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
29#define DNXHD_HEADER_PREFIX 0x0000028001
30
31static int dnxhd_find_frame_end(ParseContext *pc,
32                                const uint8_t *buf, int buf_size)
33{
34    uint64_t state = pc->state64;
35    int pic_found = pc->frame_start_found;
36    int i = 0;
37
38    if (!pic_found) {
39        for (i = 0; i < buf_size; i++) {
40            state = (state<<8) | buf[i];
41            if ((state & 0xffffffffffLL) == DNXHD_HEADER_PREFIX) {
42                i++;
43                pic_found = 1;
44                break;
45            }
46        }
47    }
48
49    if (pic_found) {
50        if (!buf_size) /* EOF considered as end of frame */
51            return 0;
52        for (; i < buf_size; i++) {
53            state = (state<<8) | buf[i];
54            if ((state & 0xffffffffffLL) == DNXHD_HEADER_PREFIX) {
55                pc->frame_start_found = 0;
56                pc->state64 = -1;
57                return i-4;
58            }
59        }
60    }
61    pc->frame_start_found = pic_found;
62    pc->state64 = state;
63    return END_NOT_FOUND;
64}
65
66static int dnxhd_parse(AVCodecParserContext *s,
67                       AVCodecContext *avctx,
68                       const uint8_t **poutbuf, int *poutbuf_size,
69                       const uint8_t *buf, int buf_size)
70{
71    ParseContext *pc = s->priv_data;
72    int next;
73
74    if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
75        next = buf_size;
76    } else {
77        next = dnxhd_find_frame_end(pc, buf, buf_size);
78        if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
79            *poutbuf = NULL;
80            *poutbuf_size = 0;
81            return buf_size;
82        }
83    }
84    *poutbuf = buf;
85    *poutbuf_size = buf_size;
86    return next;
87}
88
89AVCodecParser dnxhd_parser = {
90    { CODEC_ID_DNXHD },
91    sizeof(ParseContext),
92    NULL,
93    dnxhd_parse,
94    ff_parse_close,
95};
96