mpeg4video_parser: K&R formatting cosmetics
[libav.git] / libavcodec / mpeg4video_parser.c
1 /*
2 * MPEG4 Video frame extraction
3 * Copyright (c) 2003 Fabrice Bellard
4 * Copyright (c) 2003 Michael Niedermayer
5 *
6 * This file is part of Libav.
7 *
8 * Libav 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.
12 *
13 * Libav 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.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with Libav; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 #include "internal.h"
24 #include "parser.h"
25 #include "mpegvideo.h"
26 #include "mpeg4video.h"
27 #include "mpeg4video_parser.h"
28
29 struct Mp4vParseContext {
30 ParseContext pc;
31 struct MpegEncContext enc;
32 int first_picture;
33 };
34
35 int ff_mpeg4_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size)
36 {
37 int vop_found, i;
38 uint32_t state;
39
40 vop_found = pc->frame_start_found;
41 state = pc->state;
42
43 i = 0;
44 if (!vop_found) {
45 for (i = 0; i < buf_size; i++) {
46 state = (state << 8) | buf[i];
47 if (state == 0x1B6) {
48 i++;
49 vop_found = 1;
50 break;
51 }
52 }
53 }
54
55 if (vop_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 ((state & 0xFFFFFF00) == 0x100) {
62 pc->frame_start_found = 0;
63 pc->state = -1;
64 return i - 3;
65 }
66 }
67 }
68 pc->frame_start_found = vop_found;
69 pc->state = state;
70 return END_NOT_FOUND;
71 }
72
73 /* XXX: make it use less memory */
74 static int av_mpeg4_decode_header(AVCodecParserContext *s1,
75 AVCodecContext *avctx,
76 const uint8_t *buf, int buf_size)
77 {
78 struct Mp4vParseContext *pc = s1->priv_data;
79 MpegEncContext *s = &pc->enc;
80 GetBitContext gb1, *gb = &gb1;
81 int ret;
82
83 s->avctx = avctx;
84 s->current_picture_ptr = &s->current_picture;
85
86 if (avctx->extradata_size && pc->first_picture) {
87 init_get_bits(gb, avctx->extradata, avctx->extradata_size * 8);
88 ret = ff_mpeg4_decode_picture_header(s, gb);
89 }
90
91 init_get_bits(gb, buf, 8 * buf_size);
92 ret = ff_mpeg4_decode_picture_header(s, gb);
93 if (s->width && (!avctx->width || !avctx->height ||
94 !avctx->coded_width || !avctx->coded_height)) {
95 ret = ff_set_dimensions(avctx, s->width, s->height);
96 if (ret < 0)
97 return ret;
98 }
99 s1->pict_type = s->pict_type;
100 pc->first_picture = 0;
101 return ret;
102 }
103
104 static av_cold int mpeg4video_parse_init(AVCodecParserContext *s)
105 {
106 struct Mp4vParseContext *pc = s->priv_data;
107
108 pc->first_picture = 1;
109 pc->enc.slice_context_count = 1;
110 return 0;
111 }
112
113 static int mpeg4video_parse(AVCodecParserContext *s,
114 AVCodecContext *avctx,
115 const uint8_t **poutbuf, int *poutbuf_size,
116 const uint8_t *buf, int buf_size)
117 {
118 ParseContext *pc = s->priv_data;
119 int next;
120
121 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
122 next = buf_size;
123 } else {
124 next = ff_mpeg4_find_frame_end(pc, buf, buf_size);
125
126 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
127 *poutbuf = NULL;
128 *poutbuf_size = 0;
129 return buf_size;
130 }
131 }
132 av_mpeg4_decode_header(s, avctx, buf, buf_size);
133
134 *poutbuf = buf;
135 *poutbuf_size = buf_size;
136 return next;
137 }
138
139 AVCodecParser ff_mpeg4video_parser = {
140 .codec_ids = { AV_CODEC_ID_MPEG4 },
141 .priv_data_size = sizeof(struct Mp4vParseContext),
142 .parser_init = mpeg4video_parse_init,
143 .parser_parse = mpeg4video_parse,
144 .parser_close = ff_parse_close,
145 .split = ff_mpeg4video_split,
146 };