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