blob: 1fa718f694f121821490a7210df8aa91aa72fbac
1 | /* |
2 | * Copyright (c) 2011 Justin Ruggles |
3 | * |
4 | * This file is part of FFmpeg. |
5 | * |
6 | * FFmpeg is free software; you can redistribute it and/or |
7 | * modify it under the terms of the GNU Lesser General Public |
8 | * License as published by the Free Software Foundation; either |
9 | * version 2.1 of the License, or (at your option) any later version. |
10 | * |
11 | * FFmpeg is distributed in the hope that it will be useful, |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
14 | * Lesser General Public License for more details. |
15 | * |
16 | * You should have received a copy of the GNU Lesser General Public |
17 | * License along with FFmpeg; if not, write to the Free Software |
18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
19 | */ |
20 | |
21 | /** |
22 | * @file |
23 | * ADX audio parser |
24 | * |
25 | * Splits packets into individual blocks. |
26 | */ |
27 | |
28 | #include "libavutil/intreadwrite.h" |
29 | #include "parser.h" |
30 | #include "adx.h" |
31 | |
32 | typedef struct ADXParseContext { |
33 | ParseContext pc; |
34 | int header_size; |
35 | int block_size; |
36 | int remaining; |
37 | } ADXParseContext; |
38 | |
39 | static int adx_parse(AVCodecParserContext *s1, |
40 | AVCodecContext *avctx, |
41 | const uint8_t **poutbuf, int *poutbuf_size, |
42 | const uint8_t *buf, int buf_size) |
43 | { |
44 | ADXParseContext *s = s1->priv_data; |
45 | ParseContext *pc = &s->pc; |
46 | int next = END_NOT_FOUND; |
47 | int i; |
48 | uint64_t state = pc->state64; |
49 | |
50 | if (!s->header_size) { |
51 | for (i = 0; i < buf_size; i++) { |
52 | state = (state << 8) | buf[i]; |
53 | /* check for fixed fields in ADX header for possible match */ |
54 | if ((state & 0xFFFF0000FFFFFF00) == 0x8000000003120400ULL) { |
55 | int channels = state & 0xFF; |
56 | int header_size = ((state >> 32) & 0xFFFF) + 4; |
57 | if (channels > 0 && header_size >= 8) { |
58 | s->header_size = header_size; |
59 | s->block_size = BLOCK_SIZE * channels; |
60 | s->remaining = i - 7 + s->header_size + s->block_size; |
61 | break; |
62 | } |
63 | } |
64 | } |
65 | pc->state64 = state; |
66 | } |
67 | |
68 | if (s->header_size) { |
69 | if (!s->remaining) |
70 | s->remaining = s->block_size; |
71 | if (s->remaining <= buf_size) { |
72 | next = s->remaining; |
73 | s->remaining = 0; |
74 | } else |
75 | s->remaining -= buf_size; |
76 | } |
77 | |
78 | if (ff_combine_frame(pc, next, &buf, &buf_size) < 0 || !buf_size) { |
79 | *poutbuf = NULL; |
80 | *poutbuf_size = 0; |
81 | return buf_size; |
82 | } |
83 | |
84 | s1->duration = BLOCK_SAMPLES; |
85 | |
86 | *poutbuf = buf; |
87 | *poutbuf_size = buf_size; |
88 | return next; |
89 | } |
90 | |
91 | AVCodecParser ff_adx_parser = { |
92 | .codec_ids = { AV_CODEC_ID_ADPCM_ADX }, |
93 | .priv_data_size = sizeof(ADXParseContext), |
94 | .parser_parse = adx_parse, |
95 | .parser_close = ff_parse_close, |
96 | }; |
97 |