Libav 0.7.1
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00001 /* 00002 * MxPEG decoder 00003 * Copyright (c) 2011 Anatoly Nenashev 00004 * 00005 * This file is part of Libav. 00006 * 00007 * Libav is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * Libav is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with Libav; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00022 00028 #include "mjpeg.h" 00029 #include "mjpegdec.h" 00030 00031 typedef struct MXpegDecodeContext { 00032 MJpegDecodeContext jpg; 00033 AVFrame picture[2]; /* pictures array */ 00034 int picture_index; /* index of current picture */ 00035 int got_sof_data; /* true if SOF data successfully parsed */ 00036 int got_mxm_bitmask; /* true if MXM bitmask available */ 00037 uint8_t *mxm_bitmask; /* bitmask buffer */ 00038 unsigned bitmask_size; /* size of bitmask */ 00039 int has_complete_frame; /* true if has complete frame */ 00040 uint8_t *completion_bitmask; /* completion bitmask of macroblocks */ 00041 unsigned mb_width, mb_height; /* size of picture in MB's from MXM header */ 00042 } MXpegDecodeContext; 00043 00044 static av_cold int mxpeg_decode_init(AVCodecContext *avctx) 00045 { 00046 MXpegDecodeContext *s = avctx->priv_data; 00047 00048 s->picture[0].reference = s->picture[1].reference = 3; 00049 s->jpg.picture_ptr = &s->picture[0]; 00050 ff_mjpeg_decode_init(avctx); 00051 00052 return 0; 00053 } 00054 00055 static int mxpeg_decode_app(MXpegDecodeContext *s, 00056 const uint8_t *buf_ptr, int buf_size) 00057 { 00058 int len; 00059 if (buf_size < 2) 00060 return 0; 00061 len = AV_RB16(buf_ptr); 00062 skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size)); 00063 00064 return 0; 00065 } 00066 00067 static int mxpeg_decode_mxm(MXpegDecodeContext *s, 00068 const uint8_t *buf_ptr, int buf_size) 00069 { 00070 unsigned bitmask_size, mb_count; 00071 int i; 00072 00073 s->mb_width = AV_RL16(buf_ptr+4); 00074 s->mb_height = AV_RL16(buf_ptr+6); 00075 mb_count = s->mb_width * s->mb_height; 00076 00077 bitmask_size = (mb_count + 7) >> 3; 00078 if (bitmask_size > buf_size - 12) { 00079 av_log(s->jpg.avctx, AV_LOG_ERROR, 00080 "MXM bitmask is not complete\n"); 00081 return AVERROR(EINVAL); 00082 } 00083 00084 if (s->bitmask_size != bitmask_size) { 00085 av_freep(&s->mxm_bitmask); 00086 s->mxm_bitmask = av_malloc(bitmask_size); 00087 if (!s->mxm_bitmask) { 00088 av_log(s->jpg.avctx, AV_LOG_ERROR, 00089 "MXM bitmask memory allocation error\n"); 00090 return AVERROR(ENOMEM); 00091 } 00092 00093 av_freep(&s->completion_bitmask); 00094 s->completion_bitmask = av_mallocz(bitmask_size); 00095 if (!s->completion_bitmask) { 00096 av_log(s->jpg.avctx, AV_LOG_ERROR, 00097 "Completion bitmask memory allocation error\n"); 00098 return AVERROR(ENOMEM); 00099 } 00100 00101 s->bitmask_size = bitmask_size; 00102 } 00103 00104 memcpy(s->mxm_bitmask, buf_ptr + 12, bitmask_size); 00105 s->got_mxm_bitmask = 1; 00106 00107 if (!s->has_complete_frame) { 00108 uint8_t completion_check = 0xFF; 00109 for (i = 0; i < bitmask_size; ++i) { 00110 s->completion_bitmask[i] |= s->mxm_bitmask[i]; 00111 completion_check &= s->completion_bitmask[i]; 00112 } 00113 s->has_complete_frame = !(completion_check ^ 0xFF); 00114 } 00115 00116 return 0; 00117 } 00118 00119 static int mxpeg_decode_com(MXpegDecodeContext *s, 00120 const uint8_t *buf_ptr, int buf_size) 00121 { 00122 int len, ret = 0; 00123 if (buf_size < 2) 00124 return 0; 00125 len = AV_RB16(buf_ptr); 00126 if (len > 14 && len <= buf_size && !strncmp(buf_ptr + 2, "MXM", 3)) { 00127 ret = mxpeg_decode_mxm(s, buf_ptr + 2, len - 2); 00128 } 00129 skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size)); 00130 00131 return ret; 00132 } 00133 00134 static int mxpeg_check_dimensions(MXpegDecodeContext *s, MJpegDecodeContext *jpg, 00135 AVFrame *reference_ptr) 00136 { 00137 if ((jpg->width + 0x0F)>>4 != s->mb_width || 00138 (jpg->height + 0x0F)>>4 != s->mb_height) { 00139 av_log(jpg->avctx, AV_LOG_ERROR, 00140 "Picture dimensions stored in SOF and MXM mismatch\n"); 00141 return AVERROR(EINVAL); 00142 } 00143 00144 if (reference_ptr->data[0]) { 00145 int i; 00146 for (i = 0; i < MAX_COMPONENTS; ++i) { 00147 if ( (!reference_ptr->data[i] ^ !jpg->picture_ptr->data[i]) || 00148 reference_ptr->linesize[i] != jpg->picture_ptr->linesize[i]) { 00149 av_log(jpg->avctx, AV_LOG_ERROR, 00150 "Dimensions of current and reference picture mismatch\n"); 00151 return AVERROR(EINVAL); 00152 } 00153 } 00154 } 00155 00156 return 0; 00157 } 00158 00159 static int mxpeg_decode_frame(AVCodecContext *avctx, 00160 void *data, int *data_size, 00161 AVPacket *avpkt) 00162 { 00163 const uint8_t *buf = avpkt->data; 00164 int buf_size = avpkt->size; 00165 MXpegDecodeContext *s = avctx->priv_data; 00166 MJpegDecodeContext *jpg = &s->jpg; 00167 const uint8_t *buf_end, *buf_ptr; 00168 const uint8_t *unescaped_buf_ptr; 00169 int unescaped_buf_size; 00170 int start_code; 00171 AVFrame *picture = data; 00172 int ret; 00173 00174 buf_ptr = buf; 00175 buf_end = buf + buf_size; 00176 jpg->got_picture = 0; 00177 s->got_mxm_bitmask = 0; 00178 while (buf_ptr < buf_end) { 00179 start_code = ff_mjpeg_find_marker(jpg, &buf_ptr, buf_end, 00180 &unescaped_buf_ptr, &unescaped_buf_size); 00181 if (start_code < 0) 00182 goto the_end; 00183 { 00184 init_get_bits(&jpg->gb, unescaped_buf_ptr, unescaped_buf_size*8); 00185 00186 if (start_code >= APP0 && start_code <= APP15) { 00187 mxpeg_decode_app(s, unescaped_buf_ptr, unescaped_buf_size); 00188 } 00189 00190 switch (start_code) { 00191 case SOI: 00192 if (jpg->got_picture) //emulating EOI 00193 goto the_end; 00194 break; 00195 case EOI: 00196 goto the_end; 00197 case DQT: 00198 ret = ff_mjpeg_decode_dqt(jpg); 00199 if (ret < 0) { 00200 av_log(avctx, AV_LOG_ERROR, 00201 "quantization table decode error\n"); 00202 return ret; 00203 } 00204 break; 00205 case DHT: 00206 ret = ff_mjpeg_decode_dht(jpg); 00207 if (ret < 0) { 00208 av_log(avctx, AV_LOG_ERROR, 00209 "huffman table decode error\n"); 00210 return ret; 00211 } 00212 break; 00213 case COM: 00214 ret = mxpeg_decode_com(s, unescaped_buf_ptr, 00215 unescaped_buf_size); 00216 if (ret < 0) 00217 return ret; 00218 break; 00219 case SOF0: 00220 s->got_sof_data = 0; 00221 ret = ff_mjpeg_decode_sof(jpg); 00222 if (ret < 0) { 00223 av_log(avctx, AV_LOG_ERROR, 00224 "SOF data decode error\n"); 00225 return ret; 00226 } 00227 if (jpg->interlaced) { 00228 av_log(avctx, AV_LOG_ERROR, 00229 "Interlaced mode not supported in MxPEG\n"); 00230 return AVERROR(EINVAL); 00231 } 00232 s->got_sof_data = 1; 00233 break; 00234 case SOS: 00235 if (!s->got_sof_data) { 00236 av_log(avctx, AV_LOG_WARNING, 00237 "Can not process SOS without SOF data, skipping\n"); 00238 break; 00239 } 00240 if (!jpg->got_picture) { 00241 if (jpg->first_picture) { 00242 av_log(avctx, AV_LOG_WARNING, 00243 "First picture has no SOF, skipping\n"); 00244 break; 00245 } 00246 if (!s->got_mxm_bitmask){ 00247 av_log(avctx, AV_LOG_WARNING, 00248 "Non-key frame has no MXM, skipping\n"); 00249 break; 00250 } 00251 /* use stored SOF data to allocate current picture */ 00252 if (jpg->picture_ptr->data[0]) 00253 avctx->release_buffer(avctx, jpg->picture_ptr); 00254 if (avctx->get_buffer(avctx, jpg->picture_ptr) < 0) { 00255 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 00256 return AVERROR(ENOMEM); 00257 } 00258 jpg->picture_ptr->pict_type = AV_PICTURE_TYPE_P; 00259 jpg->picture_ptr->key_frame = 0; 00260 jpg->got_picture = 1; 00261 } else { 00262 jpg->picture_ptr->pict_type = AV_PICTURE_TYPE_I; 00263 jpg->picture_ptr->key_frame = 1; 00264 } 00265 00266 if (s->got_mxm_bitmask) { 00267 AVFrame *reference_ptr = &s->picture[s->picture_index ^ 1]; 00268 if (mxpeg_check_dimensions(s, jpg, reference_ptr) < 0) 00269 break; 00270 00271 /* allocate dummy reference picture if needed */ 00272 if (!reference_ptr->data[0] && 00273 avctx->get_buffer(avctx, reference_ptr) < 0) { 00274 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 00275 return AVERROR(ENOMEM); 00276 } 00277 00278 ff_mjpeg_decode_sos(jpg, s->mxm_bitmask, reference_ptr); 00279 } else { 00280 ff_mjpeg_decode_sos(jpg, NULL, NULL); 00281 } 00282 00283 break; 00284 } 00285 00286 buf_ptr += (get_bits_count(&jpg->gb)+7) >> 3; 00287 } 00288 00289 } 00290 00291 the_end: 00292 if (jpg->got_picture) { 00293 *data_size = sizeof(AVFrame); 00294 *picture = *jpg->picture_ptr; 00295 s->picture_index ^= 1; 00296 jpg->picture_ptr = &s->picture[s->picture_index]; 00297 00298 if (!s->has_complete_frame) { 00299 if (!s->got_mxm_bitmask) 00300 s->has_complete_frame = 1; 00301 else 00302 *data_size = 0; 00303 } 00304 } 00305 00306 return buf_ptr - buf; 00307 } 00308 00309 static av_cold int mxpeg_decode_end(AVCodecContext *avctx) 00310 { 00311 MXpegDecodeContext *s = avctx->priv_data; 00312 MJpegDecodeContext *jpg = &s->jpg; 00313 int i; 00314 00315 jpg->picture_ptr = NULL; 00316 ff_mjpeg_decode_end(avctx); 00317 00318 for (i = 0; i < 2; ++i) { 00319 if (s->picture[i].data[0]) 00320 avctx->release_buffer(avctx, &s->picture[i]); 00321 } 00322 00323 av_freep(&s->mxm_bitmask); 00324 av_freep(&s->completion_bitmask); 00325 00326 return 0; 00327 } 00328 00329 AVCodec ff_mxpeg_decoder = { 00330 .name = "mxpeg", 00331 .long_name = NULL_IF_CONFIG_SMALL("Mobotix MxPEG video"), 00332 .type = AVMEDIA_TYPE_VIDEO, 00333 .id = CODEC_ID_MXPEG, 00334 .priv_data_size = sizeof(MXpegDecodeContext), 00335 .init = mxpeg_decode_init, 00336 .close = mxpeg_decode_end, 00337 .decode = mxpeg_decode_frame, 00338 .capabilities = CODEC_CAP_DR1, 00339 .max_lowres = 3 00340 };