Merge branch 'mirror' into vdpau
[FFMpeg-mirror/ffmpeg-vdpau.git] / libavcodec / vc1_parser.c
bloba76d147079f0ed04e23a38b3297f24a6e56ae6b1
1 /*
2 * VC-1 and WMV3 parser
3 * Copyright (c) 2006-2007 Konstantin Shishkov
4 * Partly based on vc9.c (c) 2005 Anonymous, Alex Beregszaszi, Michael Niedermayer
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 vc1_parser.c
25 * VC-1 and WMV3 parser
28 #include "parser.h"
29 #include "vc1.h"
31 /**
32 * finds the end of the current frame in the bitstream.
33 * @return the position of the first byte of the next frame, or -1
35 static int vc1_find_frame_end(ParseContext *pc, const uint8_t *buf,
36 int buf_size) {
37 int pic_found, i;
38 uint32_t state;
40 pic_found= pc->frame_start_found;
41 state= pc->state;
43 i=0;
44 if(!pic_found){
45 for(i=0; i<buf_size; i++){
46 state= (state<<8) | buf[i];
47 if(state == VC1_CODE_FRAME || state == VC1_CODE_FIELD){
48 i++;
49 pic_found=1;
50 break;
55 if(pic_found){
56 /* EOF considered as end of frame */
57 if (buf_size == 0)
58 return 0;
59 for(; i<buf_size; i++){
60 state= (state<<8) | buf[i];
61 if(IS_MARKER(state) && state != VC1_CODE_FIELD && state != VC1_CODE_SLICE){
62 pc->frame_start_found=0;
63 pc->state=-1;
64 return i-3;
68 pc->frame_start_found= pic_found;
69 pc->state= state;
70 return END_NOT_FOUND;
73 static int vc1_parse(AVCodecParserContext *s,
74 AVCodecContext *avctx,
75 const uint8_t **poutbuf, int *poutbuf_size,
76 const uint8_t *buf, int buf_size)
78 ParseContext *pc = s->priv_data;
79 int next;
81 if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
82 next= buf_size;
83 }else{
84 next= vc1_find_frame_end(pc, buf, buf_size);
86 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
87 *poutbuf = NULL;
88 *poutbuf_size = 0;
89 return buf_size;
92 *poutbuf = buf;
93 *poutbuf_size = buf_size;
94 return next;
97 static int vc1_split(AVCodecContext *avctx,
98 const uint8_t *buf, int buf_size)
100 int i;
101 uint32_t state= -1;
103 for(i=0; i<buf_size; i++){
104 state= (state<<8) | buf[i];
105 if(IS_MARKER(state) && state != VC1_CODE_SEQHDR && state != VC1_CODE_ENTRYPOINT)
106 return i-3;
108 return 0;
111 AVCodecParser vc1_parser = {
112 { CODEC_ID_VC1 },
113 sizeof(ParseContext1),
114 NULL,
115 vc1_parse,
116 ff_parse1_close,
117 vc1_split,