Line data Source code
1 : /*
2 : * SBC parser
3 : *
4 : * Copyright (C) 2017 Aurelien Jacobs <aurel@gnuage.org>
5 : *
6 : * This file is part of FFmpeg.
7 : *
8 : * FFmpeg is free software; you can redistribute it and/or
9 : * modify it under the terms of the GNU Lesser General Public
10 : * License as published by the Free Software Foundation; either
11 : * version 2.1 of the License, or (at your option) any later version.
12 : *
13 : * FFmpeg is distributed in the hope that it will be useful,
14 : * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 : * Lesser General Public License for more details.
17 : *
18 : * You should have received a copy of the GNU Lesser General Public
19 : * License along with FFmpeg; if not, write to the Free Software
20 : * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 : */
22 :
23 : #include "sbc.h"
24 : #include "parser.h"
25 :
26 : typedef struct SBCParseContext {
27 : ParseContext pc;
28 : uint8_t header[3];
29 : int header_size;
30 : int buffered_size;
31 : } SBCParseContext;
32 :
33 0 : static int sbc_parse_header(AVCodecParserContext *s, AVCodecContext *avctx,
34 : const uint8_t *data, size_t len)
35 : {
36 : static const int sample_rates[4] = { 16000, 32000, 44100, 48000 };
37 : int sr, blocks, mode, subbands, bitpool, channels, joint;
38 : int length;
39 :
40 0 : if (len < 3)
41 0 : return -1;
42 :
43 0 : if (data[0] == MSBC_SYNCWORD && data[1] == 0 && data[2] == 0) {
44 0 : avctx->channels = 1;
45 0 : avctx->sample_fmt = AV_SAMPLE_FMT_S16;
46 0 : avctx->sample_rate = 16000;
47 0 : avctx->frame_size = 120;
48 0 : s->duration = avctx->frame_size;
49 0 : return 57;
50 : }
51 :
52 0 : if (data[0] != SBC_SYNCWORD)
53 0 : return -2;
54 :
55 0 : sr = (data[1] >> 6) & 0x03;
56 0 : blocks = (((data[1] >> 4) & 0x03) + 1) << 2;
57 0 : mode = (data[1] >> 2) & 0x03;
58 0 : subbands = (((data[1] >> 0) & 0x01) + 1) << 2;
59 0 : bitpool = data[2];
60 :
61 0 : channels = mode == SBC_MODE_MONO ? 1 : 2;
62 0 : joint = mode == SBC_MODE_JOINT_STEREO;
63 :
64 0 : length = 4 + (subbands * channels) / 2
65 0 : + ((((mode == SBC_MODE_DUAL_CHANNEL) + 1) * blocks * bitpool
66 0 : + (joint * subbands)) + 7) / 8;
67 :
68 0 : avctx->channels = channels;
69 0 : avctx->sample_fmt = AV_SAMPLE_FMT_S16;
70 0 : avctx->sample_rate = sample_rates[sr];
71 0 : avctx->frame_size = subbands * blocks;
72 0 : s->duration = avctx->frame_size;
73 0 : return length;
74 : }
75 :
76 0 : static int sbc_parse(AVCodecParserContext *s, AVCodecContext *avctx,
77 : const uint8_t **poutbuf, int *poutbuf_size,
78 : const uint8_t *buf, int buf_size)
79 : {
80 0 : SBCParseContext *pc = s->priv_data;
81 : int next;
82 :
83 0 : if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
84 0 : next = buf_size;
85 : } else {
86 0 : if (pc->header_size) {
87 0 : memcpy(pc->header + pc->header_size, buf,
88 0 : sizeof(pc->header) - pc->header_size);
89 0 : next = sbc_parse_header(s, avctx, pc->header, sizeof(pc->header))
90 0 : - pc->buffered_size;
91 0 : pc->header_size = 0;
92 : } else {
93 0 : next = sbc_parse_header(s, avctx, buf, buf_size);
94 0 : if (next >= buf_size)
95 0 : next = -1;
96 : }
97 :
98 0 : if (next < 0) {
99 0 : pc->header_size = FFMIN(sizeof(pc->header), buf_size);
100 0 : memcpy(pc->header, buf, pc->header_size);
101 0 : pc->buffered_size = buf_size;
102 0 : next = END_NOT_FOUND;
103 : }
104 :
105 0 : if (ff_combine_frame(&pc->pc, next, &buf, &buf_size) < 0) {
106 0 : *poutbuf = NULL;
107 0 : *poutbuf_size = 0;
108 0 : return buf_size;
109 : }
110 : }
111 :
112 0 : *poutbuf = buf;
113 0 : *poutbuf_size = buf_size;
114 0 : return next;
115 : }
116 :
117 : AVCodecParser ff_sbc_parser = {
118 : .codec_ids = { AV_CODEC_ID_SBC },
119 : .priv_data_size = sizeof(SBCParseContext),
120 : .parser_parse = sbc_parse,
121 : .parser_close = ff_parse_close,
122 : };
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