1/* 2 * MxPEG decoder 3 * Copyright (c) 2011 Anatoly Nenashev 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/** 24 * @file 25 * MxPEG decoder 26 */ 27 28#include "internal.h" 29#include "mjpeg.h" 30#include "mjpegdec.h" 31 32typedef struct MXpegDecodeContext { 33 MJpegDecodeContext jpg; 34 AVFrame *picture[2]; /* pictures array */ 35 int picture_index; /* index of current picture */ 36 int got_sof_data; /* true if SOF data successfully parsed */ 37 int got_mxm_bitmask; /* true if MXM bitmask available */ 38 uint8_t *mxm_bitmask; /* bitmask buffer */ 39 unsigned bitmask_size; /* size of bitmask */ 40 int has_complete_frame; /* true if has complete frame */ 41 uint8_t *completion_bitmask; /* completion bitmask of macroblocks */ 42 unsigned mb_width, mb_height; /* size of picture in MB's from MXM header */ 43} MXpegDecodeContext; 44 45static av_cold int mxpeg_decode_end(AVCodecContext *avctx) 46{ 47 MXpegDecodeContext *s = avctx->priv_data; 48 MJpegDecodeContext *jpg = &s->jpg; 49 int i; 50 51 jpg->picture_ptr = NULL; 52 ff_mjpeg_decode_end(avctx); 53 54 for (i = 0; i < 2; ++i) 55 av_frame_free(&s->picture[i]); 56 57 s->bitmask_size = 0; 58 av_freep(&s->mxm_bitmask); 59 av_freep(&s->completion_bitmask); 60 61 return 0; 62} 63 64static av_cold int mxpeg_decode_init(AVCodecContext *avctx) 65{ 66 MXpegDecodeContext *s = avctx->priv_data; 67 68 s->picture[0] = av_frame_alloc(); 69 s->picture[1] = av_frame_alloc(); 70 if (!s->picture[0] || !s->picture[1]) { 71 mxpeg_decode_end(avctx); 72 return AVERROR(ENOMEM); 73 } 74 75 s->jpg.picture_ptr = s->picture[0]; 76 return ff_mjpeg_decode_init(avctx); 77} 78 79static int mxpeg_decode_app(MXpegDecodeContext *s, 80 const uint8_t *buf_ptr, int buf_size) 81{ 82 int len; 83 if (buf_size < 2) 84 return 0; 85 len = AV_RB16(buf_ptr); 86 skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size)); 87 88 return 0; 89} 90 91static int mxpeg_decode_mxm(MXpegDecodeContext *s, 92 const uint8_t *buf_ptr, int buf_size) 93{ 94 unsigned bitmask_size, mb_count; 95 int i; 96 97 s->mb_width = AV_RL16(buf_ptr+4); 98 s->mb_height = AV_RL16(buf_ptr+6); 99 mb_count = s->mb_width * s->mb_height; 100 101 bitmask_size = (mb_count + 7) >> 3; 102 if (bitmask_size > buf_size - 12) { 103 av_log(s->jpg.avctx, AV_LOG_ERROR, 104 "MXM bitmask is not complete\n"); 105 return AVERROR(EINVAL); 106 } 107 108 if (s->bitmask_size != bitmask_size) { 109 s->bitmask_size = 0; 110 av_freep(&s->mxm_bitmask); 111 s->mxm_bitmask = av_malloc(bitmask_size); 112 if (!s->mxm_bitmask) { 113 av_log(s->jpg.avctx, AV_LOG_ERROR, 114 "MXM bitmask memory allocation error\n"); 115 return AVERROR(ENOMEM); 116 } 117 118 av_freep(&s->completion_bitmask); 119 s->completion_bitmask = av_mallocz(bitmask_size); 120 if (!s->completion_bitmask) { 121 av_log(s->jpg.avctx, AV_LOG_ERROR, 122 "Completion bitmask memory allocation error\n"); 123 return AVERROR(ENOMEM); 124 } 125 126 s->bitmask_size = bitmask_size; 127 } 128 129 memcpy(s->mxm_bitmask, buf_ptr + 12, bitmask_size); 130 s->got_mxm_bitmask = 1; 131 132 if (!s->has_complete_frame) { 133 uint8_t completion_check = 0xFF; 134 for (i = 0; i < bitmask_size; ++i) { 135 s->completion_bitmask[i] |= s->mxm_bitmask[i]; 136 completion_check &= s->completion_bitmask[i]; 137 } 138 s->has_complete_frame = !(completion_check ^ 0xFF); 139 } 140 141 return 0; 142} 143 144static int mxpeg_decode_com(MXpegDecodeContext *s, 145 const uint8_t *buf_ptr, int buf_size) 146{ 147 int len, ret = 0; 148 if (buf_size < 2) 149 return 0; 150 len = AV_RB16(buf_ptr); 151 if (len > 14 && len <= buf_size && !strncmp(buf_ptr + 2, "MXM", 3)) { 152 ret = mxpeg_decode_mxm(s, buf_ptr + 2, len - 2); 153 } 154 skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size)); 155 156 return ret; 157} 158 159static int mxpeg_check_dimensions(MXpegDecodeContext *s, MJpegDecodeContext *jpg, 160 AVFrame *reference_ptr) 161{ 162 if ((jpg->width + 0x0F)>>4 != s->mb_width || 163 (jpg->height + 0x0F)>>4 != s->mb_height) { 164 av_log(jpg->avctx, AV_LOG_ERROR, 165 "Picture dimensions stored in SOF and MXM mismatch\n"); 166 return AVERROR(EINVAL); 167 } 168 169 if (reference_ptr->data[0]) { 170 int i; 171 for (i = 0; i < MAX_COMPONENTS; ++i) { 172 if ( (!reference_ptr->data[i] ^ !jpg->picture_ptr->data[i]) || 173 reference_ptr->linesize[i] != jpg->picture_ptr->linesize[i]) { 174 av_log(jpg->avctx, AV_LOG_ERROR, 175 "Dimensions of current and reference picture mismatch\n"); 176 return AVERROR(EINVAL); 177 } 178 } 179 } 180 181 return 0; 182} 183 184static int mxpeg_decode_frame(AVCodecContext *avctx, 185 void *data, int *got_frame, 186 AVPacket *avpkt) 187{ 188 const uint8_t *buf = avpkt->data; 189 int buf_size = avpkt->size; 190 MXpegDecodeContext *s = avctx->priv_data; 191 MJpegDecodeContext *jpg = &s->jpg; 192 const uint8_t *buf_end, *buf_ptr; 193 const uint8_t *unescaped_buf_ptr; 194 int unescaped_buf_size; 195 int start_code; 196 int ret; 197 198 buf_ptr = buf; 199 buf_end = buf + buf_size; 200 jpg->got_picture = 0; 201 s->got_mxm_bitmask = 0; 202 while (buf_ptr < buf_end) { 203 start_code = ff_mjpeg_find_marker(jpg, &buf_ptr, buf_end, 204 &unescaped_buf_ptr, &unescaped_buf_size); 205 if (start_code < 0) 206 goto the_end; 207 { 208 init_get_bits(&jpg->gb, unescaped_buf_ptr, unescaped_buf_size*8); 209 210 if (start_code >= APP0 && start_code <= APP15) { 211 mxpeg_decode_app(s, unescaped_buf_ptr, unescaped_buf_size); 212 } 213 214 switch (start_code) { 215 case SOI: 216 if (jpg->got_picture) //emulating EOI 217 goto the_end; 218 break; 219 case EOI: 220 goto the_end; 221 case DQT: 222 ret = ff_mjpeg_decode_dqt(jpg); 223 if (ret < 0) { 224 av_log(avctx, AV_LOG_ERROR, 225 "quantization table decode error\n"); 226 return ret; 227 } 228 break; 229 case DHT: 230 ret = ff_mjpeg_decode_dht(jpg); 231 if (ret < 0) { 232 av_log(avctx, AV_LOG_ERROR, 233 "huffman table decode error\n"); 234 return ret; 235 } 236 break; 237 case COM: 238 ret = mxpeg_decode_com(s, unescaped_buf_ptr, 239 unescaped_buf_size); 240 if (ret < 0) 241 return ret; 242 break; 243 case SOF0: 244 s->got_sof_data = 0; 245 ret = ff_mjpeg_decode_sof(jpg); 246 if (ret < 0) { 247 av_log(avctx, AV_LOG_ERROR, 248 "SOF data decode error\n"); 249 return ret; 250 } 251 if (jpg->interlaced) { 252 av_log(avctx, AV_LOG_ERROR, 253 "Interlaced mode not supported in MxPEG\n"); 254 return AVERROR(EINVAL); 255 } 256 s->got_sof_data = 1; 257 break; 258 case SOS: 259 if (!s->got_sof_data) { 260 av_log(avctx, AV_LOG_WARNING, 261 "Can not process SOS without SOF data, skipping\n"); 262 break; 263 } 264 if (!jpg->got_picture) { 265 if (jpg->first_picture) { 266 av_log(avctx, AV_LOG_WARNING, 267 "First picture has no SOF, skipping\n"); 268 break; 269 } 270 if (!s->got_mxm_bitmask){ 271 av_log(avctx, AV_LOG_WARNING, 272 "Non-key frame has no MXM, skipping\n"); 273 break; 274 } 275 /* use stored SOF data to allocate current picture */ 276 av_frame_unref(jpg->picture_ptr); 277 if ((ret = ff_get_buffer(avctx, jpg->picture_ptr, 278 AV_GET_BUFFER_FLAG_REF)) < 0) 279 return ret; 280 jpg->picture_ptr->pict_type = AV_PICTURE_TYPE_P; 281 jpg->picture_ptr->key_frame = 0; 282 jpg->got_picture = 1; 283 } else { 284 jpg->picture_ptr->pict_type = AV_PICTURE_TYPE_I; 285 jpg->picture_ptr->key_frame = 1; 286 } 287 288 if (s->got_mxm_bitmask) { 289 AVFrame *reference_ptr = s->picture[s->picture_index ^ 1]; 290 if (mxpeg_check_dimensions(s, jpg, reference_ptr) < 0) 291 break; 292 293 /* allocate dummy reference picture if needed */ 294 if (!reference_ptr->data[0] && 295 (ret = ff_get_buffer(avctx, reference_ptr, 296 AV_GET_BUFFER_FLAG_REF)) < 0) 297 return ret; 298 299 ret = ff_mjpeg_decode_sos(jpg, s->mxm_bitmask, s->bitmask_size, reference_ptr); 300 if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE)) 301 return ret; 302 } else { 303 ret = ff_mjpeg_decode_sos(jpg, NULL, 0, NULL); 304 if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE)) 305 return ret; 306 } 307 308 break; 309 } 310 311 buf_ptr += (get_bits_count(&jpg->gb)+7) >> 3; 312 } 313 314 } 315 316the_end: 317 if (jpg->got_picture) { 318 int ret = av_frame_ref(data, jpg->picture_ptr); 319 if (ret < 0) 320 return ret; 321 *got_frame = 1; 322 323 s->picture_index ^= 1; 324 jpg->picture_ptr = s->picture[s->picture_index]; 325 326 if (!s->has_complete_frame) { 327 if (!s->got_mxm_bitmask) 328 s->has_complete_frame = 1; 329 else 330 *got_frame = 0; 331 } 332 } 333 334 return buf_ptr - buf; 335} 336 337AVCodec ff_mxpeg_decoder = { 338 .name = "mxpeg", 339 .long_name = NULL_IF_CONFIG_SMALL("Mobotix MxPEG video"), 340 .type = AVMEDIA_TYPE_VIDEO, 341 .id = AV_CODEC_ID_MXPEG, 342 .priv_data_size = sizeof(MXpegDecodeContext), 343 .init = mxpeg_decode_init, 344 .close = mxpeg_decode_end, 345 .decode = mxpeg_decode_frame, 346 .capabilities = CODEC_CAP_DR1, 347 .max_lowres = 3, 348}; 349