FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/mjpeg_parser.c
Date: 2025-07-14 21:09:40
Exec Total Coverage
Lines: 48 59 81.4%
Functions: 2 2 100.0%
Branches: 30 46 65.2%
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1 /*
2 * MJPEG parser
3 * Copyright (c) 2000, 2001 Fabrice Bellard
4 * Copyright (c) 2003 Alex Beregszaszi
5 * Copyright (c) 2003-2004 Michael Niedermayer
6 *
7 * This file is part of FFmpeg.
8 *
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24 /**
25 * @file
26 * MJPEG parser.
27 */
28
29 #include "parser.h"
30
31 typedef struct MJPEGParserContext{
32 ParseContext pc;
33 int size;
34 }MJPEGParserContext;
35
36 /**
37 * Find the end of the current frame in the bitstream.
38 * @return the position of the first byte of the next frame, or -1
39 */
40 163 static int find_frame_end(MJPEGParserContext *m, const uint8_t *buf, int buf_size){
41 163 ParseContext *pc= &m->pc;
42 int vop_found, i;
43 uint32_t state;
44
45 163 vop_found= pc->frame_start_found;
46 163 state= pc->state;
47
48 163 i=0;
49
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 163 if(!vop_found){
50
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 28 for(i=0; i<buf_size;){
51 28 state= (state<<8) | buf[i];
52
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 28 if(state>=0xFFC00000 && state<=0xFFFEFFFF){
53
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 7 if(state>=0xFFD8FFC0 && state<=0xFFD8FFFF){
54 7 i++;
55 7 vop_found=1;
56 7 break;
57 ✗ }else if(state<0xFFD00000 || state>0xFFD9FFFF){
58 ✗ m->size= (state&0xFFFF)-1;
59 }
60 }
61
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 21 if(m->size>0){
62 ✗ int size= FFMIN(buf_size-i, m->size);
63 ✗ i+=size;
64 ✗ m->size-=size;
65 ✗ state=0;
66 ✗ continue;
67 }else
68 21 i++;
69 }
70 }
71
72
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 163 if(vop_found){
73 /* EOF considered as end of frame */
74
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 163 if (buf_size == 0)
75 14 return 0;
76
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 584088 for(; i<buf_size;){
77 583939 state= (state<<8) | buf[i];
78
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 583939 if(state>=0xFFC00000 && state<=0xFFFEFFFF){
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 39 if(state>=0xFFD8FFC0 && state<=0xFFD8FFFF){
80 ✗ pc->frame_start_found=0;
81 ✗ pc->state=0;
82 ✗ return i-3;
83
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 39 } else if((state>>16)==0xFFD9 && (state&0xFFFF)!=0xFFD8){
84 ✗ state= 0xFFD900|(state&0xFF);
85
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 39 } else if(state<0xFFD00000 || state>0xFFD9FFFF){
86 39 m->size= (state&0xFFFF)-1;
87 }
88 }
89
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 583939 if(m->size>0){
90 39 int size= FFMIN(buf_size-i, m->size);
91 39 i+=size;
92 39 m->size-=size;
93 39 state=0;
94 39 continue;
95 }else
96 583900 i++;
97 }
98 }
99 149 pc->frame_start_found= vop_found;
100 149 pc->state= state;
101 149 return END_NOT_FOUND;
102 }
103
104 1877 static int jpeg_parse(AVCodecParserContext *s,
105 AVCodecContext *avctx,
106 const uint8_t **poutbuf, int *poutbuf_size,
107 const uint8_t *buf, int buf_size)
108 {
109 1877 MJPEGParserContext *m = s->priv_data;
110 1877 ParseContext *pc = &m->pc;
111 int next;
112
113
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 1877 if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
114 1714 next= buf_size;
115 }else{
116 163 next= find_frame_end(m, buf, buf_size);
117
118
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 163 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
119 149 *poutbuf = NULL;
120 149 *poutbuf_size = 0;
121 149 return buf_size;
122 }
123 }
124
125 1728 *poutbuf = buf;
126 1728 *poutbuf_size = buf_size;
127 1728 return next;
128 }
129
130
131 const AVCodecParser ff_mjpeg_parser = {
132 .codec_ids = { AV_CODEC_ID_MJPEG, AV_CODEC_ID_JPEGLS },
133 .priv_data_size = sizeof(MJPEGParserContext),
134 .parser_parse = jpeg_parse,
135 .parser_close = ff_parse_close,
136 };
137