1/* 2 * Beam Software VB decoder 3 * Copyright (c) 2007 Konstantin Shishkov 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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 33enum VBFlags{ 34 VB_HAS_GMC = 0x01, 35 VB_HAS_AUDIO = 0x04, 36 VB_HAS_VIDEO = 0x08, 37 VB_HAS_PALETTE = 0x10, 38 VB_HAS_LENGTH = 0x20 39}; 40 41typedef struct VBDecContext { 42 AVCodecContext *avctx; 43 AVFrame pic; 44 45 uint8_t *frame, *prev_frame; 46 uint32_t pal[AVPALETTE_COUNT]; 47 const uint8_t *stream; 48} VBDecContext; 49 50static const uint16_t vb_patterns[64] = { 51 0x0660, 0xFF00, 0xCCCC, 0xF000, 0x8888, 0x000F, 0x1111, 0xFEC8, 52 0x8CEF, 0x137F, 0xF731, 0xC800, 0x008C, 0x0013, 0x3100, 0xCC00, 53 0x00CC, 0x0033, 0x3300, 0x0FF0, 0x6666, 0x00F0, 0x0F00, 0x2222, 54 0x4444, 0xF600, 0x8CC8, 0x006F, 0x1331, 0x318C, 0xC813, 0x33CC, 55 0x6600, 0x0CC0, 0x0066, 0x0330, 0xF900, 0xC88C, 0x009F, 0x3113, 56 0x6000, 0x0880, 0x0006, 0x0110, 0xCC88, 0xFC00, 0x00CF, 0x88CC, 57 0x003F, 0x1133, 0x3311, 0xF300, 0x6FF6, 0x0603, 0x08C6, 0x8C63, 58 0xC631, 0x6310, 0xC060, 0x0136, 0x136C, 0x36C8, 0x6C80, 0x324C 59}; 60 61static void vb_decode_palette(VBDecContext *c, int data_size) 62{ 63 int start, size, i; 64 65 start = bytestream_get_byte(&c->stream); 66 size = (bytestream_get_byte(&c->stream) - 1) & 0xFF; 67 if(start + size > 255){ 68 av_log(c->avctx, AV_LOG_ERROR, "Palette change runs beyond entry 256\n"); 69 return; 70 } 71 if(size*3+2 > data_size){ 72 av_log(c->avctx, AV_LOG_ERROR, "Palette data runs beyond chunk size\n"); 73 return; 74 } 75 for(i = start; i <= start + size; i++) 76 c->pal[i] = bytestream_get_be24(&c->stream); 77} 78 79static inline int check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end) 80{ 81 return buf >= start && buf < end; 82} 83 84static inline int check_line(uint8_t *buf, uint8_t *start, uint8_t *end) 85{ 86 return buf >= start && (buf + 4) <= end; 87} 88 89static int vb_decode_framedata(VBDecContext *c, const uint8_t *buf, int data_size, int offset) 90{ 91 uint8_t *prev, *cur; 92 const uint8_t* data_end = buf + data_size; 93 int blk, blocks, t, blk2; 94 int blocktypes = 0; 95 int x, y, a, b; 96 int pattype, pattern; 97 const int width = c->avctx->width; 98 uint8_t *pstart = c->prev_frame; 99 uint8_t *pend = c->prev_frame + width*c->avctx->height; 100 101 prev = c->prev_frame + offset; 102 cur = c->frame; 103 104 blocks = (c->avctx->width >> 2) * (c->avctx->height >> 2); 105 blk2 = 0; 106 for(blk = 0; blk < blocks; blk++){ 107 if(!(blk & 3)) { 108 if(buf >= data_end){ 109 av_log(c->avctx, AV_LOG_ERROR, "Data pointer out of bounds\n"); 110 return -1; 111 } 112 blocktypes = bytestream_get_byte(&buf); 113 } 114 switch(blocktypes & 0xC0){ 115 case 0x00: //skip 116 for(y = 0; y < 4; y++) 117 if(check_line(prev + y*width, pstart, pend)) 118 memcpy(cur + y*width, prev + y*width, 4); 119 else 120 memset(cur + y*width, 0, 4); 121 break; 122 case 0x40: 123 t = bytestream_get_byte(&buf); 124 if(!t){ //raw block 125 if(buf + 16 > data_end){ 126 av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n"); 127 return -1; 128 } 129 for(y = 0; y < 4; y++) 130 memcpy(cur + y*width, buf + y*4, 4); 131 buf += 16; 132 }else{ // motion compensation 133 x = ((t & 0xF)^8) - 8; 134 y = ((t >> 4) ^8) - 8; 135 t = x + y*width; 136 for(y = 0; y < 4; y++) 137 if(check_line(prev + t + y*width, pstart, pend)) 138 memcpy(cur + y*width, prev + t + y*width, 4); 139 else 140 memset(cur + y*width, 0, 4); 141 } 142 break; 143 case 0x80: // fill 144 t = bytestream_get_byte(&buf); 145 for(y = 0; y < 4; y++) 146 memset(cur + y*width, t, 4); 147 break; 148 case 0xC0: // pattern fill 149 if(buf + 2 > data_end){ 150 av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n"); 151 return -1; 152 } 153 t = bytestream_get_byte(&buf); 154 pattype = t >> 6; 155 pattern = vb_patterns[t & 0x3F]; 156 switch(pattype){ 157 case 0: 158 a = bytestream_get_byte(&buf); 159 b = bytestream_get_byte(&buf); 160 for(y = 0; y < 4; y++) 161 for(x = 0; x < 4; x++, pattern >>= 1) 162 cur[x + y*width] = (pattern & 1) ? b : a; 163 break; 164 case 1: 165 pattern = ~pattern; 166 case 2: 167 a = bytestream_get_byte(&buf); 168 for(y = 0; y < 4; y++) 169 for(x = 0; x < 4; x++, pattern >>= 1) 170 if(pattern & 1 && check_pixel(prev + x + y*width, pstart, pend)) 171 cur[x + y*width] = prev[x + y*width]; 172 else 173 cur[x + y*width] = a; 174 break; 175 case 3: 176 av_log(c->avctx, AV_LOG_ERROR, "Invalid opcode seen @%d\n",blk); 177 return -1; 178 } 179 break; 180 } 181 blocktypes <<= 2; 182 cur += 4; 183 prev += 4; 184 blk2++; 185 if(blk2 == (width >> 2)){ 186 blk2 = 0; 187 cur += width * 3; 188 prev += width * 3; 189 } 190 } 191 return 0; 192} 193 194static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) 195{ 196 const uint8_t *buf = avpkt->data; 197 int buf_size = avpkt->size; 198 VBDecContext * const c = avctx->priv_data; 199 uint8_t *outptr, *srcptr; 200 int i, j; 201 int flags; 202 uint32_t size; 203 int rest = buf_size; 204 int offset = 0; 205 206 if(c->pic.data[0]) 207 avctx->release_buffer(avctx, &c->pic); 208 c->pic.reference = 1; 209 if(avctx->get_buffer(avctx, &c->pic) < 0){ 210 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 211 return -1; 212 } 213 214 c->stream = buf; 215 flags = bytestream_get_le16(&c->stream); 216 rest -= 2; 217 218 if(flags & VB_HAS_GMC){ 219 i = (int16_t)bytestream_get_le16(&c->stream); 220 j = (int16_t)bytestream_get_le16(&c->stream); 221 offset = i + j * avctx->width; 222 rest -= 4; 223 } 224 if(flags & VB_HAS_VIDEO){ 225 size = bytestream_get_le32(&c->stream); 226 if(size > rest){ 227 av_log(avctx, AV_LOG_ERROR, "Frame size is too big\n"); 228 return -1; 229 } 230 vb_decode_framedata(c, c->stream, size, offset); 231 c->stream += size - 4; 232 rest -= size; 233 } 234 if(flags & VB_HAS_PALETTE){ 235 size = bytestream_get_le32(&c->stream); 236 if(size > rest){ 237 av_log(avctx, AV_LOG_ERROR, "Palette size is too big\n"); 238 return -1; 239 } 240 vb_decode_palette(c, size); 241 rest -= size; 242 } 243 244 memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE); 245 c->pic.palette_has_changed = flags & VB_HAS_PALETTE; 246 247 outptr = c->pic.data[0]; 248 srcptr = c->frame; 249 250 for(i = 0; i < avctx->height; i++){ 251 memcpy(outptr, srcptr, avctx->width); 252 srcptr += avctx->width; 253 outptr += c->pic.linesize[0]; 254 } 255 256 FFSWAP(uint8_t*, c->frame, c->prev_frame); 257 258 *data_size = sizeof(AVFrame); 259 *(AVFrame*)data = c->pic; 260 261 /* always report that the buffer was completely consumed */ 262 return buf_size; 263} 264 265static av_cold int decode_init(AVCodecContext *avctx) 266{ 267 VBDecContext * const c = avctx->priv_data; 268 269 c->avctx = avctx; 270 avctx->pix_fmt = PIX_FMT_PAL8; 271 272 c->frame = av_mallocz(avctx->width * avctx->height); 273 c->prev_frame = av_mallocz(avctx->width * avctx->height); 274 275 return 0; 276} 277 278static av_cold int decode_end(AVCodecContext *avctx) 279{ 280 VBDecContext *c = avctx->priv_data; 281 282 av_freep(&c->frame); 283 av_freep(&c->prev_frame); 284 if(c->pic.data[0]) 285 avctx->release_buffer(avctx, &c->pic); 286 287 return 0; 288} 289 290AVCodec vb_decoder = { 291 "vb", 292 AVMEDIA_TYPE_VIDEO, 293 CODEC_ID_VB, 294 sizeof(VBDecContext), 295 decode_init, 296 NULL, 297 decode_end, 298 decode_frame, 299 .long_name = NULL_IF_CONFIG_SMALL("Beam Software VB"), 300}; 301 302