FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/h261_parser.c
Date: 2021-09-26 18:22:30
Exec Total Coverage
Lines: 7 32 21.9%
Branches: 1 20 5.0%

Line Branch Exec Source
1 /*
2 * H.261 parser
3 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
4 * Copyright (c) 2004 Maarten Daniels
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 * H.261 parser
26 */
27
28 #include "parser.h"
29
30 static int h261_find_frame_end(ParseContext *pc, AVCodecContext *avctx,
31 const uint8_t *buf, int buf_size)
32 {
33 int vop_found, i, j;
34 uint32_t state;
35
36 vop_found = pc->frame_start_found;
37 state = pc->state;
38
39 for (i = 0; i < buf_size && !vop_found; i++) {
40 state = (state << 8) | buf[i];
41 for (j = 0; j < 8; j++) {
42 if (((state >> j) & 0xFFFFF0) == 0x000100) {
43 vop_found = 1;
44 break;
45 }
46 }
47 }
48 if (vop_found) {
49 for (; i < buf_size; i++) {
50 state = (state << 8) | buf[i];
51 for (j = 0; j < 8; j++) {
52 if (((state >> j) & 0xFFFFF0) == 0x000100) {
53 pc->frame_start_found = 0;
54 pc->state = (state >> (3 * 8)) + 0xFF00;
55 return i - 2;
56 }
57 }
58 }
59 }
60
61 pc->frame_start_found = vop_found;
62 pc->state = state;
63 return END_NOT_FOUND;
64 }
65
66 332 static int h261_parse(AVCodecParserContext *s,
67 AVCodecContext *avctx,
68 const uint8_t **poutbuf, int *poutbuf_size,
69 const uint8_t *buf, int buf_size)
70 {
71 332 ParseContext *pc = s->priv_data;
72 int next;
73
74
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332 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
75 332 next = buf_size;
76 } else {
77 next = h261_find_frame_end(pc, avctx, buf, buf_size);
78 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
79 *poutbuf = NULL;
80 *poutbuf_size = 0;
81 return buf_size;
82 }
83 }
84 332 *poutbuf = buf;
85 332 *poutbuf_size = buf_size;
86 332 return next;
87 }
88
89 const AVCodecParser ff_h261_parser = {
90 .codec_ids = { AV_CODEC_ID_H261 },
91 .priv_data_size = sizeof(ParseContext),
92 .parser_parse = h261_parse,
93 .parser_close = ff_parse_close,
94 };
95