GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/kmvc.c Lines: 124 210 59.0 %
Date: 2021-04-20 04:37:23 Branches: 90 156 57.7 %

Line Branch Exec Source
1
/*
2
 * KMVC decoder
3
 * Copyright (c) 2006 Konstantin Shishkov
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
 * Karl Morton's Video Codec decoder
25
 */
26
27
#include <stdio.h>
28
#include <stdlib.h>
29
30
#include "avcodec.h"
31
#include "bytestream.h"
32
#include "decode.h"
33
#include "internal.h"
34
#include "libavutil/common.h"
35
36
#define KMVC_KEYFRAME 0x80
37
#define KMVC_PALETTE  0x40
38
#define KMVC_METHOD   0x0F
39
#define MAX_PALSIZE   256
40
41
/*
42
 * Decoder context
43
 */
44
typedef struct KmvcContext {
45
    AVCodecContext *avctx;
46
47
    GetByteContext g;
48
    uint8_t *cur, *prev;
49
    int setpal;
50
    int palsize;
51
    uint32_t pal[MAX_PALSIZE];
52
    uint8_t frm0[320 * 200], frm1[320 * 200];
53
} KmvcContext;
54
55
typedef struct BitBuf {
56
    int bits;
57
    int bitbuf;
58
} BitBuf;
59
60
#define BLK(data, x, y)  data[av_clip((x) + (y) * 320, 0, 320 * 200 -1)]
61
62
#define kmvc_init_getbits(bb, g)  bb.bits = 7; bb.bitbuf = bytestream2_get_byte(g);
63
64
#define kmvc_getbit(bb, g, res) {\
65
    res = 0; \
66
    if (bb.bitbuf & (1 << bb.bits)) res = 1; \
67
    bb.bits--; \
68
    if(bb.bits == -1) { \
69
        bb.bitbuf = bytestream2_get_byte(g); \
70
        bb.bits = 7; \
71
    } \
72
}
73
74
1
static int kmvc_decode_intra_8x8(KmvcContext * ctx, int w, int h)
75
{
76
    BitBuf bb;
77
    int res, val;
78
    int i, j;
79
    int bx, by;
80
    int l0x, l1x, l0y, l1y;
81
    int mx, my;
82
83
1
    kmvc_init_getbits(bb, &ctx->g);
84
85
21
    for (by = 0; by < h; by += 8)
86
820
        for (bx = 0; bx < w; bx += 8) {
87
800
            if (!bytestream2_get_bytes_left(&ctx->g)) {
88
                av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
89
                return AVERROR_INVALIDDATA;
90
            }
91

800
            kmvc_getbit(bb, &ctx->g, res);
92
800
            if (!res) {         // fill whole 8x8 block
93
800
                val = bytestream2_get_byte(&ctx->g);
94
52000
                for (i = 0; i < 64; i++)
95
51200
                    BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
96
            } else {            // handle four 4x4 subblocks
97
                for (i = 0; i < 4; i++) {
98
                    l0x = bx + (i & 1) * 4;
99
                    l0y = by + (i & 2) * 2;
100
                    kmvc_getbit(bb, &ctx->g, res);
101
                    if (!res) {
102
                        kmvc_getbit(bb, &ctx->g, res);
103
                        if (!res) {     // fill whole 4x4 block
104
                            val = bytestream2_get_byte(&ctx->g);
105
                            for (j = 0; j < 16; j++)
106
                                BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
107
                        } else {        // copy block from already decoded place
108
                            val = bytestream2_get_byte(&ctx->g);
109
                            mx = val & 0xF;
110
                            my = val >> 4;
111
                            if ((l0x-mx) + 320*(l0y-my) < 0 || (l0x-mx) + 320*(l0y-my) > 320*197 - 4) {
112
                                av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
113
                                return AVERROR_INVALIDDATA;
114
                            }
115
                            for (j = 0; j < 16; j++)
116
                                BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
117
                                    BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my);
118
                        }
119
                    } else {    // descend to 2x2 sub-sub-blocks
120
                        for (j = 0; j < 4; j++) {
121
                            l1x = l0x + (j & 1) * 2;
122
                            l1y = l0y + (j & 2);
123
                            kmvc_getbit(bb, &ctx->g, res);
124
                            if (!res) {
125
                                kmvc_getbit(bb, &ctx->g, res);
126
                                if (!res) {     // fill whole 2x2 block
127
                                    val = bytestream2_get_byte(&ctx->g);
128
                                    BLK(ctx->cur, l1x, l1y) = val;
129
                                    BLK(ctx->cur, l1x + 1, l1y) = val;
130
                                    BLK(ctx->cur, l1x, l1y + 1) = val;
131
                                    BLK(ctx->cur, l1x + 1, l1y + 1) = val;
132
                                } else {        // copy block from already decoded place
133
                                    val = bytestream2_get_byte(&ctx->g);
134
                                    mx = val & 0xF;
135
                                    my = val >> 4;
136
                                    if ((l1x-mx) + 320*(l1y-my) < 0 || (l1x-mx) + 320*(l1y-my) > 320*199 - 2) {
137
                                        av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
138
                                        return AVERROR_INVALIDDATA;
139
                                    }
140
                                    BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my);
141
                                    BLK(ctx->cur, l1x + 1, l1y) =
142
                                        BLK(ctx->cur, l1x + 1 - mx, l1y - my);
143
                                    BLK(ctx->cur, l1x, l1y + 1) =
144
                                        BLK(ctx->cur, l1x - mx, l1y + 1 - my);
145
                                    BLK(ctx->cur, l1x + 1, l1y + 1) =
146
                                        BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my);
147
                                }
148
                            } else {    // read values for block
149
                                BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
150
                                BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
151
                                BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
152
                                BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
153
                            }
154
                        }
155
                    }
156
                }
157
            }
158
        }
159
160
1
    return 0;
161
}
162
163
75
static int kmvc_decode_inter_8x8(KmvcContext * ctx, int w, int h)
164
{
165
    BitBuf bb;
166
    int res, val;
167
    int i, j;
168
    int bx, by;
169
    int l0x, l1x, l0y, l1y;
170
    int mx, my;
171
172
75
    kmvc_init_getbits(bb, &ctx->g);
173
174
1575
    for (by = 0; by < h; by += 8)
175
61500
        for (bx = 0; bx < w; bx += 8) {
176

60000
            kmvc_getbit(bb, &ctx->g, res);
177
60000
            if (!res) {
178

40230
                kmvc_getbit(bb, &ctx->g, res);
179
40230
                if (!res) {     // fill whole 8x8 block
180
39003
                    if (!bytestream2_get_bytes_left(&ctx->g)) {
181
                        av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
182
                        return AVERROR_INVALIDDATA;
183
                    }
184
39003
                    val = bytestream2_get_byte(&ctx->g);
185
2535195
                    for (i = 0; i < 64; i++)
186
2496192
                        BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
187
                } else {        // copy block from previous frame
188
79755
                    for (i = 0; i < 64; i++)
189
78528
                        BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) =
190
78528
                            BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3));
191
                }
192
            } else {            // handle four 4x4 subblocks
193
19770
                if (!bytestream2_get_bytes_left(&ctx->g)) {
194
                    av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
195
                    return AVERROR_INVALIDDATA;
196
                }
197
98850
                for (i = 0; i < 4; i++) {
198
79080
                    l0x = bx + (i & 1) * 4;
199
79080
                    l0y = by + (i & 2) * 2;
200

79080
                    kmvc_getbit(bb, &ctx->g, res);
201
79080
                    if (!res) {
202

15620
                        kmvc_getbit(bb, &ctx->g, res);
203
15620
                        if (!res) {     // fill whole 4x4 block
204
6017
                            val = bytestream2_get_byte(&ctx->g);
205
102289
                            for (j = 0; j < 16; j++)
206
96272
                                BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
207
                        } else {        // copy block
208
9603
                            val = bytestream2_get_byte(&ctx->g);
209
9603
                            mx = (val & 0xF) - 8;
210
9603
                            my = (val >> 4) - 8;
211

9603
                            if ((l0x+mx) + 320*(l0y+my) < 0 || (l0x+mx) + 320*(l0y+my) > 320*197 - 4) {
212
                                av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
213
                                return AVERROR_INVALIDDATA;
214
                            }
215
163251
                            for (j = 0; j < 16; j++)
216
153648
                                BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
217
153648
                                    BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my);
218
                        }
219
                    } else {    // descend to 2x2 sub-sub-blocks
220
317300
                        for (j = 0; j < 4; j++) {
221
253840
                            l1x = l0x + (j & 1) * 2;
222
253840
                            l1y = l0y + (j & 2);
223

253840
                            kmvc_getbit(bb, &ctx->g, res);
224
253840
                            if (!res) {
225

126609
                                kmvc_getbit(bb, &ctx->g, res);
226
126609
                                if (!res) {     // fill whole 2x2 block
227
21343
                                    val = bytestream2_get_byte(&ctx->g);
228
21343
                                    BLK(ctx->cur, l1x, l1y) = val;
229
21343
                                    BLK(ctx->cur, l1x + 1, l1y) = val;
230
21343
                                    BLK(ctx->cur, l1x, l1y + 1) = val;
231
21343
                                    BLK(ctx->cur, l1x + 1, l1y + 1) = val;
232
                                } else {        // copy block
233
105266
                                    val = bytestream2_get_byte(&ctx->g);
234
105266
                                    mx = (val & 0xF) - 8;
235
105266
                                    my = (val >> 4) - 8;
236

105266
                                    if ((l1x+mx) + 320*(l1y+my) < 0 || (l1x+mx) + 320*(l1y+my) > 320*199 - 2) {
237
                                        av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
238
                                        return AVERROR_INVALIDDATA;
239
                                    }
240
105266
                                    BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my);
241
105266
                                    BLK(ctx->cur, l1x + 1, l1y) =
242
105266
                                        BLK(ctx->prev, l1x + 1 + mx, l1y + my);
243
105266
                                    BLK(ctx->cur, l1x, l1y + 1) =
244
105266
                                        BLK(ctx->prev, l1x + mx, l1y + 1 + my);
245
105266
                                    BLK(ctx->cur, l1x + 1, l1y + 1) =
246
105266
                                        BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my);
247
                                }
248
                            } else {    // read values for block
249
127231
                                BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
250
127231
                                BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
251
127231
                                BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
252
127231
                                BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
253
                            }
254
                        }
255
                    }
256
                }
257
            }
258
        }
259
260
75
    return 0;
261
}
262
263
76
static int decode_frame(AVCodecContext * avctx, void *data, int *got_frame,
264
                        AVPacket *avpkt)
265
{
266
76
    KmvcContext *const ctx = avctx->priv_data;
267
76
    AVFrame *frame = data;
268
    uint8_t *out, *src;
269
    int i, ret;
270
    int header;
271
    int blocksize;
272
273
76
    bytestream2_init(&ctx->g, avpkt->data, avpkt->size);
274
275
76
    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
276
        return ret;
277
278
76
    frame->palette_has_changed = ff_copy_palette(ctx->pal, avpkt, avctx);
279
280
76
    header = bytestream2_get_byte(&ctx->g);
281
282
    /* blocksize 127 is really palette change event */
283
76
    if (bytestream2_peek_byte(&ctx->g) == 127) {
284
        bytestream2_skip(&ctx->g, 3);
285
        for (i = 0; i < 127; i++) {
286
            ctx->pal[i + (header & 0x81)] = 0xFFU << 24 | bytestream2_get_be24(&ctx->g);
287
            bytestream2_skip(&ctx->g, 1);
288
        }
289
        bytestream2_seek(&ctx->g, -127 * 4 - 3, SEEK_CUR);
290
    }
291
292
76
    if (header & KMVC_KEYFRAME) {
293
1
        frame->key_frame = 1;
294
1
        frame->pict_type = AV_PICTURE_TYPE_I;
295
    } else {
296
75
        frame->key_frame = 0;
297
75
        frame->pict_type = AV_PICTURE_TYPE_P;
298
    }
299
300
76
    if (header & KMVC_PALETTE) {
301
1
        frame->palette_has_changed = 1;
302
        // palette starts from index 1 and has 127 entries
303
256
        for (i = 1; i <= ctx->palsize; i++) {
304
255
            ctx->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&ctx->g);
305
        }
306
    }
307
308
76
    if (ctx->setpal) {
309
        ctx->setpal = 0;
310
        frame->palette_has_changed = 1;
311
    }
312
313
    /* make the palette available on the way out */
314
76
    memcpy(frame->data[1], ctx->pal, 1024);
315
316
76
    blocksize = bytestream2_get_byte(&ctx->g);
317
318

76
    if (blocksize != 8 && blocksize != 127) {
319
        av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize);
320
        return AVERROR_INVALIDDATA;
321
    }
322
76
    memset(ctx->cur, 0, 320 * 200);
323

76
    switch (header & KMVC_METHOD) {
324
    case 0:
325
    case 1: // used in palette changed event
326
        memcpy(ctx->cur, ctx->prev, 320 * 200);
327
        break;
328
1
    case 3:
329
1
        kmvc_decode_intra_8x8(ctx, avctx->width, avctx->height);
330
1
        break;
331
75
    case 4:
332
75
        kmvc_decode_inter_8x8(ctx, avctx->width, avctx->height);
333
75
        break;
334
    default:
335
        av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD);
336
        return AVERROR_INVALIDDATA;
337
    }
338
339
76
    out = frame->data[0];
340
76
    src = ctx->cur;
341
12236
    for (i = 0; i < avctx->height; i++) {
342
12160
        memcpy(out, src, avctx->width);
343
12160
        src += 320;
344
12160
        out += frame->linesize[0];
345
    }
346
347
    /* flip buffers */
348
76
    FFSWAP(uint8_t *, ctx->cur, ctx->prev);
349
350
76
    *got_frame = 1;
351
352
    /* always report that the buffer was completely consumed */
353
76
    return avpkt->size;
354
}
355
356
357
358
/*
359
 * Init kmvc decoder
360
 */
361
2
static av_cold int decode_init(AVCodecContext * avctx)
362
{
363
2
    KmvcContext *const c = avctx->priv_data;
364
    int i;
365
366
2
    c->avctx = avctx;
367
368

2
    if (avctx->width > 320 || avctx->height > 200) {
369
        av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n");
370
        return AVERROR(EINVAL);
371
    }
372
373
2
    c->cur = c->frm0;
374
2
    c->prev = c->frm1;
375
376
514
    for (i = 0; i < 256; i++) {
377
512
        c->pal[i] = 0xFFU << 24 | i * 0x10101;
378
    }
379
380
2
    if (avctx->extradata_size < 12) {
381
        av_log(avctx, AV_LOG_WARNING,
382
               "Extradata missing, decoding may not work properly...\n");
383
        c->palsize = 127;
384
    } else {
385
2
        c->palsize = AV_RL16(avctx->extradata + 10);
386
2
        if (c->palsize >= (unsigned)MAX_PALSIZE) {
387
            c->palsize = 127;
388
            av_log(avctx, AV_LOG_ERROR, "KMVC palette too large\n");
389
            return AVERROR_INVALIDDATA;
390
        }
391
    }
392
393
2
    if (avctx->extradata_size == 1036) {        // palette in extradata
394
        uint8_t *src = avctx->extradata + 12;
395
        for (i = 0; i < 256; i++) {
396
            c->pal[i] = AV_RL32(src);
397
            src += 4;
398
        }
399
        c->setpal = 1;
400
    }
401
402
2
    avctx->pix_fmt = AV_PIX_FMT_PAL8;
403
404
2
    return 0;
405
}
406
407
AVCodec ff_kmvc_decoder = {
408
    .name           = "kmvc",
409
    .long_name      = NULL_IF_CONFIG_SMALL("Karl Morton's video codec"),
410
    .type           = AVMEDIA_TYPE_VIDEO,
411
    .id             = AV_CODEC_ID_KMVC,
412
    .priv_data_size = sizeof(KmvcContext),
413
    .init           = decode_init,
414
    .decode         = decode_frame,
415
    .capabilities   = AV_CODEC_CAP_DR1,
416
};