GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/xxan.c Lines: 228 269 84.8 %
Date: 2020-08-13 15:06:06 Branches: 87 123 70.7 %

Line Branch Exec Source
1
/*
2
 * Wing Commander/Xan Video Decoder
3
 * Copyright (C) 2011 Konstantin Shishkov
4
 * based on work by Mike Melanson
5
 *
6
 * This file is part of FFmpeg.
7
 *
8
 * FFmpeg is free software; you can redistribute it and/or
9
 * modify it under the terms of the GNU Lesser General Public
10
 * License as published by the Free Software Foundation; either
11
 * version 2.1 of the License, or (at your option) any later version.
12
 *
13
 * FFmpeg is distributed in the hope that it will be useful,
14
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16
 * Lesser General Public License for more details.
17
 *
18
 * You should have received a copy of the GNU Lesser General Public
19
 * License along with FFmpeg; if not, write to the Free Software
20
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21
 */
22
23
#include "libavutil/intreadwrite.h"
24
#include "libavutil/mem.h"
25
26
#include "avcodec.h"
27
#include "bytestream.h"
28
#include "internal.h"
29
30
typedef struct XanContext {
31
    AVCodecContext *avctx;
32
    AVFrame *pic;
33
34
    uint8_t *y_buffer;
35
    uint8_t *scratch_buffer;
36
    int     buffer_size;
37
    GetByteContext gb;
38
} XanContext;
39
40
3
static av_cold int xan_decode_end(AVCodecContext *avctx)
41
{
42
3
    XanContext *s = avctx->priv_data;
43
44
3
    av_frame_free(&s->pic);
45
46
3
    av_freep(&s->y_buffer);
47
3
    av_freep(&s->scratch_buffer);
48
49
3
    return 0;
50
}
51
52
3
static av_cold int xan_decode_init(AVCodecContext *avctx)
53
{
54
3
    XanContext *s = avctx->priv_data;
55
56
3
    s->avctx = avctx;
57
58
3
    avctx->pix_fmt = AV_PIX_FMT_YUV420P;
59
60
3
    if (avctx->height < 8) {
61
        av_log(avctx, AV_LOG_ERROR, "Invalid frame height: %d.\n", avctx->height);
62
        return AVERROR(EINVAL);
63
    }
64
3
    if (avctx->width & 1) {
65
        av_log(avctx, AV_LOG_ERROR, "Invalid frame width: %d.\n", avctx->width);
66
        return AVERROR(EINVAL);
67
    }
68
69
3
    s->buffer_size = avctx->width * avctx->height;
70
3
    s->y_buffer = av_malloc(s->buffer_size);
71
3
    if (!s->y_buffer)
72
        return AVERROR(ENOMEM);
73
3
    s->scratch_buffer = av_malloc(s->buffer_size + 130);
74
3
    if (!s->scratch_buffer) {
75
        xan_decode_end(avctx);
76
        return AVERROR(ENOMEM);
77
    }
78
79
3
    s->pic = av_frame_alloc();
80
3
    if (!s->pic) {
81
        xan_decode_end(avctx);
82
        return AVERROR(ENOMEM);
83
    }
84
85
3
    return 0;
86
}
87
88
21
static int xan_unpack_luma(XanContext *s,
89
                           uint8_t *dst, const int dst_size)
90
{
91
    int tree_size, eof;
92
    int bits, mask;
93
    int tree_root, node;
94
21
    const uint8_t *dst_end = dst + dst_size;
95
21
    GetByteContext tree = s->gb;
96
21
    int start_off = bytestream2_tell(&tree);
97
98
21
    tree_size = bytestream2_get_byte(&s->gb);
99
21
    eof       = bytestream2_get_byte(&s->gb);
100
21
    tree_root = eof + tree_size;
101
21
    bytestream2_skip(&s->gb, tree_size * 2);
102
103
21
    node = tree_root;
104
21
    bits = bytestream2_get_byte(&s->gb);
105
21
    mask = 0x80;
106
691350
    for (;;) {
107
691371
        int bit = !!(bits & mask);
108
691371
        mask >>= 1;
109
691371
        bytestream2_seek(&tree, start_off + node*2 + bit - eof * 2, SEEK_SET);
110
691371
        node = bytestream2_get_byte(&tree);
111
691371
        if (node == eof)
112
21
            break;
113
691350
        if (node < eof) {
114
554400
            *dst++ = node;
115
554400
            if (dst > dst_end)
116
                break;
117
554400
            node = tree_root;
118
        }
119
691350
        if (!mask) {
120
86409
            if (bytestream2_get_bytes_left(&s->gb) <= 0)
121
                break;
122
86409
            bits = bytestream2_get_byteu(&s->gb);
123
86409
            mask = 0x80;
124
        }
125
    }
126
21
    return dst != dst_end ? AVERROR_INVALIDDATA : 0;
127
}
128
129
/* almost the same as in xan_wc3 decoder */
130
26
static int xan_unpack(XanContext *s,
131
                      uint8_t *dest, const int dest_len)
132
{
133
    uint8_t opcode;
134
    int size;
135
26
    uint8_t *orig_dest = dest;
136
26
    const uint8_t *dest_end = dest + dest_len;
137
138
11861
    while (dest < dest_end) {
139
11856
        if (bytestream2_get_bytes_left(&s->gb) <= 0)
140
            return AVERROR_INVALIDDATA;
141
142
11856
        opcode = bytestream2_get_byteu(&s->gb);
143
144
11856
        if (opcode < 0xe0) {
145
            int size2, back;
146
11348
            if ((opcode & 0x80) == 0) {
147
7882
                size  = opcode & 3;
148
7882
                back  = ((opcode & 0x60) << 3) + bytestream2_get_byte(&s->gb) + 1;
149
7882
                size2 = ((opcode & 0x1c) >> 2) + 3;
150
3466
            } else if ((opcode & 0x40) == 0) {
151
3066
                size  = bytestream2_peek_byte(&s->gb) >> 6;
152
3066
                back  = (bytestream2_get_be16(&s->gb) & 0x3fff) + 1;
153
3066
                size2 = (opcode & 0x3f) + 4;
154
            } else {
155
400
                size  = opcode & 3;
156
400
                back  = ((opcode & 0x10) << 12) + bytestream2_get_be16(&s->gb) + 1;
157
400
                size2 = ((opcode & 0x0c) <<  6) + bytestream2_get_byte(&s->gb) + 5;
158
400
                if (size + size2 > dest_end - dest)
159
                    break;
160
            }
161
11348
            if (dest + size + size2 > dest_end ||
162
11348
                dest - orig_dest + size < back)
163
                return AVERROR_INVALIDDATA;
164
11348
            bytestream2_get_buffer(&s->gb, dest, size);
165
11348
            dest += size;
166
11348
            av_memcpy_backptr(dest, back, size2);
167
11348
            dest += size2;
168
        } else {
169
508
            int finish = opcode >= 0xfc;
170
171
508
            size = finish ? opcode & 3 : ((opcode & 0x1f) << 2) + 4;
172
508
            if (dest_end - dest < size)
173
                return AVERROR_INVALIDDATA;
174
508
            bytestream2_get_buffer(&s->gb, dest, size);
175
508
            dest += size;
176
508
            if (finish)
177
21
                break;
178
        }
179
    }
180
26
    return dest - orig_dest;
181
}
182
183
21
static int xan_decode_chroma(AVCodecContext *avctx, unsigned chroma_off)
184
{
185
21
    XanContext *s = avctx->priv_data;
186
    uint8_t *U, *V;
187
    int val, uval, vval;
188
    int i, j;
189
    const uint8_t *src, *src_end;
190
    const uint8_t *table;
191
    int mode, offset, dec_size, table_size;
192
193
21
    if (!chroma_off)
194
        return 0;
195
21
    if (chroma_off + 4 >= bytestream2_get_bytes_left(&s->gb)) {
196
        av_log(avctx, AV_LOG_ERROR, "Invalid chroma block position\n");
197
        return AVERROR_INVALIDDATA;
198
    }
199
21
    bytestream2_seek(&s->gb, chroma_off + 4, SEEK_SET);
200
21
    mode        = bytestream2_get_le16(&s->gb);
201
21
    table       = s->gb.buffer;
202
21
    table_size  = bytestream2_get_le16(&s->gb);
203
21
    offset      = table_size * 2;
204
21
    table_size += 1;
205
206
21
    if (offset >= bytestream2_get_bytes_left(&s->gb)) {
207
        av_log(avctx, AV_LOG_ERROR, "Invalid chroma block offset\n");
208
        return AVERROR_INVALIDDATA;
209
    }
210
211
21
    bytestream2_skip(&s->gb, offset);
212
21
    memset(s->scratch_buffer, 0, s->buffer_size);
213
21
    dec_size = xan_unpack(s, s->scratch_buffer, s->buffer_size);
214
21
    if (dec_size < 0) {
215
        av_log(avctx, AV_LOG_ERROR, "Chroma unpacking failed\n");
216
        return dec_size;
217
    }
218
219
21
    U = s->pic->data[1];
220
21
    V = s->pic->data[2];
221
21
    src     = s->scratch_buffer;
222
21
    src_end = src + dec_size;
223
21
    if (mode) {
224
332
        for (j = 0; j < avctx->height >> 1; j++) {
225
52808
            for (i = 0; i < avctx->width >> 1; i++) {
226
52480
                if (src_end - src < 1)
227
                    return 0;
228
52480
                val = *src++;
229
52480
                if (val) {
230
52480
                    if (val >= table_size)
231
                        return AVERROR_INVALIDDATA;
232
52480
                    val  = AV_RL16(table + (val << 1));
233
52480
                    uval = (val >> 3) & 0xF8;
234
52480
                    vval = (val >> 8) & 0xF8;
235
52480
                    U[i] = uval | (uval >> 5);
236
52480
                    V[i] = vval | (vval >> 5);
237
                }
238
            }
239
328
            U += s->pic->linesize[1];
240
328
            V += s->pic->linesize[2];
241
        }
242
4
        if (avctx->height & 1) {
243
4
            memcpy(U, U - s->pic->linesize[1], avctx->width >> 1);
244
4
            memcpy(V, V - s->pic->linesize[2], avctx->width >> 1);
245
        }
246
    } else {
247
17
        uint8_t *U2 = U + s->pic->linesize[1];
248
17
        uint8_t *V2 = V + s->pic->linesize[2];
249
250
714
        for (j = 0; j < avctx->height >> 2; j++) {
251
56457
            for (i = 0; i < avctx->width >> 1; i += 2) {
252
55760
                if (src_end - src < 1)
253
                    return 0;
254
55760
                val = *src++;
255
55760
                if (val) {
256
17613
                    if (val >= table_size)
257
                        return AVERROR_INVALIDDATA;
258
17613
                    val  = AV_RL16(table + (val << 1));
259
17613
                    uval = (val >> 3) & 0xF8;
260
17613
                    vval = (val >> 8) & 0xF8;
261
17613
                    U[i] = U[i+1] = U2[i] = U2[i+1] = uval | (uval >> 5);
262
17613
                    V[i] = V[i+1] = V2[i] = V2[i+1] = vval | (vval >> 5);
263
                }
264
            }
265
697
            U  += s->pic->linesize[1] * 2;
266
697
            V  += s->pic->linesize[2] * 2;
267
697
            U2 += s->pic->linesize[1] * 2;
268
697
            V2 += s->pic->linesize[2] * 2;
269
        }
270
17
        if (avctx->height & 3) {
271
17
            int lines = ((avctx->height + 1) >> 1) - (avctx->height >> 2) * 2;
272
273
17
            memcpy(U, U - lines * s->pic->linesize[1], lines * s->pic->linesize[1]);
274
17
            memcpy(V, V - lines * s->pic->linesize[2], lines * s->pic->linesize[2]);
275
        }
276
    }
277
278
21
    return 0;
279
}
280
281
5
static int xan_decode_frame_type0(AVCodecContext *avctx)
282
{
283
5
    XanContext *s = avctx->priv_data;
284
5
    uint8_t *ybuf, *prev_buf, *src = s->scratch_buffer;
285
    unsigned  chroma_off, corr_off;
286
    int cur, last;
287
    int i, j;
288
    int ret;
289
290
5
    chroma_off = bytestream2_get_le32(&s->gb);
291
5
    corr_off   = bytestream2_get_le32(&s->gb);
292
293
5
    if ((ret = xan_decode_chroma(avctx, chroma_off)) != 0)
294
        return ret;
295
296
5
    if (corr_off >= bytestream2_size(&s->gb)) {
297
        av_log(avctx, AV_LOG_WARNING, "Ignoring invalid correction block position\n");
298
        corr_off = 0;
299
    }
300
5
    bytestream2_seek(&s->gb, 12, SEEK_SET);
301
5
    ret = xan_unpack_luma(s, src, s->buffer_size >> 1);
302
5
    if (ret) {
303
        av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
304
        return ret;
305
    }
306
307
5
    ybuf = s->y_buffer;
308
5
    last = *src++;
309
5
    ybuf[0] = last << 1;
310
800
    for (j = 1; j < avctx->width - 1; j += 2) {
311
795
        cur = (last + *src++) & 0x1F;
312
795
        ybuf[j]   = last + cur;
313
795
        ybuf[j+1] = cur << 1;
314
795
        last = cur;
315
    }
316
5
    ybuf[j]  = last << 1;
317
5
    prev_buf = ybuf;
318
5
    ybuf += avctx->width;
319
320
825
    for (i = 1; i < avctx->height; i++) {
321
820
        last = ((prev_buf[0] >> 1) + *src++) & 0x1F;
322
820
        ybuf[0] = last << 1;
323
131200
        for (j = 1; j < avctx->width - 1; j += 2) {
324
130380
            cur = ((prev_buf[j + 1] >> 1) + *src++) & 0x1F;
325
130380
            ybuf[j]   = last + cur;
326
130380
            ybuf[j+1] = cur << 1;
327
130380
            last = cur;
328
        }
329
820
        ybuf[j] = last << 1;
330
820
        prev_buf = ybuf;
331
820
        ybuf += avctx->width;
332
    }
333
334
5
    if (corr_off) {
335
        int dec_size;
336
337
5
        bytestream2_seek(&s->gb, 8 + corr_off, SEEK_SET);
338
5
        dec_size = xan_unpack(s, s->scratch_buffer, s->buffer_size / 2);
339
5
        if (dec_size < 0)
340
            dec_size = 0;
341
        else
342
5
            dec_size = FFMIN(dec_size, s->buffer_size/2 - 1);
343
344
132000
        for (i = 0; i < dec_size; i++)
345
131995
            s->y_buffer[i*2+1] = (s->y_buffer[i*2+1] + (s->scratch_buffer[i] << 1)) & 0x3F;
346
    }
347
348
5
    src  = s->y_buffer;
349
5
    ybuf = s->pic->data[0];
350
830
    for (j = 0; j < avctx->height; j++) {
351
264825
        for (i = 0; i < avctx->width; i++)
352
264000
            ybuf[i] = (src[i] << 2) | (src[i] >> 3);
353
825
        src  += avctx->width;
354
825
        ybuf += s->pic->linesize[0];
355
    }
356
357
5
    return 0;
358
}
359
360
16
static int xan_decode_frame_type1(AVCodecContext *avctx)
361
{
362
16
    XanContext *s = avctx->priv_data;
363
16
    uint8_t *ybuf, *src = s->scratch_buffer;
364
    int cur, last;
365
    int i, j;
366
    int ret;
367
368
16
    if ((ret = xan_decode_chroma(avctx, bytestream2_get_le32(&s->gb))) != 0)
369
        return ret;
370
371
16
    bytestream2_seek(&s->gb, 16, SEEK_SET);
372
16
    ret = xan_unpack_luma(s, src,
373
16
                          s->buffer_size >> 1);
374
16
    if (ret) {
375
        av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
376
        return ret;
377
    }
378
379
16
    ybuf = s->y_buffer;
380
2656
    for (i = 0; i < avctx->height; i++) {
381
2640
        last = (ybuf[0] + (*src++ << 1)) & 0x3F;
382
2640
        ybuf[0] = last;
383
422400
        for (j = 1; j < avctx->width - 1; j += 2) {
384
419760
            cur = (ybuf[j + 1] + (*src++ << 1)) & 0x3F;
385
419760
            ybuf[j]   = (last + cur) >> 1;
386
419760
            ybuf[j+1] = cur;
387
419760
            last = cur;
388
        }
389
2640
        ybuf[j] = last;
390
2640
        ybuf += avctx->width;
391
    }
392
393
16
    src = s->y_buffer;
394
16
    ybuf = s->pic->data[0];
395
2656
    for (j = 0; j < avctx->height; j++) {
396
847440
        for (i = 0; i < avctx->width; i++)
397
844800
            ybuf[i] = (src[i] << 2) | (src[i] >> 3);
398
2640
        src  += avctx->width;
399
2640
        ybuf += s->pic->linesize[0];
400
    }
401
402
16
    return 0;
403
}
404
405
21
static int xan_decode_frame(AVCodecContext *avctx,
406
                            void *data, int *got_frame,
407
                            AVPacket *avpkt)
408
{
409
21
    XanContext *s = avctx->priv_data;
410
    int ftype;
411
    int ret;
412
413
21
    if ((ret = ff_reget_buffer(avctx, s->pic, 0)) < 0)
414
        return ret;
415
416
21
    bytestream2_init(&s->gb, avpkt->data, avpkt->size);
417
21
    ftype = bytestream2_get_le32(&s->gb);
418
21
    switch (ftype) {
419
5
    case 0:
420
5
        ret = xan_decode_frame_type0(avctx);
421
5
        break;
422
16
    case 1:
423
16
        ret = xan_decode_frame_type1(avctx);
424
16
        break;
425
    default:
426
        av_log(avctx, AV_LOG_ERROR, "Unknown frame type %d\n", ftype);
427
        return AVERROR_INVALIDDATA;
428
    }
429
21
    if (ret)
430
        return ret;
431
432
21
    if ((ret = av_frame_ref(data, s->pic)) < 0)
433
        return ret;
434
435
21
    *got_frame = 1;
436
437
21
    return avpkt->size;
438
}
439
440
AVCodec ff_xan_wc4_decoder = {
441
    .name           = "xan_wc4",
442
    .long_name      = NULL_IF_CONFIG_SMALL("Wing Commander IV / Xxan"),
443
    .type           = AVMEDIA_TYPE_VIDEO,
444
    .id             = AV_CODEC_ID_XAN_WC4,
445
    .priv_data_size = sizeof(XanContext),
446
    .init           = xan_decode_init,
447
    .close          = xan_decode_end,
448
    .decode         = xan_decode_frame,
449
    .capabilities   = AV_CODEC_CAP_DR1,
450
};