| 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 | #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 | |
| 45 | uint8_t *frame, *prev_frame; |
| 46 | uint32_t pal[AVPALETTE_COUNT]; |
| 47 | GetByteContext stream; |
| 48 | } VBDecContext; |
| 49 | |
| 50 | static 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 | |
| 61 | static 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] = 0xFFU << 24 | bytestream2_get_be24(&c->stream); |
| 77 | } |
| 78 | |
| 79 | static inline int check_pixel(uint8_t *buf, uint8_t *start, uint8_t *end) |
| 80 | { |
| 81 | return buf >= start && buf < end; |
| 82 | } |
| 83 | |
| 84 | static inline int check_line(uint8_t *buf, uint8_t *start, uint8_t *end) |
| 85 | { |
| 86 | return buf >= start && (buf + 4) <= end; |
| 87 | } |
| 88 | |
| 89 | static 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 AVERROR_INVALIDDATA; |
| 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 AVERROR_INVALIDDATA; |
| 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 | |
| 187 | static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, |
| 188 | AVPacket *avpkt) |
| 189 | { |
| 190 | VBDecContext * const c = avctx->priv_data; |
| 191 | AVFrame *frame = 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 ((ret = ff_get_buffer(avctx, frame, 0)) < 0) |
| 201 | return ret; |
| 202 | |
| 203 | flags = bytestream2_get_le16(&c->stream); |
| 204 | |
| 205 | if (flags & VB_HAS_GMC) { |
| 206 | i = (int16_t)bytestream2_get_le16(&c->stream); |
| 207 | j = (int16_t)bytestream2_get_le16(&c->stream); |
| 208 | offset = i + j * avctx->width; |
| 209 | } |
| 210 | if (flags & VB_HAS_VIDEO) { |
| 211 | size = bytestream2_get_le32(&c->stream); |
| 212 | if(size > bytestream2_get_bytes_left(&c->stream)+4 || size<4){ |
| 213 | av_log(avctx, AV_LOG_ERROR, "Frame size invalid\n"); |
| 214 | return -1; |
| 215 | } |
| 216 | vb_decode_framedata(c, offset); |
| 217 | bytestream2_skip(&c->stream, size - 4); |
| 218 | } |
| 219 | if (flags & VB_HAS_PALETTE) { |
| 220 | size = bytestream2_get_le32(&c->stream); |
| 221 | vb_decode_palette(c, size); |
| 222 | } |
| 223 | |
| 224 | memcpy(frame->data[1], c->pal, AVPALETTE_SIZE); |
| 225 | frame->palette_has_changed = flags & VB_HAS_PALETTE; |
| 226 | |
| 227 | outptr = frame->data[0]; |
| 228 | srcptr = c->frame; |
| 229 | |
| 230 | for (i = 0; i < avctx->height; i++) { |
| 231 | memcpy(outptr, srcptr, avctx->width); |
| 232 | srcptr += avctx->width; |
| 233 | outptr += frame->linesize[0]; |
| 234 | } |
| 235 | |
| 236 | FFSWAP(uint8_t*, c->frame, c->prev_frame); |
| 237 | |
| 238 | *got_frame = 1; |
| 239 | |
| 240 | /* always report that the buffer was completely consumed */ |
| 241 | return avpkt->size; |
| 242 | } |
| 243 | |
| 244 | static av_cold int decode_init(AVCodecContext *avctx) |
| 245 | { |
| 246 | VBDecContext * const c = avctx->priv_data; |
| 247 | |
| 248 | c->avctx = avctx; |
| 249 | avctx->pix_fmt = AV_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 | |
| 257 | static 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 | |
| 264 | return 0; |
| 265 | } |
| 266 | |
| 267 | AVCodec ff_vb_decoder = { |
| 268 | .name = "vb", |
| 269 | .long_name = NULL_IF_CONFIG_SMALL("Beam Software VB"), |
| 270 | .type = AVMEDIA_TYPE_VIDEO, |
| 271 | .id = AV_CODEC_ID_VB, |
| 272 | .priv_data_size = sizeof(VBDecContext), |
| 273 | .init = decode_init, |
| 274 | .close = decode_end, |
| 275 | .decode = decode_frame, |
| 276 | .capabilities = CODEC_CAP_DR1, |
| 277 | }; |