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     GetByteContext g;
  50 } KmvcContext;
  51
  52 typedef struct BitBuf {
  53     int bits;
  54     int bitbuf;
  55 } BitBuf;
  56
  57 #define BLK(data, x, y)  data[(x) + (y) * 320]
  58
  59 #define kmvc_init_getbits(bb, g)  bb.bits = 7; bb.bitbuf = bytestream2_get_byte(g);
  60
  61 #define kmvc_getbit(bb, g, res) {\
  62     res = 0; \
  63     if (bb.bitbuf & (1 << bb.bits)) res = 1; \
  64     bb.bits--; \
  65     if(bb.bits == -1) { \
  66         bb.bitbuf = bytestream2_get_byte(g); \
  67         bb.bits = 7; \
  68     } \
  69 }
  70
  71 static int kmvc_decode_intra_8x8(KmvcContext * ctx, int w, int h)
  72 {
  73     BitBuf bb;
  74     int res, val;
  75     int i, j;
  76     int bx, by;
  77     int l0x, l1x, l0y, l1y;
  78     int mx, my;
  79
  80     kmvc_init_getbits(bb, &ctx->g);
  81
  82     for (by = 0; by < h; by += 8)
  83         for (bx = 0; bx < w; bx += 8) {
  84             if (!bytestream2_get_bytes_left(&ctx->g)) {
  85                 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
  86                 return AVERROR_INVALIDDATA;
  87             }
  88             kmvc_getbit(bb, &ctx->g, res);
  89             if (!res) {         // fill whole 8x8 block
  90                 val = bytestream2_get_byte(&ctx->g);
  91                 for (i = 0; i < 64; i++)
  92                     BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
  93             } else {            // handle four 4x4 subblocks
  94                 for (i = 0; i < 4; i++) {
  95                     l0x = bx + (i & 1) * 4;
  96                     l0y = by + (i & 2) * 2;
  97                     kmvc_getbit(bb, &ctx->g, res);
  98                     if (!res) {
  99                         kmvc_getbit(bb, &ctx->g, res);
 100                         if (!res) {     // fill whole 4x4 block
 101                             val = bytestream2_get_byte(&ctx->g);
 102                             for (j = 0; j < 16; j++)
 103                                 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
 104                         } else {        // copy block from already decoded place
 105                             val = bytestream2_get_byte(&ctx->g);
 106                             mx = val & 0xF;
 107                             my = val >> 4;
 108                             for (j = 0; j < 16; j++)
 109                                 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
 110                                     BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my);
 111                         }
 112                     } else {    // descend to 2x2 sub-sub-blocks
 113                         for (j = 0; j < 4; j++) {
 114                             l1x = l0x + (j & 1) * 2;
 115                             l1y = l0y + (j & 2);
 116                             kmvc_getbit(bb, &ctx->g, res);
 117                             if (!res) {
 118                                 kmvc_getbit(bb, &ctx->g, res);
 119                                 if (!res) {     // fill whole 2x2 block
 120                                     val = bytestream2_get_byte(&ctx->g);
 121                                     BLK(ctx->cur, l1x, l1y) = val;
 122                                     BLK(ctx->cur, l1x + 1, l1y) = val;
 123                                     BLK(ctx->cur, l1x, l1y + 1) = val;
 124                                     BLK(ctx->cur, l1x + 1, l1y + 1) = val;
 125                                 } else {        // copy block from already decoded place
 126                                     val = bytestream2_get_byte(&ctx->g);
 127                                     mx = val & 0xF;
 128                                     my = val >> 4;
 129                                     BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my);
 130                                     BLK(ctx->cur, l1x + 1, l1y) =
 131                                         BLK(ctx->cur, l1x + 1 - mx, l1y - my);
 132                                     BLK(ctx->cur, l1x, l1y + 1) =
 133                                         BLK(ctx->cur, l1x - mx, l1y + 1 - my);
 134                                     BLK(ctx->cur, l1x + 1, l1y + 1) =
 135                                         BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my);
 136                                 }
 137                             } else {    // read values for block
 138                                 BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
 139                                 BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
 140                                 BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
 141                                 BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
 142                             }
 143                         }
 144                     }
 145                 }
 146             }
 147         }
 148
 149     return 0;
 150 }
 151
 152 static int kmvc_decode_inter_8x8(KmvcContext * ctx, int w, int h)
 153 {
 154     BitBuf bb;
 155     int res, val;
 156     int i, j;
 157     int bx, by;
 158     int l0x, l1x, l0y, l1y;
 159     int mx, my;
 160
 161     kmvc_init_getbits(bb, &ctx->g);
 162
 163     for (by = 0; by < h; by += 8)
 164         for (bx = 0; bx < w; bx += 8) {
 165             kmvc_getbit(bb, &ctx->g, res);
 166             if (!res) {
 167                 kmvc_getbit(bb, &ctx->g, res);
 168                 if (!res) {     // fill whole 8x8 block
 169                     if (!bytestream2_get_bytes_left(&ctx->g)) {
 170                         av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
 171                         return AVERROR_INVALIDDATA;
 172                     }
 173                     val = bytestream2_get_byte(&ctx->g);
 174                     for (i = 0; i < 64; i++)
 175                         BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
 176                 } else {        // copy block from previous frame
 177                     for (i = 0; i < 64; i++)
 178                         BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) =
 179                             BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3));
 180                 }
 181             } else {            // handle four 4x4 subblocks
 182                 if (!bytestream2_get_bytes_left(&ctx->g)) {
 183                     av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
 184                     return AVERROR_INVALIDDATA;
 185                 }
 186                 for (i = 0; i < 4; i++) {
 187                     l0x = bx + (i & 1) * 4;
 188                     l0y = by + (i & 2) * 2;
 189                     kmvc_getbit(bb, &ctx->g, res);
 190                     if (!res) {
 191                         kmvc_getbit(bb, &ctx->g, res);
 192                         if (!res) {     // fill whole 4x4 block
 193                             val = bytestream2_get_byte(&ctx->g);
 194                             for (j = 0; j < 16; j++)
 195                                 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
 196                         } else {        // copy block
 197                             val = bytestream2_get_byte(&ctx->g);
 198                             mx = (val & 0xF) - 8;
 199                             my = (val >> 4) - 8;
 200                             for (j = 0; j < 16; j++)
 201                                 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
 202                                     BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my);
 203                         }
 204                     } else {    // descend to 2x2 sub-sub-blocks
 205                         for (j = 0; j < 4; j++) {
 206                             l1x = l0x + (j & 1) * 2;
 207                             l1y = l0y + (j & 2);
 208                             kmvc_getbit(bb, &ctx->g, res);
 209                             if (!res) {
 210                                 kmvc_getbit(bb, &ctx->g, res);
 211                                 if (!res) {     // fill whole 2x2 block
 212                                     val = bytestream2_get_byte(&ctx->g);
 213                                     BLK(ctx->cur, l1x, l1y) = val;
 214                                     BLK(ctx->cur, l1x + 1, l1y) = val;
 215                                     BLK(ctx->cur, l1x, l1y + 1) = val;
 216                                     BLK(ctx->cur, l1x + 1, l1y + 1) = val;
 217                                 } else {        // copy block
 218                                     val = bytestream2_get_byte(&ctx->g);
 219                                     mx = (val & 0xF) - 8;
 220                                     my = (val >> 4) - 8;
 221                                     BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my);
 222                                     BLK(ctx->cur, l1x + 1, l1y) =
 223                                         BLK(ctx->prev, l1x + 1 + mx, l1y + my);
 224                                     BLK(ctx->cur, l1x, l1y + 1) =
 225                                         BLK(ctx->prev, l1x + mx, l1y + 1 + my);
 226                                     BLK(ctx->cur, l1x + 1, l1y + 1) =
 227                                         BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my);
 228                                 }
 229                             } else {    // read values for block
 230                                 BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
 231                                 BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
 232                                 BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
 233                                 BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
 234                             }
 235                         }
 236                     }
 237                 }
 238             }
 239         }
 240
 241     return 0;
 242 }
 243
 244 static int decode_frame(AVCodecContext * avctx, void *data, int *data_size, AVPacket *avpkt)
 245 {
 246     KmvcContext *const ctx = avctx->priv_data;
 247     uint8_t *out, *src;
 248     int i;
 249     int header;
 250     int blocksize;
 251     const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
 252
 253     bytestream2_init(&ctx->g, avpkt->data, avpkt->size);
 254     if (ctx->pic.data[0])
 255         avctx->release_buffer(avctx, &ctx->pic);
 256
 257     ctx->pic.reference = 1;
 258     ctx->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
 259     if (avctx->get_buffer(avctx, &ctx->pic) < 0) {
 260         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 261         return -1;
 262     }
 263
 264     header = bytestream2_get_byte(&ctx->g);
 265
 266     /* blocksize 127 is really palette change event */
 267     if (bytestream2_peek_byte(&ctx->g) == 127) {
 268         bytestream2_skip(&ctx->g, 3);
 269         for (i = 0; i < 127; i++) {
 270             ctx->pal[i + (header & 0x81)] = bytestream2_get_be24(&ctx->g);
 271             bytestream2_skip(&ctx->g, 1);
 272         }
 273         bytestream2_seek(&ctx->g, -127 * 4 - 3, SEEK_CUR);
 274     }
 275
 276     if (header & KMVC_KEYFRAME) {
 277         ctx->pic.key_frame = 1;
 278         ctx->pic.pict_type = AV_PICTURE_TYPE_I;
 279     } else {
 280         ctx->pic.key_frame = 0;
 281         ctx->pic.pict_type = AV_PICTURE_TYPE_P;
 282     }
 283
 284     if (header & KMVC_PALETTE) {
 285         ctx->pic.palette_has_changed = 1;
 286         // palette starts from index 1 and has 127 entries
 287         for (i = 1; i <= ctx->palsize; i++) {
 288             ctx->pal[i] = bytestream2_get_be24(&ctx->g);
 289         }
 290     }
 291
 292     if (pal) {
 293         ctx->pic.palette_has_changed = 1;
 294         memcpy(ctx->pal, pal, AVPALETTE_SIZE);
 295     }
 296
 297     if (ctx->setpal) {
 298         ctx->setpal = 0;
 299         ctx->pic.palette_has_changed = 1;
 300     }
 301
 302     /* make the palette available on the way out */
 303     memcpy(ctx->pic.data[1], ctx->pal, 1024);
 304
 305     blocksize = bytestream2_get_byte(&ctx->g);
 306
 307     if (blocksize != 8 && blocksize != 127) {
 308         av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize);
 309         return -1;
 310     }
 311     memset(ctx->cur, 0, 320 * 200);
 312     switch (header & KMVC_METHOD) {
 313     case 0:
 314     case 1: // used in palette changed event
 315         memcpy(ctx->cur, ctx->prev, 320 * 200);
 316         break;
 317     case 3:
 318         kmvc_decode_intra_8x8(ctx, avctx->width, avctx->height);
 319         break;
 320     case 4:
 321         kmvc_decode_inter_8x8(ctx, avctx->width, avctx->height);
 322         break;
 323     default:
 324         av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD);
 325         return -1;
 326     }
 327
 328     out = ctx->pic.data[0];
 329     src = ctx->cur;
 330     for (i = 0; i < avctx->height; i++) {
 331         memcpy(out, src, avctx->width);
 332         src += 320;
 333         out += ctx->pic.linesize[0];
 334     }
 335
 336     /* flip buffers */
 337     if (ctx->cur == ctx->frm0) {
 338         ctx->cur = ctx->frm1;
 339         ctx->prev = ctx->frm0;
 340     } else {
 341         ctx->cur = ctx->frm0;
 342         ctx->prev = ctx->frm1;
 343     }
 344
 345     *data_size = sizeof(AVFrame);
 346     *(AVFrame *) data = ctx->pic;
 347
 348     /* always report that the buffer was completely consumed */
 349     return avpkt->size;
 350 }
 351
 352
 353
 354 /*
 355  * Init kmvc decoder
 356  */
 357 static av_cold int decode_init(AVCodecContext * avctx)
 358 {
 359     KmvcContext *const c = avctx->priv_data;
 360     int i;
 361
 362     c->avctx = avctx;
 363
 364     if (avctx->width > 320 || avctx->height > 200) {
 365         av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n");
 366         return -1;
 367     }
 368
 369     c->frm0 = av_mallocz(320 * 200);
 370     c->frm1 = av_mallocz(320 * 200);
 371     c->cur = c->frm0;
 372     c->prev = c->frm1;
 373
 374     for (i = 0; i < 256; i++) {
 375         c->pal[i] = i * 0x10101;
 376     }
 377
 378     if (avctx->extradata_size < 12) {
 379         av_log(NULL, 0, "Extradata missing, decoding may not work properly...\n");
 380         c->palsize = 127;
 381     } else {
 382         c->palsize = AV_RL16(avctx->extradata + 10);
 383     }
 384
 385     if (avctx->extradata_size == 1036) {        // palette in extradata
 386         uint8_t *src = avctx->extradata + 12;
 387         for (i = 0; i < 256; i++) {
 388             c->pal[i] = AV_RL32(src);
 389             src += 4;
 390         }
 391         c->setpal = 1;
 392     }
 393
 394     avctx->pix_fmt = PIX_FMT_PAL8;
 395
 396     return 0;
 397 }
 398
 399
 400
 401 /*
 402  * Uninit kmvc decoder
 403  */
 404 static av_cold int decode_end(AVCodecContext * avctx)
 405 {
 406     KmvcContext *const c = avctx->priv_data;
 407
 408     av_freep(&c->frm0);
 409     av_freep(&c->frm1);
 410     if (c->pic.data[0])
 411         avctx->release_buffer(avctx, &c->pic);
 412
 413     return 0;
 414 }
 415
 416 AVCodec ff_kmvc_decoder = {
 417     .name           = "kmvc",
 418     .type           = AVMEDIA_TYPE_VIDEO,
 419     .id             = CODEC_ID_KMVC,
 420     .priv_data_size = sizeof(KmvcContext),
 421     .init           = decode_init,
 422     .close          = decode_end,
 423     .decode         = decode_frame,
 424     .capabilities   = CODEC_CAP_DR1,
 425     .long_name = NULL_IF_CONFIG_SMALL("Karl Morton's video codec"),
 426 };