
 350         break;
 351     case 3:
 352         kmvc_decode_intra_8x8(ctx, buf, buf_size, avctx->width, avctx->height);
 353         break;
 354     case 4:
 355         kmvc_decode_inter_8x8(ctx, buf, buf_size, avctx->width, avctx->height);
 356         break;
 357     default:
 358         av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD);
 359         return -1;
 360     }
 361
 362     out = ctx->pic.data[0];
 363     src = ctx->cur;
 364     for (i = 0; i < avctx->height; i++) {
 365         memcpy(out, src, avctx->width);
 366         src += 320;
 367         out += ctx->pic.linesize[0];
 368     }
 369
 370     /* flip buffers */
 371     if (ctx->cur == ctx->frm0) {
 372         ctx->cur = ctx->frm1;
 373         ctx->prev = ctx->frm0;
 374     } else {
 375         ctx->cur = ctx->frm0;
 376         ctx->prev = ctx->frm1;
 377     }
 378
 379     *data_size = sizeof(AVFrame);
 380     *(AVFrame *) data = ctx->pic;
 381
 382     /* always report that the buffer was completely consumed */
 383     return buf_size;
 384 }
 385
 386
 387
 388 /*
 389  * Init kmvc decoder
 390  */
 391 static av_cold int decode_init(AVCodecContext * avctx)
 392 {
 393     KmvcContext *const c = avctx->priv_data;
 394     int i;
 395
 396     c->avctx = avctx;
 397
 398     if (avctx->width > 320 || avctx->height > 200) {
 399         av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n");
 400         return -1;
 401     }
 402
 403     c->frm0 = av_mallocz(320 * 200);
 404     c->frm1 = av_mallocz(320 * 200);
 405     c->cur = c->frm0;
 406     c->prev = c->frm1;
 407
 408     for (i = 0; i < 256; i++) {
 409         c->pal[i] = i * 0x10101;
 410     }
 411
 412     if (avctx->extradata_size < 12) {
 413         av_log(NULL, 0, "Extradata missing, decoding may not work properly...\n");
 414         c->palsize = 127;
 415     } else {
 416         c->palsize = AV_RL16(avctx->extradata + 10);
 417     }
 418
 419     if (avctx->extradata_size == 1036) {        // palette in extradata
 420         uint8_t *src = avctx->extradata + 12;
 421         for (i = 0; i < 256; i++) {
 422             c->pal[i] = AV_RL32(src);
 423             src += 4;
 424         }
 425         c->setpal = 1;
 426     }
 427
 428     avctx->pix_fmt = PIX_FMT_PAL8;
 429
 430     return 0;
 431 }
 432
 433
 434
 435 /*
 436  * Uninit kmvc decoder
 437  */
 438 static av_cold int decode_end(AVCodecContext * avctx)
 439 {
 440     KmvcContext *const c = avctx->priv_data;
 441
 442     av_freep(&c->frm0);
 443     av_freep(&c->frm1);
 444     if (c->pic.data[0])
 445         avctx->release_buffer(avctx, &c->pic);
 446
 447     return 0;
 448 }
 449
 450 AVCodec ff_kmvc_decoder = {
 451     .name           = "kmvc",
 452     .type           = AVMEDIA_TYPE_VIDEO,
 453     .id             = CODEC_ID_KMVC,
 454     .priv_data_size = sizeof(KmvcContext),
 455     .init           = decode_init,
 456     .close          = decode_end,
 457     .decode         = decode_frame,
 458     .capabilities   = CODEC_CAP_DR1,
 459     .long_name = NULL_IF_CONFIG_SMALL("Karl Morton's video codec"),
 460 };