1 /*
2 * DNxHD/VC-3 parser
3 * Copyright (c) 2008 Baptiste Coudurier <baptiste.coudurier@free.fr>
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 * DNxHD/VC-3 parser
25 */
26
27 #include "parser.h"
28 #include "dnxhddata.h"
29
30 typedef struct {
31 ParseContext pc;
32 int cur_byte;
33 int remaining;
34 int w, h;
35 } DNXHDParserContext;
36
dnxhd_find_frame_end(DNXHDParserContext * dctx,const uint8_t * buf,int buf_size)37 static int dnxhd_find_frame_end(DNXHDParserContext *dctx,
38 const uint8_t *buf, int buf_size)
39 {
40 ParseContext *pc = &dctx->pc;
41 uint64_t state = pc->state64;
42 int pic_found = pc->frame_start_found;
43 int i = 0;
44
45 if (!pic_found) {
46 for (i = 0; i < buf_size; i++) {
47 state = (state << 8) | buf[i];
48 if (ff_dnxhd_check_header_prefix(state & 0xffffffffff00LL) != 0) {
49 i++;
50 pic_found = 1;
51 dctx->cur_byte = 0;
52 dctx->remaining = 0;
53 break;
54 }
55 }
56 }
57
58 if (pic_found && !dctx->remaining) {
59 if (!buf_size) /* EOF considered as end of frame */
60 return 0;
61 for (; i < buf_size; i++) {
62 dctx->cur_byte++;
63 state = (state << 8) | buf[i];
64
65 if (dctx->cur_byte == 24) {
66 dctx->h = (state >> 32) & 0xFFFF;
67 } else if (dctx->cur_byte == 26) {
68 dctx->w = (state >> 32) & 0xFFFF;
69 } else if (dctx->cur_byte == 42) {
70 int cid = (state >> 32) & 0xFFFFFFFF;
71 int remaining;
72
73 if (cid <= 0)
74 continue;
75
76 remaining = avpriv_dnxhd_get_frame_size(cid);
77 if (remaining <= 0) {
78 remaining = avpriv_dnxhd_get_hr_frame_size(cid, dctx->w, dctx->h);
79 if (remaining <= 0)
80 continue;
81 }
82 remaining += i - 47;
83 dctx->remaining = remaining;
84 if (buf_size >= dctx->remaining) {
85 pc->frame_start_found = 0;
86 pc->state64 = -1;
87 dctx->cur_byte = 0;
88 dctx->remaining = 0;
89 return remaining;
90 } else {
91 dctx->remaining -= buf_size;
92 // Update variables for correctness, they are currently not used beyond here
93 state = -1;
94 dctx->cur_byte += buf_size - i;
95 break;
96 }
97 }
98 }
99 } else if (pic_found) {
100 if (dctx->remaining > buf_size) {
101 dctx->remaining -= buf_size;
102 } else {
103 int remaining = dctx->remaining;
104
105 pc->frame_start_found = 0;
106 pc->state64 = -1;
107 dctx->cur_byte = 0;
108 dctx->remaining = 0;
109 return remaining;
110 }
111 }
112 pc->frame_start_found = pic_found;
113 pc->state64 = state;
114 return END_NOT_FOUND;
115 }
116
dnxhd_parse(AVCodecParserContext * s,AVCodecContext * avctx,const uint8_t ** poutbuf,int * poutbuf_size,const uint8_t * buf,int buf_size)117 static int dnxhd_parse(AVCodecParserContext *s,
118 AVCodecContext *avctx,
119 const uint8_t **poutbuf, int *poutbuf_size,
120 const uint8_t *buf, int buf_size)
121 {
122 DNXHDParserContext *dctx = s->priv_data;
123 ParseContext *pc = &dctx->pc;
124 int next;
125
126 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
127 next = buf_size;
128 } else {
129 next = dnxhd_find_frame_end(dctx, buf, buf_size);
130 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
131 *poutbuf = NULL;
132 *poutbuf_size = 0;
133 return buf_size;
134 }
135 }
136 *poutbuf = buf;
137 *poutbuf_size = buf_size;
138 return next;
139 }
140
141 AVCodecParser ff_dnxhd_parser = {
142 .codec_ids = { AV_CODEC_ID_DNXHD },
143 .priv_data_size = sizeof(DNXHDParserContext),
144 .parser_parse = dnxhd_parse,
145 .parser_close = ff_parse_close,
146 };
147