Rename function
[FFMpeg-mirror/DVCPRO-HD.git] / libavcodec / h261_parser.c
blob3f3aac6e471e731fbcb409f554235304c4ce28e9
1 /*
2 * H261 parser
3 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
4 * Copyright (c) 2004 Maarten Daniels
6 * This file is part of FFmpeg.
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.
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.
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
23 /**
24 * @file h261_parser.c
25 * h261codec.
28 #include "parser.h"
31 static int h261_find_frame_end(ParseContext *pc, AVCodecContext* avctx, const uint8_t *buf, int buf_size){
32 int vop_found, i, j;
33 uint32_t state;
35 vop_found= pc->frame_start_found;
36 state= pc->state;
38 for(i=0; i<buf_size && !vop_found; i++){
39 state= (state<<8) | buf[i];
40 for(j=0; j<8; j++){
41 if(((state>>j)&0xFFFFF0) == 0x000100){
42 vop_found=1;
43 break;
47 if(vop_found){
48 for(; i<buf_size; i++){
49 state= (state<<8) | buf[i];
50 for(j=0; j<8; j++){
51 if(((state>>j)&0xFFFFF0) == 0x000100){
52 pc->frame_start_found=0;
53 pc->state= (state>>(3*8))+0xFF00;
54 return i-2;
60 pc->frame_start_found= vop_found;
61 pc->state= state;
62 return END_NOT_FOUND;
65 static int h261_parse(AVCodecParserContext *s,
66 AVCodecContext *avctx,
67 const uint8_t **poutbuf, int *poutbuf_size,
68 const uint8_t *buf, int buf_size)
70 ParseContext *pc = s->priv_data;
71 int next;
73 next= h261_find_frame_end(pc,avctx, buf, buf_size);
74 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
75 *poutbuf = NULL;
76 *poutbuf_size = 0;
77 return buf_size;
79 *poutbuf = buf;
80 *poutbuf_size = buf_size;
81 return next;
84 AVCodecParser h261_parser = {
85 { CODEC_ID_H261 },
86 sizeof(ParseContext),
87 NULL,
88 h261_parse,
89 ff_parse_close,