split h264.c to move parser in its own file
[libav.git] / libavcodec / h264_parser.c
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AJ
1/*
2 * H.26L/H.264/AVC/JVT/14496-10/... parser
3 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
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
23/**
24 * @file h264_parser.c
25 * H.264 / AVC / MPEG4 part10 parser.
26 * @author Michael Niedermayer <michaelni@gmx.at>
27 */
28
29#include "parser.h"
30#include "h264_parser.h"
31
32#include <assert.h>
33
34
35int ff_h264_find_frame_end(H264Context *h, const uint8_t *buf, int buf_size)
36{
37 int i;
38 uint32_t state;
39 ParseContext *pc = &(h->s.parse_context);
40//printf("first %02X%02X%02X%02X\n", buf[0], buf[1],buf[2],buf[3]);
41// mb_addr= pc->mb_addr - 1;
42 state= pc->state;
43 if(state>13)
44 state= 7;
45
46 for(i=0; i<buf_size; i++){
47 if(state==7){
48 for(; i<buf_size; i++){
49 if(!buf[i]){
50 state=2;
51 break;
52 }
53 }
54 }else if(state<=2){
55 if(buf[i]==1) state^= 5; //2->7, 1->4, 0->5
56 else if(buf[i]) state = 7;
57 else state>>=1; //2->1, 1->0, 0->0
58 }else if(state<=5){
59 int v= buf[i] & 0x1F;
60 if(v==7 || v==8 || v==9){
61 if(pc->frame_start_found){
62 i++;
63found:
64 pc->state=7;
65 pc->frame_start_found= 0;
66 return i-(state&5);
67 }
68 }else if(v==1 || v==2 || v==5){
69 if(pc->frame_start_found){
70 state+=8;
71 continue;
72 }else
73 pc->frame_start_found = 1;
74 }
75 state= 7;
76 }else{
77 if(buf[i] & 0x80)
78 goto found;
79 state= 7;
80 }
81 }
82 pc->state= state;
83 return END_NOT_FOUND;
84}
85
86static int h264_parse(AVCodecParserContext *s,
87 AVCodecContext *avctx,
88 const uint8_t **poutbuf, int *poutbuf_size,
89 const uint8_t *buf, int buf_size)
90{
91 H264Context *h = s->priv_data;
92 ParseContext *pc = &h->s.parse_context;
93 int next;
94
95 if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
96 next= buf_size;
97 }else{
98 next= ff_h264_find_frame_end(h, buf, buf_size);
99
100 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
101 *poutbuf = NULL;
102 *poutbuf_size = 0;
103 return buf_size;
104 }
105
106 if(next<0 && next != END_NOT_FOUND){
107 assert(pc->last_index + next >= 0 );
108 ff_h264_find_frame_end(h, &pc->buffer[pc->last_index + next], -next); //update state
109 }
110 }
111
112 *poutbuf = buf;
113 *poutbuf_size = buf_size;
114 return next;
115}
116
117static int h264_split(AVCodecContext *avctx,
118 const uint8_t *buf, int buf_size)
119{
120 int i;
121 uint32_t state = -1;
122 int has_sps= 0;
123
124 for(i=0; i<=buf_size; i++){
125 if((state&0xFFFFFF1F) == 0x107)
126 has_sps=1;
127/* if((state&0xFFFFFF1F) == 0x101 || (state&0xFFFFFF1F) == 0x102 || (state&0xFFFFFF1F) == 0x105){
128 }*/
129 if((state&0xFFFFFF00) == 0x100 && (state&0xFFFFFF1F) != 0x107 && (state&0xFFFFFF1F) != 0x108 && (state&0xFFFFFF1F) != 0x109){
130 if(has_sps){
131 while(i>4 && buf[i-5]==0) i--;
132 return i-4;
133 }
134 }
135 if (i<buf_size)
136 state= (state<<8) | buf[i];
137 }
138 return 0;
139}
140
141
142AVCodecParser h264_parser = {
143 { CODEC_ID_H264 },
144 sizeof(H264Context),
145 NULL,
146 h264_parse,
147 ff_parse_close,
148 h264_split,
149};