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
adx_parse(AVCodecParserContext * s1,AVCodecContext * avctx,const uint8_t ** poutbuf,int * poutbuf_size,const uint8_t * buf,int buf_size)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 const 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