blob: 6067a39826cd892235cc51f5e1b175b69a688d4c
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 | }; |
107 |