libavcodec/vb.c

   1 /*
   2  * Beam Software VB decoder
   3  * Copyright (c) 2007 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  * VB Video 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 enum VBFlags {
  35     VB_HAS_GMC     = 0x01,
  36     VB_HAS_AUDIO   = 0x04,
  37     VB_HAS_VIDEO   = 0x08,
  38     VB_HAS_PALETTE = 0x10,
  39     VB_HAS_LENGTH  = 0x20
  40 };
  41
  42 typedef struct VBDecContext {
  43     AVCodecContext *avctx;
  44     AVFrame pic;
  45
  46     uint8_t *frame, *prev_frame;
  47     uint32_t pal[AVPALETTE_COUNT];
  48     GetByteContext stream;
  49 } VBDecContext;
  50
  51 static const uint16_t vb_patterns[64] = {
  52     0x0660, 0xFF00, 0xCCCC, 0xF000, 0x8888, 0x000F, 0x1111, 0xFEC8,
  53     0x8CEF, 0x137F, 0xF731, 0xC800, 0x008C, 0x0013, 0x3100, 0xCC00,
  54     0x00CC, 0x0033, 0x3300, 0x0FF0, 0x6666, 0x00F0, 0x0F00, 0x2222,
  55     0x4444, 0xF600, 0x8CC8, 0x006F, 0x1331, 0x318C, 0xC813, 0x33CC,
  56     0x6600, 0x0CC0, 0x0066, 0x0330, 0xF900, 0xC88C, 0x009F, 0x3113,
  57     0x6000, 0x0880, 0x0006, 0x0110, 0xCC88, 0xFC00, 0x00CF, 0x88CC,
  58     0x003F, 0x1133, 0x3311, 0xF300, 0x6FF6, 0x0603, 0x08C6, 0x8C63,
  59     0xC631, 0x6310, 0xC060, 0x0136, 0x136C, 0x36C8, 0x6C80, 0x324C
  60 };
  61
  62 static void vb_decode_palette(VBDecContext *c, int data_size)
  63 {
  64     int start, size, i;
  65
  66     start = bytestream2_get_byte(&c->stream);
  67     size  = (bytestream2_get_byte(&c->stream) - 1) & 0xFF;
  68     if (start + size > 255) {
  69         av_log(c->avctx, AV_LOG_ERROR, "Palette change runs beyond entry 256\n");
  70         return;
  71     }
  72     if (size*3+2 > data_size) {
  73         av_log(c->avctx, AV_LOG_ERROR, "Palette data runs beyond chunk size\n");
  74         return;
  75     }
  76     for (i = start; i <= start + size; i++)
  77         c->pal[i] = bytestream2_get_be24(&c->stream);
  78 }
  79
  80 static inline int check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end)
  81 {
  82     return buf >= start && buf < end;
  83 }
  84
  85 static inline int check_line(uint8_t *buf, uint8_t *start, uint8_t *end)
  86 {
  87     return buf >= start && (buf + 4) <= end;
  88 }
  89
  90 static int vb_decode_framedata(VBDecContext *c, int offset)
  91 {
  92     GetByteContext g;
  93     uint8_t *prev, *cur;
  94     int blk, blocks, t, blk2;
  95     int blocktypes = 0;
  96     int x, y, a, b;
  97     int pattype, pattern;
  98     const int width = c->avctx->width;
  99     uint8_t *pstart = c->prev_frame;
 100     uint8_t *pend   = c->prev_frame + width*c->avctx->height;
 101
 102     g = c->stream;
 103
 104     prev = c->prev_frame + offset;
 105     cur  = c->frame;
 106
 107     blocks = (c->avctx->width >> 2) * (c->avctx->height >> 2);
 108     blk2   = 0;
 109     for (blk = 0; blk < blocks; blk++) {
 110         if (!(blk & 3)) {
 111             blocktypes = bytestream2_get_byte(&g);
 112         }
 113         switch (blocktypes & 0xC0) {
 114         case 0x00: //skip
 115             for (y = 0; y < 4; y++)
 116                 if (check_line(prev + y*width, pstart, pend))
 117                     memcpy(cur + y*width, prev + y*width, 4);
 118                 else
 119                     memset(cur + y*width, 0, 4);
 120             break;
 121         case 0x40:
 122             t = bytestream2_get_byte(&g);
 123             if (!t) { //raw block
 124                 if (bytestream2_get_bytes_left(&g) < 16) {
 125                     av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n");
 126                     return AVERROR_INVALIDDATA;
 127                 }
 128                 for (y = 0; y < 4; y++)
 129                     bytestream2_get_buffer(&g, cur + y * width, 4);
 130             } else { // motion compensation
 131                 x = ((t & 0xF)^8) - 8;
 132                 y = ((t >> 4) ^8) - 8;
 133                 t = x + y*width;
 134                 for (y = 0; y < 4; y++)
 135                     if (check_line(prev + t + y*width, pstart, pend))
 136                         memcpy(cur + y*width, prev + t + y*width, 4);
 137                     else
 138                         memset(cur + y*width, 0, 4);
 139             }
 140             break;
 141         case 0x80: // fill
 142             t = bytestream2_get_byte(&g);
 143             for (y = 0; y < 4; y++)
 144                 memset(cur + y*width, t, 4);
 145             break;
 146         case 0xC0: // pattern fill
 147             t       = bytestream2_get_byte(&g);
 148             pattype = t >> 6;
 149             pattern = vb_patterns[t & 0x3F];
 150             switch (pattype) {
 151             case 0:
 152                 a = bytestream2_get_byte(&g);
 153                 b = bytestream2_get_byte(&g);
 154                 for (y = 0; y < 4; y++)
 155                     for (x = 0; x < 4; x++, pattern >>= 1)
 156                         cur[x + y*width] = (pattern & 1) ? b : a;
 157                 break;
 158             case 1:
 159                 pattern = ~pattern;
 160             case 2:
 161                 a = bytestream2_get_byte(&g);
 162                 for (y = 0; y < 4; y++)
 163                     for (x = 0; x < 4; x++, pattern >>= 1)
 164                         if (pattern & 1 && check_pixel(prev + x + y*width, pstart, pend))
 165                             cur[x + y*width] = prev[x + y*width];
 166                         else
 167                             cur[x + y*width] = a;
 168                 break;
 169             case 3:
 170                 av_log(c->avctx, AV_LOG_ERROR, "Invalid opcode seen @%d\n", blk);
 171                 return AVERROR_INVALIDDATA;
 172             }
 173             break;
 174         }
 175         blocktypes <<= 2;
 176         cur  += 4;
 177         prev += 4;
 178         blk2++;
 179         if (blk2 == (width >> 2)) {
 180             blk2  = 0;
 181             cur  += width * 3;
 182             prev += width * 3;
 183         }
 184     }
 185     return 0;
 186 }
 187
 188 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
 189                         AVPacket *avpkt)
 190 {
 191     VBDecContext * const c = avctx->priv_data;
 192     uint8_t *outptr, *srcptr;
 193     int i, j, ret;
 194     int flags;
 195     uint32_t size;
 196     int offset = 0;
 197
 198     bytestream2_init(&c->stream, avpkt->data, avpkt->size);
 199
 200     if (c->pic.data[0])
 201         avctx->release_buffer(avctx, &c->pic);
 202     c->pic.reference = 1;
 203     if ((ret = ff_get_buffer(avctx, &c->pic)) < 0) {
 204         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 205         return ret;
 206     }
 207
 208     flags = bytestream2_get_le16(&c->stream);
 209
 210     if (flags & VB_HAS_GMC) {
 211         i = (int16_t)bytestream2_get_le16(&c->stream);
 212         j = (int16_t)bytestream2_get_le16(&c->stream);
 213         offset = i + j * avctx->width;
 214     }
 215     if (flags & VB_HAS_VIDEO) {
 216         size = bytestream2_get_le32(&c->stream);
 217         vb_decode_framedata(c, offset);
 218         bytestream2_skip(&c->stream, size - 4);
 219     }
 220     if (flags & VB_HAS_PALETTE) {
 221         size = bytestream2_get_le32(&c->stream);
 222         vb_decode_palette(c, size);
 223     }
 224
 225     memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE);
 226     c->pic.palette_has_changed = flags & VB_HAS_PALETTE;
 227
 228     outptr = c->pic.data[0];
 229     srcptr = c->frame;
 230
 231     for (i = 0; i < avctx->height; i++) {
 232         memcpy(outptr, srcptr, avctx->width);
 233         srcptr += avctx->width;
 234         outptr += c->pic.linesize[0];
 235     }
 236
 237     FFSWAP(uint8_t*, c->frame, c->prev_frame);
 238
 239     *got_frame = 1;
 240     *(AVFrame*)data = c->pic;
 241
 242     /* always report that the buffer was completely consumed */
 243     return avpkt->size;
 244 }
 245
 246 static av_cold int decode_init(AVCodecContext *avctx)
 247 {
 248     VBDecContext * const c = avctx->priv_data;
 249
 250     c->avctx       = avctx;
 251     avctx->pix_fmt = AV_PIX_FMT_PAL8;
 252
 253     c->frame      = av_mallocz(avctx->width * avctx->height);
 254     c->prev_frame = av_mallocz(avctx->width * avctx->height);
 255
 256     return 0;
 257 }
 258
 259 static av_cold int decode_end(AVCodecContext *avctx)
 260 {
 261     VBDecContext *c = avctx->priv_data;
 262
 263     av_freep(&c->frame);
 264     av_freep(&c->prev_frame);
 265     if(c->pic.data[0])
 266         avctx->release_buffer(avctx, &c->pic);
 267
 268     return 0;
 269 }
 270
 271 AVCodec ff_vb_decoder = {
 272     .name           = "vb",
 273     .type           = AVMEDIA_TYPE_VIDEO,
 274     .id             = AV_CODEC_ID_VB,
 275     .priv_data_size = sizeof(VBDecContext),
 276     .init           = decode_init,
 277     .close          = decode_end,
 278     .decode         = decode_frame,
 279     .long_name      = NULL_IF_CONFIG_SMALL("Beam Software VB"),
 280     .capabilities   = CODEC_CAP_DR1,
 281 };