libavcodec/xxan.c

   1 /*
   2  * Wing Commander/Xan Video Decoder
   3  * Copyright (C) 2011 Konstantin Shishkov
   4  * based on work by Mike Melanson
   5  *
   6  * This file is part of Libav.
   7  *
   8  * Libav is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * Libav is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with Libav; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include "avcodec.h"
  24 #include "libavutil/intreadwrite.h"
  25 #include "libavutil/mem.h"
  26 #include "bytestream.h"
  27 #define BITSTREAM_READER_LE
  28 #include "get_bits.h"
  29
  30 typedef struct XanContext {
  31     AVCodecContext *avctx;
  32     AVFrame pic;
  33
  34     uint8_t *y_buffer;
  35     uint8_t *scratch_buffer;
  36     int     buffer_size;
  37     GetByteContext gb;
  38 } XanContext;
  39
  40 static av_cold int xan_decode_init(AVCodecContext *avctx)
  41 {
  42     XanContext *s = avctx->priv_data;
  43
  44     s->avctx = avctx;
  45
  46     avctx->pix_fmt = AV_PIX_FMT_YUV420P;
  47
  48     if (avctx->height < 8) {
  49         av_log(avctx, AV_LOG_ERROR, "Invalid frame height: %d.\n", avctx->height);
  50         return AVERROR(EINVAL);
  51     }
  52
  53     s->buffer_size = avctx->width * avctx->height;
  54     s->y_buffer = av_malloc(s->buffer_size);
  55     if (!s->y_buffer)
  56         return AVERROR(ENOMEM);
  57     s->scratch_buffer = av_malloc(s->buffer_size + 130);
  58     if (!s->scratch_buffer) {
  59         av_freep(&s->y_buffer);
  60         return AVERROR(ENOMEM);
  61     }
  62
  63     return 0;
  64 }
  65
  66 static int xan_unpack_luma(XanContext *s,
  67                            uint8_t *dst, const int dst_size)
  68 {
  69     int tree_size, eof;
  70     int bits, mask;
  71     int tree_root, node;
  72     const uint8_t *dst_end = dst + dst_size;
  73     GetByteContext tree = s->gb;
  74     int start_off = bytestream2_tell(&tree);
  75
  76     tree_size = bytestream2_get_byte(&s->gb);
  77     eof       = bytestream2_get_byte(&s->gb);
  78     tree_root = eof + tree_size;
  79     bytestream2_skip(&s->gb, tree_size * 2);
  80
  81     node = tree_root;
  82     bits = bytestream2_get_byte(&s->gb);
  83     mask = 0x80;
  84     for (;;) {
  85         int bit = !!(bits & mask);
  86         mask >>= 1;
  87         bytestream2_seek(&tree, start_off + node*2 + bit - eof * 2, SEEK_SET);
  88         node = bytestream2_get_byte(&tree);
  89         if (node == eof)
  90             break;
  91         if (node < eof) {
  92             *dst++ = node;
  93             if (dst > dst_end)
  94                 break;
  95             node = tree_root;
  96         }
  97         if (!mask) {
  98             if (bytestream2_get_bytes_left(&s->gb) <= 0)
  99                 break;
 100             bits = bytestream2_get_byteu(&s->gb);
 101             mask = 0x80;
 102         }
 103     }
 104     return dst != dst_end ? AVERROR_INVALIDDATA : 0;
 105 }
 106
 107 /* almost the same as in xan_wc3 decoder */
 108 static int xan_unpack(XanContext *s,
 109                       uint8_t *dest, const int dest_len)
 110 {
 111     uint8_t opcode;
 112     int size;
 113     uint8_t *orig_dest = dest;
 114     const uint8_t *dest_end = dest + dest_len;
 115
 116     while (dest < dest_end) {
 117         if (bytestream2_get_bytes_left(&s->gb) <= 0)
 118             return AVERROR_INVALIDDATA;
 119
 120         opcode = bytestream2_get_byteu(&s->gb);
 121
 122         if (opcode < 0xe0) {
 123             int size2, back;
 124             if ((opcode & 0x80) == 0) {
 125                 size  = opcode & 3;
 126                 back  = ((opcode & 0x60) << 3) + bytestream2_get_byte(&s->gb) + 1;
 127                 size2 = ((opcode & 0x1c) >> 2) + 3;
 128             } else if ((opcode & 0x40) == 0) {
 129                 size  = bytestream2_peek_byte(&s->gb) >> 6;
 130                 back  = (bytestream2_get_be16(&s->gb) & 0x3fff) + 1;
 131                 size2 = (opcode & 0x3f) + 4;
 132             } else {
 133                 size  = opcode & 3;
 134                 back  = ((opcode & 0x10) << 12) + bytestream2_get_be16(&s->gb) + 1;
 135                 size2 = ((opcode & 0x0c) <<  6) + bytestream2_get_byte(&s->gb) + 5;
 136                 if (size + size2 > dest_end - dest)
 137                     break;
 138             }
 139             if (dest + size + size2 > dest_end ||
 140                 dest - orig_dest + size < back)
 141                 return AVERROR_INVALIDDATA;
 142             bytestream2_get_buffer(&s->gb, dest, size);
 143             dest += size;
 144             av_memcpy_backptr(dest, back, size2);
 145             dest += size2;
 146         } else {
 147             int finish = opcode >= 0xfc;
 148
 149             size = finish ? opcode & 3 : ((opcode & 0x1f) << 2) + 4;
 150             if (dest_end - dest < size)
 151                 return AVERROR_INVALIDDATA;
 152             bytestream2_get_buffer(&s->gb, dest, size);
 153             dest += size;
 154             if (finish)
 155                 break;
 156         }
 157     }
 158     return dest - orig_dest;
 159 }
 160
 161 static int xan_decode_chroma(AVCodecContext *avctx, unsigned chroma_off)
 162 {
 163     XanContext *s = avctx->priv_data;
 164     uint8_t *U, *V;
 165     int val, uval, vval;
 166     int i, j;
 167     const uint8_t *src, *src_end;
 168     const uint8_t *table;
 169     int mode, offset, dec_size, table_size;
 170
 171     if (!chroma_off)
 172         return 0;
 173     if (chroma_off + 4 >= bytestream2_get_bytes_left(&s->gb)) {
 174         av_log(avctx, AV_LOG_ERROR, "Invalid chroma block position\n");
 175         return AVERROR_INVALIDDATA;
 176     }
 177     bytestream2_seek(&s->gb, chroma_off + 4, SEEK_SET);
 178     mode        = bytestream2_get_le16(&s->gb);
 179     table       = s->gb.buffer;
 180     table_size  = bytestream2_get_le16(&s->gb);
 181     offset      = table_size * 2;
 182     table_size += 1;
 183
 184     if (offset >= bytestream2_get_bytes_left(&s->gb)) {
 185         av_log(avctx, AV_LOG_ERROR, "Invalid chroma block offset\n");
 186         return AVERROR_INVALIDDATA;
 187     }
 188
 189     bytestream2_skip(&s->gb, offset);
 190     memset(s->scratch_buffer, 0, s->buffer_size);
 191     dec_size = xan_unpack(s, s->scratch_buffer, s->buffer_size);
 192     if (dec_size < 0) {
 193         av_log(avctx, AV_LOG_ERROR, "Chroma unpacking failed\n");
 194         return dec_size;
 195     }
 196
 197     U = s->pic.data[1];
 198     V = s->pic.data[2];
 199     src     = s->scratch_buffer;
 200     src_end = src + dec_size;
 201     if (mode) {
 202         for (j = 0; j < avctx->height >> 1; j++) {
 203             for (i = 0; i < avctx->width >> 1; i++) {
 204                 val = *src++;
 205                 if (val && val < table_size) {
 206                     val  = AV_RL16(table + (val << 1));
 207                     uval = (val >> 3) & 0xF8;
 208                     vval = (val >> 8) & 0xF8;
 209                     U[i] = uval | (uval >> 5);
 210                     V[i] = vval | (vval >> 5);
 211                 }
 212                 if (src == src_end)
 213                     return 0;
 214             }
 215             U += s->pic.linesize[1];
 216             V += s->pic.linesize[2];
 217         }
 218         if (avctx->height & 1) {
 219             memcpy(U, U - s->pic.linesize[1], avctx->width >> 1);
 220             memcpy(V, V - s->pic.linesize[2], avctx->width >> 1);
 221         }
 222     } else {
 223         uint8_t *U2 = U + s->pic.linesize[1];
 224         uint8_t *V2 = V + s->pic.linesize[2];
 225
 226         for (j = 0; j < avctx->height >> 2; j++) {
 227             for (i = 0; i < avctx->width >> 1; i += 2) {
 228                 val = *src++;
 229                 if (val && val < table_size) {
 230                     val  = AV_RL16(table + (val << 1));
 231                     uval = (val >> 3) & 0xF8;
 232                     vval = (val >> 8) & 0xF8;
 233                     U[i] = U[i+1] = U2[i] = U2[i+1] = uval | (uval >> 5);
 234                     V[i] = V[i+1] = V2[i] = V2[i+1] = vval | (vval >> 5);
 235                 }
 236             }
 237             U  += s->pic.linesize[1] * 2;
 238             V  += s->pic.linesize[2] * 2;
 239             U2 += s->pic.linesize[1] * 2;
 240             V2 += s->pic.linesize[2] * 2;
 241         }
 242         if (avctx->height & 3) {
 243             int lines = ((avctx->height + 1) >> 1) - (avctx->height >> 2) * 2;
 244
 245             memcpy(U, U - lines * s->pic.linesize[1], lines * s->pic.linesize[1]);
 246             memcpy(V, V - lines * s->pic.linesize[2], lines * s->pic.linesize[2]);
 247         }
 248     }
 249
 250     return 0;
 251 }
 252
 253 static int xan_decode_frame_type0(AVCodecContext *avctx)
 254 {
 255     XanContext *s = avctx->priv_data;
 256     uint8_t *ybuf, *prev_buf, *src = s->scratch_buffer;
 257     unsigned  chroma_off, corr_off;
 258     int cur, last;
 259     int i, j;
 260     int ret;
 261
 262     chroma_off = bytestream2_get_le32(&s->gb);
 263     corr_off   = bytestream2_get_le32(&s->gb);
 264
 265     if ((ret = xan_decode_chroma(avctx, chroma_off)) != 0)
 266         return ret;
 267
 268     if (corr_off >= (s->gb.buffer_end - s->gb.buffer_start)) {
 269         av_log(avctx, AV_LOG_WARNING, "Ignoring invalid correction block position\n");
 270         corr_off = 0;
 271     }
 272     bytestream2_seek(&s->gb, 12, SEEK_SET);
 273     ret = xan_unpack_luma(s, src, s->buffer_size >> 1);
 274     if (ret) {
 275         av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
 276         return ret;
 277     }
 278
 279     ybuf = s->y_buffer;
 280     last = *src++;
 281     ybuf[0] = last << 1;
 282     for (j = 1; j < avctx->width - 1; j += 2) {
 283         cur = (last + *src++) & 0x1F;
 284         ybuf[j]   = last + cur;
 285         ybuf[j+1] = cur << 1;
 286         last = cur;
 287     }
 288     ybuf[j]  = last << 1;
 289     prev_buf = ybuf;
 290     ybuf += avctx->width;
 291
 292     for (i = 1; i < avctx->height; i++) {
 293         last = ((prev_buf[0] >> 1) + *src++) & 0x1F;
 294         ybuf[0] = last << 1;
 295         for (j = 1; j < avctx->width - 1; j += 2) {
 296             cur = ((prev_buf[j + 1] >> 1) + *src++) & 0x1F;
 297             ybuf[j]   = last + cur;
 298             ybuf[j+1] = cur << 1;
 299             last = cur;
 300         }
 301         ybuf[j] = last << 1;
 302         prev_buf = ybuf;
 303         ybuf += avctx->width;
 304     }
 305
 306     if (corr_off) {
 307         int dec_size;
 308
 309         bytestream2_seek(&s->gb, 8 + corr_off, SEEK_SET);
 310         dec_size = xan_unpack(s, s->scratch_buffer, s->buffer_size);
 311         if (dec_size < 0)
 312             dec_size = 0;
 313         for (i = 0; i < dec_size; i++)
 314             s->y_buffer[i*2+1] = (s->y_buffer[i*2+1] + (s->scratch_buffer[i] << 1)) & 0x3F;
 315     }
 316
 317     src  = s->y_buffer;
 318     ybuf = s->pic.data[0];
 319     for (j = 0; j < avctx->height; j++) {
 320         for (i = 0; i < avctx->width; i++)
 321             ybuf[i] = (src[i] << 2) | (src[i] >> 3);
 322         src  += avctx->width;
 323         ybuf += s->pic.linesize[0];
 324     }
 325
 326     return 0;
 327 }
 328
 329 static int xan_decode_frame_type1(AVCodecContext *avctx)
 330 {
 331     XanContext *s = avctx->priv_data;
 332     uint8_t *ybuf, *src = s->scratch_buffer;
 333     int cur, last;
 334     int i, j;
 335     int ret;
 336
 337     if ((ret = xan_decode_chroma(avctx, bytestream2_get_le32(&s->gb))) != 0)
 338         return ret;
 339
 340     bytestream2_seek(&s->gb, 16, SEEK_SET);
 341     ret = xan_unpack_luma(s, src,
 342                           s->buffer_size >> 1);
 343     if (ret) {
 344         av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
 345         return ret;
 346     }
 347
 348     ybuf = s->y_buffer;
 349     for (i = 0; i < avctx->height; i++) {
 350         last = (ybuf[0] + (*src++ << 1)) & 0x3F;
 351         ybuf[0] = last;
 352         for (j = 1; j < avctx->width - 1; j += 2) {
 353             cur = (ybuf[j + 1] + (*src++ << 1)) & 0x3F;
 354             ybuf[j]   = (last + cur) >> 1;
 355             ybuf[j+1] = cur;
 356             last = cur;
 357         }
 358         ybuf[j] = last;
 359         ybuf += avctx->width;
 360     }
 361
 362     src = s->y_buffer;
 363     ybuf = s->pic.data[0];
 364     for (j = 0; j < avctx->height; j++) {
 365         for (i = 0; i < avctx->width; i++)
 366             ybuf[i] = (src[i] << 2) | (src[i] >> 3);
 367         src  += avctx->width;
 368         ybuf += s->pic.linesize[0];
 369     }
 370
 371     return 0;
 372 }
 373
 374 static int xan_decode_frame(AVCodecContext *avctx,
 375                             void *data, int *got_frame,
 376                             AVPacket *avpkt)
 377 {
 378     XanContext *s = avctx->priv_data;
 379     int ftype;
 380     int ret;
 381
 382     s->pic.reference = 1;
 383     s->pic.buffer_hints = FF_BUFFER_HINTS_VALID |
 384                           FF_BUFFER_HINTS_PRESERVE |
 385                           FF_BUFFER_HINTS_REUSABLE;
 386     if ((ret = avctx->reget_buffer(avctx, &s->pic))) {
 387         av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
 388         return ret;
 389     }
 390
 391     bytestream2_init(&s->gb, avpkt->data, avpkt->size);
 392     ftype = bytestream2_get_le32(&s->gb);
 393     switch (ftype) {
 394     case 0:
 395         ret = xan_decode_frame_type0(avctx);
 396         break;
 397     case 1:
 398         ret = xan_decode_frame_type1(avctx);
 399         break;
 400     default:
 401         av_log(avctx, AV_LOG_ERROR, "Unknown frame type %d\n", ftype);
 402         return AVERROR_INVALIDDATA;
 403     }
 404     if (ret)
 405         return ret;
 406
 407     *got_frame = 1;
 408     *(AVFrame*)data = s->pic;
 409
 410     return avpkt->size;
 411 }
 412
 413 static av_cold int xan_decode_end(AVCodecContext *avctx)
 414 {
 415     XanContext *s = avctx->priv_data;
 416
 417     if (s->pic.data[0])
 418         avctx->release_buffer(avctx, &s->pic);
 419
 420     av_freep(&s->y_buffer);
 421     av_freep(&s->scratch_buffer);
 422
 423     return 0;
 424 }
 425
 426 AVCodec ff_xan_wc4_decoder = {
 427     .name           = "xan_wc4",
 428     .type           = AVMEDIA_TYPE_VIDEO,
 429     .id             = AV_CODEC_ID_XAN_WC4,
 430     .priv_data_size = sizeof(XanContext),
 431     .init           = xan_decode_init,
 432     .close          = xan_decode_end,
 433     .decode         = xan_decode_frame,
 434     .capabilities   = CODEC_CAP_DR1,
 435     .long_name      = NULL_IF_CONFIG_SMALL("Wing Commander IV / Xxan"),
 436 };