1/*
2 * DPX parser
3 * Copyright (c) 2013 Paul B Mahol
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 * DPX parser
25 */
26
27#include "libavutil/bswap.h"
28#include "libavutil/common.h"
29
30#include "parser.h"
31
32typedef struct DPXParseContext {
33    ParseContext pc;
34    uint32_t index;
35    uint32_t fsize;
36    uint32_t remaining_size;
37    int is_be;
38} DPXParseContext;
39
40static int dpx_parse(AVCodecParserContext *s, AVCodecContext *avctx,
41                     const uint8_t **poutbuf, int *poutbuf_size,
42                     const uint8_t *buf, int buf_size)
43{
44    DPXParseContext *d = s->priv_data;
45    uint32_t state = d->pc.state;
46    int next = END_NOT_FOUND;
47    int i = 0;
48
49    s->pict_type = AV_PICTURE_TYPE_I;
50
51    *poutbuf_size = 0;
52    if (buf_size == 0)
53        next = 0;
54
55    if (!d->pc.frame_start_found) {
56        for (; i < buf_size; i++) {
57            state = (state << 8) | buf[i];
58            if (state == MKBETAG('S','D','P','X') ||
59                state == MKTAG('S','D','P','X')) {
60                d->pc.frame_start_found = 1;
61                d->is_be = state == MKBETAG('S','D','P','X');
62                d->index = 0;
63                break;
64            }
65        }
66        d->pc.state = state;
67    } else {
68        if (d->remaining_size) {
69            i = FFMIN(d->remaining_size, buf_size);
70            d->remaining_size -= i;
71            if (d->remaining_size)
72                goto flush;
73        }
74    }
75
76    for (; d->pc.frame_start_found && i < buf_size; i++) {
77        d->pc.state = (d->pc.state << 8) | buf[i];
78        d->index++;
79        if (d->index == 17) {
80            d->fsize = d->is_be ? d->pc.state : av_bswap32(d->pc.state);
81            if (d->fsize <= 1664) {
82                d->pc.frame_start_found = 0;
83                goto flush;
84            }
85            if (d->fsize > buf_size - i + 19)
86                d->remaining_size = d->fsize - buf_size + i - 19;
87            else
88                i += d->fsize - 19;
89
90            break;
91        } else if (d->index > 17) {
92            if (d->pc.state == MKBETAG('S','D','P','X') ||
93                d->pc.state == MKTAG('S','D','P','X')) {
94                next = i - 3;
95                break;
96            }
97        }
98    }
99
100flush:
101    if (ff_combine_frame(&d->pc, next, &buf, &buf_size) < 0)
102        return buf_size;
103
104    d->pc.frame_start_found = 0;
105
106    *poutbuf      = buf;
107    *poutbuf_size = buf_size;
108    return next;
109}
110
111const AVCodecParser ff_dpx_parser = {
112    .codec_ids      = { AV_CODEC_ID_DPX },
113    .priv_data_size = sizeof(DPXParseContext),
114    .parser_parse   = dpx_parse,
115    .parser_close   = ff_parse_close,
116};
117