mxpegdec.c 11.1 KB
Newer Older
anatoly's avatar
anatoly committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49
/*
 * MxPEG decoder
 * Copyright (c) 2011 Anatoly Nenashev
 *
 * This file is part of Libav.
 *
 * Libav is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * Libav is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */


/**
 * @file
 * MxPEG decoder
 */

#include "mjpeg.h"
#include "mjpegdec.h"

typedef struct MXpegDecodeContext {
    MJpegDecodeContext jpg;
    AVFrame picture[2]; /* pictures array */
    int picture_index; /* index of current picture */
    int got_sof_data; /* true if SOF data successfully parsed */
    int got_mxm_bitmask; /* true if MXM bitmask available */
    uint8_t *mxm_bitmask; /* bitmask buffer */
    unsigned bitmask_size; /* size of bitmask */
    int has_complete_frame; /* true if has complete frame */
    uint8_t *completion_bitmask; /* completion bitmask of macroblocks */
    unsigned mb_width, mb_height; /* size of picture in MB's from MXM header */
} MXpegDecodeContext;

static av_cold int mxpeg_decode_init(AVCodecContext *avctx)
{
    MXpegDecodeContext *s = avctx->priv_data;

    s->picture[0].reference = s->picture[1].reference = 3;
    s->jpg.picture_ptr      = &s->picture[0];
50
    return ff_mjpeg_decode_init(avctx);
anatoly's avatar
anatoly committed
51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255
}

static int mxpeg_decode_app(MXpegDecodeContext *s,
                            const uint8_t *buf_ptr, int buf_size)
{
    int len;
    if (buf_size < 2)
        return 0;
    len = AV_RB16(buf_ptr);
    skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size));

    return 0;
}

static int mxpeg_decode_mxm(MXpegDecodeContext *s,
                            const uint8_t *buf_ptr, int buf_size)
{
    unsigned bitmask_size, mb_count;
    int i;

    s->mb_width  = AV_RL16(buf_ptr+4);
    s->mb_height = AV_RL16(buf_ptr+6);
    mb_count = s->mb_width * s->mb_height;

    bitmask_size = (mb_count + 7) >> 3;
    if (bitmask_size > buf_size - 12) {
        av_log(s->jpg.avctx, AV_LOG_ERROR,
               "MXM bitmask is not complete\n");
        return AVERROR(EINVAL);
    }

    if (s->bitmask_size != bitmask_size) {
        av_freep(&s->mxm_bitmask);
        s->mxm_bitmask = av_malloc(bitmask_size);
        if (!s->mxm_bitmask) {
            av_log(s->jpg.avctx, AV_LOG_ERROR,
                   "MXM bitmask memory allocation error\n");
            return AVERROR(ENOMEM);
        }

        av_freep(&s->completion_bitmask);
        s->completion_bitmask = av_mallocz(bitmask_size);
        if (!s->completion_bitmask) {
            av_log(s->jpg.avctx, AV_LOG_ERROR,
                   "Completion bitmask memory allocation error\n");
            return AVERROR(ENOMEM);
        }

        s->bitmask_size = bitmask_size;
    }

    memcpy(s->mxm_bitmask, buf_ptr + 12, bitmask_size);
    s->got_mxm_bitmask = 1;

    if (!s->has_complete_frame) {
        uint8_t completion_check = 0xFF;
        for (i = 0; i < bitmask_size; ++i) {
            s->completion_bitmask[i] |= s->mxm_bitmask[i];
            completion_check &= s->completion_bitmask[i];
        }
        s->has_complete_frame = !(completion_check ^ 0xFF);
    }

    return 0;
}

static int mxpeg_decode_com(MXpegDecodeContext *s,
                            const uint8_t *buf_ptr, int buf_size)
{
    int len, ret = 0;
    if (buf_size < 2)
        return 0;
    len = AV_RB16(buf_ptr);
    if (len > 14 && len <= buf_size && !strncmp(buf_ptr + 2, "MXM", 3)) {
        ret = mxpeg_decode_mxm(s, buf_ptr + 2, len - 2);
    }
    skip_bits(&s->jpg.gb, 8*FFMIN(len,buf_size));

    return ret;
}

static int mxpeg_check_dimensions(MXpegDecodeContext *s, MJpegDecodeContext *jpg,
                                  AVFrame *reference_ptr)
{
    if ((jpg->width + 0x0F)>>4 != s->mb_width ||
        (jpg->height + 0x0F)>>4 != s->mb_height) {
        av_log(jpg->avctx, AV_LOG_ERROR,
               "Picture dimensions stored in SOF and MXM mismatch\n");
        return AVERROR(EINVAL);
    }

    if (reference_ptr->data[0]) {
        int i;
        for (i = 0; i < MAX_COMPONENTS; ++i) {
            if ( (!reference_ptr->data[i] ^ !jpg->picture_ptr->data[i]) ||
                 reference_ptr->linesize[i] != jpg->picture_ptr->linesize[i]) {
                av_log(jpg->avctx, AV_LOG_ERROR,
                       "Dimensions of current and reference picture mismatch\n");
                return AVERROR(EINVAL);
            }
        }
    }

    return 0;
}

static int mxpeg_decode_frame(AVCodecContext *avctx,
                          void *data, int *data_size,
                          AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    MXpegDecodeContext *s = avctx->priv_data;
    MJpegDecodeContext *jpg = &s->jpg;
    const uint8_t *buf_end, *buf_ptr;
    const uint8_t *unescaped_buf_ptr;
    int unescaped_buf_size;
    int start_code;
    AVFrame *picture = data;
    int ret;

    buf_ptr = buf;
    buf_end = buf + buf_size;
    jpg->got_picture = 0;
    s->got_mxm_bitmask = 0;
    while (buf_ptr < buf_end) {
        start_code = ff_mjpeg_find_marker(jpg, &buf_ptr, buf_end,
                                          &unescaped_buf_ptr, &unescaped_buf_size);
        if (start_code < 0)
            goto the_end;
        {
            init_get_bits(&jpg->gb, unescaped_buf_ptr, unescaped_buf_size*8);

            if (start_code >= APP0 && start_code <= APP15) {
                mxpeg_decode_app(s, unescaped_buf_ptr, unescaped_buf_size);
            }

            switch (start_code) {
            case SOI:
                if (jpg->got_picture) //emulating EOI
                    goto the_end;
                break;
            case EOI:
                goto the_end;
            case DQT:
                ret = ff_mjpeg_decode_dqt(jpg);
                if (ret < 0) {
                    av_log(avctx, AV_LOG_ERROR,
                           "quantization table decode error\n");
                    return ret;
                }
                break;
            case DHT:
                ret = ff_mjpeg_decode_dht(jpg);
                if (ret < 0) {
                    av_log(avctx, AV_LOG_ERROR,
                           "huffman table decode error\n");
                    return ret;
                }
                break;
            case COM:
                ret = mxpeg_decode_com(s, unescaped_buf_ptr,
                                       unescaped_buf_size);
                if (ret < 0)
                    return ret;
                break;
            case SOF0:
                s->got_sof_data = 0;
                ret = ff_mjpeg_decode_sof(jpg);
                if (ret < 0) {
                    av_log(avctx, AV_LOG_ERROR,
                           "SOF data decode error\n");
                    return ret;
                }
                if (jpg->interlaced) {
                    av_log(avctx, AV_LOG_ERROR,
                           "Interlaced mode not supported in MxPEG\n");
                    return AVERROR(EINVAL);
                }
                s->got_sof_data = 1;
                break;
            case SOS:
                if (!s->got_sof_data) {
                    av_log(avctx, AV_LOG_WARNING,
                           "Can not process SOS without SOF data, skipping\n");
                    break;
                }
                if (!jpg->got_picture) {
                    if (jpg->first_picture) {
                        av_log(avctx, AV_LOG_WARNING,
                               "First picture has no SOF, skipping\n");
                        break;
                    }
                    if (!s->got_mxm_bitmask){
                        av_log(avctx, AV_LOG_WARNING,
                               "Non-key frame has no MXM, skipping\n");
                        break;
                    }
                    /* use stored SOF data to allocate current picture */
                    if (jpg->picture_ptr->data[0])
                        avctx->release_buffer(avctx, jpg->picture_ptr);
                    if (avctx->get_buffer(avctx, jpg->picture_ptr) < 0) {
                        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
                        return AVERROR(ENOMEM);
                    }
256
                    jpg->picture_ptr->pict_type = AV_PICTURE_TYPE_P;
anatoly's avatar
anatoly committed
257 258 259
                    jpg->picture_ptr->key_frame = 0;
                    jpg->got_picture = 1;
                } else {
260
                    jpg->picture_ptr->pict_type = AV_PICTURE_TYPE_I;
anatoly's avatar
anatoly committed
261 262 263 264 265 266 267 268 269 270 271 272 273 274 275
                    jpg->picture_ptr->key_frame = 1;
                }

                if (s->got_mxm_bitmask) {
                    AVFrame *reference_ptr = &s->picture[s->picture_index ^ 1];
                    if (mxpeg_check_dimensions(s, jpg, reference_ptr) < 0)
                        break;

                    /* allocate dummy reference picture if needed */
                    if (!reference_ptr->data[0] &&
                        avctx->get_buffer(avctx, reference_ptr) < 0) {
                        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
                        return AVERROR(ENOMEM);
                    }

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;
anatoly's avatar
anatoly committed
279
                } else {
280
                    ret = ff_mjpeg_decode_sos(jpg, NULL, NULL);
281
                    if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
282
                        return ret;
anatoly's avatar
anatoly committed
283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341
                }

                break;
            }

            buf_ptr += (get_bits_count(&jpg->gb)+7) >> 3;
        }

    }

the_end:
    if (jpg->got_picture) {
        *data_size = sizeof(AVFrame);
        *picture = *jpg->picture_ptr;
        s->picture_index ^= 1;
        jpg->picture_ptr = &s->picture[s->picture_index];

        if (!s->has_complete_frame) {
            if (!s->got_mxm_bitmask)
                s->has_complete_frame = 1;
            else
                *data_size = 0;
        }
    }

    return buf_ptr - buf;
}

static av_cold int mxpeg_decode_end(AVCodecContext *avctx)
{
    MXpegDecodeContext *s = avctx->priv_data;
    MJpegDecodeContext *jpg = &s->jpg;
    int i;

    jpg->picture_ptr = NULL;
    ff_mjpeg_decode_end(avctx);

    for (i = 0; i < 2; ++i) {
        if (s->picture[i].data[0])
            avctx->release_buffer(avctx, &s->picture[i]);
    }

    av_freep(&s->mxm_bitmask);
    av_freep(&s->completion_bitmask);

    return 0;
}

AVCodec ff_mxpeg_decoder = {
    .name           = "mxpeg",
    .long_name      = NULL_IF_CONFIG_SMALL("Mobotix MxPEG video"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = CODEC_ID_MXPEG,
    .priv_data_size = sizeof(MXpegDecodeContext),
    .init           = mxpeg_decode_init,
    .close          = mxpeg_decode_end,
    .decode         = mxpeg_decode_frame,
    .capabilities   = CODEC_CAP_DR1,
};