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
29
32 {
33 int vop_found, i, j;
35
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) {
54 pc->
state = (state >> (3 * 8)) + 0xFF00;
55 return i - 2;
56 }
57 }
58 }
59 }
60
64 }
65
68 const uint8_t **poutbuf,
int *poutbuf_size,
70 {
72 int next;
73
75 next = buf_size;
76 } else {
80 *poutbuf_size = 0;
81 return buf_size;
82 }
83 }
85 *poutbuf_size = buf_size;
86 return next;
87 }
88
94 };
AVCodecParser ff_h261_parser
static int h261_find_frame_end(ParseContext *pc, AVCodecContext *avctx, const uint8_t *buf, int buf_size)
int ff_combine_frame(ParseContext *pc, int next, const uint8_t **buf, int *buf_size)
Combine the (truncated) bitstream to a complete frame.
void ff_parse_close(AVCodecParserContext *s)
main external API structure.
uint32_t state
contains the last few bytes in MSB order
#define PARSER_FLAG_COMPLETE_FRAMES
static int h261_parse(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size)