FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/pngdsp.c
Date: 2026-01-16 07:34:38
Exec Total Coverage
Lines: 30 30 100.0%
Functions: 3 3 100.0%
Branches: 12 12 100.0%

Line Branch Exec Source
1 /*
2 * PNG image format
3 * Copyright (c) 2008 Loren Merrit <lorenm@u.washington.edu>
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
24 #include "config.h"
25 #include "libavutil/attributes.h"
26 #include "libavutil/intreadwrite.h"
27 #include "libavutil/macros.h"
28 #include "pngdsp.h"
29
30 #if HAVE_FAST_64BIT
31 #define BITS 64
32 typedef uint64_t uint_native;
33 #else
34 #define BITS 32
35 typedef uint32_t uint_native;
36 #endif
37 #define RN AV_JOIN(AV_RN, BITS)
38 #define RNA AV_JOIN(AV_JOIN(AV_RN, BITS), A)
39 #define WN AV_JOIN(AV_WN, BITS)
40
41 // 0x7f7f7f7f or 0x7f7f7f7f7f7f7f7f or whatever, depending on the cpu's native arithmetic size
42 #define pb_7f (~(uint_native)0 / 255 * 0x7f)
43 #define pb_80 (~(uint_native)0 / 255 * 0x80)
44
45 10486 static void add_bytes_l2_c(uint8_t *dst, const uint8_t *src1,
46 const uint8_t *src2, int w)
47 {
48 long i;
49
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748578 for (i = 0; i <= w - (int) sizeof(uint_native); i += sizeof(uint_native)) {
50 738092 uint_native a = RNA(src1 + i);
51 738092 uint_native b = RN (src2 + i);
52 738092 WN(dst + i, ((a & pb_7f) + (b & pb_7f)) ^ ((a ^ b) & pb_80));
53 }
54
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32248 for (; i < w; i++)
55 21762 dst[i] = src1[i] + src2[i];
56 10486 }
57
58 208257 void ff_png_add_paeth_prediction(uint8_t *dst, const uint8_t *src,
59 const uint8_t *top, int w, int bpp)
60 {
61
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100094624 for (int i = 0; i < w; ++i) {
62 int a, b, c, p, pa, pb, pc;
63
64 99886367 a = dst[i - bpp];
65 99886367 b = top[i];
66 99886367 c = top[i - bpp];
67
68 99886367 p = b - c;
69 99886367 pc = a - c;
70
71 99886367 pa = abs(p);
72 99886367 pb = abs(pc);
73 99886367 pc = abs(p + pc);
74
75
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99886367 if (pa <= pb && pa <= pc)
76 51763039 p = a;
77
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48123328 else if (pb <= pc)
78 37848714 p = b;
79 else
80 10274614 p = c;
81 99886367 dst[i] = p + src[i];
82 }
83 208257 }
84
85 167 av_cold void ff_pngdsp_init(PNGDSPContext *dsp)
86 {
87 167 dsp->add_bytes_l2 = add_bytes_l2_c;
88 167 dsp->add_paeth_prediction = ff_png_add_paeth_prediction;
89
90 #if ARCH_X86 && HAVE_X86ASM
91 167 ff_pngdsp_init_x86(dsp);
92 #endif
93 167 }
94