GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/smc.c Lines: 177 226 78.3 %
Date: 2020-09-25 23:16:12 Branches: 105 156 67.3 %

Line Branch Exec Source
1
/*
2
 * Quicktime Graphics (SMC) Video Decoder
3
 * Copyright (C) 2003 The FFmpeg project
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
 * @file
24
 * QT SMC Video Decoder by Mike Melanson (melanson@pcisys.net)
25
 * For more information about the SMC format, visit:
26
 *   http://www.pcisys.net/~melanson/codecs/
27
 *
28
 * The SMC decoder outputs PAL8 colorspace data.
29
 */
30
31
#include <stdio.h>
32
#include <stdlib.h>
33
#include <string.h>
34
35
#include "libavutil/intreadwrite.h"
36
#include "avcodec.h"
37
#include "bytestream.h"
38
#include "internal.h"
39
40
#define CPAIR 2
41
#define CQUAD 4
42
#define COCTET 8
43
44
#define COLORS_PER_TABLE 256
45
46
typedef struct SmcContext {
47
48
    AVCodecContext *avctx;
49
    AVFrame *frame;
50
51
    GetByteContext gb;
52
53
    /* SMC color tables */
54
    unsigned char color_pairs[COLORS_PER_TABLE * CPAIR];
55
    unsigned char color_quads[COLORS_PER_TABLE * CQUAD];
56
    unsigned char color_octets[COLORS_PER_TABLE * COCTET];
57
58
    uint32_t pal[256];
59
} SmcContext;
60
61
#define GET_BLOCK_COUNT() \
62
  (opcode & 0x10) ? (1 + bytestream2_get_byte(&s->gb)) : 1 + (opcode & 0x0F);
63
64
#define ADVANCE_BLOCK() \
65
{ \
66
    pixel_ptr += 4; \
67
    if (pixel_ptr >= width) \
68
    { \
69
        pixel_ptr = 0; \
70
        row_ptr += stride * 4; \
71
    } \
72
    total_blocks--; \
73
    if (total_blocks < !!n_blocks) \
74
    { \
75
        av_log(s->avctx, AV_LOG_INFO, "warning: block counter just went negative (this should not happen)\n"); \
76
        return; \
77
    } \
78
}
79
80
120
static void smc_decode_stream(SmcContext *s)
81
{
82
120
    int width = s->avctx->width;
83
120
    int height = s->avctx->height;
84
120
    int stride = s->frame->linesize[0];
85
    int i;
86
    int chunk_size;
87
120
    int buf_size = bytestream2_size(&s->gb);
88
    unsigned char opcode;
89
    int n_blocks;
90
    unsigned int color_flags;
91
    unsigned int color_flags_a;
92
    unsigned int color_flags_b;
93
    unsigned int flag_mask;
94
95
120
    unsigned char * const pixels = s->frame->data[0];
96
97
120
    int image_size = height * s->frame->linesize[0];
98
120
    int row_ptr = 0;
99
120
    int pixel_ptr = 0;
100
    int pixel_x, pixel_y;
101
120
    int row_inc = stride - 4;
102
    int block_ptr;
103
    int prev_block_ptr;
104
    int prev_block_ptr1, prev_block_ptr2;
105
    int prev_block_flag;
106
    int total_blocks;
107
    int color_table_index;  /* indexes to color pair, quad, or octet tables */
108
    int pixel;
109
110
120
    int color_pair_index = 0;
111
120
    int color_quad_index = 0;
112
120
    int color_octet_index = 0;
113
114
    /* make the palette available */
115
120
    memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE);
116
117
120
    bytestream2_skip(&s->gb, 1);
118
120
    chunk_size = bytestream2_get_be24(&s->gb);
119
120
    if (chunk_size != buf_size)
120
        av_log(s->avctx, AV_LOG_INFO, "warning: MOV chunk size != encoded chunk size (%d != %d); using MOV chunk size\n",
121
            chunk_size, buf_size);
122
123
120
    chunk_size = buf_size;
124
120
    total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);
125
126
    /* traverse through the blocks */
127
120
    while (total_blocks) {
128
        /* sanity checks */
129
        /* make sure the row pointer hasn't gone wild */
130
130697
        if (row_ptr >= image_size) {
131
            av_log(s->avctx, AV_LOG_INFO, "SMC decoder just went out of bounds (row ptr = %d, height = %d)\n",
132
                row_ptr, image_size);
133
            return;
134
        }
135
130697
        if (bytestream2_get_bytes_left(&s->gb) < 1) {
136
            av_log(s->avctx, AV_LOG_ERROR, "input too small\n");
137
            return;
138
        }
139
140
130697
        opcode = bytestream2_get_byte(&s->gb);
141


130697
        switch (opcode & 0xF0) {
142
        /* skip n blocks */
143
28630
        case 0x00:
144
        case 0x10:
145
28630
            n_blocks = GET_BLOCK_COUNT();
146
447015
            while (n_blocks--) {
147

418385
                ADVANCE_BLOCK();
148
            }
149
28630
            break;
150
151
        /* repeat last block n times */
152
1068
        case 0x20:
153
        case 0x30:
154
1068
            n_blocks = GET_BLOCK_COUNT();
155
156
            /* sanity check */
157

1068
            if ((row_ptr == 0) && (pixel_ptr == 0)) {
158
                av_log(s->avctx, AV_LOG_INFO, "encountered repeat block opcode (%02X) but no blocks rendered yet\n",
159
                    opcode & 0xF0);
160
                return;
161
            }
162
163
            /* figure out where the previous block started */
164
1068
            if (pixel_ptr == 0)
165
                prev_block_ptr1 =
166
                    (row_ptr - s->avctx->width * 4) + s->avctx->width - 4;
167
            else
168
1068
                prev_block_ptr1 = row_ptr + pixel_ptr - 4;
169
170
3393
            while (n_blocks--) {
171
2325
                block_ptr = row_ptr + pixel_ptr;
172
2325
                prev_block_ptr = prev_block_ptr1;
173
11625
                for (pixel_y = 0; pixel_y < 4; pixel_y++) {
174
46500
                    for (pixel_x = 0; pixel_x < 4; pixel_x++) {
175
37200
                        pixels[block_ptr++] = pixels[prev_block_ptr++];
176
                    }
177
9300
                    block_ptr += row_inc;
178
9300
                    prev_block_ptr += row_inc;
179
                }
180

2325
                ADVANCE_BLOCK();
181
            }
182
1068
            break;
183
184
        /* repeat previous pair of blocks n times */
185
        case 0x40:
186
        case 0x50:
187
            n_blocks = GET_BLOCK_COUNT();
188
            n_blocks *= 2;
189
190
            /* sanity check */
191
            if ((row_ptr == 0) && (pixel_ptr < 2 * 4)) {
192
                av_log(s->avctx, AV_LOG_INFO, "encountered repeat block opcode (%02X) but not enough blocks rendered yet\n",
193
                    opcode & 0xF0);
194
                return;
195
            }
196
197
            /* figure out where the previous 2 blocks started */
198
            if (pixel_ptr == 0)
199
                prev_block_ptr1 = (row_ptr - s->avctx->width * 4) +
200
                    s->avctx->width - 4 * 2;
201
            else if (pixel_ptr == 4)
202
                prev_block_ptr1 = (row_ptr - s->avctx->width * 4) + row_inc;
203
            else
204
                prev_block_ptr1 = row_ptr + pixel_ptr - 4 * 2;
205
206
            if (pixel_ptr == 0)
207
                prev_block_ptr2 = (row_ptr - s->avctx->width * 4) + row_inc;
208
            else
209
                prev_block_ptr2 = row_ptr + pixel_ptr - 4;
210
211
            prev_block_flag = 0;
212
            while (n_blocks--) {
213
                block_ptr = row_ptr + pixel_ptr;
214
                if (prev_block_flag)
215
                    prev_block_ptr = prev_block_ptr2;
216
                else
217
                    prev_block_ptr = prev_block_ptr1;
218
                prev_block_flag = !prev_block_flag;
219
220
                for (pixel_y = 0; pixel_y < 4; pixel_y++) {
221
                    for (pixel_x = 0; pixel_x < 4; pixel_x++) {
222
                        pixels[block_ptr++] = pixels[prev_block_ptr++];
223
                    }
224
                    block_ptr += row_inc;
225
                    prev_block_ptr += row_inc;
226
                }
227
                ADVANCE_BLOCK();
228
            }
229
            break;
230
231
        /* 1-color block encoding */
232
11688
        case 0x60:
233
        case 0x70:
234
11688
            n_blocks = GET_BLOCK_COUNT();
235
11688
            pixel = bytestream2_get_byte(&s->gb);
236
237
62105
            while (n_blocks--) {
238
50417
                block_ptr = row_ptr + pixel_ptr;
239
252085
                for (pixel_y = 0; pixel_y < 4; pixel_y++) {
240
1008340
                    for (pixel_x = 0; pixel_x < 4; pixel_x++) {
241
806672
                        pixels[block_ptr++] = pixel;
242
                    }
243
201668
                    block_ptr += row_inc;
244
                }
245

50417
                ADVANCE_BLOCK();
246
            }
247
11688
            break;
248
249
        /* 2-color block encoding */
250
17912
        case 0x80:
251
        case 0x90:
252
17912
            n_blocks = (opcode & 0x0F) + 1;
253
254
            /* figure out which color pair to use to paint the 2-color block */
255
17912
            if ((opcode & 0xF0) == 0x80) {
256
                /* fetch the next 2 colors from bytestream and store in next
257
                 * available entry in the color pair table */
258
15813
                for (i = 0; i < CPAIR; i++) {
259
10542
                    pixel = bytestream2_get_byte(&s->gb);
260
10542
                    color_table_index = CPAIR * color_pair_index + i;
261
10542
                    s->color_pairs[color_table_index] = pixel;
262
                }
263
                /* this is the base index to use for this block */
264
5271
                color_table_index = CPAIR * color_pair_index;
265
5271
                color_pair_index++;
266
                /* wraparound */
267
5271
                if (color_pair_index == COLORS_PER_TABLE)
268
                    color_pair_index = 0;
269
            } else
270
12641
                color_table_index = CPAIR * bytestream2_get_byte(&s->gb);
271
272
36856
            while (n_blocks--) {
273
18944
                color_flags = bytestream2_get_be16(&s->gb);
274
18944
                flag_mask = 0x8000;
275
18944
                block_ptr = row_ptr + pixel_ptr;
276
94720
                for (pixel_y = 0; pixel_y < 4; pixel_y++) {
277
378880
                    for (pixel_x = 0; pixel_x < 4; pixel_x++) {
278
303104
                        if (color_flags & flag_mask)
279
121822
                            pixel = color_table_index + 1;
280
                        else
281
181282
                            pixel = color_table_index;
282
303104
                        flag_mask >>= 1;
283
303104
                        pixels[block_ptr++] = s->color_pairs[pixel];
284
                    }
285
75776
                    block_ptr += row_inc;
286
                }
287

18944
                ADVANCE_BLOCK();
288
            }
289
17912
            break;
290
291
        /* 4-color block encoding */
292
35882
        case 0xA0:
293
        case 0xB0:
294
35882
            n_blocks = (opcode & 0x0F) + 1;
295
296
            /* figure out which color quad to use to paint the 4-color block */
297
35882
            if ((opcode & 0xF0) == 0xA0) {
298
                /* fetch the next 4 colors from bytestream and store in next
299
                 * available entry in the color quad table */
300
72670
                for (i = 0; i < CQUAD; i++) {
301
58136
                    pixel = bytestream2_get_byte(&s->gb);
302
58136
                    color_table_index = CQUAD * color_quad_index + i;
303
58136
                    s->color_quads[color_table_index] = pixel;
304
                }
305
                /* this is the base index to use for this block */
306
14534
                color_table_index = CQUAD * color_quad_index;
307
14534
                color_quad_index++;
308
                /* wraparound */
309
14534
                if (color_quad_index == COLORS_PER_TABLE)
310
                    color_quad_index = 0;
311
            } else
312
21348
                color_table_index = CQUAD * bytestream2_get_byte(&s->gb);
313
314
77041
            while (n_blocks--) {
315
41159
                color_flags = bytestream2_get_be32(&s->gb);
316
                /* flag mask actually acts as a bit shift count here */
317
41159
                flag_mask = 30;
318
41159
                block_ptr = row_ptr + pixel_ptr;
319
205795
                for (pixel_y = 0; pixel_y < 4; pixel_y++) {
320
823180
                    for (pixel_x = 0; pixel_x < 4; pixel_x++) {
321
658544
                        pixel = color_table_index +
322
658544
                            ((color_flags >> flag_mask) & 0x03);
323
658544
                        flag_mask -= 2;
324
658544
                        pixels[block_ptr++] = s->color_quads[pixel];
325
                    }
326
164636
                    block_ptr += row_inc;
327
                }
328

41159
                ADVANCE_BLOCK();
329
            }
330
35882
            break;
331
332
        /* 8-color block encoding */
333
33474
        case 0xC0:
334
        case 0xD0:
335
33474
            n_blocks = (opcode & 0x0F) + 1;
336
337
            /* figure out which color octet to use to paint the 8-color block */
338
33474
            if ((opcode & 0xF0) == 0xC0) {
339
                /* fetch the next 8 colors from bytestream and store in next
340
                 * available entry in the color octet table */
341
98883
                for (i = 0; i < COCTET; i++) {
342
87896
                    pixel = bytestream2_get_byte(&s->gb);
343
87896
                    color_table_index = COCTET * color_octet_index + i;
344
87896
                    s->color_octets[color_table_index] = pixel;
345
                }
346
                /* this is the base index to use for this block */
347
10987
                color_table_index = COCTET * color_octet_index;
348
10987
                color_octet_index++;
349
                /* wraparound */
350
10987
                if (color_octet_index == COLORS_PER_TABLE)
351
                    color_octet_index = 0;
352
            } else
353
22487
                color_table_index = COCTET * bytestream2_get_byte(&s->gb);
354
355
76047
            while (n_blocks--) {
356
                /*
357
                  For this input of 6 hex bytes:
358
                    01 23 45 67 89 AB
359
                  Mangle it to this output:
360
                    flags_a = xx012456, flags_b = xx89A37B
361
                */
362
                /* build the color flags */
363
42573
                int val1 = bytestream2_get_be16(&s->gb);
364
42573
                int val2 = bytestream2_get_be16(&s->gb);
365
42573
                int val3 = bytestream2_get_be16(&s->gb);
366
42573
                color_flags_a = ((val1 & 0xFFF0) << 8) | (val2 >> 4);
367
42573
                color_flags_b = ((val3 & 0xFFF0) << 8) |
368
42573
                    ((val1 & 0x0F) << 8) | ((val2 & 0x0F) << 4) | (val3 & 0x0F);
369
370
42573
                color_flags = color_flags_a;
371
                /* flag mask actually acts as a bit shift count here */
372
42573
                flag_mask = 21;
373
42573
                block_ptr = row_ptr + pixel_ptr;
374
212865
                for (pixel_y = 0; pixel_y < 4; pixel_y++) {
375
                    /* reload flags at third row (iteration pixel_y == 2) */
376
170292
                    if (pixel_y == 2) {
377
42573
                        color_flags = color_flags_b;
378
42573
                        flag_mask = 21;
379
                    }
380
851460
                    for (pixel_x = 0; pixel_x < 4; pixel_x++) {
381
681168
                        pixel = color_table_index +
382
681168
                            ((color_flags >> flag_mask) & 0x07);
383
681168
                        flag_mask -= 3;
384
681168
                        pixels[block_ptr++] = s->color_octets[pixel];
385
                    }
386
170292
                    block_ptr += row_inc;
387
                }
388

42573
                ADVANCE_BLOCK();
389
            }
390
33474
            break;
391
392
        /* 16-color block encoding (every pixel is a different color) */
393
2043
        case 0xE0:
394
2043
            n_blocks = (opcode & 0x0F) + 1;
395
396
4240
            while (n_blocks--) {
397
2197
                block_ptr = row_ptr + pixel_ptr;
398
10985
                for (pixel_y = 0; pixel_y < 4; pixel_y++) {
399
43940
                    for (pixel_x = 0; pixel_x < 4; pixel_x++) {
400
35152
                        pixels[block_ptr++] = bytestream2_get_byte(&s->gb);
401
                    }
402
8788
                    block_ptr += row_inc;
403
                }
404

2197
                ADVANCE_BLOCK();
405
            }
406
2043
            break;
407
408
        case 0xF0:
409
            avpriv_request_sample(s->avctx, "0xF0 opcode");
410
            break;
411
        }
412
130817
    }
413
414
120
    return;
415
}
416
417
2
static av_cold int smc_decode_init(AVCodecContext *avctx)
418
{
419
2
    SmcContext *s = avctx->priv_data;
420
421
2
    s->avctx = avctx;
422
2
    avctx->pix_fmt = AV_PIX_FMT_PAL8;
423
424
2
    s->frame = av_frame_alloc();
425
2
    if (!s->frame)
426
        return AVERROR(ENOMEM);
427
428
2
    return 0;
429
}
430
431
120
static int smc_decode_frame(AVCodecContext *avctx,
432
                             void *data, int *got_frame,
433
                             AVPacket *avpkt)
434
{
435
120
    const uint8_t *buf = avpkt->data;
436
120
    int buf_size = avpkt->size;
437
120
    SmcContext *s = avctx->priv_data;
438
    int pal_size;
439
120
    const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, &pal_size);
440
    int ret;
441
120
    int total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);
442
443
120
    if (total_blocks / 1024 > avpkt->size)
444
        return AVERROR_INVALIDDATA;
445
446
120
    bytestream2_init(&s->gb, buf, buf_size);
447
448
120
    if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
449
        return ret;
450
451

120
    if (pal && pal_size == AVPALETTE_SIZE) {
452
1
        s->frame->palette_has_changed = 1;
453
1
        memcpy(s->pal, pal, AVPALETTE_SIZE);
454
119
    } else if (pal) {
455
        av_log(avctx, AV_LOG_ERROR, "Palette size %d is wrong\n", pal_size);
456
    }
457
458
120
    smc_decode_stream(s);
459
460
120
    *got_frame      = 1;
461
120
    if ((ret = av_frame_ref(data, s->frame)) < 0)
462
        return ret;
463
464
    /* always report that the buffer was completely consumed */
465
120
    return buf_size;
466
}
467
468
2
static av_cold int smc_decode_end(AVCodecContext *avctx)
469
{
470
2
    SmcContext *s = avctx->priv_data;
471
472
2
    av_frame_free(&s->frame);
473
474
2
    return 0;
475
}
476
477
AVCodec ff_smc_decoder = {
478
    .name           = "smc",
479
    .long_name      = NULL_IF_CONFIG_SMALL("QuickTime Graphics (SMC)"),
480
    .type           = AVMEDIA_TYPE_VIDEO,
481
    .id             = AV_CODEC_ID_SMC,
482
    .priv_data_size = sizeof(SmcContext),
483
    .init           = smc_decode_init,
484
    .close          = smc_decode_end,
485
    .decode         = smc_decode_frame,
486
    .capabilities   = AV_CODEC_CAP_DR1,
487
};