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
30typedef struct {
31    ParseContext pc;
32    int cur_byte;
33    int remaining;
34    int w, h;
35} DNXHDParserContext;
36
37static 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 = ff_dnxhd_get_frame_size(cid);
77                if (remaining <= 0) {
78                    remaining = ff_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
117static 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
141const 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