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