path: root/libavcodec/dnxhd_parser.c (plain)
blob: a1f632a620ec3f116504e8f7702b793ea2190cd2

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
37	static int dnxhd_get_hr_frame_size(int cid, int w, int h)
38	{
39	int result, i = ff_dnxhd_get_cid_table(cid);
40
41	if (i < 0)
42	return i;
43
44	result = ((h + 15) / 16) * ((w + 15) / 16) * ff_dnxhd_cid_table[i].packet_scale.num / ff_dnxhd_cid_table[i].packet_scale.den;
45	result = (result + 2048) / 4096 * 4096;
46
47	return FFMAX(result, 8192);
48	}
49
50	static int dnxhd_find_frame_end(DNXHDParserContext *dctx,
51	const uint8_t *buf, int buf_size)
52	{
53	ParseContext *pc = &dctx->pc;
54	uint64_t state = pc->state64;
55	int pic_found = pc->frame_start_found;
56	int i = 0;
57
58	if (!pic_found) {
59	for (i = 0; i < buf_size; i++) {
60	state = (state << 8) | buf[i];
61	if (ff_dnxhd_check_header_prefix(state & 0xffffffffff00LL) != 0) {
62	i++;
63	pic_found = 1;
64	dctx->cur_byte = 0;
65	dctx->remaining = 0;
66	break;
67	}
68	}
69	}
70
71	if (pic_found && !dctx->remaining) {
72	if (!buf_size) /* EOF considered as end of frame */
73	return 0;
74	for (; i < buf_size; i++) {
75	dctx->cur_byte++;
76	state = (state << 8) | buf[i];
77
78	if (dctx->cur_byte == 24) {
79	dctx->h = (state >> 32) & 0xFFFF;
80	} else if (dctx->cur_byte == 26) {
81	dctx->w = (state >> 32) & 0xFFFF;
82	} else if (dctx->cur_byte == 42) {
83	int cid = (state >> 32) & 0xFFFFFFFF;
84
85	if (cid <= 0)
86	continue;
87
88	dctx->remaining = avpriv_dnxhd_get_frame_size(cid);
89	if (dctx->remaining <= 0) {
90	dctx->remaining = dnxhd_get_hr_frame_size(cid, dctx->w, dctx->h);
91	if (dctx->remaining <= 0)
92	return dctx->remaining;
93	}
94	if (buf_size - i + 47 >= dctx->remaining) {
95	int remaining = dctx->remaining;
96
97	pc->frame_start_found = 0;
98	pc->state64 = -1;
99	dctx->cur_byte = 0;
100	dctx->remaining = 0;
101	return remaining;
102	} else {
103	dctx->remaining -= buf_size;
104	}
105	}
106	}
107	} else if (pic_found) {
108	if (dctx->remaining > buf_size) {
109	dctx->remaining -= buf_size;
110	} else {
111	int remaining = dctx->remaining;
112
113	pc->frame_start_found = 0;
114	pc->state64 = -1;
115	dctx->cur_byte = 0;
116	dctx->remaining = 0;
117	return remaining;
118	}
119	}
120	pc->frame_start_found = pic_found;
121	pc->state64 = state;
122	return END_NOT_FOUND;
123	}
124
125	static int dnxhd_parse(AVCodecParserContext *s,
126	AVCodecContext *avctx,
127	const uint8_t **poutbuf, int *poutbuf_size,
128	const uint8_t *buf, int buf_size)
129	{
130	DNXHDParserContext *dctx = s->priv_data;
131	ParseContext *pc = &dctx->pc;
132	int next;
133
134	if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
135	next = buf_size;
136	} else {
137	next = dnxhd_find_frame_end(dctx, buf, buf_size);
138	if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
139	*poutbuf = NULL;
140	*poutbuf_size = 0;
141	return buf_size;
142	}
143	}
144	*poutbuf = buf;
145	*poutbuf_size = buf_size;
146	return next;
147	}
148
149	AVCodecParser ff_dnxhd_parser = {
150	.codec_ids = { AV_CODEC_ID_DNXHD },
151	.priv_data_size = sizeof(DNXHDParserContext),
152	.parser_parse = dnxhd_parse,
153	.parser_close = ff_parse_close,
154	};
155