GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/mpeg12.c Lines: 135 144 93.8 %
Date: 2019-11-18 18:00:01 Branches: 72 80 90.0 %

Line Branch Exec Source
1
/*
2
 * MPEG-1/2 decoder
3
 * Copyright (c) 2000, 2001 Fabrice Bellard
4
 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
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
/**
24
 * @file
25
 * MPEG-1/2 decoder
26
 */
27
28
#define UNCHECKED_BITSTREAM_READER 1
29
30
#include "libavutil/attributes.h"
31
#include "libavutil/avassert.h"
32
#include "libavutil/timecode.h"
33
34
#include "internal.h"
35
#include "avcodec.h"
36
#include "mpegvideo.h"
37
#include "error_resilience.h"
38
#include "mpeg12.h"
39
#include "mpeg12data.h"
40
#include "mpegvideodata.h"
41
#include "bytestream.h"
42
#include "thread.h"
43
44
uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
45
46
static const uint8_t table_mb_ptype[7][2] = {
47
    { 3, 5 }, // 0x01 MB_INTRA
48
    { 1, 2 }, // 0x02 MB_PAT
49
    { 1, 3 }, // 0x08 MB_FOR
50
    { 1, 1 }, // 0x0A MB_FOR|MB_PAT
51
    { 1, 6 }, // 0x11 MB_QUANT|MB_INTRA
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    { 1, 5 }, // 0x12 MB_QUANT|MB_PAT
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    { 2, 5 }, // 0x1A MB_QUANT|MB_FOR|MB_PAT
54
};
55
56
static const uint8_t table_mb_btype[11][2] = {
57
    { 3, 5 }, // 0x01 MB_INTRA
58
    { 2, 3 }, // 0x04 MB_BACK
59
    { 3, 3 }, // 0x06 MB_BACK|MB_PAT
60
    { 2, 4 }, // 0x08 MB_FOR
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    { 3, 4 }, // 0x0A MB_FOR|MB_PAT
62
    { 2, 2 }, // 0x0C MB_FOR|MB_BACK
63
    { 3, 2 }, // 0x0E MB_FOR|MB_BACK|MB_PAT
64
    { 1, 6 }, // 0x11 MB_QUANT|MB_INTRA
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    { 2, 6 }, // 0x16 MB_QUANT|MB_BACK|MB_PAT
66
    { 3, 6 }, // 0x1A MB_QUANT|MB_FOR|MB_PAT
67
    { 2, 5 }, // 0x1E MB_QUANT|MB_FOR|MB_BACK|MB_PAT
68
};
69
70
236
av_cold void ff_init_2d_vlc_rl(RLTable *rl, unsigned static_size, int flags)
71
{
72
    int i;
73
236
    VLC_TYPE table[680][2] = {{0}};
74
236
    VLC vlc = { .table = table, .table_allocated = static_size };
75
236
    av_assert0(static_size <= FF_ARRAY_ELEMS(table));
76
236
    init_vlc(&vlc, TEX_VLC_BITS, rl->n + 2, &rl->table_vlc[0][1], 4, 2, &rl->table_vlc[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC | flags);
77
78
160002
    for (i = 0; i < vlc.table_size; i++) {
79
159766
        int code = vlc.table[i][0];
80
159766
        int len  = vlc.table[i][1];
81
        int level, run;
82
83
159766
        if (len == 0) { // illegal code
84
4946
            run   = 65;
85
4946
            level = MAX_LEVEL;
86
154820
        } else if (len<0) { //more bits needed
87
1531
            run   = 0;
88
1531
            level = code;
89
        } else {
90
153289
            if (code == rl->n) { //esc
91
1888
                run   = 65;
92
1888
                level = 0;
93
151401
            } else if (code == rl->n+1) { //eob
94
18784
                run   = 0;
95
18784
                level = 127;
96
            } else {
97
132617
                run   = rl->table_run  [code] + 1;
98
132617
                level = rl->table_level[code];
99
            }
100
        }
101
159766
        rl->rl_vlc[0][i].len   = len;
102
159766
        rl->rl_vlc[0][i].level = level;
103
159766
        rl->rl_vlc[0][i].run   = run;
104
    }
105
236
}
106
107
302
av_cold void ff_mpeg12_common_init(MpegEncContext *s)
108
{
109
110
302
    s->y_dc_scale_table =
111
302
    s->c_dc_scale_table = ff_mpeg2_dc_scale_table[s->intra_dc_precision];
112
113
302
}
114
115
398058
void ff_mpeg1_clean_buffers(MpegEncContext *s)
116
{
117
398058
    s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
118
398058
    s->last_dc[1] = s->last_dc[0];
119
398058
    s->last_dc[2] = s->last_dc[0];
120
398058
    memset(s->last_mv, 0, sizeof(s->last_mv));
121
398058
}
122
123
124
/******************************************/
125
/* decoding */
126
127
VLC ff_mv_vlc;
128
129
VLC ff_dc_lum_vlc;
130
VLC ff_dc_chroma_vlc;
131
132
VLC ff_mbincr_vlc;
133
VLC ff_mb_ptype_vlc;
134
VLC ff_mb_btype_vlc;
135
VLC ff_mb_pat_vlc;
136
137
268
av_cold void ff_mpeg12_init_vlcs(void)
138
{
139
    static int done = 0;
140
141
268
    if (!done) {
142
117
        done = 1;
143
144
117
        INIT_VLC_STATIC(&ff_dc_lum_vlc, DC_VLC_BITS, 12,
145
                        ff_mpeg12_vlc_dc_lum_bits, 1, 1,
146
                        ff_mpeg12_vlc_dc_lum_code, 2, 2, 512);
147
117
        INIT_VLC_STATIC(&ff_dc_chroma_vlc,  DC_VLC_BITS, 12,
148
                        ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
149
                        ff_mpeg12_vlc_dc_chroma_code, 2, 2, 514);
150
117
        INIT_VLC_STATIC(&ff_mv_vlc, MV_VLC_BITS, 17,
151
                        &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
152
                        &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 518);
153
117
        INIT_VLC_STATIC(&ff_mbincr_vlc, MBINCR_VLC_BITS, 36,
154
                        &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
155
                        &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 538);
156
117
        INIT_VLC_STATIC(&ff_mb_pat_vlc, MB_PAT_VLC_BITS, 64,
157
                        &ff_mpeg12_mbPatTable[0][1], 2, 1,
158
                        &ff_mpeg12_mbPatTable[0][0], 2, 1, 512);
159
160
117
        INIT_VLC_STATIC(&ff_mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
161
                        &table_mb_ptype[0][1], 2, 1,
162
                        &table_mb_ptype[0][0], 2, 1, 64);
163
117
        INIT_VLC_STATIC(&ff_mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
164
                        &table_mb_btype[0][1], 2, 1,
165
                        &table_mb_btype[0][0], 2, 1, 64);
166
117
        ff_rl_init(&ff_rl_mpeg1, ff_mpeg12_static_rl_table_store[0]);
167
117
        ff_rl_init(&ff_rl_mpeg2, ff_mpeg12_static_rl_table_store[1]);
168
169
117
        INIT_2D_VLC_RL(ff_rl_mpeg1, 680, 0);
170
117
        INIT_2D_VLC_RL(ff_rl_mpeg2, 674, 0);
171
    }
172
268
}
173
174
/**
175
 * Find the end of the current frame in the bitstream.
176
 * @return the position of the first byte of the next frame, or -1
177
 */
178
44988
int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size, AVCodecParserContext *s)
179
{
180
    int i;
181
44988
    uint32_t state = pc->state;
182
183
    /* EOF considered as end of frame */
184
44988
    if (buf_size == 0)
185
307
        return 0;
186
187
/*
188
 0  frame start         -> 1/4
189
 1  first_SEQEXT        -> 0/2
190
 2  first field start   -> 3/0
191
 3  second_SEQEXT       -> 2/0
192
 4  searching end
193
*/
194
195
249791
    for (i = 0; i < buf_size; i++) {
196
        av_assert1(pc->frame_start_found >= 0 && pc->frame_start_found <= 4);
197
210701
        if (pc->frame_start_found & 1) {
198

20835
            if (state == EXT_START_CODE && (buf[i] & 0xF0) != 0x80)
199
2094
                pc->frame_start_found--;
200
18741
            else if (state == EXT_START_CODE + 2) {
201
6247
                if ((buf[i] & 3) == 3)
202
3892
                    pc->frame_start_found = 0;
203
                else
204
2355
                    pc->frame_start_found = (pc->frame_start_found + 1) & 3;
205
            }
206
20835
            state++;
207
        } else {
208
189866
            i = avpriv_find_start_code(buf + i, buf + buf_size, &state) - buf - 1;
209

189866
            if (pc->frame_start_found == 0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE) {
210
6021
                i++;
211
6021
                pc->frame_start_found = 4;
212
            }
213
189866
            if (state == SEQ_END_CODE) {
214
8
                pc->frame_start_found = 0;
215
8
                pc->state=-1;
216
8
                return i+1;
217
            }
218

189858
            if (pc->frame_start_found == 2 && state == SEQ_START_CODE)
219
                pc->frame_start_found = 0;
220

189858
            if (pc->frame_start_found  < 4 && state == EXT_START_CODE)
221
8341
                pc->frame_start_found++;
222

189858
            if (pc->frame_start_found == 4 && (state & 0xFFFFFF00) == 0x100) {
223

114897
                if (state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE) {
224
5583
                    pc->frame_start_found = 0;
225
5583
                    pc->state             = -1;
226
5583
                    return i - 3;
227
                }
228
            }
229

184275
            if (pc->frame_start_found == 0 && s && state == PICTURE_START_CODE) {
230
5982
                ff_fetch_timestamp(s, i - 3, 1, i > 3);
231
            }
232
        }
233
    }
234
39090
    pc->state = state;
235
39090
    return END_NOT_FOUND;
236
}
237
238
#define MAX_INDEX (64 - 1)
239
240
176526
int ff_mpeg1_decode_block_intra(GetBitContext *gb,
241
                                const uint16_t *quant_matrix,
242
                                uint8_t *const scantable, int last_dc[3],
243
                                int16_t *block, int index, int qscale)
244
{
245
176526
    int dc, diff, i = 0, component;
246
176526
    RLTable *rl = &ff_rl_mpeg1;
247
248
    /* DC coefficient */
249
176526
    component = index <= 3 ? 0 : index - 4 + 1;
250
251
176526
    diff = decode_dc(gb, component);
252
176526
    if (diff >= 0xffff)
253
        return AVERROR_INVALIDDATA;
254
255
176526
    dc  = last_dc[component];
256
176526
    dc += diff;
257
176526
    last_dc[component] = dc;
258
259
176526
    block[0] = dc * quant_matrix[0];
260
261
    {
262
176526
        OPEN_READER(re, gb);
263
176526
        UPDATE_CACHE(re, gb);
264
176526
        if (((int32_t)GET_CACHE(re, gb)) <= (int32_t)0xBFFFFFFF)
265
36372
            goto end;
266
267
        /* now quantify & encode AC coefficients */
268
1334388
        while (1) {
269
            int level, run, j;
270
271
1474542
            GET_RL_VLC(level, run, re, gb, rl->rl_vlc[0],
272
                       TEX_VLC_BITS, 2, 0);
273
274
1474542
            if (level != 0) {
275
1469278
                i += run;
276
1469278
                if (i > MAX_INDEX)
277
                    break;
278
279
1469278
                j = scantable[i];
280
1469278
                level = (level * qscale * quant_matrix[j]) >> 4;
281
1469278
                level = (level - 1) | 1;
282
1469278
                level = (level ^ SHOW_SBITS(re, gb, 1)) -
283
1469278
                        SHOW_SBITS(re, gb, 1);
284
1469278
                SKIP_BITS(re, gb, 1);
285
            } else {
286
                /* escape */
287
5264
                run = SHOW_UBITS(re, gb, 6) + 1;
288
5264
                LAST_SKIP_BITS(re, gb, 6);
289
5264
                UPDATE_CACHE(re, gb);
290
5264
                level = SHOW_SBITS(re, gb, 8);
291
5264
                SKIP_BITS(re, gb, 8);
292
293
5264
                if (level == -128) {
294
                    level = SHOW_UBITS(re, gb, 8) - 256;
295
                    SKIP_BITS(re, gb, 8);
296
5264
                } else if (level == 0) {
297
                    level = SHOW_UBITS(re, gb, 8);
298
                    SKIP_BITS(re, gb, 8);
299
                }
300
301
5264
                i += run;
302
5264
                if (i > MAX_INDEX)
303
                    break;
304
305
5264
                j = scantable[i];
306
5264
                if (level < 0) {
307
2967
                    level = -level;
308
2967
                    level = (level * qscale * quant_matrix[j]) >> 4;
309
2967
                    level = (level - 1) | 1;
310
2967
                    level = -level;
311
                } else {
312
2297
                    level = (level * qscale * quant_matrix[j]) >> 4;
313
2297
                    level = (level - 1) | 1;
314
                }
315
            }
316
317
1474542
            block[j] = level;
318
1474542
            if (((int32_t)GET_CACHE(re, gb)) <= (int32_t)0xBFFFFFFF)
319
140154
               break;
320
321
1334388
            UPDATE_CACHE(re, gb);
322
        }
323
176526
end:
324
176526
        LAST_SKIP_BITS(re, gb, 2);
325
176526
        CLOSE_READER(re, gb);
326
    }
327
328
176526
    if (i > MAX_INDEX)
329
        i = AVERROR_INVALIDDATA;
330
331
176526
    return i;
332
}