1/* 2 * QPEG codec 3 * Copyright (c) 2004 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 * QPEG codec. 25 */ 26 27#include "avcodec.h" 28 29typedef struct QpegContext{ 30 AVCodecContext *avctx; 31 AVFrame pic; 32 uint8_t *refdata; 33} QpegContext; 34 35static void qpeg_decode_intra(const uint8_t *src, uint8_t *dst, int size, 36 int stride, int width, int height) 37{ 38 int i; 39 int code; 40 int c0, c1; 41 int run, copy; 42 int filled = 0; 43 int rows_to_go; 44 45 rows_to_go = height; 46 height--; 47 dst = dst + height * stride; 48 49 while((size > 0) && (rows_to_go > 0)) { 50 code = *src++; 51 size--; 52 run = copy = 0; 53 if(code == 0xFC) /* end-of-picture code */ 54 break; 55 if(code >= 0xF8) { /* very long run */ 56 c0 = *src++; 57 c1 = *src++; 58 size -= 2; 59 run = ((code & 0x7) << 16) + (c0 << 8) + c1 + 2; 60 } else if (code >= 0xF0) { /* long run */ 61 c0 = *src++; 62 size--; 63 run = ((code & 0xF) << 8) + c0 + 2; 64 } else if (code >= 0xE0) { /* short run */ 65 run = (code & 0x1F) + 2; 66 } else if (code >= 0xC0) { /* very long copy */ 67 c0 = *src++; 68 c1 = *src++; 69 size -= 2; 70 copy = ((code & 0x3F) << 16) + (c0 << 8) + c1 + 1; 71 } else if (code >= 0x80) { /* long copy */ 72 c0 = *src++; 73 size--; 74 copy = ((code & 0x7F) << 8) + c0 + 1; 75 } else { /* short copy */ 76 copy = code + 1; 77 } 78 79 /* perform actual run or copy */ 80 if(run) { 81 int p; 82 83 p = *src++; 84 size--; 85 for(i = 0; i < run; i++) { 86 dst[filled++] = p; 87 if (filled >= width) { 88 filled = 0; 89 dst -= stride; 90 rows_to_go--; 91 if(rows_to_go <= 0) 92 break; 93 } 94 } 95 } else { 96 size -= copy; 97 for(i = 0; i < copy; i++) { 98 dst[filled++] = *src++; 99 if (filled >= width) { 100 filled = 0; 101 dst -= stride; 102 rows_to_go--; 103 if(rows_to_go <= 0) 104 break; 105 } 106 } 107 } 108 } 109} 110 111static const int qpeg_table_h[16] = 112 { 0x00, 0x20, 0x20, 0x20, 0x18, 0x10, 0x10, 0x20, 0x10, 0x08, 0x18, 0x08, 0x08, 0x18, 0x10, 0x04}; 113static const int qpeg_table_w[16] = 114 { 0x00, 0x20, 0x18, 0x08, 0x18, 0x10, 0x20, 0x10, 0x08, 0x10, 0x20, 0x20, 0x08, 0x10, 0x18, 0x04}; 115 116/* Decodes delta frames */ 117static void qpeg_decode_inter(const uint8_t *src, uint8_t *dst, int size, 118 int stride, int width, int height, 119 int delta, const uint8_t *ctable, uint8_t *refdata) 120{ 121 int i, j; 122 int code; 123 int filled = 0; 124 int orig_height; 125 126 /* copy prev frame */ 127 for(i = 0; i < height; i++) 128 memcpy(refdata + (i * width), dst + (i * stride), width); 129 130 orig_height = height; 131 height--; 132 dst = dst + height * stride; 133 134 while((size > 0) && (height >= 0)) { 135 code = *src++; 136 size--; 137 138 if(delta) { 139 /* motion compensation */ 140 while((code & 0xF0) == 0xF0) { 141 if(delta == 1) { 142 int me_idx; 143 int me_w, me_h, me_x, me_y; 144 uint8_t *me_plane; 145 int corr, val; 146 147 /* get block size by index */ 148 me_idx = code & 0xF; 149 me_w = qpeg_table_w[me_idx]; 150 me_h = qpeg_table_h[me_idx]; 151 152 /* extract motion vector */ 153 corr = *src++; 154 size--; 155 156 val = corr >> 4; 157 if(val > 7) 158 val -= 16; 159 me_x = val; 160 161 val = corr & 0xF; 162 if(val > 7) 163 val -= 16; 164 me_y = val; 165 166 /* check motion vector */ 167 if ((me_x + filled < 0) || (me_x + me_w + filled > width) || 168 (height - me_y - me_h < 0) || (height - me_y > orig_height) || 169 (filled + me_w > width) || (height - me_h < 0)) 170 av_log(NULL, AV_LOG_ERROR, "Bogus motion vector (%i,%i), block size %ix%i at %i,%i\n", 171 me_x, me_y, me_w, me_h, filled, height); 172 else { 173 /* do motion compensation */ 174 me_plane = refdata + (filled + me_x) + (height - me_y) * width; 175 for(j = 0; j < me_h; j++) { 176 for(i = 0; i < me_w; i++) 177 dst[filled + i - (j * stride)] = me_plane[i - (j * width)]; 178 } 179 } 180 } 181 code = *src++; 182 size--; 183 } 184 } 185 186 if(code == 0xE0) /* end-of-picture code */ 187 break; 188 if(code > 0xE0) { /* run code: 0xE1..0xFF */ 189 int p; 190 191 code &= 0x1F; 192 p = *src++; 193 size--; 194 for(i = 0; i <= code; i++) { 195 dst[filled++] = p; 196 if(filled >= width) { 197 filled = 0; 198 dst -= stride; 199 height--; 200 } 201 } 202 } else if(code >= 0xC0) { /* copy code: 0xC0..0xDF */ 203 code &= 0x1F; 204 205 for(i = 0; i <= code; i++) { 206 dst[filled++] = *src++; 207 if(filled >= width) { 208 filled = 0; 209 dst -= stride; 210 height--; 211 } 212 } 213 size -= code + 1; 214 } else if(code >= 0x80) { /* skip code: 0x80..0xBF */ 215 int skip; 216 217 code &= 0x3F; 218 /* codes 0x80 and 0x81 are actually escape codes, 219 skip value minus constant is in the next byte */ 220 if(!code) 221 skip = (*src++) + 64; 222 else if(code == 1) 223 skip = (*src++) + 320; 224 else 225 skip = code; 226 filled += skip; 227 while( filled >= width) { 228 filled -= width; 229 dst -= stride; 230 height--; 231 if(height < 0) 232 break; 233 } 234 } else { 235 /* zero code treated as one-pixel skip */ 236 if(code) 237 dst[filled++] = ctable[code & 0x7F]; 238 else 239 filled++; 240 if(filled >= width) { 241 filled = 0; 242 dst -= stride; 243 height--; 244 } 245 } 246 } 247} 248 249static int decode_frame(AVCodecContext *avctx, 250 void *data, int *data_size, 251 AVPacket *avpkt) 252{ 253 const uint8_t *buf = avpkt->data; 254 int buf_size = avpkt->size; 255 QpegContext * const a = avctx->priv_data; 256 AVFrame * const p= (AVFrame*)&a->pic; 257 uint8_t* outdata; 258 int delta; 259 260 if(p->data[0]) 261 avctx->release_buffer(avctx, p); 262 263 p->reference= 0; 264 if(avctx->get_buffer(avctx, p) < 0){ 265 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 266 return -1; 267 } 268 outdata = a->pic.data[0]; 269 if(buf[0x85] == 0x10) { 270 qpeg_decode_intra(buf+0x86, outdata, buf_size - 0x86, a->pic.linesize[0], avctx->width, avctx->height); 271 } else { 272 delta = buf[0x85]; 273 qpeg_decode_inter(buf+0x86, outdata, buf_size - 0x86, a->pic.linesize[0], avctx->width, avctx->height, delta, buf + 4, a->refdata); 274 } 275 276 /* make the palette available on the way out */ 277 memcpy(a->pic.data[1], a->avctx->palctrl->palette, AVPALETTE_SIZE); 278 if (a->avctx->palctrl->palette_changed) { 279 a->pic.palette_has_changed = 1; 280 a->avctx->palctrl->palette_changed = 0; 281 } 282 283 *data_size = sizeof(AVFrame); 284 *(AVFrame*)data = a->pic; 285 286 return buf_size; 287} 288 289static av_cold int decode_init(AVCodecContext *avctx){ 290 QpegContext * const a = avctx->priv_data; 291 292 if (!avctx->palctrl) { 293 av_log(avctx, AV_LOG_FATAL, "Missing required palette via palctrl\n"); 294 return -1; 295 } 296 a->avctx = avctx; 297 avctx->pix_fmt= PIX_FMT_PAL8; 298 a->refdata = av_malloc(avctx->width * avctx->height); 299 300 return 0; 301} 302 303static av_cold int decode_end(AVCodecContext *avctx){ 304 QpegContext * const a = avctx->priv_data; 305 AVFrame * const p= (AVFrame*)&a->pic; 306 307 if(p->data[0]) 308 avctx->release_buffer(avctx, p); 309 310 av_free(a->refdata); 311 return 0; 312} 313 314AVCodec qpeg_decoder = { 315 "qpeg", 316 AVMEDIA_TYPE_VIDEO, 317 CODEC_ID_QPEG, 318 sizeof(QpegContext), 319 decode_init, 320 NULL, 321 decode_end, 322 decode_frame, 323 CODEC_CAP_DR1, 324 .long_name = NULL_IF_CONFIG_SMALL("Q-team QPEG"), 325}; 326