/src/ffmpeg/libavcodec/dnxuc_parser.c
Line | Count | Source |
1 | | /* |
2 | | * Avid DNxUncomressed / SMPTE RDD 50 parser |
3 | | * Copyright (c) 2024 Martin Schitter |
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 | | * This parser for DNxUncompressed video data is mostly based on the public |
24 | | * SMPTE RDD 50:2019 specification. |
25 | | */ |
26 | | |
27 | | #include "parser.h" |
28 | | #include "parser_internal.h" |
29 | | #include "libavutil/bswap.h" |
30 | | |
31 | | typedef struct DNxUcParseContext { |
32 | | ParseContext pc; |
33 | | uint32_t remaining; |
34 | | } DNxUcParseContext; |
35 | | |
36 | | static int dnxuc_parse(AVCodecParserContext *s, |
37 | | AVCodecContext *avctx, |
38 | | const uint8_t **poutbuf, int *poutbuf_size, |
39 | | const uint8_t *buf, int buf_size) |
40 | 20 | { |
41 | 20 | DNxUcParseContext *ipc = s->priv_data; |
42 | 20 | int next = END_NOT_FOUND; |
43 | | |
44 | 20 | s->pict_type = AV_PICTURE_TYPE_NONE; |
45 | | |
46 | 20 | *poutbuf_size = 0; |
47 | 20 | *poutbuf = NULL; |
48 | | |
49 | 20 | if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { |
50 | 12 | next = buf_size; |
51 | 12 | } else { |
52 | 8 | if (ipc->remaining == 0) { |
53 | 2 | uint64_t state = ipc->pc.state64; |
54 | 16 | for (int i = 0; i < buf_size; i++) { |
55 | 16 | state = (state << 8) | buf[i]; |
56 | 16 | if (ipc->pc.index + i >= 7 && (uint32_t)state == MKBETAG('p','a','c','k')) { |
57 | 2 | uint32_t size = av_bswap32(state >> 32); |
58 | 2 | if (size >= 8) { |
59 | 2 | next = i - 7; |
60 | 2 | ipc->remaining = size + FFMIN(next, 0); |
61 | 2 | break; |
62 | 2 | } |
63 | 2 | } |
64 | 16 | } |
65 | 2 | ipc->pc.state64 = state; |
66 | 6 | } else if (ipc->remaining <= buf_size) { |
67 | 0 | next = ipc->remaining; |
68 | 0 | ipc->remaining = 0; |
69 | 6 | } else { |
70 | 6 | ipc->remaining -= buf_size; |
71 | 6 | } |
72 | 8 | if (ff_combine_frame(&ipc->pc, next, &buf, &buf_size) < 0) { |
73 | 2 | *poutbuf = NULL; |
74 | 2 | *poutbuf_size = 0; |
75 | 2 | return buf_size; |
76 | 2 | } |
77 | 8 | } |
78 | | |
79 | 18 | *poutbuf = buf; |
80 | 18 | *poutbuf_size = buf_size; |
81 | | |
82 | 18 | return next; |
83 | 20 | } |
84 | | |
85 | | const FFCodecParser ff_dnxuc_parser = { |
86 | | PARSER_CODEC_LIST(AV_CODEC_ID_DNXUC), |
87 | | .priv_data_size = sizeof(DNxUcParseContext), |
88 | | .parse = dnxuc_parse, |
89 | | .close = ff_parse_close, |
90 | | }; |