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1 | /* |
2 | * Chinese AVS video (AVS1-P2, JiZhun profile) parser. | |
3 | * Copyright (c) 2006 Stefan Gehrer <stefan.gehrer@gmx.de> | |
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 | * @file | |
24 | * Chinese AVS video (AVS1-P2, JiZhun profile) parser | |
25 | * @author Stefan Gehrer <stefan.gehrer@gmx.de> | |
26 | */ | |
27 | ||
28 | #include "parser.h" | |
29 | #include "cavs.h" | |
30 | ||
31 | ||
32 | /** | |
33 | * Find the end of the current frame in the bitstream. | |
34 | * @return the position of the first byte of the next frame, or -1 | |
35 | */ | |
36 | static int cavs_find_frame_end(ParseContext *pc, const uint8_t *buf, | |
37 | int buf_size) { | |
38 | int pic_found, i; | |
39 | uint32_t state; | |
40 | ||
41 | pic_found= pc->frame_start_found; | |
42 | state= pc->state; | |
43 | ||
44 | i=0; | |
45 | if(!pic_found){ | |
46 | for(i=0; i<buf_size; i++){ | |
47 | state= (state<<8) | buf[i]; | |
48 | if(state == PIC_I_START_CODE || state == PIC_PB_START_CODE){ | |
49 | i++; | |
50 | pic_found=1; | |
51 | break; | |
52 | } | |
53 | } | |
54 | } | |
55 | ||
56 | if(pic_found){ | |
57 | /* EOF considered as end of frame */ | |
58 | if (buf_size == 0) | |
59 | return 0; | |
60 | for(; i<buf_size; i++){ | |
61 | state= (state<<8) | buf[i]; | |
62 | if((state&0xFFFFFF00) == 0x100){ | |
63 | if(state > SLICE_MAX_START_CODE){ | |
64 | pc->frame_start_found=0; | |
65 | pc->state=-1; | |
66 | return i-3; | |
67 | } | |
68 | } | |
69 | } | |
70 | } | |
71 | pc->frame_start_found= pic_found; | |
72 | pc->state= state; | |
73 | return END_NOT_FOUND; | |
74 | } | |
75 | ||
76 | static int cavsvideo_parse(AVCodecParserContext *s, | |
77 | AVCodecContext *avctx, | |
78 | const uint8_t **poutbuf, int *poutbuf_size, | |
79 | const uint8_t *buf, int buf_size) | |
80 | { | |
81 | ParseContext *pc = s->priv_data; | |
82 | int next; | |
83 | ||
84 | if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){ | |
85 | next= buf_size; | |
86 | }else{ | |
87 | next= cavs_find_frame_end(pc, buf, buf_size); | |
88 | ||
89 | if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) { | |
90 | *poutbuf = NULL; | |
91 | *poutbuf_size = 0; | |
92 | return buf_size; | |
93 | } | |
94 | } | |
95 | *poutbuf = buf; | |
96 | *poutbuf_size = buf_size; | |
97 | return next; | |
98 | } | |
99 | ||
100 | AVCodecParser ff_cavsvideo_parser = { | |
101 | .codec_ids = { AV_CODEC_ID_CAVS }, | |
102 | .priv_data_size = sizeof(ParseContext), | |
103 | .parser_parse = cavsvideo_parse, | |
104 | .parser_close = ff_parse_close, | |
105 | .split = ff_mpeg4video_split, | |
106 | }; |