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 #include "internal.h"
  33
  34 #define KMVC_KEYFRAME 0x80
  35 #define KMVC_PALETTE  0x40
  36 #define KMVC_METHOD   0x0F
  37 #define MAX_PALSIZE   256
  38
  39 /*
  40  * Decoder context
  41  */
  42 typedef struct KmvcContext {
  43     AVCodecContext *avctx;
  44     AVFrame pic;
  45
  46     int setpal;
  47     int palsize;
  48     uint32_t pal[MAX_PALSIZE];
  49     uint8_t *cur, *prev;
  50     uint8_t *frm0, *frm1;
  51     GetByteContext g;
  52 } KmvcContext;
  53
  54 typedef struct BitBuf {
  55     int bits;
  56     int bitbuf;
  57 } BitBuf;
  58
  59 #define BLK(data, x, y)  data[(x) + (y) * 320]
  60
  61 #define kmvc_init_getbits(bb, g)  bb.bits = 7; bb.bitbuf = bytestream2_get_byte(g);
  62
  63 #define kmvc_getbit(bb, g, res) {\
  64     res = 0; \
  65     if (bb.bitbuf & (1 << bb.bits)) res = 1; \
  66     bb.bits--; \
  67     if(bb.bits == -1) { \
  68         bb.bitbuf = bytestream2_get_byte(g); \
  69         bb.bits = 7; \
  70     } \
  71 }
  72
  73 static int kmvc_decode_intra_8x8(KmvcContext * ctx, int w, int h)
  74 {
  75     BitBuf bb;
  76     int res, val;
  77     int i, j;
  78     int bx, by;
  79     int l0x, l1x, l0y, l1y;
  80     int mx, my;
  81
  82     kmvc_init_getbits(bb, &ctx->g);
  83
  84     for (by = 0; by < h; by += 8)
  85         for (bx = 0; bx < w; bx += 8) {
  86             if (!bytestream2_get_bytes_left(&ctx->g)) {
  87                 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
  88                 return AVERROR_INVALIDDATA;
  89             }
  90             kmvc_getbit(bb, &ctx->g, res);
  91             if (!res) {         // fill whole 8x8 block
  92                 val = bytestream2_get_byte(&ctx->g);
  93                 for (i = 0; i < 64; i++)
  94                     BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
  95             } else {            // handle four 4x4 subblocks
  96                 for (i = 0; i < 4; i++) {
  97                     l0x = bx + (i & 1) * 4;
  98                     l0y = by + (i & 2) * 2;
  99                     kmvc_getbit(bb, &ctx->g, res);
 100                     if (!res) {
 101                         kmvc_getbit(bb, &ctx->g, res);
 102                         if (!res) {     // fill whole 4x4 block
 103                             val = bytestream2_get_byte(&ctx->g);
 104                             for (j = 0; j < 16; j++)
 105                                 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
 106                         } else {        // copy block from already decoded place
 107                             val = bytestream2_get_byte(&ctx->g);
 108                             mx = val & 0xF;
 109                             my = val >> 4;
 110                             for (j = 0; j < 16; j++)
 111                                 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
 112                                     BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my);
 113                         }
 114                     } else {    // descend to 2x2 sub-sub-blocks
 115                         for (j = 0; j < 4; j++) {
 116                             l1x = l0x + (j & 1) * 2;
 117                             l1y = l0y + (j & 2);
 118                             kmvc_getbit(bb, &ctx->g, res);
 119                             if (!res) {
 120                                 kmvc_getbit(bb, &ctx->g, res);
 121                                 if (!res) {     // fill whole 2x2 block
 122                                     val = bytestream2_get_byte(&ctx->g);
 123                                     BLK(ctx->cur, l1x, l1y) = val;
 124                                     BLK(ctx->cur, l1x + 1, l1y) = val;
 125                                     BLK(ctx->cur, l1x, l1y + 1) = val;
 126                                     BLK(ctx->cur, l1x + 1, l1y + 1) = val;
 127                                 } else {        // copy block from already decoded place
 128                                     val = bytestream2_get_byte(&ctx->g);
 129                                     mx = val & 0xF;
 130                                     my = val >> 4;
 131                                     BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my);
 132                                     BLK(ctx->cur, l1x + 1, l1y) =
 133                                         BLK(ctx->cur, l1x + 1 - mx, l1y - my);
 134                                     BLK(ctx->cur, l1x, l1y + 1) =
 135                                         BLK(ctx->cur, l1x - mx, l1y + 1 - my);
 136                                     BLK(ctx->cur, l1x + 1, l1y + 1) =
 137                                         BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my);
 138                                 }
 139                             } else {    // read values for block
 140                                 BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
 141                                 BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
 142                                 BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
 143                                 BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
 144                             }
 145                         }
 146                     }
 147                 }
 148             }
 149         }
 150
 151     return 0;
 152 }
 153
 154 static int kmvc_decode_inter_8x8(KmvcContext * ctx, int w, int h)
 155 {
 156     BitBuf bb;
 157     int res, val;
 158     int i, j;
 159     int bx, by;
 160     int l0x, l1x, l0y, l1y;
 161     int mx, my;
 162
 163     kmvc_init_getbits(bb, &ctx->g);
 164
 165     for (by = 0; by < h; by += 8)
 166         for (bx = 0; bx < w; bx += 8) {
 167             kmvc_getbit(bb, &ctx->g, res);
 168             if (!res) {
 169                 kmvc_getbit(bb, &ctx->g, res);
 170                 if (!res) {     // fill whole 8x8 block
 171                     if (!bytestream2_get_bytes_left(&ctx->g)) {
 172                         av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
 173                         return AVERROR_INVALIDDATA;
 174                     }
 175                     val = bytestream2_get_byte(&ctx->g);
 176                     for (i = 0; i < 64; i++)
 177                         BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
 178                 } else {        // copy block from previous frame
 179                     for (i = 0; i < 64; i++)
 180                         BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) =
 181                             BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3));
 182                 }
 183             } else {            // handle four 4x4 subblocks
 184                 if (!bytestream2_get_bytes_left(&ctx->g)) {
 185                     av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
 186                     return AVERROR_INVALIDDATA;
 187                 }
 188                 for (i = 0; i < 4; i++) {
 189                     l0x = bx + (i & 1) * 4;
 190                     l0y = by + (i & 2) * 2;
 191                     kmvc_getbit(bb, &ctx->g, res);
 192                     if (!res) {
 193                         kmvc_getbit(bb, &ctx->g, res);
 194                         if (!res) {     // fill whole 4x4 block
 195                             val = bytestream2_get_byte(&ctx->g);
 196                             for (j = 0; j < 16; j++)
 197                                 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
 198                         } else {        // copy block
 199                             val = bytestream2_get_byte(&ctx->g);
 200                             mx = (val & 0xF) - 8;
 201                             my = (val >> 4) - 8;
 202                             for (j = 0; j < 16; j++)
 203                                 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
 204                                     BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my);
 205                         }
 206                     } else {    // descend to 2x2 sub-sub-blocks
 207                         for (j = 0; j < 4; j++) {
 208                             l1x = l0x + (j & 1) * 2;
 209                             l1y = l0y + (j & 2);
 210                             kmvc_getbit(bb, &ctx->g, res);
 211                             if (!res) {
 212                                 kmvc_getbit(bb, &ctx->g, res);
 213                                 if (!res) {     // fill whole 2x2 block
 214                                     val = bytestream2_get_byte(&ctx->g);
 215                                     BLK(ctx->cur, l1x, l1y) = val;
 216                                     BLK(ctx->cur, l1x + 1, l1y) = val;
 217                                     BLK(ctx->cur, l1x, l1y + 1) = val;
 218                                     BLK(ctx->cur, l1x + 1, l1y + 1) = val;
 219                                 } else {        // copy block
 220                                     val = bytestream2_get_byte(&ctx->g);
 221                                     mx = (val & 0xF) - 8;
 222                                     my = (val >> 4) - 8;
 223                                     BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my);
 224                                     BLK(ctx->cur, l1x + 1, l1y) =
 225                                         BLK(ctx->prev, l1x + 1 + mx, l1y + my);
 226                                     BLK(ctx->cur, l1x, l1y + 1) =
 227                                         BLK(ctx->prev, l1x + mx, l1y + 1 + my);
 228                                     BLK(ctx->cur, l1x + 1, l1y + 1) =
 229                                         BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my);
 230                                 }
 231                             } else {    // read values for block
 232                                 BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
 233                                 BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
 234                                 BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
 235                                 BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
 236                             }
 237                         }
 238                     }
 239                 }
 240             }
 241         }
 242
 243     return 0;
 244 }
 245
 246 static int decode_frame(AVCodecContext * avctx, void *data, int *got_frame,
 247                         AVPacket *avpkt)
 248 {
 249     KmvcContext *const ctx = avctx->priv_data;
 250     uint8_t *out, *src;
 251     int i, ret;
 252     int header;
 253     int blocksize;
 254     const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
 255
 256     bytestream2_init(&ctx->g, avpkt->data, avpkt->size);
 257     if (ctx->pic.data[0])
 258         avctx->release_buffer(avctx, &ctx->pic);
 259
 260     ctx->pic.reference = 1;
 261     ctx->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
 262     if ((ret = ff_get_buffer(avctx, &ctx->pic)) < 0) {
 263         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 264         return ret;
 265     }
 266
 267     header = bytestream2_get_byte(&ctx->g);
 268
 269     /* blocksize 127 is really palette change event */
 270     if (bytestream2_peek_byte(&ctx->g) == 127) {
 271         bytestream2_skip(&ctx->g, 3);
 272         for (i = 0; i < 127; i++) {
 273             ctx->pal[i + (header & 0x81)] = bytestream2_get_be24(&ctx->g);
 274             bytestream2_skip(&ctx->g, 1);
 275         }
 276         bytestream2_seek(&ctx->g, -127 * 4 - 3, SEEK_CUR);
 277     }
 278
 279     if (header & KMVC_KEYFRAME) {
 280         ctx->pic.key_frame = 1;
 281         ctx->pic.pict_type = AV_PICTURE_TYPE_I;
 282     } else {
 283         ctx->pic.key_frame = 0;
 284         ctx->pic.pict_type = AV_PICTURE_TYPE_P;
 285     }
 286
 287     if (header & KMVC_PALETTE) {
 288         ctx->pic.palette_has_changed = 1;
 289         // palette starts from index 1 and has 127 entries
 290         for (i = 1; i <= ctx->palsize; i++) {
 291             ctx->pal[i] = bytestream2_get_be24(&ctx->g);
 292         }
 293     }
 294
 295     if (pal) {
 296         ctx->pic.palette_has_changed = 1;
 297         memcpy(ctx->pal, pal, AVPALETTE_SIZE);
 298     }
 299
 300     if (ctx->setpal) {
 301         ctx->setpal = 0;
 302         ctx->pic.palette_has_changed = 1;
 303     }
 304
 305     /* make the palette available on the way out */
 306     memcpy(ctx->pic.data[1], ctx->pal, 1024);
 307
 308     blocksize = bytestream2_get_byte(&ctx->g);
 309
 310     if (blocksize != 8 && blocksize != 127) {
 311         av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize);
 312         return AVERROR_INVALIDDATA;
 313     }
 314     memset(ctx->cur, 0, 320 * 200);
 315     switch (header & KMVC_METHOD) {
 316     case 0:
 317     case 1: // used in palette changed event
 318         memcpy(ctx->cur, ctx->prev, 320 * 200);
 319         break;
 320     case 3:
 321         kmvc_decode_intra_8x8(ctx, avctx->width, avctx->height);
 322         break;
 323     case 4:
 324         kmvc_decode_inter_8x8(ctx, avctx->width, avctx->height);
 325         break;
 326     default:
 327         av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD);
 328         return AVERROR_INVALIDDATA;
 329     }
 330
 331     out = ctx->pic.data[0];
 332     src = ctx->cur;
 333     for (i = 0; i < avctx->height; i++) {
 334         memcpy(out, src, avctx->width);
 335         src += 320;
 336         out += ctx->pic.linesize[0];
 337     }
 338
 339     /* flip buffers */
 340     if (ctx->cur == ctx->frm0) {
 341         ctx->cur = ctx->frm1;
 342         ctx->prev = ctx->frm0;
 343     } else {
 344         ctx->cur = ctx->frm0;
 345         ctx->prev = ctx->frm1;
 346     }
 347
 348     *got_frame = 1;
 349     *(AVFrame *) data = ctx->pic;
 350
 351     /* always report that the buffer was completely consumed */
 352     return avpkt->size;
 353 }
 354
 355
 356
 357 /*
 358  * Init kmvc decoder
 359  */
 360 static av_cold int decode_init(AVCodecContext * avctx)
 361 {
 362     KmvcContext *const c = avctx->priv_data;
 363     int i;
 364
 365     c->avctx = avctx;
 366
 367     if (avctx->width > 320 || avctx->height > 200) {
 368         av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n");
 369         return AVERROR(EINVAL);
 370     }
 371
 372     c->frm0 = av_mallocz(320 * 200);
 373     c->frm1 = av_mallocz(320 * 200);
 374     c->cur = c->frm0;
 375     c->prev = c->frm1;
 376
 377     for (i = 0; i < 256; i++) {
 378         c->pal[i] = i * 0x10101;
 379     }
 380
 381     if (avctx->extradata_size < 12) {
 382         av_log(avctx, AV_LOG_WARNING,
 383                "Extradata missing, decoding may not work properly...\n");
 384         c->palsize = 127;
 385     } else {
 386         c->palsize = AV_RL16(avctx->extradata + 10);
 387         if (c->palsize >= MAX_PALSIZE) {
 388             av_log(avctx, AV_LOG_ERROR, "KMVC palette too large\n");
 389             return AVERROR_INVALIDDATA;
 390         }
 391     }
 392
 393     if (avctx->extradata_size == 1036) {        // palette in extradata
 394         uint8_t *src = avctx->extradata + 12;
 395         for (i = 0; i < 256; i++) {
 396             c->pal[i] = AV_RL32(src);
 397             src += 4;
 398         }
 399         c->setpal = 1;
 400     }
 401
 402     avctx->pix_fmt = AV_PIX_FMT_PAL8;
 403
 404     return 0;
 405 }
 406
 407
 408
 409 /*
 410  * Uninit kmvc decoder
 411  */
 412 static av_cold int decode_end(AVCodecContext * avctx)
 413 {
 414     KmvcContext *const c = avctx->priv_data;
 415
 416     av_freep(&c->frm0);
 417     av_freep(&c->frm1);
 418     if (c->pic.data[0])
 419         avctx->release_buffer(avctx, &c->pic);
 420
 421     return 0;
 422 }
 423
 424 AVCodec ff_kmvc_decoder = {
 425     .name           = "kmvc",
 426     .type           = AVMEDIA_TYPE_VIDEO,
 427     .id             = AV_CODEC_ID_KMVC,
 428     .priv_data_size = sizeof(KmvcContext),
 429     .init           = decode_init,
 430     .close          = decode_end,
 431     .decode         = decode_frame,
 432     .capabilities   = CODEC_CAP_DR1,
 433     .long_name      = NULL_IF_CONFIG_SMALL("Karl Morton's video codec"),
 434 };