libavcodec/mxpegdec.c

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