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 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 GetByteContext 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 = bytestream2_get_byte(&c->stream); 66 size = (bytestream2_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] = bytestream2_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, int offset) 90{ 91 GetByteContext g; 92 uint8_t *prev, *cur; 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 g = c->stream; 102 103 prev = c->prev_frame + offset; 104 cur = c->frame; 105 106 blocks = (c->avctx->width >> 2) * (c->avctx->height >> 2); 107 blk2 = 0; 108 for(blk = 0; blk < blocks; blk++){ 109 if(!(blk & 3)) { 110 blocktypes = bytestream2_get_byte(&g); 111 } 112 switch(blocktypes & 0xC0){ 113 case 0x00: //skip 114 for(y = 0; y < 4; y++) 115 if(check_line(prev + y*width, pstart, pend)) 116 memcpy(cur + y*width, prev + y*width, 4); 117 else 118 memset(cur + y*width, 0, 4); 119 break; 120 case 0x40: 121 t = bytestream2_get_byte(&g); 122 if(!t){ //raw block 123 if (bytestream2_get_bytes_left(&g) < 16) { 124 av_log(c->avctx, AV_LOG_ERROR, "Insufficient data\n"); 125 return -1; 126 } 127 for(y = 0; y < 4; y++) 128 bytestream2_get_buffer(&g, cur + y * width, 4); 129 }else{ // motion compensation 130 x = ((t & 0xF)^8) - 8; 131 y = ((t >> 4) ^8) - 8; 132 t = x + y*width; 133 for(y = 0; y < 4; y++) 134 if(check_line(prev + t + y*width, pstart, pend)) 135 memcpy(cur + y*width, prev + t + y*width, 4); 136 else 137 memset(cur + y*width, 0, 4); 138 } 139 break; 140 case 0x80: // fill 141 t = bytestream2_get_byte(&g); 142 for(y = 0; y < 4; y++) 143 memset(cur + y*width, t, 4); 144 break; 145 case 0xC0: // pattern fill 146 t = bytestream2_get_byte(&g); 147 pattype = t >> 6; 148 pattern = vb_patterns[t & 0x3F]; 149 switch(pattype){ 150 case 0: 151 a = bytestream2_get_byte(&g); 152 b = bytestream2_get_byte(&g); 153 for(y = 0; y < 4; y++) 154 for(x = 0; x < 4; x++, pattern >>= 1) 155 cur[x + y*width] = (pattern & 1) ? b : a; 156 break; 157 case 1: 158 pattern = ~pattern; 159 case 2: 160 a = bytestream2_get_byte(&g); 161 for(y = 0; y < 4; y++) 162 for(x = 0; x < 4; x++, pattern >>= 1) 163 if(pattern & 1 && check_pixel(prev + x + y*width, pstart, pend)) 164 cur[x + y*width] = prev[x + y*width]; 165 else 166 cur[x + y*width] = a; 167 break; 168 case 3: 169 av_log(c->avctx, AV_LOG_ERROR, "Invalid opcode seen @%d\n",blk); 170 return -1; 171 } 172 break; 173 } 174 blocktypes <<= 2; 175 cur += 4; 176 prev += 4; 177 blk2++; 178 if(blk2 == (width >> 2)){ 179 blk2 = 0; 180 cur += width * 3; 181 prev += width * 3; 182 } 183 } 184 return 0; 185} 186 187static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) 188{ 189 VBDecContext * const c = avctx->priv_data; 190 uint8_t *outptr, *srcptr; 191 int i, j; 192 int flags; 193 uint32_t size; 194 int offset = 0; 195 196 bytestream2_init(&c->stream, avpkt->data, avpkt->size); 197 198 if(c->pic.data[0]) 199 avctx->release_buffer(avctx, &c->pic); 200 c->pic.reference = 1; 201 if(avctx->get_buffer(avctx, &c->pic) < 0){ 202 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 203 return -1; 204 } 205 206 flags = bytestream2_get_le16(&c->stream); 207 208 if(flags & VB_HAS_GMC){ 209 i = (int16_t)bytestream2_get_le16(&c->stream); 210 j = (int16_t)bytestream2_get_le16(&c->stream); 211 offset = i + j * avctx->width; 212 } 213 if(flags & VB_HAS_VIDEO){ 214 size = bytestream2_get_le32(&c->stream); 215 vb_decode_framedata(c, offset); 216 bytestream2_skip(&c->stream, size - 4); 217 } 218 if(flags & VB_HAS_PALETTE){ 219 size = bytestream2_get_le32(&c->stream); 220 vb_decode_palette(c, size); 221 } 222 223 memcpy(c->pic.data[1], c->pal, AVPALETTE_SIZE); 224 c->pic.palette_has_changed = flags & VB_HAS_PALETTE; 225 226 outptr = c->pic.data[0]; 227 srcptr = c->frame; 228 229 for(i = 0; i < avctx->height; i++){ 230 memcpy(outptr, srcptr, avctx->width); 231 srcptr += avctx->width; 232 outptr += c->pic.linesize[0]; 233 } 234 235 FFSWAP(uint8_t*, c->frame, c->prev_frame); 236 237 *data_size = sizeof(AVFrame); 238 *(AVFrame*)data = c->pic; 239 240 /* always report that the buffer was completely consumed */ 241 return avpkt->size; 242} 243 244static av_cold int decode_init(AVCodecContext *avctx) 245{ 246 VBDecContext * const c = avctx->priv_data; 247 248 c->avctx = avctx; 249 avctx->pix_fmt = PIX_FMT_PAL8; 250 251 c->frame = av_mallocz(avctx->width * avctx->height); 252 c->prev_frame = av_mallocz(avctx->width * avctx->height); 253 254 return 0; 255} 256 257static av_cold int decode_end(AVCodecContext *avctx) 258{ 259 VBDecContext *c = avctx->priv_data; 260 261 av_freep(&c->frame); 262 av_freep(&c->prev_frame); 263 if(c->pic.data[0]) 264 avctx->release_buffer(avctx, &c->pic); 265 266 return 0; 267} 268 269AVCodec ff_vb_decoder = { 270 .name = "vb", 271 .type = AVMEDIA_TYPE_VIDEO, 272 .id = CODEC_ID_VB, 273 .priv_data_size = sizeof(VBDecContext), 274 .init = decode_init, 275 .close = decode_end, 276 .decode = decode_frame, 277 .long_name = NULL_IF_CONFIG_SMALL("Beam Software VB"), 278}; 279 280