aboutsummaryrefslogtreecommitdiffstats
path: root/libavformat/jpegxl_probe.c
blob: 3de002f004503ba841a6cdd6597514b0c2cc2b70 (plain) (blame)
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
50
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
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
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
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
/*
 * Jpeg XL header verification
 * Copyright (c) 2022 Leo Izen <leo.izen@gmail.com>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg 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.
 *
 * FFmpeg 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 FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "jpegxl_probe.h"

#define BITSTREAM_READER_LE
#include "libavcodec/get_bits.h"

enum JpegXLExtraChannelType {
    FF_JPEGXL_CT_ALPHA = 0,
    FF_JPEGXL_CT_DEPTH,
    FF_JPEGXL_CT_SPOT_COLOR,
    FF_JPEGXL_CT_SELECTION_MASK,
    FF_JPEGXL_CT_BLACK,
    FF_JPEGXL_CT_CFA,
    FF_JPEGXL_CT_THERMAL,
    FF_JPEGXL_CT_NON_OPTIONAL = 15,
    FF_JPEGXL_CT_OPTIONAL
};

enum JpegXLColorSpace {
    FF_JPEGXL_CS_RGB = 0,
    FF_JPEGXL_CS_GRAY,
    FF_JPEGXL_CS_XYB,
    FF_JPEGXL_CS_UNKNOWN
};

enum JpegXLWhitePoint {
    FF_JPEGXL_WP_D65 = 1,
    FF_JPEGXL_WP_CUSTOM,
    FF_JPEGXL_WP_E = 10,
    FF_JPEGXL_WP_DCI = 11
};

enum JpegXLPrimaries {
    FF_JPEGXL_PR_SRGB = 1,
    FF_JPEGXL_PR_CUSTOM,
    FF_JPEGXL_PR_2100 = 9,
    FF_JPEGXL_PR_P3 = 11,
};

#define jxl_bits(n) get_bits_long(gb, (n))
#define jxl_bits_skip(n) skip_bits_long(gb, (n))
#define jxl_u32(c0, c1, c2, c3, u0, u1, u2, u3) jpegxl_u32(gb, \
    (const uint32_t[]){c0, c1, c2, c3}, (const uint32_t[]){u0, u1, u2, u3})
#define jxl_u64() jpegxl_u64(gb)
#define jxl_enum() jxl_u32(0, 1, 2, 18, 0, 0, 4, 6)

/* read a U32(c_i + u(u_i)) */
static uint32_t jpegxl_u32(GetBitContext *gb,
                           const uint32_t constants[4], const uint32_t ubits[4])
{
    uint32_t ret, choice = jxl_bits(2);

    ret = constants[choice];
    if (ubits[choice])
        ret += jxl_bits(ubits[choice]);

    return ret;
}

/* read a U64() */
static uint64_t jpegxl_u64(GetBitContext *gb)
{
    uint64_t shift = 12, ret;

    switch (jxl_bits(2)) {
    case 0:
        ret = 0;
        break;
    case 1:
        ret = 1 + jxl_bits(4);
        break;
    case 2:
        ret = 17 + jxl_bits(8);
        break;
    case 3:
        ret = jxl_bits(12);
        while (jxl_bits(1)) {
            if (shift < 60) {
                ret |= (uint64_t)jxl_bits(8) << shift;
                shift += 8;
            } else {
                ret |= (uint64_t)jxl_bits(4) << shift;
                break;
            }
        }
        break;
    }

    return ret;
}

static uint32_t jpegxl_width_from_ratio(uint32_t height, int ratio)
{
    uint64_t height64 = height; /* avoid integer overflow */
    switch (ratio) {
    case 1:
        return height;
    case 2:
        return (uint32_t)((height64 * 12) / 10);
    case 3:
        return (uint32_t)((height64 * 4) / 3);
    case 4:
        return (uint32_t)((height64 * 3) / 2);
    case 5:
        return (uint32_t)((height64 * 16) / 9);
    case 6:
        return (uint32_t)((height64 * 5) / 4);
    case 7:
        return (uint32_t)(height64 * 2);
    default:
        break;
    }

    return 0; /* manual width */
}

/**
 * validate a Jpeg XL Size Header
 * @return >= 0 upon valid size, < 0 upon invalid size found
 */
static int jpegxl_read_size_header(GetBitContext *gb)
{
    uint32_t width, height;

    if (jxl_bits(1)) {
        /* small size header */
        height = (jxl_bits(5) + 1) << 3;
        width = jpegxl_width_from_ratio(height, jxl_bits(3));
        if (!width)
            width = (jxl_bits(5) + 1) << 3;
    } else {
        /* large size header */
        height = 1 + jxl_u32(0, 0, 0, 0, 9, 13, 18, 30);
        width = jpegxl_width_from_ratio(height, jxl_bits(3));
        if (!width)
            width = 1 + jxl_u32(0, 0, 0, 0, 9, 13, 18, 30);
    }
    if (width > (1 << 18) || height > (1 << 18)
        || (width >> 4) * (height >> 4) > (1 << 20))
        return -1;

    return 0;
}

/**
 * validate a Jpeg XL Preview Header
 * @return >= 0 upon valid size, < 0 upon invalid size found
 */
static int jpegxl_read_preview_header(GetBitContext *gb)
{
    uint32_t width, height;

    if (jxl_bits(1)) {
        /* coded height and width divided by eight */
        height = jxl_u32(16, 32, 1, 33, 0, 0, 5, 9) << 3;
        width = jpegxl_width_from_ratio(height, jxl_bits(3));
        if (!width)
            width = jxl_u32(16, 32, 1, 33, 0, 0, 5, 9) << 3;
    } else {
        /* full height and width coded */
        height = jxl_u32(1, 65, 321, 1345, 6, 8, 10, 12);
        width = jpegxl_width_from_ratio(height, jxl_bits(3));
        if (!width)
            width = jxl_u32(1, 65, 321, 1345, 6, 8, 10, 12);
    }
    if (width > 4096 || height > 4096)
        return -1;

    return 0;
}

/**
 * skip a Jpeg XL BitDepth Header. These cannot be invalid.
 */
static void jpegxl_skip_bit_depth(GetBitContext *gb)
{
    if (jxl_bits(1)) {
        /* float samples */
        jxl_u32(32, 16, 24, 1, 0, 0, 0, 6); /* mantissa */
        jxl_bits_skip(4); /* exponent */
    } else {
        /* integer samples */
        jxl_u32(8, 10, 12, 1, 0, 0, 0, 6);
    }
}

/**
 * validate a Jpeg XL Extra Channel Info bundle
 * @return >= 0 upon valid, < 0 upon invalid
 */
static int jpegxl_read_extra_channel_info(GetBitContext *gb)
{
    int all_default = jxl_bits(1);
    uint32_t type, name_len = 0;

    if (!all_default) {
        type = jxl_enum();
        if (type > 63)
            return -1; /* enum types cannot be 64+ */
        if (type == FF_JPEGXL_CT_BLACK)
            return -1;
        jpegxl_skip_bit_depth(gb);
        jxl_u32(0, 3, 4, 1, 0, 0, 0, 3); /* dim-shift */
        /* max of name_len is 1071 = 48 + 2^10 - 1 */
        name_len = jxl_u32(0, 0, 16, 48, 0, 4, 5, 10);
    } else {
        type = FF_JPEGXL_CT_ALPHA;
    }

    /* skip over the name */
    jxl_bits_skip(8 * name_len);

    if (!all_default && type == FF_JPEGXL_CT_ALPHA)
        jxl_bits_skip(1);

    if (type == FF_JPEGXL_CT_SPOT_COLOR)
        jxl_bits_skip(16 * 4);

    if (type == FF_JPEGXL_CT_CFA)
        jxl_u32(1, 0, 3, 19, 0, 2, 4, 8);

    return 0;
}

/* verify that a codestream header is valid */
int ff_jpegxl_verify_codestream_header(const uint8_t *buf, int buflen)
{
    GetBitContext gbi, *gb = &gbi;
    int all_default, extra_fields = 0;
    int xyb_encoded = 1, have_icc_profile = 0;
    uint32_t num_extra_channels;
    uint64_t extensions;
    int ret;

    ret = init_get_bits8(gb, buf, buflen);
    if (ret < 0)
        return ret;

    if (jxl_bits(16) != FF_JPEGXL_CODESTREAM_SIGNATURE_LE)
        return -1;

    if (jpegxl_read_size_header(gb) < 0)
        return -1;

    all_default = jxl_bits(1);
    if (!all_default)
        extra_fields = jxl_bits(1);

    if (extra_fields) {
        jxl_bits_skip(3); /* orientation */

        /*
         * intrinstic size
         * any size header here is valid, but as it
         * is variable length we have to read it
         */
        if (jxl_bits(1))
            jpegxl_read_size_header(gb);

        /* preview header */
        if (jxl_bits(1)) {
            if (jpegxl_read_preview_header(gb) < 0)
                return -1;
        }

        /* animation header */
        if (jxl_bits(1)) {
            jxl_u32(100, 1000, 1, 1, 0, 0, 10, 30);
            jxl_u32(1, 1001, 1, 1, 0, 0, 8, 10);
            jxl_u32(0, 0, 0, 0, 0, 3, 16, 32);
            jxl_bits_skip(1);
        }
    }

    if (!all_default) {
        jpegxl_skip_bit_depth(gb);

        /* modular_16bit_buffers must equal 1 */
        if (!jxl_bits(1))
            return -1;

        num_extra_channels = jxl_u32(0, 1, 2, 1, 0, 0, 4, 12);
        if (num_extra_channels > 4)
            return -1;
        for (uint32_t i = 0; i < num_extra_channels; i++) {
            if (jpegxl_read_extra_channel_info(gb) < 0)
                return -1;
        }

        xyb_encoded = jxl_bits(1);

        /* color encoding bundle */
        if (!jxl_bits(1)) {
            uint32_t color_space;
            have_icc_profile = jxl_bits(1);
            color_space = jxl_enum();
            if (color_space > 63)
                return -1;

            if (!have_icc_profile) {
                if (color_space != FF_JPEGXL_CS_XYB) {
                    uint32_t white_point = jxl_enum();
                    if (white_point > 63)
                        return -1;
                    if (white_point == FF_JPEGXL_WP_CUSTOM) {
                        /* ux and uy values */
                        jxl_u32(0, 524288, 1048576, 2097152, 19, 19, 20, 21);
                        jxl_u32(0, 524288, 1048576, 2097152, 19, 19, 20, 21);
                    }
                    if (color_space != FF_JPEGXL_CS_GRAY) {
                        /* primaries */
                        uint32_t primaries = jxl_enum();
                        if (primaries > 63)
                            return -1;
                        if (primaries == FF_JPEGXL_PR_CUSTOM) {
                            /* ux/uy values for r,g,b */
                            for (int i = 0; i < 6; i++)
                                jxl_u32(0, 524288, 1048576, 2097152, 19, 19, 20, 21);
                        }
                    }
                }

                /* transfer characteristics */
                if (jxl_bits(1)) {
                    /* gamma */
                    jxl_bits_skip(24);
                } else {
                    /* transfer function */
                    if (jxl_enum() > 63)
                        return -1;
                }

                /* rendering intent */
                if (jxl_enum() > 63)
                    return -1;
            }
        }

        /* tone mapping bundle */
        if (extra_fields && !jxl_bits(1))
            jxl_bits_skip(16 + 16 + 1 + 16);

        extensions = jxl_u64();
        if (extensions) {
            for (int i = 0; i < 64; i++) {
                if (extensions & (UINT64_C(1) << i))
                    jxl_u64();
            }
        }
    }

    /* default transform */
    if (!jxl_bits(1)) {
        /* opsin inverse matrix */
        if (xyb_encoded && !jxl_bits(1))
            jxl_bits_skip(16 * 16);
        /* cw_mask and default weights */
        if (jxl_bits(1))
            jxl_bits_skip(16 * 15);
        if (jxl_bits(1))
            jxl_bits_skip(16 * 55);
        if (jxl_bits(1))
            jxl_bits_skip(16 * 210);
    }

    if (!have_icc_profile) {
        int bits_remaining = 7 - (get_bits_count(gb) - 1) % 8;
        if (bits_remaining && jxl_bits(bits_remaining))
            return -1;
    }

    if (get_bits_left(gb) < 0)
        return -1;

    return 0;
}