GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/mimic.c Lines: 130 164 79.3 %
Date: 2021-04-18 10:33:33 Branches: 61 94 64.9 %

Line Branch Exec Source
1
/*
2
 * Copyright (C) 2005  Ole André Vadla Ravnås <oleavr@gmail.com>
3
 * Copyright (C) 2008  Ramiro Polla
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
#include <stdlib.h>
23
#include <string.h>
24
#include <stdint.h>
25
26
#include "libavutil/mem_internal.h"
27
#include "libavutil/thread.h"
28
29
#include "avcodec.h"
30
#include "blockdsp.h"
31
#include "internal.h"
32
#include "get_bits.h"
33
#include "bytestream.h"
34
#include "bswapdsp.h"
35
#include "hpeldsp.h"
36
#include "idctdsp.h"
37
#include "thread.h"
38
39
#define MIMIC_HEADER_SIZE   20
40
#define MIMIC_VLC_BITS      11
41
42
typedef struct MimicContext {
43
    AVCodecContext *avctx;
44
45
    int             num_vblocks[3];
46
    int             num_hblocks[3];
47
48
    void           *swap_buf;
49
    int             swap_buf_size;
50
51
    int             cur_index;
52
    int             prev_index;
53
54
    ThreadFrame     frames     [16];
55
56
    DECLARE_ALIGNED(32, int16_t, dct_block)[64];
57
58
    GetBitContext   gb;
59
    ScanTable       scantable;
60
    BlockDSPContext bdsp;
61
    BswapDSPContext bbdsp;
62
    HpelDSPContext  hdsp;
63
    IDCTDSPContext  idsp;
64
65
    /* Kept in the context so multithreading can have a constant to read from */
66
    int             next_cur_index;
67
    int             next_prev_index;
68
} MimicContext;
69
70
static VLC block_vlc;
71
72
static const uint8_t huffsyms[] = {
73
    0x10, 0x20, 0x30, 0x00, 0x11, 0x40, 0x50, 0x12, 0x13, 0x21, 0x31, 0x60,
74
    0x14, 0x15, 0x16, 0x22, 0x41, 0x17, 0x18, 0x23, 0x24, 0x25, 0x32, 0x42,
75
    0x51, 0x61, 0x70, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x26, 0x27,
76
    0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x33, 0x34, 0x35, 0x36, 0x37,
77
    0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x43, 0x44, 0x45, 0x46, 0x47,
78
    0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x52, 0x53, 0x54, 0x55, 0x56,
79
    0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x62, 0x63, 0x64, 0x65,
80
    0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x71, 0x72, 0x73,
81
    0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E,
82
};
83
84
static const uint8_t huffbits[] = {
85
     2,  2,  3,  4,  4,  4,  5,  5,  6,  6,  6,  6,  7,  7,  7,  7,  8,  8,
86
     8,  8,  9,  9,  9,  9, 10, 10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12,
87
    13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17, 17,
88
    17, 17, 18, 18, 18, 18, 19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21,
89
    22, 22, 22, 22, 23, 23, 23, 23, 24, 24, 24, 24, 25, 25, 25, 25, 26, 26,
90
    26, 26, 27, 27, 27, 27, 28, 28, 28, 28, 29, 29, 29, 29, 30, 30, 30,
91
};
92
93
static const uint8_t col_zag[64] = {
94
     0,  8,  1,  2,  9, 16, 24, 17,
95
    10,  3,  4, 11, 18, 25, 32, 40,
96
    33, 26, 19, 12,  5,  6, 13, 20,
97
    27, 34, 41, 48, 56, 49, 42, 35,
98
    28, 21, 14,  7, 15, 22, 29, 36,
99
    43, 50, 57, 58, 51, 44, 37, 30,
100
    23, 31, 38, 45, 52, 59, 39, 46,
101
    53, 60, 61, 54, 47, 55, 62, 63,
102
};
103
104
2
static av_cold int mimic_decode_end(AVCodecContext *avctx)
105
{
106
2
    MimicContext *ctx = avctx->priv_data;
107
    int i;
108
109
2
    av_freep(&ctx->swap_buf);
110
2
    ctx->swap_buf_size = 0;
111
112
34
    for (i = 0; i < FF_ARRAY_ELEMS(ctx->frames); i++) {
113
32
        if (ctx->frames[i].f)
114
32
            ff_thread_release_buffer(avctx, &ctx->frames[i]);
115
32
        av_frame_free(&ctx->frames[i].f);
116
    }
117
118
2
    return 0;
119
}
120
121
1
static av_cold void mimic_init_static(void)
122
{
123
1
    INIT_VLC_STATIC_FROM_LENGTHS(&block_vlc, MIMIC_VLC_BITS, FF_ARRAY_ELEMS(huffbits),
124
                                 huffbits, 1, huffsyms, 1, 1, 0, 0, 4368);
125
1
}
126
127
2
static av_cold int mimic_decode_init(AVCodecContext *avctx)
128
{
129
    static AVOnce init_static_once = AV_ONCE_INIT;
130
2
    MimicContext *ctx = avctx->priv_data;
131
    int i;
132
133
2
    ctx->prev_index = 0;
134
2
    ctx->cur_index  = 15;
135
136
2
    ff_blockdsp_init(&ctx->bdsp, avctx);
137
2
    ff_bswapdsp_init(&ctx->bbdsp);
138
2
    ff_hpeldsp_init(&ctx->hdsp, avctx->flags);
139
2
    ff_idctdsp_init(&ctx->idsp, avctx);
140
2
    ff_init_scantable(ctx->idsp.idct_permutation, &ctx->scantable, col_zag);
141
142
34
    for (i = 0; i < FF_ARRAY_ELEMS(ctx->frames); i++) {
143
32
        ctx->frames[i].f = av_frame_alloc();
144
32
        if (!ctx->frames[i].f)
145
            return AVERROR(ENOMEM);
146
    }
147
148
2
    ff_thread_once(&init_static_once, mimic_init_static);
149
150
2
    return 0;
151
}
152
153
#if HAVE_THREADS
154
static int mimic_decode_update_thread_context(AVCodecContext *avctx, const AVCodecContext *avctx_from)
155
{
156
    MimicContext *dst = avctx->priv_data, *src = avctx_from->priv_data;
157
    int i, ret;
158
159
    if (avctx == avctx_from)
160
        return 0;
161
162
    dst->cur_index  = src->next_cur_index;
163
    dst->prev_index = src->next_prev_index;
164
165
    for (i = 0; i < FF_ARRAY_ELEMS(dst->frames); i++) {
166
        ff_thread_release_buffer(avctx, &dst->frames[i]);
167
        if (i != src->next_cur_index && src->frames[i].f->data[0]) {
168
            ret = ff_thread_ref_frame(&dst->frames[i], &src->frames[i]);
169
            if (ret < 0)
170
                return ret;
171
        }
172
    }
173
174
    return 0;
175
}
176
#endif
177
178
static const int8_t vlcdec_lookup[9][64] = {
179
    {    0, },
180
    {   -1,   1, },
181
    {   -3,   3,   -2,   2, },
182
    {   -7,   7,   -6,   6,   -5,   5,   -4,   4, },
183
    {  -15,  15,  -14,  14,  -13,  13,  -12,  12,
184
       -11,  11,  -10,  10,   -9,   9,   -8,   8, },
185
    {  -31,  31,  -30,  30,  -29,  29,  -28,  28,
186
       -27,  27,  -26,  26,  -25,  25,  -24,  24,
187
       -23,  23,  -22,  22,  -21,  21,  -20,  20,
188
       -19,  19,  -18,  18,  -17,  17,  -16,  16, },
189
    {  -63,  63,  -62,  62,  -61,  61,  -60,  60,
190
       -59,  59,  -58,  58,  -57,  57,  -56,  56,
191
       -55,  55,  -54,  54,  -53,  53,  -52,  52,
192
       -51,  51,  -50,  50,  -49,  49,  -48,  48,
193
       -47,  47,  -46,  46,  -45,  45,  -44,  44,
194
       -43,  43,  -42,  42,  -41,  41,  -40,  40,
195
       -39,  39,  -38,  38,  -37,  37,  -36,  36,
196
       -35,  35,  -34,  34,  -33,  33,  -32,  32, },
197
    { -127, 127, -126, 126, -125, 125, -124, 124,
198
      -123, 123, -122, 122, -121, 121, -120, 120,
199
      -119, 119, -118, 118, -117, 117, -116, 116,
200
      -115, 115, -114, 114, -113, 113, -112, 112,
201
      -111, 111, -110, 110, -109, 109, -108, 108,
202
      -107, 107, -106, 106, -105, 105, -104, 104,
203
      -103, 103, -102, 102, -101, 101, -100, 100,
204
       -99,  99,  -98,  98,  -97,  97,  -96,  96, },
205
    {  -95,  95,  -94,  94,  -93,  93,  -92,  92,
206
       -91,  91,  -90,  90,  -89,  89,  -88,  88,
207
       -87,  87,  -86,  86,  -85,  85,  -84,  84,
208
       -83,  83,  -82,  82,  -81,  81,  -80,  80,
209
       -79,  79,  -78,  78,  -77,  77,  -76,  76,
210
       -75,  75,  -74,  74,  -73,  73,  -72,  72,
211
       -71,  71,  -70,  70,  -69,  69,  -68,  68,
212
       -67,  67,  -66,  66,  -65,  65,  -64,  64, },
213
};
214
215
44548
static int vlc_decode_block(MimicContext *ctx, int num_coeffs, int qscale)
216
{
217
44548
    int16_t *block = ctx->dct_block;
218
    unsigned int pos;
219
220
44548
    ctx->bdsp.clear_block(block);
221
222
44548
    block[0] = get_bits(&ctx->gb, 8) << 3;
223
224
304893
    for (pos = 1; pos < num_coeffs; pos++) {
225
        uint32_t vlc, num_bits;
226
        int value;
227
        int coeff;
228
229
302169
        vlc = get_vlc2(&ctx->gb, block_vlc.table, MIMIC_VLC_BITS, 3);
230
302169
        if (!vlc) /* end-of-block code */
231
41824
            return 0;
232
260345
        if (vlc == -1)
233
            return AVERROR_INVALIDDATA;
234
235
        /* pos_add and num_bits are coded in the vlc code */
236
260345
        pos     += vlc & 15; // pos_add
237
260345
        num_bits = vlc >> 4; // num_bits
238
239
260345
        if (pos >= 64)
240
            return AVERROR_INVALIDDATA;
241
242
260345
        value = get_bits(&ctx->gb, num_bits);
243
244
        /* FFmpeg's IDCT behaves somewhat different from the original code, so
245
         * a factor of 4 was added to the input */
246
247
260345
        coeff = ((int8_t*)vlcdec_lookup[num_bits])[value];
248
260345
        if (pos < 3)
249
50048
            coeff *= 16;
250
        else /* TODO Use >> 10 instead of / 1001 */
251
210297
            coeff = (coeff * qscale) / 1001;
252
253
260345
        block[ctx->scantable.permutated[pos]] = coeff;
254
    }
255
256
2724
    return 0;
257
}
258
259
77
static int decode(MimicContext *ctx, int quality, int num_coeffs,
260
                  int is_iframe)
261
{
262
77
    int ret, y, x, plane, cur_row = 0;
263
264
308
    for (plane = 0; plane < 3; plane++) {
265
231
        const int is_chroma = !!plane;
266
231
        const int qscale    = av_clip(10000 - quality, is_chroma ? 1000 : 2000,
267
                                      10000) << 2;
268
231
        const int stride    = ctx->frames[ctx->cur_index ].f->linesize[plane];
269
231
        const uint8_t *src  = ctx->frames[ctx->prev_index].f->data[plane];
270
231
        uint8_t       *dst  = ctx->frames[ctx->cur_index ].f->data[plane];
271
272
4851
        for (y = 0; y < ctx->num_vblocks[plane]; y++) {
273
143220
            for (x = 0; x < ctx->num_hblocks[plane]; x++) {
274
                /* Check for a change condition in the current block.
275
                 * - iframes always change.
276
                 * - Luma plane changes on get_bits1 == 0
277
                 * - Chroma planes change on get_bits1 == 1 */
278

138600
                if (is_iframe || get_bits1(&ctx->gb) == is_chroma) {
279
                    /* Luma planes may use a backreference from the 15 last
280
                     * frames preceding the previous. (get_bits1 == 1)
281
                     * Chroma planes don't use backreferences. */
282

50491
                    if (is_chroma || is_iframe || !get_bits1(&ctx->gb)) {
283
44548
                        if ((ret = vlc_decode_block(ctx, num_coeffs,
284
                                                    qscale)) < 0) {
285
                            av_log(ctx->avctx, AV_LOG_ERROR, "Error decoding "
286
                                   "block.\n");
287
                            return ret;
288
                        }
289
44548
                        ctx->idsp.idct_put(dst, stride, ctx->dct_block);
290
                    } else {
291
5943
                        unsigned int backref = get_bits(&ctx->gb, 4);
292
5943
                        int index            = (ctx->cur_index + backref) & 15;
293
5943
                        uint8_t *p           = ctx->frames[index].f->data[0];
294
295

5943
                        if (index != ctx->cur_index && p) {
296
5943
                            ff_thread_await_progress(&ctx->frames[index],
297
                                                     cur_row, 0);
298
5943
                            p += src -
299
5943
                                 ctx->frames[ctx->prev_index].f->data[plane];
300
5943
                            ctx->hdsp.put_pixels_tab[1][0](dst, p, stride, 8);
301
                        } else {
302
                            av_log(ctx->avctx, AV_LOG_ERROR,
303
                                     "No such backreference! Buggy sample.\n");
304
                        }
305
                    }
306
                } else {
307
88109
                    ff_thread_await_progress(&ctx->frames[ctx->prev_index],
308
                                             cur_row, 0);
309
88109
                    ctx->hdsp.put_pixels_tab[1][0](dst, src, stride, 8);
310
                }
311
138600
                src += 8;
312
138600
                dst += 8;
313
            }
314
4620
            src += (stride - ctx->num_hblocks[plane]) << 3;
315
4620
            dst += (stride - ctx->num_hblocks[plane]) << 3;
316
317
4620
            ff_thread_report_progress(&ctx->frames[ctx->cur_index],
318
                                      cur_row++, 0);
319
        }
320
    }
321
322
77
    return 0;
323
}
324
325
/**
326
 * Flip the buffer upside-down and put it in the YVU order to revert the
327
 * way Mimic encodes frames.
328
 */
329
77
static void flip_swap_frame(AVFrame *f)
330
{
331
    int i;
332
77
    uint8_t *data_1 = f->data[1];
333
77
    f->data[0] = f->data[0] + ( f->height       - 1) * f->linesize[0];
334
77
    f->data[1] = f->data[2] + ((f->height >> 1) - 1) * f->linesize[2];
335
77
    f->data[2] = data_1     + ((f->height >> 1) - 1) * f->linesize[1];
336
308
    for (i = 0; i < 3; i++)
337
231
        f->linesize[i] *= -1;
338
77
}
339
340
77
static int mimic_decode_frame(AVCodecContext *avctx, void *data,
341
                              int *got_frame, AVPacket *avpkt)
342
{
343
77
    const uint8_t *buf = avpkt->data;
344
77
    int buf_size       = avpkt->size;
345
77
    int swap_buf_size  = buf_size - MIMIC_HEADER_SIZE;
346
77
    MimicContext *ctx  = avctx->priv_data;
347
    GetByteContext gb;
348
    int is_pframe;
349
    int width, height;
350
    int quality, num_coeffs;
351
    int res;
352
353
77
    if (buf_size <= MIMIC_HEADER_SIZE) {
354
        av_log(avctx, AV_LOG_ERROR, "insufficient data\n");
355
        return AVERROR_INVALIDDATA;
356
    }
357
358
77
    bytestream2_init(&gb, buf, MIMIC_HEADER_SIZE);
359
77
    bytestream2_skip(&gb, 2); /* some constant (always 256) */
360
77
    quality    = bytestream2_get_le16u(&gb);
361
77
    width      = bytestream2_get_le16u(&gb);
362
77
    height     = bytestream2_get_le16u(&gb);
363
77
    bytestream2_skip(&gb, 4); /* some constant */
364
77
    is_pframe  = bytestream2_get_le32u(&gb);
365
77
    num_coeffs = bytestream2_get_byteu(&gb);
366
77
    bytestream2_skip(&gb, 3); /* some constant */
367
368
77
    if (!ctx->avctx) {
369
        int i;
370
371

2
        if (!(width == 160 && height == 120) &&
372
2
            !(width == 320 && height == 240)) {
373
            av_log(avctx, AV_LOG_ERROR, "invalid width/height!\n");
374
            return AVERROR_INVALIDDATA;
375
        }
376
377
2
        res = ff_set_dimensions(avctx, width, height);
378
2
        if (res < 0)
379
            return res;
380
381
2
        ctx->avctx     = avctx;
382
2
        avctx->pix_fmt = AV_PIX_FMT_YUV420P;
383
8
        for (i = 0; i < 3; i++) {
384
6
            ctx->num_vblocks[i] = AV_CEIL_RSHIFT(height,   3 + !!i);
385
6
            ctx->num_hblocks[i] =                width >> (3 + !!i);
386
        }
387

75
    } else if (width != ctx->avctx->width || height != ctx->avctx->height) {
388
        avpriv_request_sample(avctx, "Resolution changing");
389
        return AVERROR_PATCHWELCOME;
390
    }
391
392

77
    if (is_pframe && !ctx->frames[ctx->prev_index].f->data[0]) {
393
        av_log(avctx, AV_LOG_ERROR, "decoding must start with keyframe\n");
394
        return AVERROR_INVALIDDATA;
395
    }
396
397
77
    ff_thread_release_buffer(avctx, &ctx->frames[ctx->cur_index]);
398
77
    ctx->frames[ctx->cur_index].f->pict_type = is_pframe ? AV_PICTURE_TYPE_P :
399
                                                           AV_PICTURE_TYPE_I;
400
77
    if ((res = ff_thread_get_buffer(avctx, &ctx->frames[ctx->cur_index],
401
                                    AV_GET_BUFFER_FLAG_REF)) < 0)
402
        return res;
403
404
77
    ctx->next_prev_index = ctx->cur_index;
405
77
    ctx->next_cur_index  = (ctx->cur_index - 1) & 15;
406
407
77
    ff_thread_finish_setup(avctx);
408
409
77
    av_fast_padded_malloc(&ctx->swap_buf, &ctx->swap_buf_size, swap_buf_size);
410
77
    if (!ctx->swap_buf)
411
        return AVERROR(ENOMEM);
412
413
77
    ctx->bbdsp.bswap_buf(ctx->swap_buf,
414
77
                         (const uint32_t *) (buf + MIMIC_HEADER_SIZE),
415
                         swap_buf_size >> 2);
416
77
    init_get_bits(&ctx->gb, ctx->swap_buf, swap_buf_size << 3);
417
418
77
    res = decode(ctx, quality, num_coeffs, !is_pframe);
419
77
    ff_thread_report_progress(&ctx->frames[ctx->cur_index], INT_MAX, 0);
420
77
    if (res < 0) {
421
        if (!(avctx->active_thread_type & FF_THREAD_FRAME))
422
            ff_thread_release_buffer(avctx, &ctx->frames[ctx->cur_index]);
423
        return res;
424
    }
425
426
77
    if ((res = av_frame_ref(data, ctx->frames[ctx->cur_index].f)) < 0)
427
        return res;
428
77
    *got_frame      = 1;
429
430
77
    flip_swap_frame(data);
431
432
77
    ctx->prev_index = ctx->next_prev_index;
433
77
    ctx->cur_index  = ctx->next_cur_index;
434
435
77
    return buf_size;
436
}
437
438
AVCodec ff_mimic_decoder = {
439
    .name                  = "mimic",
440
    .long_name             = NULL_IF_CONFIG_SMALL("Mimic"),
441
    .type                  = AVMEDIA_TYPE_VIDEO,
442
    .id                    = AV_CODEC_ID_MIMIC,
443
    .priv_data_size        = sizeof(MimicContext),
444
    .init                  = mimic_decode_init,
445
    .close                 = mimic_decode_end,
446
    .decode                = mimic_decode_frame,
447
    .capabilities          = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
448
    .update_thread_context = ONLY_IF_THREADS_ENABLED(mimic_decode_update_thread_context),
449
    .caps_internal         = FF_CODEC_CAP_ALLOCATE_PROGRESS |
450
                             FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_INIT_THREADSAFE,
451
};